The Foliar Application of Rice Phyllosphere Bacteria induces Drought-Stress Tolerance in Oryza sativa (L.)

Abstract

: This study assessed the potential of Bacillus endophyticus PB3, Bacillus altitudinis PB46, and Bacillus megaterium PB50 to induce drought tolerance in a susceptible rice cultivar. The leaves of the potted rice plants subjected to physical drought stress for 10 days during the flowering stage were inoculated with single-strain suspensions. Control pots of irrigated and drought-stressed plants were included in the experiment for comparison. In all treatments, the plant stress-related physiochemical and biochemical changes were examined and the expression of six stress-responsive genes in rice leaves was evaluated. The colonization potential on the surface of the rice leaves and stomata of the most successful strain in terms of induced tolerance was confirmed in the gnotobiotic experiment. The plants sprayed with B. megaterium PB50 showed an elevated stress tolerance based on their higher relative water content and increased contents of total sugars, proteins, proline, phenolics, potassium, calcium, abscisic acid, and indole acetic acid, as well as a high expression of stress-related genes (LEA, RAB16B, HSP70, SNAC1, and bZIP23). Moreover, this strain improved yield parameters compared to other treatments and also confirmed its leaf surface colonization. Overall, this study indicates that the foliar application of B. megaterium PB50 can induce tolerance to drought stress in rice.

Genome-Wide Identification and Expression Analysis of Heat Shock Protein 70 (HSP70) Gene Family in Pumpkin (Cucurbita moschata) Rootstock under Drought Stress Suggested the Potential Role of these Chaperones in Stress Tolerance

“…The higher expression of HSP70 in disease-resistant sunflowers than susceptible genotypes in response to powdery mildew has been reported recently [23]. An up-regulation of HSP70 was associated with drought tolerance in rice [24], Arabidopsis [25], tobacco [26], sugarcane [27], and chrysanthemum [28]. An overexpression of CaHSP70-2 (an HSP70 gene that belongs to pepper) in Arabidopsis induced the expression of stress-responsive genes and subsequently led to heat tolerance in Arabidopsis [29].…”

Integration of Phenomics and Metabolomics Datasets Reveals Different Mode of Action of Biostimulants Based on Protein Hydrolysates in Lactuca sativa L. and Solanum lycopersicum L. Under Salinity

“…As the second step, after the performance of the metabolic analysis and data processing, the concordance between both datasets (phenomics + metabolomics) was performed using CIA analysis. This tool is becoming a particularly attractive method for the identification of relationships between large datasets, but it is mainly used in ecology or genetics (Bady et al, 2004;Genitsaris et al, 2016;Devarajan et al, 2021). However, there are not any case studies using this tool for integrating phenotyping data with other omics.…”

Research Progress in the Field of Microbial Mitigation of Drought Stress in Plants

“…In addition, the biochemical analysis revealed an increase in the levels of exopolysaccharides, phytohormones, soluble sugars, chlorophyll, total protein, and sugars, which improved plant survival under conditions of water constraints ( Arun et al, 2020 ). In another study ( Devarajan et al, 2021 ), rice phyllosphere bacterial strains (e.g., Bacillus endophyticus PB3, Bacillus altitudinis PB46, and Bacillus megaterium PB50) were inoculated into Oryza sativa pots in a greenhouse experiment. Drought tolerance was moderately minimized in strain PB50, resulting in significant tolerance to drought.…”