摘要
为研究紫斑牡丹种子C18不饱和脂肪酸的高积累与相关基因SAD、FAD2、FAD3、FAD7和FAD8表达间的关系,以四个不同发育时期(6月20日, 7月7日, 7月17日和7月27日)的种子为材料,利用气相色谱飞行时间质谱测定种子油脂的脂肪酸组成,采用实时荧光定量PCR方法分析相关基因的表达模式,分析相关基因在不同发育期种子中的表达差异对种子油脂中碳十八不饱和脂肪酸积累的影响。结果表明:(1)紫斑牡丹种子油脂的不饱和脂肪酸占总脂肪酸的94.09%,其中碳十八不饱和脂肪酸占93.84%;不同种子发育期的油酸和亚麻酸呈一直上升趋势,而亚油酸则呈一直下降趋势;(2)种子发育过程中,KAR基因的持续上调表达合成了更多的C16:0-ACP;FATB和Δ9D基因下调表达,分别减弱了C16:0-ACP向棕榈酸和棕榈油酸的转化,KASⅡ基因的高表达促进了C16:0-ACP向C18:0-ACP的转化,为C18脂肪酸合成提供了充足原料;(3)种子发育过程中,SAD基因持续上调表达加快了种子中油酸的合成积累;FAD2基因表达量一直维持在相对较高水平,保证了种子油脂亚油酸占比一直在20%以上;发育初期FAD3基因表达量和发育末期FAD8基因表达量的迅速上升,加快了亚麻酸的合成。紫斑牡丹种子C18不饱和脂肪酸的高积累主要来源于SAD、FAD2、FAD3和FAD8基因的协同高表达。这为理解种子油富集碳18不饱脂肪酸的基因调控机制提供了理论依据,对木本油料油脂脂肪酸组份的遗传改良具有重要意义。
In order to study the relationship between the high accumulation of carbon 18 unsaturated fatty acids and the related genes of SAD, FAD2, FAD3, FAD7 and FAD8 in seeds of Paeonia suffruticosa, the seeds of four different development periods (June 20^th, July 7^th, July 17^th and July 27^th) were used as materials. The fatty acid compositions and their relative contents of seed oils were determined by GC-TOF/MS. The expression patterns of related genes were analyzed by real-time fluorescence quantitative PCR, and the effect of the expression difference of related genes at different seed developments on accumulation of carbon 18 unsaturated fatty acids were analyzed.The results showed that the unsaturated fatty acid in the seed oils accounted for 94.09% of the total fatty acid. Among them, C18 unsaturated fatty acids accounted for 93.84%. The oleic acid and linolenic acid showed an upward trend at different seed developments, while linoleic acid showed a downward trend. During seed development, the continuous up-regulated expression of KAR gene produced more C16:0-ACP. The down-regulation of FA TB and A9D gene reduced the conversion of C16:0-ACP to palmitic acid and palmitoleic acid, respectively. The high expression of KAS H gene promoted the conversion of C16:0-ACP to C18:0-ACP, which provided sufficient raw materials for the synthesis of C18 fatty acids. During seed development, the continuous up-regulated expression of S4 D gene accelerated the synthesis and accumulation of oleic acid in seeds. FA D2 gene expression had been maintained at a relatively high level, guaranteeing that the proportion of linoleic acid in seed oil had been more than 20%. Fast increases of FAD3 gene expression at the early developmental stages and FAD8 gene expression at the late developmental stages promoted the biosynthesis and accumulation of linolenic acid. The high accumulation of C18 unsaturated fatty acids was mainly from coordinated high expression of SAD, FAD2, FAD3 and FAD8 genes in the seed of P. suffruticosa. This could provide a theoretical basis for understanding the regulative mechanism of multigenes for high accumulation of Cl8 unsaturated fatty acids in seed oils, which could be significant for genetic improvement of fatty acid compositions of woody-oil trees.
作者
韩平
阮成江
丁健
吴波
张莞晨
阮东
熊朝伟
刘文浩
王国辉
Han Ping;Ruan Chengjiang;Ding Jian;Wu Bo;Zhang Wanchen;Ruan Dong;Xiong Chaowei;Liu Wenhao;Wang Guohui(Key Laboratory of Biotechnology and Bioresources Utilization, Ministry of Education, Institute of Plant Resources, Dalian Minzu University, Dalian,116600;Demonstration Forest Farm of Forestry Science and Technology of Fuxin Mongolia Autonomous County, Fuxin, 123000)
出处
《分子植物育种》
CAS
CSCD
北大核心
2019年第7期2101-2108,共8页
Molecular Plant Breeding
基金
鞍山市科技局重点项目(20150100)
中央高校基本科研业务费自主基金(0113-20000101)共同资助
