Analysis of Non-Structural Carbohydrates and Xylem Anatomy of Leaf Petioles Offers New Insights in the Drought Response of Two Grapevine Cultivars

In grapevine, the anatomy of xylem conduits and the non-structural carbohydrates (NSCs) content of the associated living parenchyma are expected to influence water transport under water limitation. In fact, both NSC and xylem features play a role in plant recovery from drought stress. We evaluated these traits in petioles of Cabernet Sauvignon (CS) and Syrah (SY) cultivars during water stress (WS) and recovery. In CS, the stress response was associated to NSC consumption, supporting the hypothesis that starch mobilization is related to an increased supply of maltose and sucrose, putatively involved in drought stress responses at the xylem level. In contrast, in SY, the WS-induced increase in the latter soluble NSCs was maintained even 2 days after re-watering, suggesting a different pattern of utilization of NSC resources. Interestingly, the anatomical analysis revealed that conduits are constitutively wider in SY in well-watered (WW) plants, and that water stress led to the production of narrower conduits only in this cultivar.

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Summer drought stress: differential effects on cane anatomy and non-structural carbohydrate content in overwintering Cabernet Sauvignon and Syrah vines

BIO Web of Conferences ◽

10.1051/bioconf/20191303007 ◽

2019 ◽

Vol 13 ◽

pp. 03007 ◽

Cited By ~ 2

Author(s):

Rachele Falchi ◽

Elisa Petrussa ◽

Marco Zancani ◽

Valentino Casolo ◽

Paola Beraldo ◽

...

Keyword(s):

Water Stress ◽

Drought Stress ◽

Biochemical Characterization ◽

Carbon Allocation ◽

Starch Accumulation ◽

Cabernet Sauvignon ◽

Severe Drought ◽

Summer Drought ◽

Long Term Effects ◽

Experimental Conditions

Grapevines store non-structural carbohydrates (NSC) during late summer to sustain plant development at the onset of the following spring’s growth. Starch is the main stored carbohydrate, found in the wood-ray parenchyma of roots and canes. Although the relationship between hydraulic and plant photosynthetic performance is well-recognized, little research has been done on the long-term effects of drought in grapevines adopting different strategies to cope with water stress (i.e. isohydric and anisohydric). We performed our study by exposing two different grape cultivars (Syrah and Cabernet Sauvignon) to a short but severe drought stress, at two stages of the growing season (July and September). No marked differences in the physiological and hydraulic responses of the two varieties were found, probably due to our experimental conditions. However, anatomical and biochemical characterization of overwintering canes pointed out several interesting outcomes. We found a significant and parallel increase of starch and medullar ray number in both cultivars exposed to early water stress. We hypothesize that stressed vines limited their carbon allocation to growth, while shifting it to starch accumulation, with a most evident effect in the period of intense photosynthetic activity. We also speculate that a different aptitude to osmotic adjustment may underlay variation in starch increase and the specific involvement of bark NSC in the two cultivars.

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Transcriptomic and Proteomic Analysis of Drought Stress Response in Opium Poppy Plants during the First Week of Germination

Plants ◽

10.3390/plants10091878 ◽

2021 ◽

Vol 10 (9) ◽

pp. 1878

Author(s):

Kristýna Kundrátová ◽

Martin Bartas ◽

Petr Pečinka ◽

Ondřej Hejna ◽

Andrea Rychlá ◽

...

Keyword(s):

Drought Stress ◽

Stress Response ◽

Stress Responses ◽

Proteomic Analysis ◽

Large Scale ◽

Crop Yields ◽

Opium Poppy ◽

Metabolic Pathway Analysis ◽

Ubiquitin E3 Ligase ◽

Key Genes

Water deficiency is one of the most significant abiotic stresses that negatively affects growth and reduces crop yields worldwide. Most research is focused on model plants and/or crops which are most agriculturally important. In this research, drought stress was applied to two drought stress contrasting varieties of Papaver somniferum (the opium poppy), a non-model plant species, during the first week of its germination, which differ in responses to drought stress. After sowing, the poppy seedlings were immediately subjected to drought stress for 7 days. We conducted a large-scale transcriptomic and proteomic analysis for drought stress response. At first, we found that the transcriptomic and proteomic profiles significantly differ. However, the most significant findings are the identification of key genes and proteins with significantly different expressions relating to drought stress, e.g., the heat-shock protein family, dehydration responsive element-binding transcription factors, ubiquitin E3 ligase, and others. In addition, metabolic pathway analysis showed that these genes and proteins were part of several biosynthetic pathways most significantly related to photosynthetic processes, and oxidative stress responses. A future study will focus on a detailed analysis of key genes and the development of selection markers for the determination of drought-resistant varieties and the breeding of new resistant lineages.

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The Cyclophilin ROC3 Regulates ABA-Induced Stomatal Closure and the Drought Stress Response of Arabidopsis thaliana

Frontiers in Plant Science ◽

10.3389/fpls.2021.668792 ◽

2021 ◽

Vol 12 ◽

Author(s):

Huiping Liu ◽

Jianlin Shen ◽

Chao Yuan ◽

Dongxue Lu ◽

Biswa R. Acharya ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Drought Stress ◽

Stress Response ◽

Stomatal Closure ◽

Anion Channel ◽

Crop Productivity ◽

Drought Response ◽

Wild Type ◽

Ros Homeostasis ◽

Ros Accumulation

Drought causes a major constraint on plant growth, development, and crop productivity. Drought stress enhances the synthesis and mobilization of the phytohormone abscisic acid (ABA). Enhanced cellular levels of ABA promote the production of reactive oxygen species (ROS), which in turn induce anion channel activity in guard cells that consequently leads to stomatal closure. Although Cyclophilins (CYPs) are known to participate in the biotic stress response, their involvement in guard cell ABA signaling and the drought response remains to be established. The Arabidopsis thaliana gene ROC3 encodes a CYP. Arabidopsis roc3 T-DNA mutants showed a reduced level of ABA-activated S-type anion currents, and stomatal closure than wild type (WT). Also, roc3 mutants exhibited rapid loss of water in leaf than wild type. Two complementation lines of roc3 mutants showed similar stomatal response to ABA as observed for WT. Both complementation lines also showed similar water loss as WT by leaf detached assay. Biochemical assay suggested that ROC3 positively regulates ROS accumulation by inhibiting catalase activity. In response to ABA treatment or drought stress, roc3 mutant show down regulation of a number of stress responsive genes. All findings indicate that ROC3 positively regulates ABA-induced stomatal closure and the drought response by regulating ROS homeostasis and the expression of various stress-activated genes.

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Isolation and characterization of MbWRKY1, a WRKY transcription factor gene from Malus baccata (L.) Borkh involved in drought tolerance

Canadian Journal of Plant Science ◽

10.1139/cjps-2017-0355 ◽

2018 ◽

Vol 98 (5) ◽

pp. 1023-1034 ◽

Cited By ~ 3

Author(s):

Deguo Han ◽

Haibin Ding ◽

Lijing Chai ◽

Wei Liu ◽

Zhaoyuan Zhang ◽

...

Keyword(s):

Drought Stress ◽

Stress Response ◽

Transgenic Plants ◽

Stress Responses ◽

Wrky Transcription Factor ◽

Drought Treatment ◽

Isolation And Characterization ◽

Relative Water ◽

Stress Related Genes ◽

Malus Baccata

WRKY transcription factors are involved in stress responses in plants; however, their roles in abiotic stresses are still not well known in Malus plants. In the present study, a WRKY gene was isolated from Malus baccata (L.) Borkh and designated as MbWRKY1. Subcellular localization revealed that MbWRKY1 was localized in the nucleus. The expression levels of MbWRKY1 were up-regulated by dehydration, salinity, and ABA treatments in M. baccata seedlings. When MbWRKY1 was introduced into tobacco, it improved drought stress tolerance in transgenic plants. Under the drought treatment, transgenic plants had higher contents of chlorophyll, proline, relative water, AsA, and GSH than wild-type (WT) plants. Compared with WT plants, the overexpression of MbWRKY1 in transgenic tobacco also led to decreased levels of H2O2, MDA, and elecrolyte leakage when dealing with drought stress. There were increased activities of POD, CAT, SOD, and APX in transgenic tobaccos, especially when dealing with drought treatment. Moreover, the MbWRKY1 transgenic plants enhanced the expressions of oxidative stress response (NtPOD, NtCAT, NtSOD, and NtAPX) and stress-related genes (NtP5CS and NtLEA5) when dealing with drought stress. These results suggest that the MbWRKY1 gene plays a positive regulatory role in drought stress response.

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Use of DArT molecular markers for QTL analysis of drought-stress responses in soybean. I. Phenotypic evaluation of traits

Crop and Pasture Science ◽

10.1071/cp14303 ◽

2015 ◽

Vol 66 (8) ◽

pp. 802 ◽

Cited By ~ 2

Author(s):

Hang T. T. Vu ◽

A. T. James ◽

R. J. Lawn ◽

L. M. Bielig ◽

A. Kilian

Keyword(s):

Drought Stress ◽

Stress Response ◽

Stress Responses ◽

Recombinant Inbred Lines ◽

Companion Paper ◽

Severe Drought ◽

Dart Markers ◽

Phenotypic Data ◽

Relative Water ◽

Trait Locus

Physiological drought stress responses were assessed in recombinant inbred lines (RILs) from three soybean (Glycine max (L.) Merr.) crosses, in preparation for quantitative trait locus (QTL) analyses using Diversity Arrays Technology (DArT) markers. The three RIL populations were derived from pairwise crosses between three genotypes, cv. Valder, CPI 26671 and G2120, which in previous studies had differed in drought-stress response. Of particular interest was the landrace variety G2120, which in the previous reports had recovered better after severe drought. To assess drought-stress response, the plants were grown in deep cylindrical pots in the glasshouse and exposed to severe water deficit followed by re-watering. Two plants to be genotyped were grown in each pot, together with one plant of G2120, which served as a reference plant against which the responses of the two other plants were assessed. Traits recorded included measures of relative water content (RWC), epidermal conductance (ge) and recovery in growth following re-watering. The responses in the reference and parental plants and the RIL populations were broadly consistent with previous studies. As plant-available water in the soil declined, both RWC and ge declined, although the relation between RWC and ge was exponential, rather than linear as in previous studies. Analysis of variance revealed large environmental effects on most of the traits, which resulted in high coefficients of variation and low estimates of broad-sense heritability. However, there were significant differences at both the population and genotype levels for all key traits, confirming the presence of genetic variation for drought-stress response. Some opportunities for enhancing the observed genetic differences and reducing the environmental noise in future studies are canvassed. Application of the observed phenotypic data reported in this paper in subsequent QTL analyses based on DArT markers is reported in the companion paper.

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Plant Hosts Modify Belowground Microbial Community Response to Extreme Drought

mSystems ◽

10.1128/msystems.00092-20 ◽

2020 ◽

Vol 5 (3) ◽

Author(s):

Allison M. Veach ◽

Huaihai Chen ◽

Zamin K. Yang ◽

Audrey D. Labbe ◽

Nancy L. Engle ◽

...

Keyword(s):

Water Stress ◽

Drought Stress ◽

Microbial Activity ◽

Stress Responses ◽

Bacterial Community Composition ◽

Recovery Period ◽

Community Response ◽

Extreme Drought ◽

Soil Microbiome ◽

Belowground Interactions

ABSTRACT Drought stress negatively impacts microbial activity, but the magnitude of stress responses is likely dependent on a diversity of belowground interactions. Populus trichocarpa individuals and no-plant bulk soils were exposed to extended drought (∼0.03% gravimetric water content [GWC] after 12 days), rewet, and a 12-day “recovery” period to determine the effects of plant presence in mediating soil microbiome stability to water stress. Plant metabolomic analyses indicated that drought exposure increased host investment in C and N metabolic pathways (amino acids, fatty acids, phenolic glycosides) regardless of recovery. Several metabolites positively correlated with root-associated microbial alpha-diversity, but not those of soil communities. Soil bacterial community composition shifted with P. trichocarpa presence and with drought relative to irrigated controls, whereas soil fungal composition shifted only with plant presence. However, root fungal communities strongly shifted with drought, whereas root bacterial communities changed to a lesser degree. The proportion of bacterial water-stress opportunistic operational taxonomic units (OTUs) (enriched counts in drought) was high (∼11%) at the end of drying phases and maintained after rewet and recovery phases in bulk soils, but it declined over time in soils with plants present. For root fungi, opportunistic OTUs were high at the end of recovery in drought treatments (∼17% abundance), although relatively not responsive in soils, particularly planted soils (<0.5% abundance for sensitive or opportunistic). These data indicate that plants modulate soil and root-associated microbial drought responses via tight plant-microbe linkages during extreme drought scenarios, but trajectories after extreme drought vary with plant habitat and microbial functional groups. IMPORTANCE Climate change causes significant alterations in precipitation and temperature regimes that are predicted to become more extreme throughout the next century. Microorganisms are important members within ecosystems, and how they respond to these changing abiotic stressors has large implications for the functioning of ecosystems, the recycling of nutrients, and the health of the aboveground plant community. Drought stress negatively impacts microbial activity, but the magnitude of this stress response may be dependent on above- and belowground interactions. This study demonstrates that beneficial associations between plants and microbes can enhance tolerance to abiotic stress.

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Studies on the Accumulation of Drought-Induced Boiling Soluble Proteins (Hydrophilins) at Vegetative and Reproductive Phases of Drought Tolerant and Susceptible Cultivars of Triticum aestivum

Notulae Scientia Biologicae ◽

10.15835/nsb629327 ◽

2014 ◽

Vol 6 (2) ◽

pp. 225-236

Author(s):

Gurmeen RAKHRA ◽

Arun Dev SHARMA ◽

Jatinder SINGH

Keyword(s):

Water Stress ◽

Drought Stress ◽

Stress Responses ◽

Blot Analysis ◽

Soluble Proteins ◽

Dependent Manner ◽

Water Stress Tolerance ◽

Drought Tolerant ◽

Boiling Soluble Proteins

Drought is one of the major environmental constraints affecting the crops worldwide. Expression of boiling soluble proteins (BSPs) is of paramount importance, because they play important roles in the water stress responses and also in plant metabolism. In this study, the effect of drought on BSPs at vegetative (shoots) and reproductive (seeds) phases of drought tolerant (cv. ‘PBW 527’) and drought susceptible (cv. ‘PBW 343’) cultivars of Triticumaestivum were carried at three different developmental stages. The boiling soluble protein profiles of shoots and seeds were outlined via SDS-PAGE followed by immune-blot analysis using anti-HSP, anti-APase, anti-LEA, anti-SOD, anti-AQUA and anti-CAT antibodies. Western blot analysis revealed that expression of BSPs was modulated differentially in a stress, tissue, developmental stage and cultivar dependent manner. For instance, enhanced expression of seeds BSPs (APase, LEA, CAT, AQUA) was observed in the tolerant cv. ‘PBW 527’ after drought stress. However, no such enhancement was observed in the susceptible cultivar. Similarly, in shoots of cv. ‘PBW 527’, a substantial increase of BSP (SOD) expression was established after drought stress treatment, indicating their role in drought stress adaptation. Further, to gain an insight into the role of BSPs, a time course pre- and post-stress kinetic studies were also conducted in the seeds of tolerant and susceptible wheat cultivars. Based upon the observations, the possible role of boiling soluble proteins (hydrophilins) in water stress tolerance is discussed.

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Mitigating Effect of Glycinebetaine Pretreatment on Drought Stress Responses of Creeping Bentgrass

HortScience ◽

10.21273/hortsci13429-18 ◽

2018 ◽

Vol 53 (12) ◽

pp. 1842-1848 ◽

Cited By ~ 2

Author(s):

Lu Gan ◽

Xunzhong Zhang ◽

Silu Liu ◽

Shuxia Yin

Keyword(s):

Gene Expression ◽

Water Stress ◽

Drought Stress ◽

Chlorophyll Content ◽

Stress Responses ◽

Creeping Bentgrass ◽

External Application ◽

Antioxidant Enzyme System ◽

Turf Quality ◽

Mda Content

Turfgrass performance under drought stress is impeded by plant water deficit and oxidative damage, which might be improved by the external application of osmoprotectants. Creeping bentgrass (Agrostis stolonifera L.) is a valuable species for low-cut golf surfaces as a result of its high density and fine texture. However, weak tolerance to drought stress is a primary shortcoming. In this study, the effect of exogenous glycinebetaine (GB) pretreatment on mitigating the damage from drought stress in creeping bentgrass cultivar ‘T-1’ was evaluated. Pieces of creeping bentgrass sod were subjected to four treatments: 1) well-watered control, 2) well watered and sprayed with 100 mm GB, 3) drought stress, and 4) drought stress and sprayed with 100 mm GB. Drought stress resulted in a remarkable decrease in turf quality (TQ), relative water content (RWC), and chlorophyll content, with significant increases in superoxide anion content (O2–), malondialdehyde (MDA) content, superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activity. In contrast, pretreatment with 100 mm GB decreased the O2– and MDA content in water-stressed plants, and increased turf quality, chlorophyll content, SOD, CAT, and POD activity. Meanwhile, the expression level of the psbA, SAMS4, CMO, and ACS1 genes in leaf samples collected during the drought-stress stage was elevated in GB pretreatment. Notably, SAMS4 gene expression in GB pretreatment was significantly greater than in the untreated GB groups subjected to water stress. These results suggested that GB could mitigate the adverse effect of water stress on creeping bentgrass. The amelioration related strongly to the maintenance of the antioxidant enzyme system, accumulated endogenous compatible metabolites, and the elevation of gene expression levels. These findings lead us to conclude that GB pretreatment could be used as an ameliorative agent for creeping bentgrass against the deleterious effects of water stress.

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Discovery of Drought-Responsive Transposable Element-Related Peach miRNAs

10.1101/143115 ◽

2017 ◽

Author(s):

Asli Kurden Pekmezci ◽

Gökhan Karakülah ◽

Turgay Unver

Keyword(s):

Transcription Factors ◽

Drought Stress ◽

Stress Response ◽

Transposable Element ◽

Small Rna ◽

Computational Analysis ◽

Drought Response ◽

Specific Target ◽

Specific Manner ◽

Regulatory Rnas

AbstractMicroRNAs (miRNA) are small non-coding regulatory RNAs that suppress their specific target transcripts either by cleavage or inhibition of translation. Transposable element related miRNAs (TE-miRNA) have been subjected to various studies so far, and some of them were found to be involved in stress response in plants. Here, small RNA (sRNA) sequencing libraries generated from drought stress treated peach tissues were utilized to identify TE-miRNAs. Our computational analysis led to the identification of 63 TE-miRNAs, which were either locating nearby of any TE (TE-related), or overlapping with a TE (TE-derived). Furthermore, 13 out of 63 TE-miRNAs were designated as drought-responsive. Expression pattern of the identified drought-responsive TE-miRNAs are observed as tissue-specific manner, and their specific target transcripts are mostly related to transcription factors and growth-associated genes. Our findings suggest that miRNAs in relation with transposable elements might be key molecular players in the regulation of drought response.

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Shared genetic architecture underlying root metaxylem phenotypes under drought stress in cereals

10.1101/2020.11.02.365247 ◽

2020 ◽

Author(s):

Stephanie P. Klein ◽

Jenna E. Reeger ◽

Shawn M. Kaeppler ◽

Kathleen M. Brown ◽

Jonathan P. Lynch

Keyword(s):

Water Stress ◽

Drought Stress ◽

Candidate Genes ◽

Stress Responses ◽

Genetic Architecture ◽

Association Studies ◽

Multiple Root ◽

Stress Conditions ◽

Genome Wide Association Studies ◽

New Strategy

AbstractRoot metaxylem are phenotypically diverse structures whose function is related to their anatomy, particularly under drought stress. Much research has dissected the genetic machinery underlying metaxylem phenotypes in dicots, but monocots are relatively unexplored. In maize (Zea mays), a robust pipeline integrated a GWAS of root metaxylem phenes under well-watered and water stress conditions with a gene co-expression network to identify candidate genes most likely to impact metaxylem phenotypes. We identified several promising candidate genes in 14 gene co-expression modules inferred to be functionally relevant to xylem development. We also identified five gene candidates that co-localized in multiple root metaxylem phenes in both well-watered and water stress conditions. Using a rice GWAS conducted in parallel, we detected overlapping genetic architecture influencing root metaxylem phenotypes by identifying eight pairs of syntenic candidate genes significantly associated with metaxylem phenes. There is evidence that the genes of these syntenic pairs may be involved in biosynthetic processes related to the cell wall, hormone signaling, oxidative stress responses, and drought responses. Our study demonstrates a powerful new strategy for identifying promising gene candidates and suggests several gene candidates that may enhance our understanding of vascular development and responses to drought in cereals.One sentence summaryCross-species genome-wide association studies and a gene coexpression network identified genes associated with root metaxylem phenotypes in maize under water stress and non-stress and rice.

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