文献类型： 外文期刊

作者： Ding, Jian ¹ ; Ruan, Chengjiang ¹ ; Du, Wei ¹ ; Guan, Ying ² ;

作者机构： 1.Dalian Minzu Univ, Inst Plant Resources, Minist Educ, Key Lab Biotechnol & Bioresources Utilizat, 18 Liaohe West Rd, Dalian 116600, Liaoning, Peoples R China

2.Heilongjiang Acad Agr Sci, Inst Berries, 5 Fansheng St, Suiling 152230, Heilongjiang, Peoples R China

关键词： Palmitoleic acid; Hippophae L; Fatty acid biosynthesis; Oil accumulation; Berry pulp oil; Non-seed tissue

期刊名称：BMC PLANT BIOLOGY （ 影响因子：4.215； 五年影响因子：4.96 ）

ISSN： 1471-2229

年卷期： 2019 年 19 卷

页码：

收录情况： SCI

摘要： BackgroundSea buckthorn is a woody oil crop in which palmitoleic acid (C16:1n7, an omega-7 fatty acid (FA)) contributes approximately 40% of the total FA content in berry pulp (non-seed tissue). However, the molecular mechanisms contributing to the high accumulation of C16:1n7 in developing sea buckthorn berry pulp (SBP) remain poorly understood.ResultsWe identified 1737 unigenes associated with lipid metabolism through RNA-sequencing analysis of the four developmental stages of berry pulp in two sea buckthorn lines, Za56' and TF2-36'; 139 differentially expressed genes were detected between the different berry pulp developmental stages in the two lines. Analyses of the FA composition showed that the C16:1n7 contents were significantly higher in line Za56' than in line TF2-36' in the mid-late developmental stages of SBP. Additionally, qRT-PCR analyses of 15 genes involved in FA and triacylglycerol (TAG) biosynthesis in both lines revealed that delta9-ACP-desaturase (ACP-9D) competed with 3-ketoacyl-ACP-synthase II (KASII) for the substrate C16:0-ACP and that ACP-9D and delta9-CoA-desaturase (CoA-9D) gene expression positively correlated with C16:1n7 content; KASII and fatty acid elongation 1 (FAE1) gene expression positively correlated with C18:0 content in developing SBP. Specifically, the abundance of ACP-9D and CoA-9D transcripts in line Za56', which had a higher C16:1n7 content than line TF2-36', suggests that these two genes play an important role in C16:1n7 biosynthesis. Furthermore, the high expressions of the glycerol-3-phosphate dehydrogenase (GPD1) gene and the WRINKLED1 (WRI1) transcription factor contributed to increased biosynthesis of TAG precursor and FAs, respectively, in the early developmental stages of SBP, and the high expression of the diacylglycerol O-acyltransferase 1 (DGAT1) gene increased TAG assembly in the later developmental stages of SBP. Overall, we concluded that increased ACP-9D and CoA-9D levels coupled with decreased KASII and FAE1 activity is a critical event for high C16:1n7 accumulation and that the coordinated high expression of WRI1, GPD1, and DGAT1 genes resulted in high oil accumulation in SBP.ConclusionOur results provide a scientific basis for understanding the mechanism of high C16:1n7 accumulation in berry pulp (non-seed tissue) and are valuable to the genetic breeding programme for achieving a high quality and yield of SBP oil.