Plant Leaves

Koa (Acacia koa A.Gray) is a valuable tree species economically, ecologically, and culturally in Hawaii. A vascular wilt disease of koa caused by the fungal pathogen Fusarium oxysporum f. sp. koae (FOXY) causes high rates of mortality in field plantings and threatens native koa forests in Hawaii. The Hawaii Agriculture Research Center (HARC), with both public and private partners, operates a tree improvement program to develop koa wilt resistant populations in Hawaii. This applied program was started in 2003 and has made progress including the establishment of first generation seed orchards, delineation of 11 provisional seed zones, and release of the first seed with confirmed levels of genetic resistance for reforestation and restoration. Data from seedling inoculation trials and the first field trials suggest survival on infected sites may be expected to exceed 60 percent in planting using seed from the best parents compared to 30 percent or less survival in unimproved seedlings. One clonal and six seedling field trials were established between 2012-2016 using selections based on the inoculation trials. The screening method serves as a powerful tool to rapidly evaluate koa families prior to outplanting. Additional seedlings screening is on-going to identify parent trees for seed zones not yet established. This rapidly developing resistance program will need to continue the monitoring of field trials to further evaluate the durability of resistance.

Leaf senescence is a highly regulated final phase of leaf development preceding massive cell death. It results in the coordinated degradation of macromolecules and the subsequent nutrient relocation to other plant parts. Very little is still known about early stages of leaf senescence during normal leaf ontogeny that is not triggered by stress factors. This paper comprises an integrated study of natural leaf senescence in tobacco plants grown in vitro, using molecular, structural, and physiological information. We determined the time sequence of ultrastructural changes in mesophyll cells during leaf senescence, showing that the degradation of chloroplast ultrastructure fully correlated with changes in chlorophyll content. The earliest degenerative changes in chloroplast ultrastructure coinciding with early chromatin condensation were observed already in mature green leaves. A continuum of degradative changes in chloroplast ultrastructure, chromatin condensation and aggregation, alon...

Atherosclerosis, the principal contributor to the pathogenesis of myocardial and cerebral infarctions, is known to be one of the leading causes of morbidity and mortality worldwide. Hyperlipidemia and elevated plasma low-density lipoprotein cholesterol (LDLC) resulting from lipid metabolic changes are an important risk factor for the development and progression of atherosclerosis. Phenolic compounds from various sources have been reported to prevent LDL oxidation in vitro and show marked hypolipidemic activity in vivo, suggesting the effectiveness of polyphenols for the prevention and treatment of atherosclerosis. In this study, a phenolic-rich extract of olive mill wastewaters (OMW) was prepared under optimal conditions and hydroxytyrosol was purified from the obtained extract. Moreover, the effects of these phenolic on the susceptibility of human LDL to oxidation and on plasma lipids in rats fed a cholesterol-rich diet were studied. First, lipoproteins were isolated by sequential ...

A study was carried out on the sustainability of forest plantations established on soils contaminated with heavy metals in the vicinity of the former "Kremikovtsi" metalurgic plant. Soils and forest vegetation near the village of Buhovo (black pine Pinus nigra Arn.) and Lokorsko I (red oak Quercus rubra L.) and Lokorsko II (winter oak Quercus sessiliflora Salisb.) were studied. The soils of the area are geochemically enriched with lead, reaching up to 136 mg/kg for Pb under the Black Pine Plantation. The lowest levels of assimilation have the red oak leaves, as evidenced by the analysis of the heavy metals content: Zn, Cu, Pb, Cd and the biological absorption coefficient Ah, and it is recommended that for the soil reclamation to be used this tree species.

Trypanosoma evansi, the causative agent of "surra", infects many species of wild and domestic animals worldwide. In the current study, the aqueous and ethanolic extracts of six medicinal plants, namely, Aquilaria malaccensis, Derris elliptica, Garcinia hombroniana, Goniothalamus umbrosus, Nigella sativa, and Strobilanthes crispus were screened in vitro for activity against T. evansi. The cytotoxic activity of the extracts was evaluated on green monkey kidney (Vero) cells using MTT-cell proliferation assay. The median inhibitory concentrations (IC50) of the extracts ranged between 2.30 and 800.97 μg/ml and the median cytotoxic concentrations (CC50) ranged between 29.10 μg/ml and 14.53 mg/ml. The aqueous extract of G. hombroniana exhibited the highest selectivity index (SI) value of 616.36, followed by A. malaccensis aqueous extract (47.38). Phytochemical screening of the G. hombroniana aqueous extract revealed the presence of flavonoids, phenols, tannins, and saponins. It i...

Mammea americana L. is tropical plant in the Clusiaceae family that bears edible fruit. Mammea coumarins are isoprenylated derivatives of the lactones of the 2-hydroxy-Z-cinnamic acids that are bioactive and have limited distribution in three Clusiaceae genera. Qualitative and quantitative analyses were performed to determine the distribution of mammea coumarins in the seed nucleus, seed coat, fruit flesh, fruit skin, leaf, stem, and root of M. americana using high-performance liquid chromatography-photodiode array detector (HPLC-PDA) and liquid chromatography-mass spectrometry (LC-MS). Ten major mammea coumarins, mammea E/BD (1), mammea E/BC (2), mammea E/BA (3), mammea E/BB (4), mammea B/BA hydroxycyclo F (5), mammea B/BD (6), mammea B/BC (7), mammea B/BA (8), mammea B/BB (9), and mammea B/BA cyclo F (10), were isolated and identified from the seed nucleus of M. americana and employed as standards. The HPLC-PDA method was validated with respect to sensitivity, linearity, recovery, accuracy, and precision. The total content (w/w %) of the 10 major mammea coumarins in M. americana was determined to be highest in the root (0.75%), followed by the leaf (0.64%), seed nucleus (0.48%), fruit skin (0.11%), stem (0.08%), seed coat (0.02%), and fruit flesh (<0.01%). The leaf and seed nucleus are rich and sustainable natural sources of mammea coumarins. Additionally, the described HPLC-PDA and LC-MS methods are sensitive and accurate and can be applied to the analysis of mammea coumarins in other samples.

Costus spicatus Sw. (Costaceae) is a prominent medicinal herb used by Dominicans in the Dominican Republic and the United States for the treatment of diabetes, a growing epidemic in the Hispanic community. An ethnobotanical survey of the Dominican community in New York City ...

Molecular genetic studies suggest that FLORICAULA (FLO)/LEAFY (LFY) orthologs function to control compound leaf development in some legume species. However, loss-of-function mutations in the FLO/LFY orthologs result in reduction of leaf complexity to different degrees in Pisum sativum and Lotus japonicus. To further understand the role of FLO/LFY orthologs in compound leaf development in legumes, we studied compound leaf developmental processes and characterized a leaf development mutant, single leaflet1 (sgl1), from the model legume Medicago truncatula. The sgl1 mutants exhibited strong defects in compound leaf development; all adult leaves in sgl1 mutants are simple due to failure in initiating lateral leaflet primordia. In addition, the sgl1 mutants are also defective in floral development, producing inflorescence-like structures. Molecular cloning of SGL1 revealed that it encodes the M. truncatula FLO/LFY ortholog. When properly expressed, LFY rescued both floral and compound le...

Dicot leaf primordia initiate at the flanks of the shoot apical meristem and extend laterally by cell division and cell expansion to form the flat lamina, but the molecular mechanism of lamina outgrowth remains unclear. Here, we report the identification of STENOFOLIA (STF), a WUSCHEL-like homeobox transcriptional regulator, in Medicago truncatula, which is required for blade outgrowth and leaf vascular patterning. STF belongs to the MAEWEST clade and its inactivation by the transposable element of Nicotiana tabacum cell type1 (Tnt1) retrotransposon insertion leads to abortion of blade expansion in the mediolateral axis and disruption of vein patterning. We also show that the classical lam1 mutant of Nicotiana sylvestris, which is blocked in lamina formation and stem elongation, is caused by deletion of the STF ortholog. STF is expressed at the adaxial-abaxial boundary layer of leaf primordia and governs organization and outgrowth of lamina, conferring morphogenetic competence. STF ...

Background: Intensive poultry production systems depend on chemoprophylaxis with anticoccidial drugs to combat infection. A floor-pen study was conducted to evaluate the anticoccidial effect of Artemisia annua and Foeniculum vulgare on Eimeria tenella infection. Five experimental groups were established: negative control (untreated, unchallenged); positive control (untreated, challenged); a group medicated with 125 ppm lasalocid and challenged; a group medicated with A. annua leaf powder at 1.5% in feed and challenged; and a group treated with the mixed oils of A. annua and Foeniculum vulgare in equal parts, 7.5% in water and challenged. The effects of A. annua and oil extract of A. annua + F. vulgare on E. tenella infection were assessed by clinical signs, mortality, fecal oocyst output, faeces, lesion score, weight gain, and feed conversion. Results: Clinical signs were noticed only in three chickens from the lasalocid group, six from the A. annua group, and nine from the A. annua + F. vulgare group, but were present in 19 infected chickens from the positive control group. Bloody diarrhea was registered in only two chickens from A. annua group, but in 17 chickens from the positive control group. Mortality also occurred in the positive control group (7/20). Chickens treated with A. annua had a significant reduction in faecal oocysts (95.6%; P = 0.027) and in lesion score (56.3%; P = 0.005) when compared to the positive control. At the end of experiment, chickens treated with A. annua leaf powder had the highest body weight gain (68.2 g/day), after the negative control group, and the best feed conversion (1.85) among all experimental groups. Conclusions: Our results suggest that A. annua leaf powder (Aa-p), at 1.5% of the daily diet post-infection, can be a valuable alternative for synthetic coccidiostats, such as lasalocid.

Copyright © 2014 Pragati Khare et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

In mammals, cadmium is widely considered as a non-genotoxic carcinogen acting through a methylation-dependent epigenetic mechanism. Here, the effects of Cd treatment on the DNA methylation patten are examined together with its effect on chromatin reconfiguration in Posidonia oceanica. DNA methylation level and pattern were analysed in actively growing organs, under short-(6 h) and long-(2 d or 4 d) term and low (10 mM) and high (50 mM) doses of Cd, through a Methylation-Sensitive Amplification Polymorphism technique and an immunocytological approach, respectively. The expression of one member of the CHROMOMETHYLASE (CMT) family, a DNA methyltransferase, was also assessed by qRT-PCR. Nuclear chromatin ultrastructure was investigated by transmission electron microscopy. Cd treatment induced a DNA hypermethylation, as well as an up-regulation of CMT, indicating that de novo methylation did indeed occur. Moreover, a high dose of Cd led to a progressive heterochromatinization of interphase nuclei and apoptotic figures were also observed after long-term treatment. The data demonstrate that Cd perturbs the DNA methylation status through the involvement of a specific methyltransferase. Such changes are linked to nuclear chromatin reconfiguration likely to establish a new balance of expressed/repressed chromatin. Overall, the data show an epigenetic basis to the mechanism underlying Cd toxicity in plants.

In order to improve the postharvest quality and the export ability of cut rose (Rosa hybrida L.) cvs. Happy Hour and Bordeaux, the effect of 1-methylcyclopropene (1-MCP) as an ethylene inhibitor, was investigated. 1-MCP was used at 0.3, 0.4, 0.5 and 0.6 g m -3 for 18 h at 8 °C to simulate the transport of flowers. 1-MCP treatment significantly prolonged the vase life and minimized the weight loss of both cultivars compared to the control, however the response of Happy Hour cultivar was higher than the Bordeaux cultivar. 1-MCP treatment enhanced the relative water content (RWC) of flowers. The treatment of 1-MCP significantly retarded the degradation of chlorophyll and carbohydrate contents during vase life evaluation in both cultivars. The ethylene production was significantly decreased by applying 1-MCP treatment. The membrane stability index (MSI) was maintained while malondialdehyde (MDA) was decreased in response to 1-MCP treatment. The best treatments in this concern were 1-MCP at 0.4 and 0.5 g m -3 for Happy Hour and Bordeaux cultivars, respectively. 1-MCP treatment was recommended to inhibit the negative effects of ethylene on rose cultivars tested.

Cassia grandis is used for the treatment of skin disorders, back pain, aches, etc. in Vietnamese traditional medicine. In this paper, phytochemicals of the leaves were investigated. A new naphthalene derivative (1, cassgranon D) and, seven known compounds rutin (2), afzelin (3), quercitrin (4), epicatechin (5), (-)-epiafzelechin (6), isoquercitrin (7), and aloe emodin (8) were isolated from the ethyl acetate and methanol extracts. Their structures were elucidated by spectral evidences (UV, IR, MS, 1 H, 13 C, DEPT, HSQC and HMBC NMR), as well as by comparing with published data.

We investigated relationships between tree water status, vegetative growth and leaf gas exchange of peach trees growing on different rootstocks under field conditions. Tree water status was manipulated by partially covering (0, ~30 and ~60%) the tree canopies on individual days and then evaluating the effects of tree water status on vegetative growth and leaf gas exchange. Early morning stem water potentials were approximately -0.4 MPa for trees in all treatments, but mean midday values ranged from -1.1 to -1.7 MPa depending on rootstock and canopy coverage treatment. Relative shoot extension growth rate, leaf conductance, transpiration rate and net CO 2 exchange rate differed significantly among trees in the different rootstocks and canopy coverage treatments. Shoot extension growth rate, leaf conductance, leaf transpiration rate and leaf net CO 2 exchange rate were linearly correlated with midday stem water potential. These relationships were independent of the rootstock and canopy coverage treatments, indicating that tree water relations are probably directly involved in the mechanism that imparts vegetative growth control by selected peach rootstocks.

Chemical examination of the leaves of Aglaia elliptica led to the isolation of two new diamides, 10-O-acetylaglain B (1) and 4-epiaglain A (2), two known diamides, aglain A (3) and odorine (4), and three known cycloartanes (5-7). The structures of 1 and 2 were elucidated by interpretation of the spectral data.

Abstract: The lamb’s ear ( Stachys byzantina K. Koch) is an example of underutilized food species, characterized in Brazil as an unconventional vegetable. Currently, there is enough government incentive for the rescue and reintroduction of this species in the Brazilian food, however, there is little information available about the suitable techniques for its cultivation and for large-scale production. Thereon, we aimed to evaluate the lamb’s ear plants development under different levels of fertilization, supplied by NPK formulations determined by variations obtained from adjustments to the recommendations for fertilization of leafy crops, besides evaluating the behavior of the crop, when conducted at different planting densities, as well as to determining the characterization of the phenological stages of this species in the region southern Minas Gerais. Two experiments were conducted, one to determine the phenological stage, which was arranged in a design of randomized blocks with ...

PsbS is a 22-kDa Photosystem (PS) II protein involved in non-photochemical quenching (NPQ) of chlorophyll fluorescence. Rice (Oryza sativa L.) has two PsbS genes, PsbS1 and PsbS2. However, only inactivation of PsbS1, through a knockout (PsbS1-KO) or in RNAi transgenic plants, results in plants deficient in qE, the energy-dependent component of NPQ. In studies presented here, under fluctuating high light, growth of young seedlings lacking PsbS is retarded, and PSII in detached leaves of the mutants is more sensitive to photoinhibitory illumination compared with the wild type. Using both histochemical and fluorescent probes, we determined the levels of reactive oxygen species, including singlet oxygen, superoxide, and hydrogen peroxide, in leaves and thylakoids. The PsbS-deficient plants generated more superoxide and hydrogen peroxide in their chloroplasts. PSII complexes isolated from them produced more superoxide compared with the wild type, and PSII-driven superoxide production was...

Screening of crude extracts of plants facilitates the establishment of highly effective extract for mosquito control. This practice should be preferred before in depth study of plant extracts rather than spending much efforts and energy in detailed examinations for practically ineffective extracts. In this study, leaf powders of four weed plants were used for the quick screening of effective plant extract as larvicide against III instar larvae of Aedes albopictus Skuse. At the same time, effect of different seasons on the larvicidal efficacy of plants and selection of proper solvents for further investigation were also studied. Leaves of Vernonia cinerea, Prosopis juliflora, Hyptis suaveolens and Malvastrum coromandelianum plants were collected in summer, winter and rainy seasons from Madhya Pradesh region (India). To assess the larvicidal efficacy the suspensions of leaf powders in different solvents (isopropanol, methanol, acetone, dimethylsulfoxide and water) were used for larvic...

Leaves and glumes act as lateral organs and have essential effects on photosynthesis and seed morphology, thus affecting yield.  However, the molecular mechanisms controlling their polarity development in rice still need further study.  Here, we isolated a polarity defect of lateral organs 1 (pdl1) mutant in rice, which exhibits twisted/filamentous-shaped leaves and cracked/filamentous-shaped lemmas caused by defects in polarity development.  PDL1 encodes a SUPPRESSOR OF GENE SILENCING 3 protein localized in the cytoplasmic granules.  PDL1 is expressed in the shoot apical meristem, inflorescence meristem, floral meristem, and lateral organs including leaves and floral organs.  PDL1 is involved in the synthesis of tasiR-ARF, which may subsequently modulate the expression of OsARFs.  Meanwhile, the expression levels of abaxial miR165/166 and the adaxial identity genes OSHBs were respectively increased and reduced significantly.  The results of this study clarify the molecular mechanism by which PDL1-mediated tasiR-ARF synthesis regulates the lateral organ polarity development in rice.

The influence of vegetal extracts derived from red grape, blueberry fruits and hawthorn leaves on Zea mays L. plant growth and the activity of phenylalanine ammonia-lyase (PAL), a key enzyme of the phenylpropanoid pathway, was investigated in laboratory experiments. The extracts were characterized using FT-IR and Raman spectroscopies in order to obtain a pattern of the main functional groups. In addition, phenols content was determined by HPLC, whereas the content of indoleacetic acid and isopentenyladenosine hormones was determined by ELISA test and the auxin and gibberellin-like activities by plant-bioassays. The treated maize revealed increased root and leaf biomass, chlorophyll and sugars content with respect to untreated plants. Hawthorn, red grape skin and blueberry at 1.0 mL/L induced high p-coumaric content values, whilst hawthorn also showed high amounts of gallic and p-hydroxybenzoic acids. PAL activity induced by hawthorn at 1.0 mL/L had the highest values (11.1-fold UNT) and was strongly and linearly related with the sum of leaf phenols. Our results suggest that these vegetal extracts contain more than one group of plant-promoting substances.

O 2 evolution from single turnover flashes of up to 96 Wmol absorbed quanta m 32 and from multiple turnover pulses of 8.6 and 38.6 ms duration and 12 800 and 850 Wmol absorbed quanta m 32 s 31 intensity, respectively, was measured in sunflower leaves with the help of zirconium O 2 analyser. O 2 evolution from one flash could be measured with 1% accuracy on the background of 10^50 Wmol O 2 mol 31 . Before the measurements leaves were pre-adapted either at 30^60 or 1700 Wmol quanta m 32 s 31 to induce different non-photochemical excitation quenching (q N ). Short (1 min) exposures at the high light that created only energy-dependent, q E type quenching, caused no changes in the O 2 yield from saturating flashes or pulses that could be related to the q E quenching, but the yield from low intensity flashes and pulses decreased considerably. Long 30^60min exposures at the high light induced a reversible inhibitory, q I type quenching that decreased the O 2 yield from both, saturating and limiting flashes and pulses (but more from the limiting ones), which reversed within 15 min under the low light. The results are in agreement with the notion that q E is caused by a quenching process in the PSII antenna and no changes occur in the PSII centres, but the reversible (15^30 min) q I quenching is accompanied by inactivation of a part of PSII centres.

Chl fluorescence induction (FI) was recorded in sunflower leaves pre-adapted to darkness or low preferentially PSI light, or inhibited by DCMU. For analysis the FI curves were plotted against the cumulative number of excitations quenched by PSII, n q , calculated as the cumulative complementary area above the FI curve. In the ?DCMU leaves n q was \1 per PSII, suggesting pre-reduction of Q A during the dark pre-exposure. A strongly sigmoidal FI curve was constructed by complementing (shifting) the recorded FI curves to n q = 1 excitation per PSII. The full FI curve in ?DCMU leaves was well fitted by a model assuming PSII antennae are excitonically connected in domains of four PSII. This result, obtained by gradually reducing Q A in PSII with pre-blocked Q B (by DCMU or PQH 2 ), differs from that obtained by gradually blocking the Q B site (by increasing DCMU or PQH 2 level) in leaves during (quasi)steady-state e -transport (Oja and Laisk, Photosynth Res 114, 15-28, 2012). Explanations are discussed. Donor side quenching was characterized by comparison of the total n q in one and the same dark-adapted leaf, which apparently increased with increasing PFD during FI. An explanation for the donor side quenching is proposed, based on electron transfer from excited P680* to oxidized tyrosine Z (TyrZ ox ). At high PFDs the donor side quenching at the J inflection of FI is due mainly to photochemical quenching by TyrZ ox . This quenching remains active for subsequent photons while TyrZ remains oxidized, following charge transfer to Q A . During further induction this quenching disappears as soon as PQ and Q A become reduced, charge separation becomes impossible and TyrZ is reduced by the water oxidizing complex.

After darkening, isoprene emission continues for 20 to 30 min following biphasic kinetics. The initial dark release of isoprene (postillumination emission), for 200 to 300 s, occurs mainly at the expense of its immediate substrate, dimethylallyldiphosphate (DMADP), but the origin and controls of the secondary burst of isoprene release (dark-induced emission) between approximately 300 and 1,500 s, are not entirely understood. We used a fast-response gas-exchange system to characterize the controls of dark-induced isoprene emission by light, temperature, and CO 2 and oxygen concentrations preceding leaf darkening and the effects of short light pulses and changing gas concentrations during dark-induced isoprene release in hybrid aspen (Populus tremula 3 Populus tremuloides). The effect of the 2-C-methyl-D-erythritol-4-phosphate pathway inhibitor fosmidomycin was also investigated. The integral of postillumination isoprene release was considered to constitute the DMADP pool size, while the integral of dark-induced emission was defined as the "dark" pool. Overall, the steady-state emission rate in light and the maximum dark-induced emission rate responded similarly to variations in preceding environmental drivers and atmospheric composition, increasing with increasing light, having maxima at approximately 40°C and close to the CO 2 compensation point, and were suppressed by lack of oxygen. The DMADP and dark pool sizes were also similar through their environmental dependencies, except for high temperatures, where the dark pool significantly exceeded the DMADP pool. Isoprene release could be enhanced by short lightflecks early during dark-induced isoprene release, but not at later stages. Fosmidomycin strongly suppressed both the isoprene emission rates in light and in the dark, but the dark pool was only moderately affected. These results demonstrate a strong correspondence between the steady-state isoprene emission in light and the dark-induced emission and suggest that the dark pool reflects the total pool size of 2-C-methyl-D-erythritol-4phosphate pathway metabolites upstream of DMADP. These metabolites are converted to isoprene as soon as ATP and NADPH become available, likely by dark activation of chloroplastic glycolysis and chlororespiration.

Pear (Pyrus communis) is an economically important fruit crop. Drops in yield and even losses of whole plantations are caused by diseases, most importantly fire blight which is triggered by the bacterial pathogen Erwinia amylovora. In response to the infection, biphenyls and dibenzofurans are formed as phytoalexins, biosynthesis of which is initiated by biphenyl synthase (BIS). Two PcBIS transcripts were cloned from fire blight-infected leaves and the encoded enzymes were characterized regarding substrate specificities and kinetic parameters. Expression of PcBIS1 and PcBIS2 was studied in three pear cultivars after inoculation with E. amylovora. Both PcBIS1 and PcBIS2 were expressed in &#39;Harrow Sweet&#39;, while only PcBIS2 transcripts were detected in &#39;Alexander Lucas&#39; and &#39;Conference&#39;. Expression of the PcBIS genes was observed in both leaves and the transition zone of the stem; however, biphenyls and dibenzofurans were only detected in stems. The maximum phytoa...

Leaf senescence is a developmentally programmed cell death process that constitutes the final step of leaf development and involves the extensive reprogramming of gene expression. Despite the importance of senescence in plants, the underlying regulatory mechanisms are not well understood. This study reports the isolation and functional analysis of RAV1, which encodes a RAV family transcription factor. Expression of RAV1 and its homologues is closely associated with leaf maturation and senescence. RAV1 mRNA increased at a later stage of leaf maturation and reached a maximal level early in senescence, but decreased again during late senescence. This profile indicates that RAV1 could play an important regulatory role in the early events of leaf senescence. Furthermore, constitutive and inducible overexpression of RAV1 caused premature leaf senescence. These data strongly suggest that RAV1 is sufficient to cause leaf senescence and it functions as a positive regulator in this process.

As a defense mechanism of the leaves of Rhus javanica (Anacardiaceae) against the aphid Melaphis chinensis (Aphididae) attack, tannic acid is rapidly accumulated and forms galls along the midrib of the leaves resulting in a unique natural medicine Gallae Rhois. Tannic acid was found to inhibit the oxidation of l-3,4-dihydroxyphenylalanine (l-DOPA) catalyzed by tyrosinase (EC 1.14.18.1) with an IC 50 of 22 µm. The aphid would detoxify the ingested toxic tannic acid to relatively nontoxic gallic acid, whereas the non-adapted pink bollworm Pectinophora gossypiella larvae are sensitive to the ingested tannic acid.

As a defense mechanism of the leaves of Rhus javanica (Anacardiaceae) against the aphid Melaphis chinensis (Aphididae) attack, tannic acid is rapidly accumulated and forms galls along the midrib of the leaves resulting in a unique natural medicine Gallae Rhois. Tannic acid was found to inhibit the oxidation of ʟ-3,4-dihydroxyphenylalanine (ʟ-DOPA) catalyzed by tyrosinase (EC 1.14.18.1) with an IC50 of 22 μᴍ. The aphid would detoxify the ingested toxic tannic acid to relatively nontoxic gallic acid, whereas the non-adapted pink bollworm Pectinophora gossypiella larvae are sensitive to the ingested tannic acid.

Ab s t r a ct . An environmental study was performed in the years 2009-2011 to evaluate nutrients supply in apple trees in the Lubelskie Region. Apple tree leaves (cv. Szampion) were sampled from orchards situated in 17 localities, in the first half of August, from the central part of long shoots situated in various parts on the crown circumference, at mid-height, from ten trees chosen at random. The chemical analyses of those leaves were performed at the accredited laboratory of the Regional Chemical-Agricultural Station in Lublin. In the analysed material the following parameters were assayed: dry matter content, total nitrogen content, content of phosphorus, potassium, calcium, magnesium, copper, zinc, manganese, iron and boron. The average content and standard deviation of the macro-(N, P, K, Ca and Mg) and microelements (B, Cu, Zn, Fe, Mn) in the leaves were calculated. Additionally, correlations among those elements and coefficients of determination were calculated. Our evaluation has shown that apple trees cv. Szampion cultivated in the Lubelskie Region were optimally supplied in macro-elements, that is to say nitrogen, phosphorus, potassium, magnesium and calcium. The chemical analyses revealed also that the plants had optimum level of supply for boron. The occurrence of a relatively few (7) significant correlations among the assayed macro-(N, P, K, Mg, Ca) and microelements (B, Cu, Zn, Mn, Fe) was noted. For some of the microelements the values of the calculated coefficients of determination varied from 88.2 to 98.4%. Ke yw or d s : apple tree, macroelements, microelements, fertilisation.

Boron deficiency is the most frequent micronutrient disorder in olive (Olea spp.) orchards. We tested the hypothesis that plant boron status affects phenolic metabolism, which, in turn, influences several ecophysiological traits of olive (Olea europaea L.) trees, by studying the effects of boron deficiency on leaf phenolic compounds of olive in a growth chamber experiment (CE) and a field experiment (FE). In the CE, a semi-hydroponic system was used to control nutrient supply. Plants received complete nutrient solution containing either 23 (control) or 0 µM H 3 BO 3 (boron-deficient treatment). In the FE, boron-deficient trees were chosen based on visible boron-deficiency symptoms and analysis of their leaf boron concentration. Boron deficiency caused significant accumulation of phenolic compounds in leaves of CE plants (1.7 to 5.8 times more, depending on leaf age), but not in leaves of FE plants. However, in both experiments, the concentration of an unidentified phenolic compound, with a UV-spectrum resembling that of caffeic acid, increased in response to boron deficiency (by a factor of 40 to 184 in the CE and by a factor of three in the FE). Regression analysis showed that the concentration of this compound was negatively correlated to leaf boron concentration, irrespective of growth conditions and treatment. We conclude that, under field conditions, boron deficiency may not be the only factor determining the concentration of total phenolics, but it may be responsible for the accumulation of a distinct phenolic metabolite in olive leaves.

Heterobaric leaves show heterogeneous pigmentation due to the occurrence of a network of transparent areas that are created from the bundle sheaths extensions (BSEs). Image analysis showed that the percentage of photosynthetically active leaf area (A p ) of the heterobaric leaves of 31 plant species was species dependent, ranging from 91% in Malva sylvestris to only 48% in Gynerium sp. Although a significant portion of the leaf surface does not correspond to photosynthetic tissue, the photosynthetic capacity of these leaves, expressed per unit of projected area (P max ), was not considerably affected by the size of their transparent leaf area (A t ). This means that the photosynthetic capacity expressed per A p (P* max ) should increase with A t . Moreover, the expression of P* max could be allowing the interpretation of the photosynthetic performance in relation to some critical anatomical traits. The P* max , irrespective of plant species, correlated with the specific leaf transparent volume ( t ), as well as with the transparent leaf area complexity factor ( CF A t ), parameters indicating the volume per unit leaf area and length/density of the transparent tissues, respectively. Moreover, both parameters increased exponentially with leaf thickness, suggesting an essential functional role of BSEs mainly in thick leaves. The results of the present study suggest that although the A p of an heterobaric leaf is reduced, the photosynthetic performance of each areole is increased, possibly due to the light transferring capacity of BSEs. This mechanism may allow a significant increase in leaf thickness and a consequent increase of the photosynthetic capacity per unit (projected) area, offering adaptive advantages in xerothermic environments.

Plant trichomes play important protective functions and may have a major influence on leaf surface wettability. With the aim of gaining insight into trichome structure, composition, and function in relation to water-plant surface interactions, we analyzed the adaxial and abaxial leaf surface of holm oak (Quercus ilex) as a model. By measuring the leaf water potential 24 h after the deposition of water drops onto abaxial and adaxial surfaces, evidence for water penetration through the upper leaf side was gained in young and mature leaves. The structure and chemical composition of the abaxial (always present) and adaxial (occurring only in young leaves) trichomes were analyzed by various microscopic and analytical procedures. The adaxial surfaces were wettable and had a high degree of water drop adhesion in contrast to the highly unwettable and water-repellent abaxial holm oak leaf sides. The surface free energy and solubility parameter decreased with leaf age, with higher values determined for the adaxial sides. All holm oak leaf trichomes were covered with a cuticle. The abaxial trichomes were composed of 8% soluble waxes, 49% cutin, and 43% polysaccharides. For the adaxial side, it is concluded that trichomes and the scars after trichome shedding contribute to water uptake, while the abaxial leaf side is highly hydrophobic due to its high degree of pubescence and different trichome structure, composition, and density. Results are interpreted in terms of water-plant surface interactions, plant surface physical chemistry, and plant ecophysiology.

The species Kalanchoe brasiliensis and Kalanchoe pinnata, both known popularly as &quot;Saião,&quot; are used interchangeably in traditional medicine for their antiophidic properties. Studies evaluating the anti-venom activity of these species are scarce. This study aims to characterize the chemical constituents and evaluate the inhibitory effects of hydroethanolic leaf extracts of K. brasiliensis and K. pinnata against local effects induced by Bothrops jararaca snake venom. Thin Layer Chromatography (TLC) and High Performance Liquid Chromatography coupled with Diode Array Detection and Electrospray Mass Spectrometry (HPLC-DAD-MS/MS) were performed for characterization of chemical markers of the extracts from these species. For antiophidic activity evaluation, B. jararaca venom-induced paw edema and skin hemorrhage in mice were evaluated. In both models, hydroethanolic extracts (125-500 mg/kg) were administered intraperitoneally in different protocols. Inhibition of phospholipase en...

Aims: The American leaf spot, caused by Mycena citricolor, is an important disease of coffee (Coffea arabica), mostly in Central America. Currently, there are limited pathogen control alternatives that are environment friendly and economically accessible. The use of fungi isolated from the plant endomycobiota in their native habitats is on the rise because studies show their great potential for biological control. To begin to generate a green alternative to control M. citricolor, the objectives of the present study were to (i) collect, identify, screen (in vitro and in planta), and select endophytic fungi from wild Rubiaceae collected in old-growth forests of Costa Rica; (ii) confirm endophytic colonization in coffee plantlets; (iii) evaluate the effects of the endophytes on plantlet development; and (iv) corroborate the antagonistic ability in planta. Methods and results: Through in vitro and in planta antagonism assays, we found that out of the selected isolates (i.e. Daldinia eschscholzii GU11N, Nectria pseudotrichia GUHN1, Purpureocillium aff. lilacinum CT24, Sarocladium aff. kiliense CT25, Trichoderma rifaii CT5, T. aff. Crissum G1C, T. aff. atroviride G7T, T. aff. strigosellum GU12, and Xylaria multiplex GU14T), Trichoderma spp. produced the highest growth inhibition percentages in vitro. Trichoderma isolates CT5 and G1C were then tested in planta using Coffea arabica cv. caturra plantlets. Endophytic colonization was verified, followed by in planta growth promotion and antagonism assays.
Conclusions: Results show that Trichoderma isolates CT5 and G1C have potential for plant growth promotion and antagonism against Mycena citricolor, reducing incidence and severity, and preventing plant mortality.

Poly(acrylamide-co-itaconic acid) (AAm/IA) and poly(acrylamide-co-monomethoxyethyl itaconate) (AAm/MEI) hydrogels (HGs) synthesized at different molar ratios were used to study the adsorption of some metal ions as Cu 2+ , Ni 2+ , Pb 2+ , Cd 2+ , and Fe 3+ in aqueous solutions at different concentration: 10, 50, 100, 500, and 1000 mg L-1. Statistical analysis was performed and the effect of the metal ion, ion concentration, and hydrogel (HG) composition, on adsorption and adsorption efficiency, was evaluated for both HGs studied (AAm/IA and AAm/MEI) and each factor gave rise to significant differences (P ≤ 0.05). The adsorption depends on the type of ion, its concentration, and also influenced by the type and composition of the HGs. For each system the adsorption efficiencies for all ions were similar with exception of Fe 3+ , which showed the highest adsorption efficiency in AAm/MEI HG, but the less for the AAm/IA. For both systems, the maximum adsorption efficiency was observed when the molar ratio AAm/IA or AAm/MEI is 80/20. When the adsorption was carried out with individual ions, AAm/MEI HG was more efficient than AAm/IA. For a multielement sample of Cu 2+ , Ni 2+ , Pb 2+ , and Cd 2+ , both HGs could adsorb all the ions and their behavioral trend was the same in both cases, in which the adsorption efficiency was Pb 2+ > Cu 2+ > Cd 2+ > Ni 2+. The results of the statistical analysis evidence the advantage of its use in this type of studies.

Acyl sugars are allelochemicals present at high concentrations in leaves of accessions of the wild tomato Solanum pennellii; they confer resistance to a large number of arthropod pests, including the tomato pinworm, Tuta absoluta (Lepidoptera, Gelechiidae). Accession 'LA716', with high contents of acyl sugars in the leaves, was used as a source of resistance to start a genetic breeding program of processing cultivated tomato, S. lycopersicum. We selected plants of the F 2 generation of an interspecific cross (S. lycopersicum cv. 'Redenção' x S. pennellii 'LA716') for extremes of concentrations (high and low) of acyl sugars in the leaves and evaluated the resistance of selected genotypes to the tomato pinworm, compared with plants of the parental and F 1 generations. The concentrations of acyl sugars present in the genotypes selected for high contents were close to those of S. pennellii 'LA 716', while the genotypes with low concentrations of acyl sugars were close to cultivar 'Redenção'. The F 1 hybrid ('Redenção' x 'LA716') had intermediate concentrations of acyl sugars, but was closer to Redenção, indicating that the inheritance of this type of ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 12 (1): 381-389 (2013) D.M. Dias et al. character is due to a recessive major gene, along with minor genes with additive effects. There was a direct association between high contents of acyl sugars and non-preference for oviposition and suppression of larval development, indicating that the allelochemical acts through mechanisms of non-preference for oviposition and through antibiosis. Genotypes with high contents of acyl sugars were more effective in reducing the damage caused by the tomato pinworm. Genotypes RVTA-2010pl#94 and RVTA-2010pl#31, selected for high contents of acyl sugars, showed a good level of resistance to T. absoluta, similar to the wild genotype LA716. These genotypes are promising for use in a breeding program for developing commercial processing tomatoes.

The effect of ethanol leaf-extract of Gmelina arborea on liver enzymes was investigated in rats using spectrophotometric methods. Twenty albino rats were grouped into four (A, B, C and D) containing five animals in each. The animals in groups A, B, C and D were administered the extract through oral intubation at the doses (mg/kg) of 200, 400, 600 and 0 respectively for two weeks. The blood samples were collected on the fifteenth day following the last day of administration. The aspartate aminotransferase (AST) activities (u/l) recorded 30.60 ± 2.13, 40.40 ± 3.70, 62.82 ± 3.39 and 26.00 ±1.41 for the animals in groups A, B, C and D respectively with corresponding activities (u/l) of alkaline phosphatase (ALP) as 16.80 ± 1.21, 27.40 ± 1.77, 39.60 ± 2.01 and 16.30 ± 1.77. The alanine aminotransferase (ALT) activities (u/l) recorded 2.88 ± 0.53, 3.42 ± 0.44, 4.64 ± 0.21and 2.28 ± 0.49 for the animals in groups A, B, C and D respectively. The results indicated a dose-dependent significant (p< 0.05) increase in the activities of liver enzymes of the animals that received the ethanol leafextract of Gmelina arborea, hence the ethanol leaf-extract of Gmelina arborea could be hepatotoxic.

Sickle cell disease (SCD) treatment and management remain a challenging puzzle, especially among developing Nations. We evaluated catechin’s sickling-suppressive properties using in-vitro and bioinformatics approaches in human sickle erythrocytes. Sickling was maximally induced (76%) using 2% sodium metabisulfite (SMS) at 3h. Addition of catechin prevented the sickling by SMS at 1mM (81.19%) and reversed the same at 1mM (84.63%), with IC50 values of 1.026µM and 1.103µM, respectively. Based on functional chemistry, catechin alters the functional groups of certain notable compounds within erythrocytes, favouring its anti-sickling effects, as indicated by the observed bends and shifts. From GC-MS and LC-MS analyses, it was observed that catechin treatment favours fatty acid alkyl monoesters (FAMEs) production with concomitant shutting down effects on selenocompound metabolism. Pathway enrichment and topology analyses revealed activation of fatty acid biosynthesis, linoleic acid metabolism and steroid hormone biosynthesis pathways upon catechin treatment. Thus, sickling-suppressive effects of catechin could potentially be associated with modulation of oxygenated and deoxygenated haemoglobin via alteration of human sickle erythrocytes’ functional chemistry and metabolic pathways implicated in SCD crisis.

Paints have been used since ancient times and there several paints of varying chemical composition have been in use for domestic and industrial purposes. The effectiveness of the preservative used in the paint samples which is easily available in the market was evaluated against different microorganisms as the consequences of microbial deterioration have serious economic implications on the paint industry. The aim of this study was, therefore, to investigate the microbial quality of paints with a view to improving the shelf life of paint and paint products. This study was carried to evaluate the resistance of emulsion paints in the container against microorganisms such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Aspergillus niger and Candida albicans. It can be observed from this study that the concentration of preservative component in the emulsion paint is directly proportional to the inhibition of the bacterial growth irrespective of its pathogenicity.

A gain-of-function mutation in resistance (R) gene SSI4 causes constitutive activation of defense responses, spontaneous necrotic lesion formation, enhanced resistance against virulent pathogens, and a severe dwarf phenotype. Genetic analysis revealed that ssi4-induced H2O2 accumulation and spontaneous cell death require RAR1, whereas ssi4-mediated stunting is dependent on SGT1b. By contrast, both RAR1 and SGT1b are required in a genetically additive manner for ssi4-induced disease resistance, SA accumulation, and lesion formation after pathogen infection. These data point to cooperative yet distinct functions of RAR1 and SGT1b in responses conditioned by a deregulated nucleotide-binding leucine-rich repeat protein. We also found that RAR1 and SGT1b together contribute to basal resistance because an ssi4 rar1 sgt1b triple mutant exhibited enhanced susceptibility to virulent pathogen infection compared with wild-type SSI4 plants. All ssi4-induced phenotypes were suppressed when plant...

A new species of Talaromyces C. R. Benjamin, T. assiutensis, is described and illustrated. It was isolated from Egyptian soil amended with crushed buffalo hooves and incubated for five months at 35°C. T. assiutensis is characterized by white to pale yellow ascomata, small, smooth-walledto finely roughened ascospores and short biverticillate conidiophores. The taxa of Talaromyces published after 1972 are briefly discussed.

Ricinus communis has been used as a traditional remedy for inflammation, rheumatism, liver disorders, headache, backache, abscesses, warts, dropsy, microbial infections and other ailments. The current study was mainly focused on its anti-ulcer and antioxidant activities against aspirin-induced gastric ulcer in albino rabbits. R. communis leaves ethanolic extract was subjected to preliminary phytochemical screening and elemental analysis. For the evaluation of antiulcer and antioxidant activities, rabbits were randomly divided into 6 groups (n = 6) as normal control, aspirin (150 mg kg-1 day-1) alone treated group, aspirin receiving groups treated with standard anti-ulcer drug ranitidine (20 mg kg-1 day-1), and R. communis extract at 150, 300 and 450 mg kg-1 day-1, respectively via oral route. Blood and organ samples were collected for assessment of gastroprotective and antioxidant activities. Phytochemical analysis detected various phytoconstituents and significant concentrations of calcium, copper, iron, zinc, manganese and cobalt plant extract. Aspirin administration showed a significant (P < 0.01) increase in gastric acidic pH, acid volume, total acid output, ulcer score and ulcer index. Treatment with R. communis extract significantly (P < 0.05) attenuated the ulcerogenic effects of aspirin. Also, R. communis treated groups showed a dose-dependent increase in antioxidant biomarkers (TAC, CAT) and reduction in oxidative stress biomarkers (TOS, MDA). Histopathological examination showed normalization of gastric mucosa in R. communis treated animals. Moreover, R. communis showed 69.25% gastric ulcer protection against aspirin as compared to ranitidine (72.17%). Collectively, it can be concluded that R. communis leaves extract could provide gastroprotection in NSAIDs receiving patients.

Qualitative composition of volatile emissions of litter of five species of deciduous trees was investigated by GC-MS. The list of identified substances contains more than 70 organic compounds of various classes. It was established that the composition of components emitted by the litter into the gas phase greatly differs from that of essential oils extracted by hydrodistillation from turned leaves collected from trees during fall. It is suggested that most compounds found in litter emissions are products of vital activity of microorganisms decomposing it. The reported data indicate that after the vegetative period is over the decomposition processes of litter are important seasonal sources of reactive organic compounds under the forest canopy.

The continuously growing interest in small regulatory RNA exploration is one of the important factors that have inspired the recent development of new high throughput techniques such as DNA microarrays or next generation sequencing. Each of these methods offers some significant advantages but at the same time each of them is expensive, laborious and challenging especially in terms of data analysis. Therefore, there is still a need to develop new analytical methods enabling the fast, simple and costeffective examination of the complex RNA mixtures. Recently, increasing attention has been focused on the RNA degradome as a potential source of riboregulators. Accordingly, we attempted to employ a two-dimensional gel electrophoresis as a quick and uncomplicated method of profiling RNA degradome in plant or human cells. This technique has been successfully used in proteome analysis. However, its application in nucleic acids studies has been very limited. Here we demonstrate that two dimensional electrophoresis is a technique which allows one to quickly and cost-effectively identify and compare the profiles of 10-90 nucleotide long RNA accumulation in various cells and organs.

Epiphylls widely colonize vascular leaves in moist tropical forests. Understanding the effects of epiphylls on leaf traits of host plants is critical for understanding ecological function of epiphylls. A study was conducted in a rain forest to investigate leaf traits of the host plants Photinia prunifolia colonized with epiphyllous liverworts and foliicolous lichens as well as those of uncolonized leaves. Our results found that the colonization of lichens significantly decreased leaf water content (LWC), chlorophyll (Chl) a and a + b content, and Chl a/b of P. prunifolia but increased Chl b content, while that of liverworts did not affect them as a whole. The variations of net photosynthetic rates (P n ) among host leaves colonized with different coverage of lichens before or after removal treatment (a treatment to remove epiphylls from leaf surface) were greater than that colonized with liverworts. The full cover of lichens induced an increase of light compensation point (LCP) by 2...

In this paper, the compounds identified from the essential oil of the leaf of Piper longum L. are described. The essential oil which was hydrodistilled from the air-dried leaf of P. longum was characterized for the constituents by means of gas chromatography (GC) and gas chromatography coupled to mass spectrometry GC-MS). The yield of the colorless essential oil was 0.12% (v/w) calculated on a dry weight basis. The main constituent of the oil was fonenol (40.5%). The chemical compositions of the studied oil sample were considerably different from data observed from other samples around the world.

Gross primary production (GPP) is closely associated with processes such as photosynthesis and transpiration within ecosystems, which is a vital component of the global carbon-water-energy cycle. Accurate prediction of GPP in terrestrial ecosystems is essential for evaluating terrestrial carbon cycle processes. Machine learning (ML) models provide significant technical support in this domain. Presently, there is a deficiency of high-precision and robust GPP prediction variables and models. Challenges such as unclear contributions of predictive variables, extended model training durations, and limited robustness must be addressed. Solar-induced chlorophyll fluorescence (SIF), optimized multilayer perceptron neural networks, and ensemble learning models show the potential to overcome these challenges. This study aimed to develop an optimized multilayer perceptron neural network model and an ensemble learning model, while objectively assessing the capacity of SIF to predict GPP. Identifying robust models capable of enhancing the accuracy of GPP predictions was the ultimate goal. This study utilized continuous observations of SIF and meteorological data collected from 2020 to 2021 at a designated research observation station within the Populus plantation ecosystem of the Huanghuaihai agricultural protective forest system in Henan Province, China. By optimizing and evaluating the predictive accuracy and robustness of the models across different temporal scales (half-hourly and daily scales), a multi-layer perceptron (MLP) neural network optimization model based on the back propagation (BP) neural network (BPNN) algorithm (BP/MLP) and MLP and random forest (RF) integration (MLP-RF) ensemble models were constructed, utilizing SIF as the primary predictive variable for GPP. Both the BP/MLP (half-hourly scale model R 2 = 0.885, daily scale model R 2 = 0.921) and the MLP-RF (half-hourly scale model R 2 = 0.845, daily scale model R 2 = 0.914) models showed superior accuracy compared to the BPNN (half-hourly scale model R 2 = 0.841, daily scale model R 2 = 0.918) and the traditional RF (half-hourly scale model R 2 = 0.798, daily scale model R 2 = 0.867) models, with the BP/MLP model consistently outperforming the MLP-RF model. The BP/MLP model, which was optimized through particle swarm optimization (PSO), significantly enhanced the robustness of GPP predictions on a half-hourly scale and daily scale. Considering both half-hourly scale and daily scale in the PSO-BP/MLP modeling, the four indicators, light-use efficiency (LUE), photosynthetically active radiation (PAR), absorbed photosynthetically active radiation (APAR), and the variation in SIF with NIR v P (f SIF (NIR v P)), exhibited the potential for enhancing the accuracy of GPP predictions. This study employed a series of model optimization techniques to develop a GPP prediction model with enhanced performance that objectively evaluated the contributions of the predictive variables. This approach provided an innovative and effective method for assessing the carbon cycle in terrestrial ecosystems.