PDF(Pubmed)
Abstract：
Rapeseed (Brassica napus L.) with short or no dormancy period are easy to germinate before harvest (pre-harvest sprouting, PHS). PHS has seriously decreased seed weight and oil content in B. napus. Short-chain dehydrogenase/ reductase (SDR) genes have been found to related to seed dormancy by promoting ABA biosynthesis in rice and Arabidopsis. In order to clarify whether SDR genes are the key factor of seed dormancy in B. napus, homology sequence blast, protein physicochemical properties, conserved motif, gene structure, cis-acting element, gene expression and variation analysis were conducted in present study. Results shown that 142 BnaSDR genes, unevenly distributed on 19 chromosomes, have been identified in B. napus genome. Among them, four BnaSDR gene clusters present in chromosome A04、A05、C03、C04 were also identified. These 142 BnaSDR genes were divided into four subfamilies on phylogenetic tree. Members of the same subgroup have similar protein characters, conserved motifs, gene structure, cis-acting elements and tissue expression profiles. Specially, the expression levels of genes in subgroup A, B and C were gradually decreased, but increased in subgroup D with the development of seeds. Among seven higher expressed genes in group D, six BnaSDR genes were significantly higher expressed in weak dormancy line than that in nondormancy line. And the significant effects of BnaC01T0313900ZS and BnaC03T0300500ZS variation on seed dormancy were also demonstrated in present study. These findings provide a key information for investigating the function of BnaSDRs on seed dormancy in B. napus.
摘要：
休眠期短或无休眠期的油菜（BrassicanapusL.）在收获前容易发芽（收获前发芽，PHS）。PHS严重降低了甘蓝型油菜的种子重量和油含量。已发现短链脱氢酶/还原酶（SDR）基因通过促进水稻和拟南芥中的ABA生物合成与种子休眠有关。为了阐明SDR基因是否是油菜种子休眠的关键因素,同源序列blast，蛋白质理化性质,保守的图案，基因结构，顺式作用元素，本研究进行基因表达和变异分析。结果显示142个BnaSDR基因,不均匀地分布在19条染色体上,已在甘蓝型油菜基因组中鉴定。其中,还鉴定了染色体A04，A05，C03，C04中存在的四个BnaSDR基因簇。这142个BnaSDR基因在系统进化树上分为四个亚家族。同一亚组的成员具有相似的蛋白质特征，保守的图案，基因结构，顺式作用元件和组织表达谱。特别是,A亚群基因的表达水平,B和C逐渐减少，但随着种子的发育，D亚群增加。在D组的七个较高表达基因中，六个BnaSDR基因在弱休眠系中的表达明显高于非休眠系。本研究还证明了BnaC01T0313900ZS和BnaC03T0300500ZS变异对种子休眠的显着影响。这些发现为研究BnaSDRs对油菜种子休眠的作用提供了关键信息。
