MicroRNAs contribute to enhanced salt adaptation of the autopolyploid Hordeum bulbosum compared to its diploid ancestor

Abstract

Several studies have shown that autopolyploid species can tolerate abiotic stresses better than their diploid ancestor. However, the underlying molecular mechanism is poorly understood. Whole genome duplication can result in the expansion of miRNA families, and the innovative miRNA-target interaction is vital for adaptive response to various environments. The new microRNAs which were induced by genome duplication, also associated with stress response, and the distinctive microRNA networks in tetraploid and diploid Hordeum bulbosum by using high-throughput sequencing. Five miRNAs affected by genome doubling were involved in salt stress response. Of these, miR528b-3p was only detected in the tetraploid plants, and down - regulated in salt stress tetraploid plants relative to that in tetraploid check (CK). Moreover, it was found that miR528b-3p was not only involved in DNA replication and repair but also affected salt stress response. Finally, distinguished microRNAs-targets regulatory networks in both diploid and tetraploid plants were discovered.