Genome-Wide Identification and Characterization of the RCI2 Gene Family in Allotetraploid Brassica napus Compared with Its Diploid Progenitors

Abstract

Brassica napus and its diploid progenitors (B. rapa and B. oleracea) are suitable for studying the problems associated with polyploidization. As an important anti-stress protein, RCI2 proteins widely exist in various tissues of plants, and are crucial to plant growth, development, and stress response. In this study, the RCI2 gene family was comprehensively identified and analyzed, and 9, 9, and 24 RCI2 genes were identified in B. rapa, B. oleracea, and B. napus, respectively. Phylogenetic analysis showed that all of the identified RCI2 genes were divided into two groups, and further divided into three subgroups. Ka/Ks analysis showed that most of the identified RCI2 genes underwent a purifying selection after the duplication events. Moreover, gene structure analysis showed that the structure of RCI2 genes is largely conserved during polyploidization. The promoters of the RCI2 genes in B. napus contained more cis-acting elements, which were mainly involved in plant development and growth, plant hormone response, and stress responses. Thus, B. napus might have potential advantages in some biological aspects. In addition, the changes of RCI2 genes during polyploidization were also discussed from the aspects of gene number, gene structure, gene relative location, and gene expression, which can provide reference for future polyploidization analysis.

The Stilbene Synthase Family in Arachis: A Genome-Wide Study and Functional Characterization in Response to Stress

“…As expected, the number of CHS (6) and STS (46) genes in the tetraploid A. hypogaea is almost equivalent to the combined value in its diploid wild progenitors, i.e., 8 CHS and 45 STS. Similar results have been reported for genome-wide analysis of the Phospholipase D gene family in Arachis [47] and for other gene families in Brassica and Gossypium allotetraploid species when compared with their corresponding diploid progenitors [48][49][50].…”