UNDERSTANDING AND IMPROVEMENT OF SOYBEAN TOLERANCE TO INDIVIDUAL AND COMBINED COLD AND WATERLOGGING STRESSES AT EARLY GROWTH STAGE

Expansion of soybean cultivation to the northern regions of United States and attempt to plant soybean earlier to avoid drought and heat stresses at the flowering stage require research effort to address the adverse effects of weather conditions (wet/waterlogging and cold) in late spring-early summer. Climate change has caused more temperature fluctuations in the soybean planting season, accompanied by the increasing frequency of heavy precipitations in late spring-early summer. An unexpected heavy cold rain after soybean planting can lead to severe problems in seedling establishment posing significant economic loss to farmers. Thus, it is imperative to develop waterlogging-tolerant and/or cold-tolerant soybean varieties through soybean breeding and genetic engineering strategies. Our groups have developed soybean pan-genome genomic resource for gene discovery and discovered the genetic diversity of soybean germplasm in terms of their responses to waterlogging and/or cold stresses. In this proposal, we aim to characterize genetic diversity in soybean germplasm in responses to waterlogging, cold and their combination, identify stress tolerance-related genes, reveal molecular mechanisms underlying the observed stress tolerance-associated traits through transcriptomics and metabolomics analyses, and develop strategies to develop new soybean varieties with improved tolerance to waterlogging and/or cold stresses at early growth stage. Outcomes will include a comprehensive understanding of genetic diversity and architecture of soybean tolerance to the early season waterlogging and/or cold stresses and knowledge on the physiological and molecular regulation of the tolerance-related traits to design strategies for developing future climate-smart soybeans. New stress-resilient soybean lines are expected by completing this project.