Liu Wei, Li Wei, He Qiuling, Daud Muhammad Khan, Chen Jinhong, Zhu Shuijin
Department of Agronomy, Zhejiang University, Hangzhou, 310058, China.
Department of Agronomy, Zhejiang University, Hangzhou, 310058, China; Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, 26000, Pakistan.
PLoS One. 2015 Apr 20;10(4):e0123281. doi: 10.1371/journal.pone.0123281. eCollection 2015.
To produce unsaturated fatty acids, membrane-bound fatty acid desaturases (FADs) can be exploited to introduce double bonds into the acyl chains of fatty acids. In this study, 19 membrane-bound FAD genes were identified in Gossypium raimondii through database searches and were classified into four different subfamilies based on phylogenetic analysis. All 19 membrane-bound FAD proteins shared three highly conserved histidine boxes, except for GrFAD2.1, which lost the third histidine box in the C-terminal region. In the G. raimondii genome, tandem duplication might have led to the increasing size of the FAD2 cluster in the Omega Desaturase subfamily, whereas segmental duplication appeared to be the dominant mechanism for the expansion of the Sphingolipid and Front-end Desaturase subfamilies. Gene expression analysis showed that seven membrane-bound FAD genes were significantly up-regulated and that five genes were greatly suppressed in G. raimondii leaves exposed to low temperature conditions.
为了产生不饱和脂肪酸，可以利用膜结合脂肪酸去饱和酶（FADs）将双键引入脂肪酸的酰基链中。在本研究中，通过数据库搜索在雷蒙德氏棉中鉴定出19个膜结合FAD基因，并根据系统发育分析将其分为四个不同的亚家族。除GrFAD2.1在C端区域失去了第三个组氨酸框外，所有19个膜结合FAD蛋白均共享三个高度保守的组氨酸框。在雷蒙德氏棉基因组中，串联重复可能导致了Omega去饱和酶亚家族中FAD2簇的大小增加，而片段重复似乎是鞘脂和前端去饱和酶亚家族扩张的主要机制。基因表达分析表明，在低温条件下的雷蒙德氏棉叶片中，7个膜结合FAD基因显著上调，5个基因受到极大抑制。
