Natural GmACO1 allelic variations confer drought tolerance and influence nodule formation in soybean

This study is led by Professor Shulin Liu (Key Laboratory of Seed Innovation, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China). The authors evaluated the standard drought tolerance index in a natural soybean population. Through GWAS they identified one significant association locus located on chromosome 8, which conferred drought tolerance variations. Through haplotype analysis and expression pattern analysis, the author focused on an ACC oxidase (GmACO1). GmACO1 was highly expressed in roots, and its expression level was induced after 15% PEG solution treatment.

There are two nonsynonymous SNPs existed in the predicted protein domain, and the SNP affected the oxidase enzyme activity. Genetic validation and RNA sequencing analysis showed that GmACO1 plays a positive role in conferring drought tolerance in soybean through affecting multiple pathways involved in the response to drought tolerance. Ethylene also acts as a negative regulator of rhizobial infection and inhibits the formation of nodules. Consequently, the authors checked the expression level of GmACO1 after rhizobial infection and determined that it was reduced, and GmACO1 RNAi transgenic lines had more nodules than did the DN50 plants, indicating that GmACO1 negatively regulates nodule formation in soybean.

Taken together, the authors identified an ACC oxidase that positively regulated drought tolerance through GWAS in soybean, which provides a valuable genetic resource for developing drought tolerant soybean varieties via molecular design breeding. Furthermore, this gene has multiple genetic effects and can be applied to soybean breeding for different purposes.

See the article:

Natural GmACO1 allelic variations confer drought tolerance and influence nodule formation in soybean

https://link.springer.com/article/10.1007/s42994-024-00160-w