Influence of severe drought on leaf response in ABA contrasting tomato genotypes (wild type and flacca mutant)

Plant physiological responses to various stresses are characterized by interaction and coupling, while the intrinsic mechanism remains unclear. The effects of intraspecific competition on plant growth, stomatal opening, and hormone concentrations were investigated with three tomato genotypes (WT-wild type, Ailsa Craig; FL-a abscisic acid (ABA) deficient mutant, flacca; NR-a partially ethylene-insensitive genotype) under two water regimes (full irrigation, irrigation amount = daily transpiration; deficit irrigation, 60% of irrigation amount in full irrigation) in this study. Three kinds of competitions were designed, i.e., root and canopy competition, non-root competition, and non-canopy competition, respectively. Intraspecific competition reduced plant leaf area and stomatal conductance (gs) of wild-type tomato, accompanied by ABA accumulation and ethylene evolution. Intraspecific competition-induced decrease in gs was absent in FL and NR, indicating ABA and ethylene involved in plant response to intraspecific competition. As soil water becomes dry, the competition decreased gs by elevating ABA and ethylene accumulations. Under severe drought, the competition-induced decline in gs was covered by the severe drought-induced decrease in gs, as hydraulic signals most probably dominate. The absence of canopy competition insignificantly influenced plant stomatal opening of well-watered tomato, as canopy separation minimized the plant neighbor sensing by ethylene and other signals. Whereas under water deficit condition, the absence of canopy competition significantly reduced ABA accumulation in roots and then stomatal conductance, indicating the belowground neighbor detection signals maybe enhanced by soil drought. The absence of root competition increased ethylene evolution, confirming the importance of ethylene in neighbor detection and plant response to environmental stress.

Download Full-text

Function Analysis of Drought Resistance Related Gene TaGAPCs and TaWRKYs in Wheat

10.21203/rs.3.rs-565097/v1 ◽

2021 ◽

Author(s):

Qiuzhu Wang ◽

Lin Zhang ◽

Shushen Yang

Keyword(s):

Transcription Factors ◽

Drought Stress ◽

Function Analysis ◽

Severe Drought ◽

Primary Metabolism ◽

Wild Type ◽

Drought Treatment ◽

Biological Regulation ◽

Wheat Seedlings ◽

Differential Genes

Abstract Backgrounds: Wheat (Triticum aestivum L.) is one of the most important food crops in the world. It faces various abiotic stresses during its growth. Drought is one of the main factors limiting the growth and development of wheat. Severe drought stress will Lead to a decline in wheat production. Cytoplasmic glyceraldehyde-3-phosphate dehydrogenase (GAPC) is an important member of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) family, which is widely present in plant cytoplasm. Plants play an important role in the process of primary metabolism and stress resistance.Result: In this study, a comparative transcriptomic analysis of the TaGAPCs-RNAi strain of Changwu 134 and the wild-type wheat seedlings of Changwu 134 under natural drought conditions was carried out. A total of 30067 differentially expressed genes were screened in RNAi strains and wild-type strains, of which 19,959 genes were up-regulated in RNAi strains and 10,108 genes were down-regulated in transcription. GO analysis shows that differential genes are mainly enriched in biological regulation, cellular processes, metabolic processes, and responses to stimuli. KEGG analysis showed that the differential genes were mainly concentrated in the biosynthesis of phenylpropane, plant hormone signal transduction and flavonoid biosynthesis pathways. By analyzing the expression levels of differential transcription factors, the significantly down-regulated transcription factor WRKY family member TaWRKY2 / 22/28/29/33/40/47/52 in wheat was screened out. The TaWRKY28/33/40/47 gene silencing line was successfully obtained using the barley stripe mosaic virus (BSMV-VIGS) technology. The plants with TaWRKY28/33/40/47 gene silenced were subjected to natural drought treatment, and physiological and biochemical index tests were carried out. The results showed that the growth status of gene-silenced plants was worse than that of wild-type plants, and the relative water content and chlorophyll content decreased. The content of MDA, H2O2 and superoxide anion increases, the activity of antioxidant enzymes (SOD, POD, CAT) decreases, and the content of proline decreases. Conclusion: The results showed that TaGAPCs regulates the expression of some TaWRKYs transcription factors, activates antioxidant pathways, enhances tolerance of wheat to drought stress.

Download Full-text

Ppd-H1 integrates drought stress signals to control spike development and flowering time in barley

Journal of Experimental Botany ◽

10.1093/jxb/eraa261 ◽

2020 ◽

Cited By ~ 1

Author(s):

Leonard Gol ◽

Einar B Haraldsson ◽

Maria von Korff

Keyword(s):

Drought Stress ◽

Developmental Plasticity ◽

Floral Development ◽

Spring Barley ◽

Introgression Lines ◽

Photoperiod Response ◽

Severe Drought ◽

Wild Type ◽

Spike Development ◽

Stress Signals

Abstract Drought impairs growth and spike development, and is therefore a major cause of yield losses in the temperate cereals barley and wheat. Here, we show that the photoperiod response gene PHOTOPERIOD-H1 (Ppd-H1) interacts with drought stress signals to modulate spike development. We tested the effects of a continuous mild and a transient severe drought stress on developmental timing and spike development in spring barley cultivars with a natural mutation in ppd-H1 and derived introgression lines carrying the wild-type Ppd-H1 allele from wild barley. Mild drought reduced the spikelet number and delayed floral development in spring cultivars but not in the introgression lines with a wild-type Ppd-H1 allele. Similarly, drought-triggered reductions in plant height, and tiller and spike number were more pronounced in the parental lines compared with the introgression lines. Transient severe stress halted growth and floral development; upon rewatering, introgression lines, but not the spring cultivars, accelerated development so that control and stressed plants flowered almost simultaneously. These genetic differences in development were correlated with a differential down-regulation of the flowering promotors FLOWERING LOCUS T1 and the BARLEY MADS-box genes BM3 and BM8. Our findings therefore demonstrate that Ppd-H1 affects developmental plasticity in response to drought in barley.

Download Full-text

Role of GmNAC019 transcription factor in salinity and drought tolerance of transgenic Arabidopsis thaliana

Vietnam Journal of Biotechnology ◽

10.15625/1811-4989/16/4/12549 ◽

2020 ◽

Vol 16 (4) ◽

pp. 611-619

Author(s):

Thai Ha Vy ◽

Nguyen Cao Nguyen ◽

Hoang Thi Lan Xuan ◽

Nguyen Phuong Thao

Keyword(s):

Transcription Factor ◽

Survival Rate ◽

Water Loss ◽

Global Climate ◽

Crop Improvement ◽

Plant Response ◽

Root Growth Inhibition ◽

Severe Drought ◽

Wild Type ◽

Drought Treatment

Increasingly severe drought and salinity stress due to global climate change have made these stresses bigger threats to ecosystem and agriculture. Previous studies reported that GmNAC019, a soybean NAC transcription factor - encoding gene, displayed induced expression upon drought treatment in wild-type cultivars. In this study, drought and salinity stresses were applied on GmNAC019-overexpressing Arabidopsis plants to verify the contribution of GmNAC019 in regulating plant response to the stress conditions. Results from the water loss rate and survival rate assays revealed that the transgenic line conferred improved tolerance to drought stress as evidenced by lower leaf water loss and significantly higher rate of survival than seen in the wild-type plants. Similarly, the survival rate assay for testing salinity effects on plants by growing the plants on MS medium supplemented with different NaCl concentrations also indicated that the transgenic plants had a better tolerance to salt stress as they displayed lower rate of root growth inhibition and higher survival rate. Taken these results altogether, it is suggested that GmNAC019 might play important role in aiding plant response to drought and salinity stresses. Specific functions of this gene should be elaborated in future studies to evaluate its potential application for crop improvement.

Download Full-text

Differential Response of Two Tomato Genotypes, Wild Type cv. Ailsa Craig and Its ABA-Deficient Mutant flacca to Short-Termed Drought Cycles

Plants ◽

10.3390/plants10112308 ◽

2021 ◽

Vol 10 (11) ◽

pp. 2308

Author(s):

Bojana Živanović ◽

Sonja Milić Komić ◽

Nenad Nikolić ◽

Dragosav Mutavdžić ◽

Tatjana Srećković ◽

...

Keyword(s):

Cell Wall ◽

Growth Regulation ◽

Stomatal Closure ◽

Dry Weight ◽

Wall Material ◽

Wild Type ◽

Spectra Analysis ◽

Isolated Cell ◽

Tomato Genotypes

Two tomato genotypes with constitutively different ABA level, flacca mutant and wild type of Ailsa Craig cv. (WT), were subjected to three repeated drought cycles, with the aim to reveal the role of the abscisic acid (ABA) threshold in developing drought tolerance. Differential responses to drought of two genotypes were obtained: more pronounced stomatal closure, ABA biosynthesis and proline accumulation in WT compared to the mutant were compensated by dry weight accumulation accompanied by transient redox disbalance in flacca. Fourier-transform infrared (FTIR) spectra analysis of isolated cell wall material and morphological parameter measurements on tomato leaves indicated changes in dry weight accumulation and carbon re-allocation to cell wall constituents in flacca, but not in WT. A higher proportion of cellulose, pectin and lignin in isolated cell walls from flacca leaves further increased with repeated drought cycles. Different ABA-dependent stomatal closure between drought cycles implies that acquisition of stomatal sensitivity may be a part of stress memory mechanism developed under given conditions. The regulatory role of ABA in the cell wall restructuring and growth regulation under low leaf potential was discussed with emphasis on the beneficial effects of drought priming in developing differential defense strategies against drought.

Download Full-text

A transcriptomic approach to identify regulatory genes involved in fruit set of wild-type and parthenocarpic tomato genotypes

Plant Molecular Biology ◽

10.1007/s11103-015-0367-1 ◽

2015 ◽

Vol 89 (3) ◽

pp. 263-278 ◽

Cited By ~ 15

Author(s):

Fabrizio Ruiu ◽

Maurizio Enea Picarella ◽

Shunsuke Imanishi ◽

Andrea Mazzucato

Keyword(s):

Fruit Set ◽

Regulatory Genes ◽

Wild Type ◽

Tomato Genotypes

Download Full-text

Interactive Effects of Intraspecific Competition and Drought on Stomatal Conductance and Hormone Concentrations in Different Tomato Genotypes

10.21203/rs.3.rs-942000/v1 ◽

2021 ◽

Author(s):

Yang Gao ◽

Yueping Liang ◽

Shuang Li ◽

Zhuanyun Si ◽

Abdoul.Kader.Mounkaila Hamani

Keyword(s):

Stomatal Conductance ◽

Intraspecific Competition ◽

Plant Response ◽

Stomatal Opening ◽

Interactive Effects ◽

Root Competition ◽

Soil Drought ◽

Severe Drought ◽

Ethylene Evolution ◽

Tomato Genotypes

Abstract We elucidated the effects of intraspecific competition on plant growth, stomatal opening and hormone concentrations in different tomato genotypes under different water regimes. Intraspecific competition reduced plant leaf area and stomatal conductance (gs) of wild-type tomato (Ailsa Craig), which was accompanied by abscisic acid (ABA) accumulation and ethylene evolution. Intraspecific competition-induced decrease in gs was absent in flacca, an ABA-deficient mutant, and in never-ripe, a partially ethylene-insensitive genotype, indicating ABA and ethylene involved in plant response to intraspecific competition. As soil water becomes dry, the competition decreased gs by elevating ABA and ethylene accumulations. Under severe drought, the competition-induced decline in gs was covered by the severe drought-induced decrease in gs, as hydraulic signals most probably dominate. Absence of canopy competition had no significant influence on plant stomatal opening of well-watered tomato, due to canopy separation minimized the plant neighbor sensing by ethylene and other signals. Whereas under water deficit condition, absence of canopy competition significantly reduced ABA accumulation in roots and then stomatal conductance, indicating the belowground neighbour detection signals maybe enhanced by soil drought. Absence of root competition increased ethylene evolution, confirming the importance of ethylene in neighbor detection and plant response to environmental stress.

Download Full-text

Ppd-H1 integrates drought stress signals to control spike development and flowering time in barley

10.1101/2020.03.26.010173 ◽

2020 ◽

Author(s):

Leonard Gol ◽

Einar B. Haraldsson ◽

Maria von Korff

Keyword(s):

Drought Stress ◽

Developmental Plasticity ◽

Floral Development ◽

Introgression Lines ◽

Photoperiod Response ◽

Severe Drought ◽

Wild Type ◽

Spike Development ◽

Flowering Locus ◽

Stress Signals

AbstractDrought impairs growth and spike development and is therefore a major cause of yield losses in the temperate cereals barley and wheat. Here, we show that the photoperiod response gene PHOTOPERIOD-H1 (Ppd-H1) interacts with drought stress signals to modulate spike development. We tested the effects of a continuous mild and a transient severe drought stress on developmental timing and spike development in spring barley cultivars with a natural mutation in ppd-H1 and derived introgression lines carrying the wild-type Ppd-H1 allele from wild barley. Mild drought reduced the spikelet number and delayed floral development in spring cultivars but not the introgression lines with a wild-type Ppd-H1 allele. Similarly, drought-triggered reductions in plant height, tiller and spike number were more pronounced in the parental lines compared to the introgression lines. Transient severe stress halted growth and floral development, upon rewatering introgression lines, but not the spring cultivars, accelerated development so that control and stressed plants flowered almost simultaneously. These genetic differences in development were correlated with a differential downregulation of the flowering promotors FLOWERING LOCUS T1 and the BARLEY MADS-box genes BM3 and BM8. Our findings, therefore, demonstrate that Ppd-H1 affects developmental plasticity in response to drought in barley.HighlightWe show that Ppd-H1 integrates photoperiod and drought stress signals via FLOWERING LOCUS T 1 (FT1) and the downstream MADS-box genes BM3 and BM8 to modulate reproductive development, and shoot and spike morphology in barley.

Download Full-text

Growth, nutrition, and soil respiration of a mycorrhiza-defective tomato mutant and its mycorrhizal wild-type progenitor

Functional Plant Biology ◽

10.1071/fp07281 ◽

2008 ◽

Vol 35 (3) ◽

pp. 228 ◽

Cited By ~ 30

Author(s):

Timothy R. Cavagnaro ◽

Adam J. Langley ◽

Louise E. Jackson ◽

Sean M. Smukler ◽

George W. Koch

Keyword(s):

Soil Respiration ◽

Microbial Communities ◽

Phospholipid Fatty Acid ◽

Soil Microbial Communities ◽

Dry Weight ◽

Microbial Biomass C ◽

Wild Type ◽

Soil Microbial ◽

Mycorrhizal Roots ◽

Tomato Genotypes

The effects of colonisation of roots by arbuscular mycorrhizal fungi (AMF) on soil respiration, plant growth, nutrition, and soil microbial communities were assessed using a mycorrhiza-defective tomato (Solanum lycopersicum L.) mutant and its mycorrhizal wild-type progenitor. Plants were grown in rhizocosms in an automated respiration monitoring system over the course of the experiment (79 days). Soil respiration was similar in the two tomato genotypes, and between P treatments with plants. Mycorrhizal colonisation increased P and Zn content and decreased root biomass, but did not affect aboveground plant biomass. Soil microbial biomass C and soil microbial communities based on phospholipid fatty acid (PLFA) analysis were similar across all treatments, suggesting that the two genotypes differed little in their effect on soil activity. Although approximately similar amounts of C may have been expended belowground in both genotypes, they may have differed in the relative C allocation to root construction v. respiration. Further, net soil respiration did not differ between the two tomato genotypes, but root dry weight was lower in mycorrhizal roots, and respiration of mycorrhizal roots per unit dry weight was higher than nonmycorrhizal roots. This indicates that the AM contribution to soil respiration may indeed be significant, and nutrient uptake per unit C expenditure belowground in this experiment appeared to be higher in mycorrhizal plants.

Download Full-text

Ultrastructure of Melanin Formation in Curvularia sp., Alternaria sp., and Drechslera Sorokiniana

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100079449 ◽

1977 ◽

Vol 35 ◽

pp. 398-399

Author(s):

M. H. Wheeler ◽

W. J. Tolmsoff ◽

A. A. Bell

Keyword(s):

Potassium Phosphate ◽

Thielaviopsis Basicola ◽

Wild Type ◽

Potassium Phosphate Buffer ◽

Transmission Microscopy ◽

Electron Transmission ◽

Melanin Formation ◽

Before And After ◽

Alternaria Sp ◽

Electron Transmission Microscopy

(+)-Scytalone [3,4-dihydro-3,6,8-trihydroxy-l-(2Hj-naphthalenone] and 1,8-di- hydroxynaphthalene (DHN) have been proposed as intermediates of melanin synthesis in the fungi Verticillium dahliae (1, 2, 3, 4) and Thielaviopsis basicola (4, 5). Scytalone is enzymatically dehydrated by V. dahliae to 1,3,8-trihydroxynaphthalene which is then reduced to (-)-vermelone [(-)-3,4- dihydro-3,8-dihydroxy-1(2H)-naphthalenone]. Vermelone is subsequently dehydrated to DHN which is enzymatically polymerized to melanin.Melanin formation in Curvularia sp., Alternaria sp., and Drechslera soro- kiniana was examined by light and electron-transmission microscopy. Wild-type isolates of each fungus were compared with albino mutants before and after treatment with 1 mM scytalone or 0.1 mM DHN in 50 mM potassium phosphate buffer, pH 7.0. Both chemicals were converted to dark pigments in the walls of hyphae and conidia of the albino mutants. The darkened cells were similar in appearance to corresponding cells of the wild types under the light microscope.

Download Full-text