Climate Change and Plant–Microbe Interactions: Implications for Agricultural Sustainability

Abstract

Crop production systems are increasingly under threat of increased temperature exposure, water-deficit stress and a combination of these, which may directly damage plant physiology, but also alter the beneficial microflora associated with crop resilience. The impacts of plant-microbe interactions under different climate-related stresses along with their consequences on agricultural sustainability under the various experimental treatments were studied in an experimental design, comprising a selected plant species grown under normal condition, elevated temperature, water-deficit stress, and combined heat and drought stress, both with and without the application of beneficial plant growth promoting microorganisms, such as selected rhizobacteria and mycorrhizal fungi. The experiment was laid out in Randomized Complete Block Design (RCBD) using four replications and the data were collected for plant height, root biomass, shoot biomass, leaf area, chlorophyll, relative water content, photosynthetic performance, crop yield, soil microbial activity, soil microbial biomass, and soil nutrient parameters. Results of analysis of variance showed that all three treatments (climate stress, microbial inoculation and interaction between climate stress and microbial inoculation) had highly significant effects on the growth, physiological and yield traits. Significant reduction in all plant growth, physiological performance and yield attributes were observed under all the climate-stress treatments with the combined heat and drought stress treatment showing the highest reduction which is similar to the synergistic effect of combined abiotic stress. All inoculated plants showed higher RWC, chlorophyll content and photosynthetic performance compared to uninoculated plants and the soil microbial biomass and activity were also better preserved in the inoculated plants under stress, irrespective of the type and amount of climate stress applied.The RWC, chlorophyll content, and photosynthetic performance of all inoculated plants were greater than all uninoculated plants, and soil microbial biomass and activity were also better preserved in all inoculated plants under stress, regardless of the kind and level of stress applied. The results suggest that beneficial plant–microbe interactions significantly either alleviate abiotic stress under climate change on the plant's performance or assist in incorporating microbial inoculants into climate resilient and sustainable agricultural management practices.