Divergent homoeolog evolution of the anthocyanin regulatory gene R in Oryza allopolyploids  

作　　者：Ying Bao Xiao-Lin Zhu Xiang Jing Mei Liu 

机构地区：[1]School of Life Sciences, Qufu Normal University, Qufu, Shandong 273165, China

出　　处：《Journal of Systematics and Evolution》2016年第5期511-518,共8页植物分类学报（英文版）

基　　金：We thank the International Rice GenBank at IRRI （Los Bafios, Philippines） for providing plant seeds. This work was supported by the National Natural Science Foundation of China （Grant No. 31570218）, Shandong Provincial Natural Science Foundation, China （Grant No. ZR2012CM024）, and the State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences （Grant No. LSEB2011-01）.

摘　　要：Polyploidization is an important evolutionary force in plant speciation and diversification. Retention and elimination of homoeologs derived by polyploidization are prevalent, whereas the evolutionary details of some duplicated genes in closely related natural polyploids are largely unknown. In the present study, we used an important regulatory gene （R） that encodes a bHLH protein in the anthocyanin metabolism pathway to demonstrate divergent evolutionary fates of homoeologs among four related Oryza allotetraploids. The BBCC genome species O. punctata Kotschy ex Steud. maintained both of its homoeologs, whereas three CCDD genome species （O. alta Swallen, O. grandiglumis （D611） Prod., and O. latifolia Desv.） lost their C subgenome homoeologous copies. In addition, the evolutionary rates of the homoeologs in the polyploids were equivalent to their corresponding homologs in diploids. We also found a slightly higher level of nucleotide diversity in R for the C subgenome homoeolog than for the B subgenome counterpart in O. punctata. After comparing the two types of polyploids, we conclude that inconsistent evolutionary patterns of R in these polyploids are probably associated with different evolutionary time, asymmetrical subgenome evolutionary dynamics, and unique demographical characteristics of these species.Polyploidization is an important evolutionary force in plant speciation and diversification. Retention and elimination of homoeologs derived by polyploidization are prevalent, whereas the evolutionary details of some duplicated genes in closely related natural polyploids are largely unknown. In the present study, we used an important regulatory gene （R） that encodes a bHLH protein in the anthocyanin metabolism pathway to demonstrate divergent evolutionary fates of homoeologs among four related Oryza allotetraploids. The BBCC genome species O. punctata Kotschy ex Steud. maintained both of its homoeologs, whereas three CCDD genome species （O. alta Swallen, O. grandiglumis （D611） Prod., and O. latifolia Desv.） lost their C subgenome homoeologous copies. In addition, the evolutionary rates of the homoeologs in the polyploids were equivalent to their corresponding homologs in diploids. We also found a slightly higher level of nucleotide diversity in R for the C subgenome homoeolog than for the B subgenome counterpart in O. punctata. After comparing the two types of polyploids, we conclude that inconsistent evolutionary patterns of R in these polyploids are probably associated with different evolutionary time, asymmetrical subgenome evolutionary dynamics, and unique demographical characteristics of these species.

关 键 词：BBCC  CCDD  duplication elimination  retention. 

分 类 号：Q0[生物学]