Acid In Leaf Tissue Research Articles

Forest tree extracts induce resistance to Pseudomonas syringae pv. tomato in Arabidopsis.

The widespread use of conventional pesticides for plant pathogen control poses significant risks to human health and the environment, and it is therefore crucial to develop environmentally friendly, human-safe alternatives to these products that offer a sustainable approach for crop protection. Here, we examined the potential of ethanolic extracts from four forest tree species for their antibacterial activity against the bacterial pathogenPseudomonas syringaepv.tomato (Pst) and their ability to trigger effective defense responses in the model plantArabidopsis thaliana. The extracts exhibited direct toxic effects against Pst and triggered the expression of defense-related genes naturally induced by oxidative stress cues or the defense elicitor salicylic acid in leaf tissue. The direct antibacterial effects of the tree extracts, together with their defense gene-inducing effectsin planta, resulted in a strong host plant-protecting effect againstPst. These findings suggest the eventual effectiveness of forest tree extracts as plant protectants against the bacterial pathogenPst. They also suggest the potential of these extracts as a sustainable, eco-friendly alternative to conventional pesticides for the management of economically important plant pathogens.

Knock-Out Mutatıon of Cat2 Drastıcally Reduced The Melatonın-Medıated Resıstance to Boron Toxıcıty in Arabıdopsıs thalıana

The role of catalase in resistance to boron toxicity after melatonin application (MEL) was investigated in Arabidopsis thaliana plants. Col-0 and cat2-2 plants were exposed to 50 μM MEL followed by boron toxicity (BT) in a medium containing 10 mM H 3BO 3. Pigment loss and accordingly chlorosis were reduced by melatonin under BT conditions, while they were more prominent in cat2-2 mutants. Moreover, TBARS and H 2O 2 contents, which increased due to BT, decreased as a result of melatonin application and the levels of these parameters in cat2-2 mutants were higher than the values in Col-0. Antioxidant enzyme activity of SOD and SOD1 gen transcript were induced by MEL under BT. Conversely, APX4, PER10 and CAT1 transcripts were down-regulated by MEL under BT. In addition, antioxidant enzyme activities and their transcript levels were lower than those of Col-0. Thus, we suggested that MEL scavenged ROS directly under BT. Melatonin also reduced the accumulation of boric acid in leaf tissues of Col-0, but not cat2-2. Finally, even though melatonin application provided a degree of endurance, the cat2 mutation resulted in increased sensitivity to BT.

EFFECT OF IRRIGATION WATER QUANTITY AND SOME ANTIOXIDANTS ON YIELD AND SOME PHYSIOLOGICAL TRAITS OF SNAP BEAN GROWN UNDER SANDY SOIL CONDITIONS

A field experiment was carried out during the two successive summer seasons of 2017 and 2018 under sandy soil conditions at EL-Khattara Experimental Farm, Fac. Agric., Zagazig University, to study the effect of irrigation water quantity (1000, 1500 and 2000 m3/fed.) and foliar spray with some antioxidants (salicylic cid at 200 ppm, ascorbic acid at 300 ppm beside control treatments ( sprayed with tap water ) on growth, plant water relationship, yield and pod quality of snap bean cv, Bronco. The most important findings could be summarized as follows: The interactions between irrigation of snap bean plants at 2000 m3/fed. and spraying with SA at 200 ppm recorded the highest values of dry weight of branches, leaves and total dry weight/ plant, increasing chlorophyll a, b and total chlorophyll (a+b) in leaf tissues, average pod weight , yield / plant and total pods yield/fed., and TSS in green pods. However, the interaction between irrigation water quantity at 2000 m3/fed. and spraying with ascorbic acid at 300 ppm recorded the highest values of total and free water (%) in leaf tissues and total carbohydrates and Vit. C in green pods in both seasons, whereas interaction treatment between 1000 m3 water/fed., without antioxidants resulted in the highest values represented bound water and proline amino acid in leaf tissues and total fiber contents in green pods. On the other hand, the interactions between irrigation water quantity at 1000 m3 water/ fed., and spraying with SA at 200 ppm recorded the highest values of water use efficiency (2.692 and 2.731 kg green pods/m3 water) in the 1st and 2nd seasons, respectively.

EFFECT OF PLANTING DATE , IRRIGATION LEVEL AND FOLIAR SPRAYING WITH CALCIUM AND BORON TREATMENTS ON POTATO 1. PLANT GROWTH , PLANT WATER RELATIONSHIP AND PLANT CHEMICAL CONSTITUENTS

ABSTRACT A filed experiment was carried out during the two successive seasons of 2016/2017 and 2017/2018 at the Experimental Farm of El- Gemmeiza, Agric Res. Station, A. R.C., Gharbya Governorate (Middle Delta, Egypt) to study the effect of planting date (20th September (Sep.) and 10th October (Oct.), irrigation water level at 50, 75 and 100 % from the filed capacity (FC) and two foliar spray treatments with calcium chloride (1%) and boron ( 60 ppm) singly or in combinations, beside unsprayed treatment as well as their interactions on growth, plant water relationship and plant chemical compositionof potato(Mondial cv.) under clay soil conditions using flood irrigation system. These treatments were arranged in a split split plot design with three replicates. Planting date was arranged in the main plots, irrigation water quantities were in the sub plots, while foliar spray treatments were randomly distributed in the sub sub plots. The obtained results indicate that, the tertiary interactions of planting on 10th Oct., irrigation at 100 % of FC and spraying potato plants with calcium and boron in combination gave the highest values of plant height , both fresh and dry weight of shoot/ plant, total and free water % as well as total chlorophyll ( a+b) in leaf tissues, N, P, K, Ca , Boron and total carbohydrates contents in shoots in both seasons. While the tertiary interactions of planting on 20th Sep., irrigation level at 50 % from FC and unsprayed with calcium and boron gave the highest values of bound water % and proline amino acid in leaf tissues in both seasons. Conclusively, under similar conditions it could be concluded that , the tertiary interaction of planting on 10th Oct , irrigation at 100 % FC and sprayed plants with Ca + B were the best interaction treatments for enhancing plant growth and chemical constituents in shoot of potato grown in clay soil under the same conditions.

Development of an efficient high-performance thin layer chromatography method for determination of jasmonic acid in leaf tissue of Stevia rebaudiana (Bertoni) Bertoni

Determination of endogenous levels of jasmonic acid (JA) is essential, as it plays a pivotal role in the physiological processes during a plant’s life cycle. A high performance thin layer chromatography (HPTLC) method was developed for the detection and quantification of JA in leaf extracts of medicinal plant, Stevia rebaudiana (Bertoni) Bertoni. The separation was achieved using the solvents ethyl acetate–benzene (1:1, v/v) as the mobile phase, followed by scanning and quantification at 295 nm. Densitometric analysis of leaf extract resulted in compact spots for JA at Rf = 0.45 ± 0.02. The linear regression analysis showed good relationship with r value. The recovery rate of JA indicated good reproducibility and repeatability of the assay. The statistical analysis proved the reproducibility of the method; therefore, it can be employed for routine quantification of JA in different tissue samples of S. rebaudiana and may also be extrapolated to other biological samples.

De novo transcriptome analysis of rose-scented geranium provides insights into the metabolic specificity of terpene and tartaric acid biosynthesis

BackgroundRose-scented geranium (Pelargonium sp.) is a perennial herb that produces a high value essential oil of fragrant significance due to the characteristic compositional blend of rose-oxide and acyclic monoterpenoids in foliage. Recently, the plant has also been shown to produce tartaric acid in leaf tissues. Rose-scented geranium represents top-tier cash crop in terms of economic returns and significance of the plant and plant products. However, there has hardly been any study on its metabolism and functional genomics, nor any genomic expression dataset resource is available in public domain. Therefore, to begin the gains in molecular understanding of specialized metabolic pathways of the plant, de novo sequencing of rose-scented geranium leaf transcriptome, transcript assembly, annotation, expression profiling as well as their validation were carried out.ResultsDe novo transcriptome analysis resulted a total of 78,943 unique contigs (average length: 623 bp, and N50 length: 752 bp) from 15.44 million high quality raw reads. In silico functional annotation led to the identification of several putative genes representing terpene, ascorbic acid and tartaric acid biosynthetic pathways, hormone metabolism, and transcription factors. Additionally, a total of 6,040 simple sequence repeat (SSR) motifs were identified in 6.8% of the expressed transcripts. The highest frequency of SSR was of tri-nucleotides (50%). Further, transcriptome assembly was validated for randomly selected putative genes by standard PCR-based approach. In silico expression profile of assembled contigs were validated by real-time PCR analysis of selected transcripts.ConclusionBeing the first report on transcriptome analysis of rose-scented geranium the data sets and the leads and directions reflected in this investigation will serve as a foundation for pursuing and understanding molecular aspects of its biology, and specialized metabolic pathways, metabolic engineering, genetic diversity as well as molecular breeding.

Two activities of long-chain acyl-coenzyme A synthetase are involved in lipid trafficking between the endoplasmic reticulum and the plastid in Arabidopsis.

In plants, fatty acids are synthesized within the plastid and need to be distributed to the different sites of lipid biosynthesis within the cell. Free fatty acids released from the plastid need to be converted to their corresponding coenzyme A thioesters to become metabolically available. This activation is mediated by long-chain acyl-coenzyme A synthetases (LACSs), which are encoded by a family of nine genes in Arabidopsis (Arabidopsis thaliana). So far, it has remained unclear which of the individual LACS activities are involved in making plastid-derived fatty acids available to cytoplasmic glycerolipid biosynthesis. Because of its unique localization at the outer envelope of plastids, LACS9 was regarded as a candidate for linking plastidial fatty export and cytoplasmic use. However, data presented in this study show that LACS9 is involved in fatty acid import into the plastid. The analyses of mutant lines revealed strongly overlapping functions of LACS4 and LACS9 in lipid trafficking from the endoplasmic reticulum to the plastid. In vivo labeling experiments with lacs4 lacs9 double mutants suggest strongly reduced synthesis of endoplasmic reticulum-derived lipid precursors, which are required for the biosynthesis of glycolipids in the plastids. In conjunction with this defect, double-mutant plants accumulate significant amounts of linoleic acid in leaf tissue.

Correlation between the output and composition of essential oil and the level of salicylic acid in mint plants at different ontogenetic stages

Dynamic changes in the content of acetylsalicylic acid and the output and qualitative composition of essential oil have been studied in mint plants (Mentha spicata L. and cultivar Medichka) during their ontogenesis with allowance for changes in weather conditions. Ontogenetic changes in the level of acetylsalicylic acid in leaf tissues are found to be similar in both cv. Medichka and M. spicata. In the case of cv. Medichka, this change is connected with the dynamics of the production and the qualitative composition of essential oil; in the case of M. spicata, this connection is less expressed. The role of acetylsalicylic acid and essential oil in plant adaptation to the environment is discussed.

GLOBE ARTICHOKE CALLUS AS AN ALTERNATIVE SYSTEM FOR THE PRODUCTION OF DICAFFEOYLQUINIC ACIDS

Globe artichoke leaves are highly rich in phenolic acids, in particular chlorogenic acid and dicaffeoylquinic acids. The latter are of particular interest since they can exert a stronger antioxidant activity, due to the presence of two adjacent hydroxyl groups on each of their phenolic rings. Plant tissue and cell cultures have been widely exploited for the production of secondary metabolites. We compared the content of 5-O-caffeoylquinic acid (chlorogenic acid) and 1,5-O-dicaffeoylquinic acid in leaf tissues and calli obtained from leaf explants of two globe artichoke genotypes (SAROM and C3-RR) belonging to the varietal type ‘Romanesco’. HPLC analyses highlighted that chlorogenic acid accumulates preferentially in leaf tissue, while dicaffeoyquinic acid in calli. We previously set up a system, based on UV-C exposure of leaf foliar discs, which was found to induce dicaffeoylquinic acid synthesis. Preliminary results demonstrate that UV-C further increases the content of dicaffeoylquinic acid of 1.5-fold also when applied to callus tissue. Globe artichoke callus culture combined with UV-C radiation may thus represent a promising system for the production of dicaffeoylquinic acids.

EFFECT OF IRRIGATION WATER QUANTITY AND FARMYARD MANURE ON POTATO PLANT GROWN IN SANDY SOIL

This experiment was carried out during the two successive summer seasons of 2009 and 2010 at a Private Farm in EL-Salhaia El-Gadida region, Sharkia Governorate on potato plant (Solanum tuberosum L.) cultivar Diamantgrown under sandy soil conditions using drip irrigation system to study the effect of quantity of irrigation water (750, 1250 and 1750 m3/ fed.) and farmyard manure (10, 20 and 30 m3/ fed.) as well as their interactions on growth, yield and its quality as well as water use efficiency. Plant height, number of leaves/ plant, shoot dry weight, free and total water in leaf tissues, N, P and K percentages and their uptake by shoot significantly increased with increasing irrigation water quantity up to the highest level (1750 m3/ fed). Irrigation water quantity of 1250 or 1750 m3/ fed. recorded the maximum values of average tuber weight, tuber yield/ plant and total yield/ fed, N, P, carbohydrates, starch and DM percentages in tuber tissues. Bound water, cell sap, osmotic pressure and proline amino acid in leaf tissues as well as water use efficiency (WUE) by potato plants were significantly increased with decreasing irrigation water quantity up to the lowest level (750 m3/ fed). Farmyard manure (FYM) at 20 m3/ fed. significantly increased plant height, number of leaves/ plant, shoot dry weight, free and total water percentages, P % and its uptake by shoot, N, P, total carbohydrates, starch and dry matter % in tubers, on the other hand, N and K contents and their uptake by shoot, average tuber weight, yield/ plant and total yield/ fed. as well as water use efficiency were significantly increased with increasing FYM up to 30 m3/ feddan. Interaction treatment between water quantity at 1250 m3/ fed. and FYM at 30 m3/ fed. was the superior treatment for enhancing shoot dry weight/ plant, N % and its uptake by shoot, N, K and total carbohydrates in tubers. While, the interaction treatment between 1750 m3/ fed. water quantity and 30 m3/ fed. FYM gave the highest values of P and K percentages and their uptake by shoot, tuber yield/ plant and total yield/ feddan.

Environmental Factors Affecting the Accumulation of Rosmarinic Acid in Spearmint (Mentha spicata L.) and Peppermint (Mentha piperita L.)

Four spearmint, and two peppermint clonal lines, selected for enhanced rosmarinic acid content (50-120 mg g-1 rosmarinic acid DW), where up to 80% of the antioxidant activity was correlated to rosmarinic acid content, were examined to determine the effects of environmental and physiological conditions on the accumulation of rosmarinic acid in leaf tissues. Exposure to a short photoperiod of 12 hours in comparison to 16 hours reduced rosmarinic acid accumulation in two mint lines, but no significant difference was found between photoperiods of 14 and 16 hours. The physiological age of the plant strongly influenced the accumulation of rosmarinic acid with the highest levels recorded in the vegetative state, and a significant reduction in the concentration of rosmarinic acid in the leaves in both the bud initiation and flowering stages in the mint lines. Cold stress, impacted over a six week period had no effect on rosmarinic acid production. A field study of the commercial chemotype 700B indicated that soil type plays an essential role in the accumulation of rosmarinic acid in the leaf tissue, probably due to retention of moisture which favours rosmarinic acid production. For producers and extractors, taking these factors into account would significantly increase rosmarinic acid accumulation in commercially high rosmarinic acid mint and increase the quality control of plant extracts for the natural products industry.

Possible contribution of cell-wall-bound ferulic acid in drought resistance and recovery in triticale seedlings

Studies were undertaken to estimate whether the presence of free and cell-wall-bound ferulic acid in leaf tissues can support drought resistance and its recovery under rehydration. An experiment was carried out on two genotypes of winter triticale: Lamberto and Ticino, at the propagation phase. Lamberto exhibited high content of ferulic acid bound with carbohydrates of the cell-wall under drought and rehydration. The markedly better parameters of chlorophyll fluorescence for this variety under both treatments correlated strongly and positively with the high contents of cell-wall-bound ferulic acid. The photosynthetic apparatus of Lamberto, in relation to Ticino, proved to be the more efficient after 4 weeks of drought treatment. The after-effects of soil drought better elicited the function disturbances of the photosynthetic apparatus in Ticino, which did not fully recover in comparison to Lamberto. Ferulic acid covalently bound to carbohydrates of the cell wall may act as a light filter limiting mesophyll penetration under drought conditions and can also support drought adaptation by down-regulation of leaf growth. The observed increase in the content of cell-wall-bound ferulic acid, as a response to water deficit in the leaf, could be one of the protective mechanisms induced by drought conditions. The ability to accumulate phenolic compounds in dehydrated leaves might be an additional and reliable biochemical parameter indicating the resistance of plants to drought stress.

Nontarget Mechanims Involved in Glyphosate Tolerance Found in Canavalia ensiformis Plants

A glyphosate-tolerant population of Canavalia ensiformis was collected in a cover crop in citrus orchards in Veracruz (Mexico), where glyphosate had been used for the first time. A susceptible Amaranthus hybridus L. population was collected from a nearby field that had never been treated with glyphosate. Dose-response experiments indicated a glyphosate tolerance ratio [ED(50)(C. ensiformis)/ED(50) (A. hybridus)] of 7.7. The hypothesis of a high level of glyphosate tolerance was provisionally corroborated on the basis of shikimate accumulation in both species. The susceptible population accumulated 6 times more shikimic acid in leaf tissue 96 h after glyphosate application than the tolerant leguminous crop. Two different physiological factors were involved in the glyphosate tolerance of this C. ensiformis population, which were confirmed by [(14)C]glyphosate, being a lack of penetration of glyphosate through the cuticle of the leguminous plants and an impaired herbicide translocation to the roots and the rest of shoots. This paper reports that two different nontarget site-based mechanisms, limited absorption and reduced translocation, contribute to the glyphosate tolerance found in C. ensiformis.

Physiological and Biochemical Tools Useful in Drought-Tolerance Detection in Genotypes of Winter Triticale: Accumulation of Ferulic Acid Correlates with Drought Tolerance

The objectives of this study were to investigate whether a classification of triticale genotypes into drought-tolerant and drought-sensitive types based on field performance trials correlates with a classification based on measurements of some physiological and biochemical parameters in greenhouse conditions. In addition, an examination was carried out of whether ferulic acid, as the main origin of the blue fluorescence produced, contributes to drought tolerance. Ten winter triticale genotypes were examined, five known to be drought tolerant and five drought sensitive. Measurements of the osmotic potential, leaf gas exchange, chlorophyll fluorescence, and blue and red fluorescence were performed. In addition, analysis of the total pool of phenolic compounds and ferulic acid as well as the measurements of PAL (l-phenylalanine ammonia-lyase) activity were carried out. In agreement with field trials, three out of five cultivars ('Lamberto', 'Timbo' and 'Piano') were classified as drought tolerant. However, in the case of cultivar 'Babor', included in the group of drought-sensitive cultivars, the values obtained for some measured parameters were close to (F(v)(')/F(m)('), phenolics content, osmotic potential) or even better than (non-photochemical quenching, red and blue fluorescence, ferulic acid content) those for drought-tolerant genotypes. Cultivars 'Imperial', 'Ticino', 'Trimaran' and 'Boreas' were included in the drought-sensitive group, whereas cultivars 'Focus' and 'Kitaro' were included in the moderately sensitive group. The experiments confirmed that the period of flowering, the critical phase for plants as far as water demand is concerned, is suitable for plant screening and differentiation due to their tolerance to drought. The most important criteria which enabled creation of the ranking list of plants, from those sensitive to drought to those tolerant to drought, were the ability to perform the process of osmoregulation, the efficiency of the utilization of excitation energy by the photosynthetic apparatus and the functioning of protective mechanisms involving the level of ferulic acid in leaf tissues.

In vivo measurements of changes in pH triggered by oxalic acid in leaf tissue of transgenic oilseed rape

Oxalic acid (OA), a non-host-specific toxin secreted by Sclerotinia sclerotiorum during pathogenesis, has been demonstrated to be a major phytotoxic and pathogenic factor. Oxalate oxidase (OXO) is an enzyme associated with the detoxification of OA, and hence the introduction of an OXO gene into oilseed rape (Brassica napus L.) to break down OA may be an alternative way of increasing the resistance of the plant to Sclerotinia sclerotiorum. In order to investigate the activation of OXO in transgenic oilseed rape, a convenient and accessible method was used to monitor changes in pH in response to stress induced by OA. The pH sensor, a platinum microcylinder electrode modified using polyaniline film, exhibited a linear response within the pH range from 3 to 7, with a Nernst response slope of 70 mV/pH at room temperature. The linear correlation coefficient was 0.9979. Changes induced by OA in the pH values of leaf tissue of different oilseed rape species from Brassica napus L. were monitored in real time in vivo using this electrode. The results clearly showed that the transgenic oilseed rape was more resistant to OA than non-transgenic oilseed rape.

Investigating the mechanisms of glyphosate resistance in Lolium multiflorum

Evolved resistance to the herbicide glyphosate has been reported in eleven weed species, including Lolium multiflorum. Two glyphosate-resistant L. multiflorum populations were collected, one from Chile (SF) and one from Oregon, USA (OR), and the mechanisms conferring glyphosate resistance were studied. Based on a Petri dish dose-response bioassay, the OR and the SF populations were two and fivefold more resistant to glyphosate when compared to the susceptible (S) population, respectively; however, based on a whole-plant dose-response bioassay, both OR and SF populations were fivefold more resistant to glyphosate than the S population, implying that different resistance mechanisms might be involved. The S population accumulated two and three times more shikimic acid in leaf tissue 96 h after glyphosate application than the resistant OR and SF populations, respectively. There were no differences between the S and the glyphosate-resistant OR and SF populations in 14C-glyphosate leaf uptake; however, the patterns of 14C-glyphosate translocation were significantly different. In the OR population, a greater percentage of 14C-glyphosate absorbed by the plant moved distal to the treated section and accumulated in the tip of the treated leaf. In contrast, in the S and in the SF populations, a greater percentage of 14C-glyphosate moved to non-treated leaves and the stem. cDNA sequence analysis of the EPSP synthase gene indicated that the glyphosate-resistant SF population has a proline 106 to serine amino acid substitution. Here, we report that glyphosate resistance in L. multiflorum is conferred by two different mechanisms, limited translocation (nontarget site-based) and mutation of the EPSP synthase gene (target site-based).

Genetic manipulation of γ‐linolenic acid (GLA) synthesis in a commercial variety of evening primrose (Oenothera sp.)

A robust Agrobacterium-mediated transformation procedure was developed for Rigel, a commercial cultivar of evening primrose, and used to deliver a cDNA encoding a Delta(6)-desaturase from borage under the control of a cauliflower mosaic virus (CaMV) 35S promoter. Analysis of the transformed plants demonstrated an altered profile of polyunsaturated fatty acids, with an increase in gamma-linolenic acid and octadecatetraenoic acid in leaf tissues when compared with control lines.

The variations in linolenic acid and galactolipid levels in gramineae species with age of tissue and light environment

The increases in total lipid and galactolipid which occur in leaf tissue of increasing maturity appear to be dependent on increasing photosynthetic activity rather than age of tissue. Although the total amount of linolenic acid in leaf tissue increases with increased chlorophyll levels there is very little change in the relative proportions of the component fatty acids in the monogalactolipid, high levels of linolenic acid being maintained under all conditions.