Field Drought Research Articles

Microbial community response to drought depends on crop

Growing season drought can be devastating to crop yields. Soil microbial communities have the potential to buffer yield loss under drought through increasing plant drought tolerance and soil water retention. Microbial inoculation on agricultural fields has been shown to increase plant growth, but few studies have examined the impact of microbial inoculation on plant and soil microbial drought tolerance. We conducted a rainout shelter experiment and subsequent greenhouse experiment to explore 3 objectives. First, we evaluated the performance of a large rainout shelter design for studying drought in agricultural fields. Second, we tested how crop (corn vs. soybean) and microbial inoculation alter the response of soil microbial composition, diversity, and biomass to drought. Third, we tested whether field inoculation treatments and drought exposure altered microbial communities in ways that promote plant drought tolerance in future generations. In our field experiment, the effects of drought on soil bacterial composition depended on crop type, while drought decreased bacterial diversity in corn plots and drought decreased microbial biomass carbon in soybean plots. Microbial inoculation did not alter overall microbial community composition, plant growth, or drought tolerance despite our efforts to address common barriers to inoculation success. Still, a history of inoculation affected growth of future plant generations in the greenhouse. Our study demonstrates the importance of plant species in shaping microbial community responses to drought and the importance of legacy effects of microbial inoculation.

Productivity and Feed Quality Performance of Napier Grass (Cenchrus purpureus) Genotypes Growing under Different Soil Moisture Levels.

In the semi-arid and arid environments of Sub-Sharan Africa, forage availability throughout the year is insufficient and highly limited during the dry seasons due to limited precipitation. Thus, the identification of drought stress-tolerant forage cultivars is one of the main activities in forage development programs. In this study, Napier grass (Cenchrus purpureus), an important forage crop in Eastern and Central Africa that is broadly adapted to produce across tropical environments, was evaluated for its water use efficiency and production performance under field drought stress conditions. Eighty-four Napier grass genotypes were evaluated for their drought stress tolerance from 2018 to 2020 using agro-morphological and feed quality traits under two soil moisture stress regimes during the dry season, i.e., moderate (MWS) and severe (SWS) water stress conditions, and under rainfed conditions in the wet season (wet). Overall, the results indicated the existence of genotype variation for the traits studied. In general, the growth and productivity of the genotypes declined under SWS compared to MWS conditions. High biomass-yielding genotypes with enhanced WUE were consistently observed across harvests in each soil moisture stress regime. In addition, the top biomass-yielding genotypes produced the highest annual crude protein yield, indicating the possibility of developing high-feed-quality Napier grass genotypes for drought stress environments.

The combination of vermicompost and arbuscular mycorrhizal fungi improves the physiological properties and chemical composition of Opuntia ficus-indica under semi-arid conditions in the field

Drought is one of the major threats to food security in arid and semi-arid regions. Therefore, significant changes in agricultural production systems will be required to meet the challenges of food security while addressing water scarcity. Prickly pear is a drought tolerant plant, as well as a source of sustainable food and feed. Nonetheless, in dry conditions, its growth and performance are restricted. The aim of this study was to evaluate the effect of arbuscular mycorrhizal fungi (AMF), vermicompost (Vc) or the combination of AMF + Vc on yield, growth and physio-chemical parameters of cactus grown under field drought conditions. Two irrigation regimes were applied, non-irrigated (grown under rainfed conditions) and irrigated plants (8 mm of water per week). After eight months of cultivation, the finding demonstrated that drought reduced growth, physiological and biochemical parameters of cactus. However, the application of biostimulants, especially Vc and AMF + Vc, can mitigate the negative effect of drought by increasing cladode dry weight (93% and 109%), total chlorophyll (78% and 75%), total phenolic content (83% and 81%). Those treatments are also efficient in enhancing activities of enzymatic and non enzymatic antioxidants in cactus cladodes and fruits. These results suggest that the use of these biostimulants can mitigate the challenges associated with drought, by improving the physiological and biochemical responses of cactus.

Standardized indices to estimate sensitivity to drought across ecosystems

AbstractQuestionClimate change scenarios predict alterations in interannual variability of precipitation and increases of extreme droughts. Drought effects will reflect ecosystems' sensitivity (i.e. the magnitude of the response relative to the change in amount of precipitation), with different consequences for plant communities and ecosystem functioning. However, sensitivity estimations across ecosystems and among years are contingent upon the metric applied. Here, we asked how different sensitivity indices reflect the responses to drought in contrasting ecosystems.MethodsWe proposed a novel index to estimate sensitivity in drought experiments, which consider the change in the response variable in relation to the reduction in precipitation, standardized by the mean precipitation use efficiency of the site, making it suitable to compare among contrasting ecosystems. We compared the information gained from the new index with two indices commonly used in experimentally induced droughts, through simulated scenarios. Besides, we applied the indices to data from previous field drought experiments to evaluate relative and absolute sensitivity to drought in worldwide grassland ecosystems along a wide precipitation gradient.ResultsWe found that both relative and absolute approaches yielded important information to determine drought sensitivity in different simulated scenarios and under interannual precipitation variability. When the indices were applied to real situations, relative sensitivity to drought showed a significant increase as mean annual precipitation decreases whereas absolute sensitivity did not change significantly with precipitation.ConclusionsOur findings highlighted that absolute and relative indices to estimate drought sensitivity, rather than being redundant, may complement each other to inform how ecosystems respond to drought and to provide a more holistic assessment of vulnerable systems toward increasing interannual precipitation variability. This complementary approach enhances our understanding of ecosystem response under different conditions of precipitation variability and of the mechanisms that determine ecosystem changes during extreme droughts.

Association Mapping of Drought Tolerance Indices in Ethiopian Durum Wheat (Triticum turgidum ssp. durum).

Ethiopia is a major producer of durum wheat in sub-Saharan Africa. However, its production is prone to drought stress as it is fully dependent on rain, which is erratic and unpredictable. This study aimed to detect marker-trait associations (MTAs) and quantitative trait loci (QTLs) related to indices. Six drought tolerance indices, i.e., drought susceptibility index (DSI), geometric mean productivity (GMP), relative drought index (RDI), stress tolerance index (STI), tolerance index (TOL), and yield stability index (YSI) were calculated from least-square means (lsmeans) of grain yield (GY) and traits significantly (p < 0.001) correlated with grain yield (GY) under field drought stress (FDS) and field non-stress (FNS) conditions. GY, days to grain filling (DGF), soil plant analysis development (SPAD) chlorophyll meter, seeds per spike (SPS), harvest index (HI), and thousand kernel weight (TKW) were used to calculate DSI, GMP, RDI, STI, TOL, and YSI drought indices. Accessions, DW084, DW082, DZ004, C037, and DW092 were selected as the top five drought-tolerant based on DSI, RDI, TOL, and YSI combined ranking. Similarly, C010, DW033, DW080, DW124-2, and C011 were selected as stable accessions based on GMP and STI combined ranking. A total of 184 MTAs were detected linked with drought indices at –log10p ≥ 4.0,79 of which were significant at a false discovery rate (FDR) of 5%. Based on the linkage disequilibrium (LD, r2 ≥ 0.2), six of the MTAs with a positive effect on GY-GMP were detected on chromosomes 2B, 3B, 4A, 5B, and 6B, explaining 14.72, 10.07, 26.61, 21.16, 21.91, and 22.21% of the phenotypic variance, respectively. The 184 MTAs were clustered into 102 QTLs. Chromosomes 1A, 2B, and 7A are QTL hotspots with 11 QTLs each. These chromosomes play a key role in drought tolerance and respective QTL may be exploited by marker-assisted selection for improving drought stress tolerance in wheat.

Genomic dissection reveals QTLs for grain biomass and correlated traits under drought stress in Ethiopian durum wheat (Triticum turgidum ssp.durum)

AbstractDrought stress seriously challenges wheat production and productivity. Grain biomass (GB) and related traits were assessed under drought stress and non‐stress for 285 and 185 durum wheat genotypes, respectively, in field and climate chamber experiments to identify quantitative trait loci (QTL). Significant correlations between traits estimated in field and climate chamber trials were observed (p &lt; .001). Genotyping with the wheat 90 K iSelect single nucleotide polymorphism (SNP) array revealed 11,919 polymorphic SNP markers distributed across the durum wheat genome. The FarmCPU (Fixed and random model Circulating Probability Unification) method was used for genome‐wide association studies (GWAS). A total of 191 significant (−log10p ≥ 4) marker‐trait associations (MTAs) were detected at a linkage disequilibrium (LD,r2 ≥ .2) at 4.78 Mb and were clustered into 70 QTLs. A total of 69 (36%) of the MTAs passed a false discovery rate (FDR) of 5%. The numbers of QTLs detected were 21, 31, 9 and 9 under field drought stress (FDS), field non‐stress (FNS), climate chamber drought stress (CCDS) and climate chamber non‐stress (CCNS) conditions, respectively. About 43% and 57% of the QTLs were located on the A and B genomes, respectively. Some of the detected QTLs were in agreement with previously reported QTLs, while others are novel ones for the traits investigated. QTLs on 1A between 495694477and ‐501944537bp, on 3B between 416256124 and 430507900 bp, on 3B between 745357158 and 759608934 bp, on 4B between 593416763 and 605142497 bp and on 4B between 658785890 and 670511624 bp were selected for validation and may be used to increase grain yield under drought stress in marker‐assisted selection (MAS) schemes.Key messageGenome‐wide association studies (GWAS) enabled detecting novel quantitative trait loci (QTLs) and identifying single nucleotide polymorphism (SNP) markers associated with grain biomass and correlated traits for drought stress tolerance in durum wheat based on a combination of climate chamber and multiyear and multilocation field experiments.

Transcriptomics analysis of field-droughted pear (Pyrus spp.) reveals potential drought stress genes and metabolic pathways.

Drought acts as a major abiotic stress that hinders plant growth and crop productivity. It is critical, as such, to discern the molecular response of plants to drought in order to enhance agricultural yields under droughts as they occur with increasing frequency. Pear trees are among the most crucial deciduous fruit trees worldwide, and yet the molecular mechanisms of drought tolerance in field-grown pear remain unclear. In this study, we analyzed the differences in transcriptome profiles of pear leaves, branches, and young fruits in irrigation vs field-drought conditions over the growing seasons. In total, 819 differentially expressed genes (DEGs) controlling drought response were identified, among which 427 DEGs were upregulated and 392 DEGs were downregulated. Drought responsive genes were enriched significantly in monoterpenoid biosynthesis, flavonoid biosynthesis, and diterpenoid biosynthesis. Fourteen phenylpropanoid, five flavonoid, and four monoterpenoid structural genes were modulated by field drought stress, thereby indicating the transcriptional regulation of these metabolic pathways in fruit exposed to drought. A total of 4,438 transcription factors (TFs) belonging to 30 TF families were differentially expressed between drought and irrigation, and such findings signal valuable information on transcriptome changes in response to drought. Our study revealed that pear trees react to drought by modulating several secondary metabolic pathways, particularly by stimulating the production of phenylpropanoids as well as volatile organic compounds like monoterpenes. Our findings are of practical importance for agricultural breeding programs, while the resulting data is a resource for improving drought tolerance through genetic engineering of non-model, but economically important, perennial plants.

Comparative study of extraction features and regression algorithms for predicting drought rates

Rice is the primary staple food source for Indonesian people, with consumption increasing so that rice production needs to be increased. Rice drought is one of the problems that can hamper rice production. This research aims to determine the best extraction feature between the normalized difference vegetation index (NDVI) and the normalized difference water index (NDWI) in describing rice fields’ dryness. Moreover, using the random forest regression algorithm. This research compares NDVI with NDWI using data originating from Sentinel-2A and retrieved via the google earth engine. Regression algorithms are used in research to predict drought in paddy fields. This research shows that NDVI is better than NDWI in predicting drought using random forest regression algorithms and logistic regression algorithms. The random forest regression algorithm based on the results obtained shows that the average root mean square error (RMSE) on NDVI is 0.018, and NDWI is 0.012. Based on the logistic regression algorithm results, it was found that the average value of RMSE on NDVI was 0.346, and NDWI was 0.336. Based on the results of the RMSE, it shows that the forecasting ability of the random forest regression algorithm is better than the logistic regression.

The cumulative drought exert disruptive effects on tropical rainforests in the northern edge of Asia - Based on decadal dendrometric measurements and eddy covariance method

Studies on the effects of drought on tropical rainforests have revealed their sensitivity on multiple levels, for example, decreased photosynthetic capacity and increased mortality. However, studies on the impact of occasional drought on the rainforests are not enough as they tend to recover from such droughts within a few years. In the present study, the Xishuangbanna rainforest, located at the northern edge of Asia, witnessed extensive damage after six years of a field drought treatment (30 m × 30 m plot; ∼35% through-fall reduction): the plant carbon pool decreased at the rate of 13.71 T ha−1 yr−1 (amount to 23% loss of plant carbon in the 10th year compared to the 7th), although soil carbon accumulated at the rate of 2.68 T ha−1 yr−1. The radial growth rate of the surviving tagged trees was not constrained by drought. Additionally, drought reduced the number of seedlings per unit area by 61% compared to the control plot. The residual analysis indicates that the net ecosystem carbon exchange (NEE) of eddy covariance (EC) flux site was insensitive to soil drought on annual scale, while regression analyses showed that photosynthetic light response parameters were inhibited by drought on decalal scale. The results of both drought experiment and flux data analysis showed that the impact of drought on the rainforest will be highly apparent on long-term scale. In order to predict the fate of forests more accurately in response to prolonged drought, it is worth reassessing the long-term drought sensitivity of forest ecosystems.

Physiological Mechanism of Exogenous Silicon Alleviating Drought Stress in Maize

With the global warming, the impact of drought on agricultural production is increasingly prominent. Maize has a long growth period, high water demand, and is more sensitive to drought. Therefore, drought has always been one of the limited factors affecting the stable and increased on global maize production. Si promotes seed germination and seedling growth, enhances agricultural sustainability. However, its effects on different growth stages and different drought degree of maize are unclear in the field. In this experiment, to study its effects of drought in the large farmland moisture control test field (Xianyu 335) combined with exogenous Si during growth and development in maize. Exposed to drought-stressed conditions, Si further aggrandized antioxidant enzyme activities, reduced ROS contents, not only moderated AsA/DHA ratio but also GSH/GSSG ratio. Adding exogenous Si, the plant height growth rate, biomass, photosynthetic pigment contents, gas exchange parameters, photosynthetic enzymes activity, the stomatal size and aperture improved significantly, the contents of osmolyte further increased, as well as the increases were greater in the jointing stage than in the tasseling stage. In summary, applying exogenous Si can enhance the photosynthesis capacity of plants, promote the synthesis of osmotic substances, thus improving plant water metabolism balance, and enhance the antioxidant system, remove toxic substances, reduce membrane peroxidation, maintain cell membrane stability, alleviate stomatal limitation, and enhance maize drought resistance of the plant, thereby increasing yield.

Response of potato (Solanum tuberosum L.) cultivars to drought stress under in vitro and field conditions

BackgroundPotato (Solanum tuberosum L.), the world’s third most important crop, is frequently thought to be sensitive to moderately sensitive to drought, and yield has fallen considerably over consecutive stress periods. Drought produces a wide range of responses in potato, from physiological alterations to variations in growth rates and yield. Knowledge about these responses is essential for getting a full understanding of drought-tolerance mechanism in potato plants which will help in the identification of drought-tolerant cultivars.ResultsA set of 21 commercial potato cultivars representing the genetic diversity in the Middle East countries market were screened for drought tolerance by measuring morpho-physiological traits and tuber production under in vitro and field trials. Cultivars were exposed to drought stress ranging from no drought to 0.1, 0.2 and 0.3 mol L−1 sorbitol in in vitro-based screening and 60, 40 and 20% soil moisture content in field-based screening. Drought stress adversely affected plant growth, yield and cultivars differed for their responses. Shoots and roots fresh weights, root length, surface area of root, no. of roots, no. of leaves, leaf area, plant water content %, K+ content, under in vitro drought treatments and shoots fresh and dry weights, no. of tubers and tuber yield under field drought treatments were examined and all decreased due to drought. The stress tolerance index decreased with increasing drought in examined cultivars; nevertheless, it revealed a degree of tolerance in some of them. Grouping cultivars by cluster analysis for response to drought resulted in: (i) a tolerant group of five cultivars, (ii) a moderately tolerant group of 11 cultivars, and (iii) a sensitive group of five cultivars. Furthermore, stress-related genes, i.e., DRO, ERECTA, ERF, DREB and StMYB were up-regulated in the five cultivars of the tolerant group. Likewise, the stomatal conductance and transpiration explained high correlation with the tuber yield in this group of cultivars.ConclusionThe diversity in germplasm indicated that potato cultivars can be developed for production under certain degrees of drought. Some cultivars are good candidates to be included in drought-tolerant breeding programs and recommended for cultivation in drought-stricken regions.Graphical

Drought assessment in paddy rice fields using remote sensing technology towards achieving food security and SDG2

PurposeThis research aims to monitor vegetation indices to assess drought in paddy rice fields in Mazandaran, Iran, and propose the best index to predict rice yield.Design/methodology/approachA three-step methodology is applied. First, the paddy rice fields are mapped by using three satellite-based datasets, namely SRTM DEM, Landsat8 TOA and MYD11A2. Second, the maps of indices are extracted using MODIS. And finally, the trend of indices over rice-growing seasons is extracted and compared with the rice yield data.FindingsRice paddies maps and vegetation indices maps are provided. Vegetation Health Index (VHI) combining average Temperature Condition Index (TCI) and minimum Vegetation Condition Index (VCI), and also VHI combining TCImin and VCImin are found to be the most proper indices to predict rice yield.Practical implicationsThe results serve as a guideline for policy-makers and practitioners in the agro-food industry to (1) support sustainable agriculture and food safety in terms of rice production; (2) help balance the supply and demand sides of the rice market and move towards SDG2; (3) use yield prediction in the rice supply chain management, pricing and trade flows management; and (4) assess drought risk in index-based insurances.Originality/valueThis study, as one of the first research assessing and mapping vegetation indices for rice paddies in northern Iran, particularly contributes to (1) extracting the map of paddy rice fields in Mazandaran Province by using satellite-based data on cloud-computing technology in the Google Earth Engine platform; (2) providing the map of VCI and TCI for the period 2010–2019 based on MODIS data and (3) specifying the best index to describe rice yield through proposing different calculation methods for VHI.

Rice microRNA171f/SCL6 module enhances drought tolerance by regulation of flavonoid biosynthesis genes.

Plants have evolved sophisticated defense systems to enhance drought tolerance. These include the microRNA (miRNA) group of small noncoding RNAs that act as post‐transcriptional regulators; however, details of the mechanisms by which they confer drought tolerance are not well understood. Here, we show that osa‐MIR171f, a member of osa‐MIR171 gene family, is mainly expressed in response to drought stress and regulates the transcript levels of SCARECROW‐LIKE6‐I (SCL6‐I) and SCL6‐II in rice ( Oryza sativa ). The SCL6 genes are known to be involved in shoot branching and flag leaf morphology. Osa‐MIR171f‐overexpressing (osa‐MIR171f‐OE) transgenic plants showed reduced drought symptoms compared with non‐transgenic (NT) control plants under both field drought and polyethylene glycol (PEG)‐mediated dehydration stress conditions. Transcriptome analysis of osa‐MIR171f‐OE plants and osa‐mir171f‐knockout (K/O) lines generated by clustered regularly interspaced short palindromic repeats (CRISPR/Cas9) revealed that osa‐mature‐miR171a‐f (osa‐miR171) regulates the expression of flavonoid biosynthesis genes, consequently leading to drought tolerance. This upregulation in the osa‐MIR171f‐OE plants, which did not occur in NT control plants, was observed under both normal and drought conditions. Our findings indicate that osa‐miR171 plays a role in drought tolerance by regulating SCL6‐I and SCL6‐II transcript levels.

Poor acclimation to experimental field drought in subalpine forest tree seedlings.

The ability of tree species to acclimate and tolerate projected increases in drought frequency and intensity has fundamental implications for future forest dynamics with climate change. Inquiries to date on the drought tolerance capacities of tree species, however, have focused almost exclusively on mature trees with scant in situ work on seedlings, despite the central role that regeneration dynamics play in forest responses to changing conditions. We subjected naturally established seedlings of co-dominant subalpine conifer species (Abies lasiocarpa and Picea engelmannii) in the southern Rocky Mountains to 2 years of in situ summer precipitation exclusion, simulating summer drought conditions similar to a failure of the North American monsoon. We compared the morphological and physiological responses of seedlings growing in drought vs. ambient conditions to assess the relative changes in drought tolerance traits as a function of seedling size. Drought treatments had a marked impact on soil moisture: volumetric water content averaged ≈5–8 % in drought treatments and ≈8–12 % in ambient controls. We detected no significant shifts in morphology (e.g. root biomass, leaf:stem area ratio) in response to drought for either species, but net photosynthesis in drought treatments was 78 % lower for spruce and 37 % lower for fir. Greater stomatal control associated with increasing stem diameter conferred greater water use efficiencies in larger seedlings in both species but was not significantly different between drought and ambient conditions, suggesting an overall lack of responsivity to water stress and a prioritization of carbon gain over investment in drought mitigation traits. These results indicate a canonization of traits that, while useful for early seedling establishment, may portend substantial vulnerability of subalpine seedling populations to prolonged or recurrent droughts, especially for spruce.

Rhizosphere microbiomes can regulate plant drought tolerance

Beneficial root-associated rhizospheric microbes play a key role in maintaining host plant growth and can potentially allow drought-resilient crop production. The complex interaction of root-associated microbes mainly depends on soil type, plant genotype, and soil moisture. However, drought is the most devastating environmental stress that strongly reduces soil biota and can restrict plant growth and yield. In this review, we discussed our mechanistic understanding of drought and microbial response traits. Additionally, we highlighted the role of beneficial microbes and plant-derived metabolites in alleviating drought stress and improving crop growth. We proposed that future research might focus on evaluating the dynamics of root-beneficial microbes under field drought conditions. The integrative use of ecology, microbial, and molecular approaches may serve as a promising strategy to produce more drought-resilient and sustainable crops.

Transcriptional activation of rice CINNAMOYL-CoA REDUCTASE 10 by OsNAC5, contributes to drought tolerance by modulating lignin accumulation in roots.

SummaryDrought is a common abiotic stress for terrestrial plants and often affects crop development and yield. Recent studies have suggested that lignin plays a crucial role in plant drought tolerance; however, the underlying molecular mechanisms are still largely unknown. Here, we report that the rice (Oryza sativa) gene CINNAMOYL‐CoA REDUCTASE 10 (OsCCR10) is directly activated by the OsNAC5 transcription factor, which mediates drought tolerance through regulating lignin accumulation. CCR is the first committed enzyme in the monolignol synthesis pathway, and the expression of 26 CCR genes was observed to be induced in rice roots under drought. Subcellular localisation assays revealed that OsCCR10 is a catalytically active enzyme that is localised in the cytoplasm. The OsCCR10 transcript levels were found to increase in response to abiotic stresses, such as drought, high salinity, and abscisic acid (ABA), and transcripts were detected in roots at all developmental stages. In vitro enzyme activity and in vivo lignin composition assay suggested that OsCCR10 is involved in H‐ and G‐lignin biosynthesis. Transgenic rice plants overexpressing OsCCR10 showed improved drought tolerance at the vegetative stages of growth, as well as higher photosynthetic efficiency, lower water loss rates, and higher lignin content in roots compared to non‐transgenic (NT) controls. In contrast, CRISPR/Cas9‐mediated OsCCR10 knock‐out mutants exhibited reduced lignin accumulation in roots and less drought tolerance. Notably, transgenic rice plants with root‐preferential overexpression of OsCCR10 exhibited higher grain yield than NT controls plants under field drought conditions, indicating that lignin biosynthesis mediated by OsCCR10 contributes to drought tolerance.

Variety-specific transcript accumulation during reproductive stage in drought-stressed rice.

The divergence of natural stress tolerance mechanisms between species is an intriguing phenomenon. To study it in rice, a comparative transcriptome analysis was carried out in 'heading' stage tissue (flag leaf, panicles and roots) of Nagina 22 (N22; drought-tolerant) and IR64 (drought-sensitive) plants subjected to field drought. Interestingly, N22 showed almost double the number of differentially expressed genes (DEGs) than IR64. Many DEGs colocalized within drought-related QTLs responsible for grain yield and drought tolerance and also associated with drought tolerance and critical drought-related plant traits such as leaf rolling, trehalose content, sucrose and cellulose content. Besides, co-expression analysis of the DEGs revealed several 'hub' genes known to actively regulate drought stress response. Strikingly, 1366 DEGs, including 21 'hub' genes, showed a distinct opposite regulation in the two rice varieties under similar drought conditions. Annotation of these variety-specific DEGs (VS-DEGs) revealed that they are distributed in various biological pathways. Furthermore, 103 VS-DEGs were found to physically interact with over 1300 genes, including 32 that physically interact with other VS-DEGs as well. The promoter region of these genes has sequence variations among the two rice varieties, which might be in part responsible for their unique expression pattern.

Transcriptomic Responses of Potato to Drought Stress

AbstractTranscriptomic changes in plants during drought stress give insights into the mechanisms with which plants stabilise their metabolic processes in order to cope with the drought condition. In potato, understanding such drought-induced transcriptomic changes is critical because prolonged field drought interferes with tuber formation and bulking period of potato development, which eventually affects yield. We hypothesised that phenotypic drought responses of potato genotypes may be linked to differences in transcriptomic changes. Using an RNA sequencing approach, we investigated such transcriptomic changes in leaves of three cultivars (Biogold, Hansa and Lady Rosetta) under drought. We found more differentially expressed genes (DEGs) in the tolerant cultivars, Lady Rosetta and Biogold, than in the sensitive cultivar (Hansa). The differential gene expression trend reflected the phenotypic drought responses of the cultivars. For instance, we found in both Biogold and Lady Rosetta but not in Hansa, an upregulation of genes involved in carbohydrate metabolism (e.g., Alpha-glucosidase), flavonoid biosynthesis (e.g., Flavanone 3 beta-hydroxylase), lipid biosynthesis/transfer (e.g., nonspecific Lipid Transfer Proteins), heat shock proteins and secondary metabolites like phenolics and lignins. Furthermore, a prolonged drought stress resulted in reduced DEGs in Biogold and Hansa, but not in Lady Rosetta that also maintained its tuber yield under such prolonged stress suggesting a more robust drought tolerance. Our findings suggest that a synergistic expression of genes involved in several different aspects of drought response is required in order to obtain a robust tolerance.

Yield and biochemical properties of grain sorghum (Sorghum bicolor L. Moench) affected by nano-fertilizer under field drought stress

Yield and biochemical properties of grain sorghum (Sorghum bicolor L. Moench) affected by nano-fertilizer under field drought stress

GBS-SNP and SSR based genetic mapping and QTL analysis for drought tolerance in upland cotton.

The online version contains supplementary material available at 10.1007/s12298-021-01041-y.