Cold stress‐induced miRNA and degradome changes in four soybean varieties differing in chilling resistance

Abstract

Abstract Chilling stress is one of the most important factors limiting soybean yield in the temperate climate. It significantly constraints the spatial distribution and agricultural productivity of plants, thereby affecting their growth and development. In this study, to determine the involvement of microRNAs (miRNAs) and their target genes in the chilling resistance of four soybean cultivars (Augusta, Fiskeby V, Toyomusume and Glycine soja ) with varying stress susceptibility, 72 small RNA libraries and 24 degradome libraries for high‐throughput sequencing were constructed. A total of 321 known miRNAs were identified, and 348 novel miRNAs were predicted in three analysed tissues. Moreover, under stress conditions, the differential expression of 162 known miRNAs, including well‐conserved, legume‐ and soybean‐specific miRNAs and 18 novel miRNAs, was found in the four tested cultivars. Degradome analysis allowed to assign the differentially expressed miRNAs to their potential target genes. They were found to be related to plant abiotic stress response mechanisms such as reactive oxygen species scavenging, flavonoid biosynthesis and regulation of osmotic potential based on GO and KEGG annotations. The findings of this study constitute a valuable insight into the function of miRNAs in the chilling resistance of soybean and may provide crucial knowledge in the development of new cultivars.