TY - JOUR T1 - Functional analysis of β-ketoacyl-CoA synthase from biofuel feedstock Thlaspi arvense reveals differences in the triacylglycerol biosynthetic pathway among Brassicaceae. AU - Claver,Ana, AU - de la Vega,Marina, AU - Rey-Giménez,Raquel, AU - Luján,María Á, AU - Picorel,Rafael, AU - López,M Victoria, AU - Alfonso,Miguel, Y1 - 2020/08/01/ PY - 2020/04/09/received PY - 2020/07/25/accepted PY - 2020/8/3/pubmed PY - 2020/9/29/medline PY - 2020/8/3/entrez KW - Arabidopsis thaliana KW - Erucic acid KW - Fatty acid elongase KW - Seed oil KW - Thlaspi arvense KW - Triacylglycerol SP - 283 EP - 296 JF - Plant molecular biology JO - Plant Mol Biol VL - 104 IS - 3 N2 - KEY MESSAGE: Differences in FAE1 enzyme affinity for the acyl-CoA substrates, as well as the balance between the different pathways involved in their incorporation to triacylglycerol might be determinant of the different composition of the seed oil in Brassicaceae. Brassicaceae present a great heterogeneity of seed oil and fatty acid composition, accumulating Very Long Chain Fatty Acids with industrial applications. However, the molecular determinants of these differences remain elusive. We have studied the β-ketoacyl-CoA synthase from the high erucic feedstock Thlaspi arvense (Pennycress). Functional characterization of the Pennycress FAE1 enzyme was performed in two Arabidopsis backgrounds; Col-0, with less than 2.5% of erucic acid in its seed oil and the fae1-1 mutant, deficient in FAE1 activity, that did not accumulate erucic acid. Seed-specific expression of the Pennycress FAE1 gene in Col-0 resulted in a 3 to fourfold increase of erucic acid content in the seed oil. This increase was concomitant with a decrease of eicosenoic acid levels without changes in oleic ones. Interestingly, only small changes in eicosenoic and erucic acid levels occurred when the Pennycress FAE1 gene was expressed in the fae1-1 mutant, with high levels of oleic acid available for elongation, suggesting that the Pennycress FAE1 enzyme showed higher affinity for eicosenoic acid substrates, than for oleic ones in Arabidopsis. Erucic acid was incorporated to triacylglycerol in the transgenic lines without significant changes in their levels in the diacylglycerol fraction, suggesting that erucic acid was preferentially incorporated to triacylglycerol via DGAT1. Expression analysis of FAE1, AtDGAT1, AtLPCAT1 and AtPDAT1 genes in the transgenic lines further supported this conclusion. Differences in FAE1 affinity for the oleic and eicosenoic substrates among Brassicaceae, as well as their incorporation to triacylglycerol might explain the differences in composition of their seed oil. SN - 1573-5028 UR - https://www.unboundmedicine.com/medline/citation/32740897/Functional_analysis_of_β_ketoacyl_CoA_synthase_from_biofuel_feedstock_Thlaspi_arvense_reveals_differences_in_the_triacylglycerol_biosynthetic_pathway_among_Brassicaceae_ DB - PRIME DP - Unbound Medicine ER -