Cloning and molecular characterization of three lysophosphatidic acid acyltransferases expressed in flax seeds. (March 2019)

• Record Type: Journal Article
• Authors: Fahs, Zeinab; Rossez, Yannick; Guénin, Stéphanie; Gutierrez, Laurent; Thomasset, Brigitte; Perrin, Yolande
• Is Part Of: Plant science. Volume 280(2019)
• Page Start: 41
• Page End: 50
• Publication Date: 2019-03
• Subjects: Linum usitatissimum -- Oil synthesis -- Kennedy pathway -- Acyltransferase -- Lysophosphatidic acid acyltransferase -- α-Linolenic acid; Botany -- Periodicals; Botanique -- Périodiques; 580
• DOI: 10.1016/j.plantsci.2018.10.026
• Languages: English
• ISSNs: 0168-9452

Abstract

Highlights: Developing flax seed express three microsomal lysophosphatidic acid acyltransferases. Expression of LuLPAAT2A in A. thaliana seed increases its fatty acid content. LuLPAAT2A expressed of in A. thaliana seed leads to an enrichment in linolenate. Abstract: In the context of the growing demand for α-linolenic acid due to its high nutritional value as a polyunsaturated fatty acid, we have investigated the contribution of 2-lysophosphatidic acid acyltransferase (LPAAT) enzymes from flax ( Linum usitatissimum ) in the accumulation of α-linolenic acid into the oil fraction of flax seed. We have isolated the cDNAs encoding three class A microsomal LPAAT2 isoforms from developing flax seeds. The three isoforms, denominated LPAAT2A, LPAAT2A2 and LPAAT2B, are able to complement the LPAAT deficient JC201 E. coli mutant, confirming their functionality. We have performed enzymatic assays showing that the specific activity of the LPAAT2A isoform is significantly higher than that of the LPAAT2A2 and LPAAT2B toward the unsaturated oleic, linoleic and linolenic acids. Moreover, LPAAT2A presents in vitro a high specificity and selectivity for linoleic and linolenic acids as compared to saturated fatty acids. The three isoforms are expressed during all the stages of seed development and in stem and leaf tissues, as shown by an analysis of the transcription level of the corresponding genes. The heterologous expression of LPAAT2A in Arabidopsis seeds leads to an increase in the accumulation of linoleic and linolenic acids in the oil fraction of the seeds from two transgenic lines.