甘蓝型油菜转录因子FUS3的克隆、表达分析及其与脂肪酸组分的关系

Transcription factor FUS3 and its relation to fatty acid in Brassica napus

为了探讨油菜转录因子FUS3的功能及其与脂肪酸组分的关系,从甘蓝型油菜湘油15中克隆到BnaFUS3基因的两个拷贝BnaA2.FUS3和BnaA6.FUS3。它们的CDS区序列分别长927bp和948bp,编码309和315个氨基酸,氨基酸序列变异多发生在C端。转录因子BnaA2.FUS3和BnaA6.FUS3属于含B3结构域的蛋白家族,是亲水性蛋白,无跨膜区,均是膜外蛋白。系统进化树分析表明,BnaA2.FUS3、BnaA6.FUS3两者都是Bra FUS3和AtFUS3的同源基因。荧光定量PCR分析表明,BnaA2.FUS3在根、茎、叶、角果皮中均有表达,在种子中相对稳定表达,但在角果皮中于授粉后25d达到峰值;BnaA6.FUS3为种子特异表达,在种子中于授粉后35d达到峰值;两者在角果皮中表达量均呈"M"形趋势。分析脂肪酸积累规律与BnaFUS3表达关系发现,授粉30d后,BnaA2.FUS3和BnaA6.FUS3表达迅速升高,此时各脂肪酸也进入快速增长期;授粉后45d^50d时,两拷贝表达量变化较小,脂肪酸积累亦进入缓慢增长期,并趋于平稳。表明BnaFUS3在甘蓝型油菜的胚胎形成和发育中具有重要影响,对脂肪酸的合成和油脂积累起到重要作用。

To investigate the function of rapeseed transcription factor FUS3 on fatty acids,CDS sequences of BnaA2. FUS3 and BnaA6. FUS3（ two copies of BnaFUS3 gene） were cloned from Brassica nupus ‘xiangyou15 ＇.Their CDS were 927 bp and 948 bp,encoded 309 and 315 amino acids. Amino acid sequence variation occurred in the C-terminal. Hydrophilic proteins BnaA2. FUS3 and BnaA6. FUS3 belong to B3 family,are membrane protein with no transmembrane region. Homology showed that both BnaA2. FUS3 and BnaA6. FUS3 were homologous genes of Bra FUS3 and At FUS3. Fluorescent relative quantitative analysis showed that BnaA2. FUS3 was expressed in roots,stems,leaves and horns,and was relatively stable in seeds. The expression peak appeared in pod skin at 25 d after pollination. BnaA6. FUS3 was seed-specific and the expression peak appeared at 35 d after pollination.Both expressions of BnaA2. FUS3 and BnaA6. FUS3 showed similar M-type in pod skin. The relationship between BnaFUS3 expression and accumulation of fatty acids in seed showed that,both expression BnaA2. FUS3 and BnaA6. FUS3 were rapidly increased at 30 d after pollination,when each fatty acid increased into a rapid period.They changed little at 45 to 50 d after pollination,and the fatty acid accumulation was also slowed down and became stable. This indicated that BnaFUS3 had important influence on embryogenesis and development,and played an important role in fatty acid synthesis and lipid accumulation.