High-throughput sequencing reveals the molecular mechanisms determining the stay-green characteristic in soybeans

ABSTRACT

Senescence is an internally systematized degeneration process leading to death in plants. Leaf yellowing, oneof the most prominent features of plant aging may lead to reduced crop yields. The molecular mechanism ofresponses to senescence in soybean leaves is not completely clear. In our research, two soybean varieties wereselected with different stay-green traits stay-green variety (BN106) and non-stay-green variety (KF14). RNAsamples extracted from the leaves of two varieties were sequenced and compared using high-throughputsequencing. Six key enzyme genes in chlorophyll degradation pathways were studied to analyze the changes intheir expression at seedling, flowering and maturation stage. Meanwhile, the construction of the genetictransformation process had been constructed to identify the function of putative gene by RNA-interference. Atotal of 4329 DEGs were involved in 52 functional groups and 254 KEGG pathways. Twelve genes encodingsenescence-associated and inducible chloroplast stay-green protein showed significant differential expression.MDCase and PAO have a significant expression in BN106 that may be the key factors affecting the maintenance of green characteristics. In addition, the function of GmSGRs has been identified by genetic transformation. The loss of GmSGRs may cause soybean seeds to change from yellow to green. In summary, ourresults revealed fundamental information about the molecular mechanism of aging in soybeans with differentstay-green characteristics. The work of genetic transformation lays a foundation for putative gene functionstudies that could contribute to postpone aging in soybeans