Modulation in Plant Growth and Drought Tolerance of Wheat Crop upon Inoculation of Drought-tolerant-Bacillus Species Isolated from Hot Arid Soil of India

Drought is one of the most detrimental environmental stressors to plants with the potential to decrease crop yields and affect agricultural sustainability. Native bacteria with beneficial traits enhance plant growth and help avoid and reverse the effects of drought in plants to a greater extent. In the present study, we aimed to ( i ) isolate drought-tolerant Bacillus isolates from the rhizosphere soil of wheat crop grown at different locations in Jaisalmer district, Rajasthan state and (ii) further evaluate their ability to enhance plant growth and induce drought tolerance in wheat ( Var. HD-2967) grown under drought stress conditions. Of more than 100 isolates, two putative Bacillus isolates capable of tolerating 30 % polyethylene glycol-6000 (PEG-6000) [equivalent to -9.80 MPa (Megapascal)] were identified as Bacillus altitudinis DT-89 and Bacillus paramycoides DT-113. These isolates exhibited different plant growth promoting (PGP) attributes such as phosphate solubilization, and production of siderophore, exopolysaccharide, ammonia, indole acetic acid and cytokinin at low osmotic stress of 10% PEG-6000 but shown variable response at higher osmotic stress particularly at 30% PEG-6000. However, they did not show any antifungal activity and one isolate was negative for phosphate solubilization. Of two strains, B. altitudinis DT-89 function more prominently with respect to plant growth promotion and drought tolerance to plant in the early stage but protective traits of B. paramycoides DT-113 was more prominent after 75 days as evident by increased EPS (164%), root dry weight (144.44%), chlorophyll content (90.26%), SOD (389%) and proline (99.3%). The results support both the strains as a potential candidate to alleviate drought stress and enhance plant growth in the drought regions.

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Physiological Responses under Drought Stress of Improved Drought-Tolerant Rice Lines and their Parents

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha46211188 ◽

2018 ◽

Vol 46 (2) ◽

pp. 679-687 ◽

Cited By ~ 6

Author(s):

Preeyanuch LARKUNTHOD ◽

Noppawan NOUNJAN ◽

Jonaliza L SIANGLIW ◽

Theerayut TOOJINDA ◽

Jirawat SANITCHON ◽

...

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Water Status ◽

Physiological Responses ◽

High Water ◽

Recurrent Parent ◽

Potential Candidate ◽

Substitution Lines ◽

Chromosome Segment Substitution Lines ◽

Drought Tolerant

Many of the economically important rice cultivars including ‘Khao Dawk Mali 105’ (KDML105) or jasmine rice, one of the world’s famous rice exported from Thailand suffers from drought due to erratic rainfalls and limited irrigation. To improve drought tolerance and reserve genetic background of KDML105, chromosome segment substitution lines (CSSL) containing drought tolerant quantitative trait loci (DT-QTL) has been previously developed by backcrossing between KDML105 and drought tolerant donor, IR58586-F2-CA-143 (DH212). To understand the physiological responses related to drought tolerance in CSSL lines compared to parents, two CSSLs namely CSSL1-16 and CSSL1-18, respectively were used in this study. Twenty-one-d-old hydroponically grown plants were subjected to 20% PEG for 0, 7, 14 d and then recovered from stress for 3 d. The results indicated that CSSL lines especially, CSSL1-16 showed better performance under drought stress compared to their recurrent parent. Drought tolerance superior CSSL1-16 line was indicated by high water status (high relative water content and leaf water potential), good osmotic adjustment, high proline and greater membrane stability. Moreover, this line was able to resume growth after stress recovery whereas other lines/cultivar could not recover. Similarly, drought tolerant donor showed high water status suggesting that well-maintained plant water status was associated with drought tolerant trait. It could be concluded that the highest drought tolerant line was CSSL1-16 followed by DH212, CSSL1-18 and KDML105. It would be interesting to go further into introgressed section in CSSL1-16 to identify potential candidate genes in DT-QTL for breeding drought tolerant rice in the future.

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Rhizobacteria Associated with Spilanthes acmella Murr. Confer Drought-Tolerance and Plant Growth Promotion

Biointerface Research in Applied Chemistry ◽

10.33263/briac115.1315513170 ◽

2021 ◽

Vol 11 (5) ◽

pp. 13155-13170

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Plant Growth ◽

Environmental Conditions ◽

Culturable Bacteria ◽

Drought Tolerant ◽

Plant Growth Promoting ◽

Spilanthes Acmella ◽

Growth Promoting ◽

Adverse Environmental Conditions

Plant growth-promoting rhizobacteria (PGPR) exhibit biocontrol and biofertilzer traits and help plants survive adverse environmental conditions. In this study, the rhizobacteria are explored for their ability to tolerate drought stress and their potential to act as plant growth promoters. Herein, we have isolated bacterial strains from the rhizosphere of Spilanthes acmella Murr. (toothache plant) found in the Shivalik hills region of Himachal Pradesh. We screened nine drought-tolerant culturable bacteria by analyzing their ability to survive in varying concentrations of polyethylene glycol (PEG) (10% - 50%), which is further supported by their 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity and their ability to release exopolysaccharides (EPS). Strains having these activities are identified by 16S rDNA analysis, which reveals that they belong to four different bacteria genera, namely Klebsiella, Enterobacter, Burkholderia, and Pantoea. These isolates also harbor plant growth-promoting traits such as solubilization of phosphate, production of indole-3-acetic acid (IAA), siderophore, ammonia, hydrogen cyanide (HCN), and antifungal activity. The Enterobacter cloacae showed maximum drought tolerance among all the other isolates. We found that the drought stress of 60% PEG inhibited wheat seedlings' growth, but the bacterization with the isolated strains stimulated seedling growth. Hence we conclude that these drought-tolerant PGPR from the rhizosphere of S. acmella Murr. can be utilized to enhance the survival and growth of plants under drought stress. The isolated strains not only exhibit the drought-tolerant ability but also show the biocontrol and biofertilizer traits. Inoculation of these strains could help the plant survive under adverse environmental conditions.

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Improving Drought Tolerance in Mungbean (Vigna radiata L. Wilczek): Morpho-Physiological, Biochemical and Molecular Perspectives

Agronomy ◽

10.3390/agronomy11081534 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1534

Author(s):

Chandra Mohan Singh ◽

Poornima Singh ◽

Chandrakant Tiwari ◽

Shalini Purwar ◽

Mukul Kumar ◽

...

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Crop Production ◽

Mitigation Strategies ◽

Theoretical Research ◽

Whole Genome Sequence ◽

Complex Nature ◽

Drought Tolerant ◽

Breeding Programmes ◽

The Impact

Drought stress is considered a severe threat to crop production. It adversely affects the morpho-physiological, biochemical and molecular functions of the plants, especially in short duration crops like mungbean. In the past few decades, significant progress has been made towards enhancing climate resilience in legumes through classical and next-generation breeding coupled with omics approaches. Various defence mechanisms have been reported as key players in crop adaptation to drought stress. Many researchers have identified potential donors, QTLs/genes and candidate genes associated to drought tolerance-related traits. However, cloning and exploitation of these loci/gene(s) in breeding programmes are still limited. To bridge the gap between theoretical research and practical breeding, we need to reveal the omics-assisted genetic variations associated with drought tolerance in mungbean to tackle this stress. Furthermore, the use of wild relatives in breeding programmes for drought tolerance is also limited and needs to be focused. Even after six years of decoding the whole genome sequence of mungbean, the genome-wide characterization and expression of various gene families and transcriptional factors are still lacking. Due to the complex nature of drought tolerance, it also requires integrating high throughput multi-omics approaches to increase breeding efficiency and genomic selection for rapid genetic gains to develop drought-tolerant mungbean cultivars. This review highlights the impact of drought stress on mungbean and mitigation strategies for breeding high-yielding drought-tolerant mungbean varieties through classical and modern omics technologies.

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Drought Tolerant near Isogenic Lines (NILs) of Pusa 44 Developed through Marker Assisted Introgression of qDTY2.1 and qDTY3.1 Enhances Yield under Reproductive Stage Drought Stress

Agriculture ◽

10.3390/agriculture11010064 ◽

2021 ◽

Vol 11 (1) ◽

pp. 64

Author(s):

Priyanka Dwivedi ◽

Naleeni Ramawat ◽

Gaurav Dhawan ◽

Subbaiyan Gopala Krishnan ◽

Kunnummal Kurungara Vinod ◽

...

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Grain Quality ◽

Reproductive Stage ◽

Recurrent Parent ◽

Near Isogenic Lines ◽

Improvement Project ◽

Isogenic Lines ◽

Drought Tolerant ◽

Rice Improvement

Reproductive stage drought stress (RSDS) is detrimental for rice, which affects its productivity as well as grain quality. In the present study, we introgressed two major quantitative trait loci (QTLs), namely, qDTY2.1 and qDTY3.1, governing RSDS tolerance in a popular high yielding non-aromatic rice cultivar, Pusa 44, through marker-assisted backcross breeding (MABB). Pusa 44 is highly sensitive to RSDS, which restricts its cultivation across drought-prone environments. Foreground selection was carried out using markers, RM520 for qDTY3.1 and RM 521 for qDTY2.1. Background selection was achieved with 97 polymorphic SSR markers in tandem with phenotypic selection to achieve faster recurrent parent genome (RPG) recovery. Three successive backcrosses followed by three selfings aided RPG recoveries of 98.6% to 99.4% among 31 near isogenic lines (NILs). Fourteen NILs were found to be significantly superior in yield and grain quality under RSDS with higher drought tolerance efficiency (DTE) than Pusa 44. Among these, the evaluation of two promising NILs in the multilocational trial during Kharif 2019 showed that they were significantly superior to Pusa 44 under reproductive stage drought stress, while performing on par with Pusa 44 under normal irrigated conditions. These di-QTL pyramided drought-tolerant NILs are in the final stages of testing the All India Coordinated Rice Improvement Project varietal trials for cultivar release. Alternately, the elite drought-tolerant Pusa 44 NILs will serve as an invaluable source of drought tolerance in rice improvement.

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Genetic Diversity of Selected Rice Genotypes under Water Stress Conditions

Plants ◽

10.3390/plants10010027 ◽

2020 ◽

Vol 10 (1) ◽

pp. 27

Author(s):

Mahmoud M. Gaballah ◽

Azza M. Metwally ◽

Milan Skalicky ◽

Mohamed M. Hassan ◽

Marian Brestic ◽

...

Keyword(s):

Genetic Diversity ◽

Water Stress ◽

Drought Stress ◽

Drought Tolerance ◽

Ssr Markers ◽

Similarity Index ◽

Stress Conditions ◽

Yield Potential ◽

Drought Tolerant ◽

Rice Genotypes

Drought is the most challenging abiotic stress for rice production in the world. Thus, developing new rice genotype tolerance to water scarcity is one of the best strategies to achieve and maximize high yield potential with water savings. The study aims to characterize 16 rice genotypes for grain and agronomic parameters under normal and drought stress conditions, and genetic differentiation, by determining specific DNA markers related to drought tolerance using Simple Sequence Repeats (SSR) markers and grouping cultivars, establishing their genetic relationship for different traits. The experiment was conducted under irrigated (normal) and water stress conditions. Mean squares due to genotype × environment interactions were highly significant for major traits. For the number of panicles/plants, the genotypes Giza179, IET1444, Hybrid1, and Hybrid2 showed the maximum mean values. The required sterility percentage values were produced by genotypes IET1444, Giza178, Hybrid2, and Giza179, while, Sakha101, Giza179, Hybrid1, and Hybrid2 achieved the highest values of grain yield/plant. The genotypes Giza178, Giza179, Hybrid1, and Hybrid2, produced maximum values for water use efficiency. The effective number of alleles per locus ranged from 1.20 alleles to 3.0 alleles with an average of 1.28 alleles, and the He values for all SSR markers used varied from 0.94 to 1.00 with an average of 0.98. The polymorphic information content (PIC) values for the SSR were varied from 0.83 to 0.99, with an average of 0.95 along with a highly significant correlation between PIC values and the number of amplified alleles detected per locus. The highest similarity coefficient between Giza181 and Giza182 (Indica type) was observed and are susceptible to drought stress. High similarity percentage between the genotypes (japonica type; Sakha104 with Sakha102 and Sakha106 (0.45), Sakha101 with Sakha102 and Sakha106 (0.40), Sakha105 with Hybrid1 (0.40), Hybrid1 with Giza178 (0.40) and GZ1368-S-5-4 with Giza181 (0.40)) was also observed, which are also susceptible to drought stress. All genotypes are grouped into two major clusters in the dendrogram at 66% similarity based on Jaccard’s similarity index. The first cluster (A) was divided into two minor groups A1 and A2, in which A1 had two groups A1-1 and A1-2, containing drought-tolerant genotypes like IET1444, GZ1386-S-5-4 and Hybrid1. On the other hand, the A1-2 cluster divided into A1-2-1 containing Hybrid2 genotype and A1-2-2 containing Giza179 and Giza178 at coefficient 0.91, showing moderate tolerance to drought stress. The genotypes GZ1368-S-5-4, IET1444, Giza 178, and Giza179, could be included as appropriate materials for developing a drought-tolerant variety breeding program. Genetic diversity to grow new rice cultivars that combine drought tolerance with high grain yields is essential to maintaining food security.

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Drought Stress in Grain Legumes: Effects, Tolerance Mechanisms and Management

Agronomy ◽

10.3390/agronomy11122374 ◽

2021 ◽

Vol 11 (12) ◽

pp. 2374

Author(s):

Marium Khatun ◽

Sumi Sarkar ◽

Farzana Mustafa Era ◽

A. K. M. Mominul Islam ◽

Md. Parvez Anwar ◽

...

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Association Studies ◽

Stomatal Closure ◽

Grain Legumes ◽

Grain Legume ◽

Developmental Cycle ◽

Genome Wide Association Studies ◽

Tolerance Mechanisms ◽

Drought Tolerant

Grain legumes are important sources of proteins, essential micronutrients and vitamins and for human nutrition. Climate change, including drought, is a severe threat to grain legume production throughout the world. In this review, the morpho-physiological, physio-biochemical and molecular levels of drought stress in legumes are described. Moreover, different tolerance mechanisms, such as the morphological, physio-biochemical and molecular mechanisms of legumes, are also reviewed. Moreover, various management approaches for mitigating the drought stress effects in grain legumes are assessed. Reduced leaf area, shoot and root growth, chlorophyll content, stomatal conductance, CO2 influx, nutrient uptake and translocation, and water-use efficiency (WUE) ultimately affect legume yields. The yield loss of grain legumes varies from species to species, even variety to variety within a species, depending upon the severity of drought stress and several other factors, such as phenology, soil textures and agro-climatic conditions. Closure of stomata leads to an increase in leaf temperature by reducing the transpiration rate, and, so, the legume plant faces another stress under drought stress. The biosynthesis of reactive oxygen species (ROS) is the most detrimental effect of drought stress. Legumes can adapt to the drought stress by changing their morphology, physiology and molecular mechanism. Improved root system architecture (RSA), reduced number and size of leaves, stress-induced phytohormone, stomatal closure, antioxidant defense system, solute accumulation (e.g., proline) and altered gene expression play a crucial role in drought tolerance. Several agronomic, breeding both conventional and molecular, biotechnological approaches are used as management practices for developing a drought-tolerant legume without affecting crop yield. Exogenous application of plant-growth regulators (PGRs), osmoprotectants and inoculation by Rhizobacteria and arbuscular mycorrhizal fungi promotes drought tolerance in legumes. Genome-wide association studies (GWASs), genomic selection (GS), marker-assisted selection (MAS), OMICS-based technology and CRISPR/Cas9 make the breeding work easy and save time in the developmental cycle to get resistant legumes. Several drought-resistant grain legumes, such as the chickpea, faba bean, common bean and pigeon pea, were developed by different institutions. Drought-tolerant transgenic legumes, for example, chickpeas, are developed by introgressing desired genes through breeding and biotechnological approaches. Several quantitative trait loci (QTLs), candidate genes occupying drought-tolerant traits, are identified from a variety of grain legumes, but not all are under proper implementation. Hence, more research should be conducted to improve the drought-tolerant traits of grain legumes for avoiding losses during drought.

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Enhancement of drought tolerance in diverse Vicia faba cultivars by inoculation with plant growth-promoting rhizobacteria under newly reclaimed soil conditions

Scientific Reports ◽

10.1038/s41598-021-02847-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Elsayed Mansour ◽

Hany A. M. Mahgoub ◽

Samir A. Mahgoub ◽

El-Sayed E. A. El-Sobky ◽

Mohamed I. Abdul-Hamid ◽

...

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Plant Growth ◽

Plant Growth Promoting Rhizobacteria ◽

Severe Drought ◽

Drought Conditions ◽

Moderate Drought ◽

Plant Growth Promoting ◽

Growth Promoting ◽

Effects Of Drought

AbstractWater deficit has devastating impacts on legume production, particularly with the current abrupt climate changes in arid environments. The application of plant growth-promoting rhizobacteria (PGPR) is an effective approach for producing natural nitrogen and attenuating the detrimental effects of drought stress. This study investigated the influence of inoculation with the PGPR Rhizobium leguminosarum biovar viciae (USDA 2435) and Pseudomonas putida (RA MTCC5279) solely or in combination on the physio-biochemical and agronomic traits of five diverse Vicia faba cultivars under well-watered (100% crop evapotranspiration [ETc]), moderate drought (75% ETc), and severe drought (50% ETc) conditions in newly reclaimed poor-fertility sandy soil. Drought stress substantially reduced the expression of photosynthetic pigments and water relation parameters. In contrast, antioxidant enzyme activities and osmoprotectants were considerably increased in plants under drought stress compared with those in well-watered plants. These adverse effects of drought stress reduced crop water productivity (CWP) and seed yield‐related traits. However, the application of PGPR, particularly a consortium of both strains, improved these parameters and increased seed yield and CWP. The evaluated cultivars displayed varied tolerance to drought stress: Giza-843 and Giza-716 had the highest tolerance under well-watered and moderate drought conditions, whereas Giza-843 and Sakha-4 were more tolerant under severe drought conditions. Thus, co-inoculation of drought-tolerant cultivars with R. leguminosarum and P. putida enhanced their tolerance and increased their yield and CWP under water-deficit stress conditions. This study showed for the first time that the combined use of R. leguminosarum and P. putida is a promising and ecofriendly strategy for increasing drought tolerance in legume crops.

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Phytohormone cross-talk and antioxidant gadgets tussles osmotic stress in indigenous rice landraces during seed germination

10.21203/rs.3.rs-80159/v1 ◽

2020 ◽

Author(s):

R. Anupriya ◽

Sugitha Thankappan ◽

A. Senthil ◽

D. Rajakumar ◽

Geetha S ◽

...

Keyword(s):

Drought Stress ◽

Seed Germination ◽

Drought Tolerance ◽

Cross Talk ◽

Tamil Nadu ◽

Critical Role ◽

Hydrolytic Enzyme ◽

Rice Landraces ◽

Drought Tolerant ◽

Root And Shoot Length

Abstract Seed germination plays a critical role in determining rice productivity under drought stress. We evaluated 100 traditional rice landraces originated from different agro-ecological zones of Tamil Nadu along with drought- susceptible (IR 64) and drought- tolerant (IR 64 DRT) checks. Moisture stress was induced using PEG 6000 and screening done over a range of osmotic potentials (-) 10 bars, (-) 12.5 bars and (-)15 bars for a period of 5 d. Physio-morphological traits such as germination rate, survival per cent, root and shoot length, vigor index, RS ratio and relative water content (RWC) were assessed during early drought stress. We observed significant changes in the seed macromolecules, phytohormone levels (GA and IAA), osmolytes and antioxidant responses (catalase and superoxide dismutase) between drought stress and control treatments. Kuliyadichan registered significantly higher IAA and GA (44% and 35% respectively over drought tolerant check IR 64 DRT) at drought stress, whereas all the landraces showed an elevated catalase activity. In PC analysis, first three PCs captured 88.93% of the total variation; significant differences were detected among genotypes with respect to the studied parameters. Six traditional landraces such as Kuliyadichan, Rajalakshmi, Sabhagidhan, Nootripathu, Chandaikar and Mallikar were selected and their inherent drought tolerance was associated with metabolic responses viz., triggered hydrolytic enzyme activities, hormonal cross-talk, ROS signaling and catalase under drought stress compared to drought sensitive IR64. Hence, these genotypes can be used as potential donor candidates towards genetic improvement of drought tolerance in rice.

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Groundnut mutants with end-of-season drought tolerance for the marginal dry lands of North Kordofan State, Sudan.

10.1079/9781789249095.0025 ◽

2021 ◽

pp. 243-257

Author(s):

Elgailani Abdalla ◽

Tarig Ahmed ◽

Omar Bakhit ◽

Yasir Gamar ◽

Salih Elshaikh ◽

...

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Small Scale ◽

Mutation Induction ◽

Total Production ◽

Drought Period ◽

Dry Lands ◽

Terminal Drought ◽

Drought Tolerant ◽

Terminal Drought Stress

Abstract Groundnut (Arachis hypogaea L.), produced in the traditional small-scale rainfed sector of Western Sudan, accounts for 80% of the total annual groundnut acreage, producing 70% of the total production. Low productivity of groundnut is a characteristic feature in North Kordofan State, which is characterized as the most vulnerable state to the impact of climate change. Terminal drought stress resulting from reduction in rainfall amount and distribution at the end of the season is the most deleterious drought period, as it coincides with groundnut pod filling and maturation periods. High and stable yields under subsistence farming conditions in North Kordofan State could be realized only by using adapted high-yielding, drought-tolerant genotypes. Mutation induction by gamma-rays of 200 and 300 Gy was utilized to irradiate 500 dry seeds of the Spanish-type groundnut genotypes, Barberton, Sodari, ICGV 89104, ICGV 86743, ICGV 86744 and ICG 221, aiming at increasing the chances of obtaining genotypes with the desired drought-tolerant traits. Mutants were selected from the M3 plants using visual morphological traits. Groundnut mutants at the M4 and M5 generations, advanced by single seed descent, were evaluated for end-of-season drought tolerance. A terminal drought period of 25 days was imposed after 60 days from planting, using a rainout shelter. Mutants that survived 25 days of terminal drought stress were further evaluated for agronomic performance under rainfed field conditions. The groundnut mutant, Barberton-b-30-3-B, produced 1024 kg/ha, a significantly higher mean pod yield over 12 seasons compared with 926 kg/ha for 'Gubeish', the widely grown released check cultivar, showing overall yield advantage of 11%. Under 5 years of participatory research, Barberton-b-30-3-B was ranked the best with yield increment of 21% over 'Gubeish' under the mother trials. The GGE biplot analysis for 12 and five seasons, respectively, showed that Barberton-b-30-3-B was stable and produced a good yield in both high and low rainfall situations. Hence, Barberton-b-30-3-B was found to be a suitable mutant for sustainable profitable yields in the marginal dry lands of North Kordofan State and was officially released as 'Tafra-1' by the National Variety Release Committee during its second meeting of April 2018.

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Comparative Proteomics and Physiological Analyses Reveal Important Maize Filling-Kernel Drought-Responsive Genes and Metabolic Pathways

International Journal of Molecular Sciences ◽

10.3390/ijms20153743 ◽

2019 ◽

Vol 20 (15) ◽

pp. 3743 ◽

Cited By ~ 7

Author(s):

Xuan Wang ◽

Tinashe Zenda ◽

Songtao Liu ◽

Guo Liu ◽

Hongyu Jin ◽

...

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Protein Interactions ◽

Stress Responses ◽

Metabolic Pathways ◽

Storage Proteins ◽

Seed Storage Proteins ◽

Comparative Proteomics ◽

Venn Diagram ◽

Drought Tolerant

Despite recent scientific headway in deciphering maize (Zea mays L.) drought stress responses, the overall picture of key proteins and genes, pathways, and protein–protein interactions regulating maize filling-kernel drought tolerance is still fragmented. Yet, maize filling-kernel drought stress remains devastating and its study is critical for tolerance breeding. Here, through a comprehensive comparative proteomics analysis of filling-kernel proteomes of two contrasting (drought-tolerant YE8112 and drought-sensitive MO17) inbred lines, we report diverse but key molecular actors mediating drought tolerance in maize. Using isobaric tags for relative quantification approach, a total of 5175 differentially abundant proteins (DAPs) were identified from four experimental comparisons. By way of Venn diagram analysis, four critical sets of drought-responsive proteins were mined out and further analyzed by bioinformatics techniques. The YE8112-exclusive DAPs chiefly participated in pathways related to “protein processing in the endoplasmic reticulum” and “tryptophan metabolism”, whereas MO17-exclusive DAPs were involved in “starch and sucrose metabolism” and “oxidative phosphorylation” pathways. Most notably, we report that YE8112 kernels were comparatively drought tolerant to MO17 kernels attributable to their redox post translational modifications and epigenetic regulation mechanisms, elevated expression of heat shock proteins, enriched energy metabolism and secondary metabolites biosynthesis, and up-regulated expression of seed storage proteins. Further, comparative physiological analysis and quantitative real time polymerase chain reaction results substantiated the proteomics findings. Our study presents an elaborate understanding of drought-responsive proteins and metabolic pathways mediating maize filling-kernel drought tolerance, and provides important candidate genes for subsequent functional validation.

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