A Conserved Glycine Is Identified to be Essential for Desaturase Activity of IpFAD2s by Analyzing Natural Variants from Idesia polycarpa

International Journal of Molecular Sciences

Huayan Zhao¹  Shiyou Lü²  Tao Feng²  Lingling Zhang²  Pan Wu²  Wenying Lu²  Jianzhong Li³ 

[1] Applied Biotechnology Center, Wuhan Institute of Bioengineering, Wuhan 430415, China;Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China;Tianjin Garrison hangu farm, Tianjin 300480, China;

关键词: Idesia polycarpa var;    glycine;    FAD2;    linoleic acid;    oleic acid;   

DOI  :  10.3390/ijms19123932

来源: DOAJ

【 摘 要 】

High amounts of polyunsaturated fatty acids (PUFAs) in vegetable oil are not desirable for biodiesel or food oil due to their lower oxidative stability. The oil from Idesia polycarpa fruit contains 65⁻80% (mol%) linoleic acid (C18:2). Therefore, development of Idesia polycarpa cultivars with low PUFAs is highly desirable for Idesia polycarpa oil quality. Fatty acid desaturase 2 (FAD2) is the key enzyme converting oleic acid (C18:1) to C18:2. We isolated four FAD2 homologs from the fruit of Idesia polycarpa. Yeast transformed with IpFAD2-1, IpFAD2-2 and IpFAD2-3 can generate appreciable amounts of hexadecadienoic acid (C16:2) and C18:2, which are not present in wild-type yeast cells, revealing that the proteins encoded by these genes have Δ¹² desaturase activity. Only trace amounts of C18:2 and little C16:2 were detected in yeast cells transformed with IpFAD2-4, suggesting IpFAD2-4 displays low activity. We also analyzed the activity of several FAD2 natural variants of Idesia polycarpa in yeast and found that a highly conserved Gly376 substitution caused the markedly reduced products catalyzed by IpFAD2-3. This glycine is also essential for the activity of IpFAD2-1 and IpFAD2-2, but its replacement in other plant FAD2 proteins displays different effects on the desaturase activity, suggesting its distinct roles across plant FAD2s proteins.

【 授权许可】

Unknown