Unlocking the Drought-Relief Partnership: Exploring the Role of Sulfate-Reducing Bacteria and Salep Gum in Alleviating Drought Stress in Lettuce (Lactuca sativa)

Document Type : Research paper

Authors

1 Agricultural Biotechnology Research Institute of Iran (ABRII)

2 Department of Plant Sciences and Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran

3 Department of Plant Sciences and Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran.

10.22059/ijhst.2024.380585.902

Abstract

Drought stress is a critical factor limiting plant growth and productivity. In the present study, effects of three drought stress levels (40%, 60% and 80%) and application of salep gum (SG) and sulfate reductase bacteria (SRB) on various physiological parameters of lettuce plants were investigated. Drought stress significantly reduced germination percentage, whereas SG and SRB positively influenced germination, particularly under severe drought conditions. Root growth increased under 60% drought stress, while SG and SRB treatments exhibited positive effects under 80% drought stress. Leaf area decreased under 80% drought stress but increased with SG and SRB treatments under milder drought levels. Relative water content (RWC) decreased under mild and moderate drought stress, but increased under severe drought stress with all treatments, particularly SG. H2O2 levels increased under 80% drought stress with SG and SRB treatments, accompanied by a decrease in catalase (CAT) activity under 80% stress conditions. Superoxide dismutase (SOD) activity increased under 80% drought stress with SG treatment. Fv/Fm decreased under 80% stress but recovered with SG and SRB treatments. PiABS decreased with drought stress, while SG treatment increased Pi levels. ABS/RC and TRO/RC decreased with drought stress but increased with treatments under severe drought conditions. Overall, SG and SRB treatments positively affected germination, root growth, leaf area, RWC, H2O2 levels, Antioxidant enzyme activity and photosynthetic functionality under different drought stress conditions. These findings contribute to understanding plant responses to drought stress and suggest the potential of SG and SRB treatments for mitigating its negative effects.

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