甘蓝型油菜开花相关基因的鉴定及进化与表达分析

Flowering genes in oilseed rape: identification, characterization, evolutionary and expression analysis

开花是开花植物繁衍后代的前提,控制开花时间对农作物获得高产稳产具有重要影响。然而,关于甘蓝型油菜基因组水平上开花相关基因的信息报道较少。本研究对甘蓝型油菜开花相关的基因进行了鉴定、特征分析、进化与表达模式分析。结果表明,基因组水平上共鉴定到甘蓝型油菜1173个开花相关基因,这些基因分为9类,且不均匀地分布在染色体上;与白菜(AA,2n=20)和甘蓝(CC,2n=18)相比,甘蓝型油菜(AACC,2n=38)经过自然杂交和染色体加倍后,使开花相关基因的数目显著扩增;选择压力分析表明,糖代谢信号途径的基因比自发途径的开花相关基因受到的选择压力更大;仍有一些开花相关基因在拟南芥和油菜基因组内非常保守。甘蓝型油菜基因数目的扩增和功能分化导致其开花调控机制更加复杂,本研究为油菜开花途径提供更多的信息,也为阐明拟南芥和油菜开花基因的进化关系指明了方向。

Flowering is a prerequisite for successful sexual reproduction. Controlling of flowering time is important for crop pro- duction in different geographical regions. However, few information regarding flowering genes or their evolution at genome-wide level in Brassica napus has been reported. In this study, identification, characterization, evolutionary and expression analysis of flowering genes in oilseed rape were performed. In total, 1173 flowering-related genes classified into nine types and distributed unevenly on the chromosomes were identified at the genome level of Brassica napus. Compared with Brassica rapa (AA, 2n = 20) and Brassica oleraca (CC, 2n = 18), B. napus (AACC, 2n = 38) showed significantly enlarge number of flowering-related genes due to natural hybridization and chromosome doubling. Selective pressure analysis showed that the autonomous pathway genes had less selection pressure than the genes involved in sugar metabolic pathway, suggesting that some key flowering-related genes are relatively conserved between B. napus and Arabidopsis thaliana. The present study provides more information on the B. napus flowering pathways and sheds light on the evolutionary relationship of flowering-related genes between B. napus and A. thaliana.