Genome-wide analysis of the Glycerol-3-Phosphate Acyltransferase (GPAT) gene family reveals the evolution and diversification of plant GPATs

Abstract sn-Glycerol-3-phosphate 1-O-acyltransferase (GPAT) is an important enzyme that catalyzes the transfer of an acyl group from acyl-CoA or acyl-ACP to the sn-1 or sn-2 position of sn-glycerol-3-phosphate (G3P) to generate lysophosphatidic acids (LPAs). The functional studies of GPAT in plants demonstrated its importance in controlling storage and membrane lipid. Identifying genes encoding GPAT in a variety of plant species is crucial to understand their involvement in different metabolic pathways and physiological functions. Here, we performed genome-wide and evolutionary analyses of GPATs in plants. GPAT genes were identified in all algae and plants studied. The phylogenetic analysis showed that these genes group into three main clades. While clades I (GPAT9) and II (soluble GPAT) include GPATs from algae and plants, clade III (GPAT1-8) includes GPATs specific from plants that are involved in the biosynthesis of cutin or suberin. Gene organization and the expression pattern of GPATs in plants corroborate with clade formation in the phylogeny, suggesting that the evolutionary patterns is reflected in their functionality. Overall, our results provide important insights into the evolution of the plant GPATs and allowed us to explore the evolutionary mechanism underlying the functional diversification among these genes.

摘要：sn-甘油-3-磷酸1-O-酰基转移酶（sn-Glycerol-3-phosphate 1-O-acyltransferase，GPAT）是一类重要的酶，可催化酰基从酰基辅酶A（acyl-CoA）或酰基载体蛋白（acyl-ACP）转移至sn-甘油-3-磷酸（G3P）的sn-1或sn-2位，进而生成溶血磷脂酸（LPAs）。针对植物GPAT的功能研究已证实，其在调控储藏脂质与膜脂代谢过程中发挥关键作用。在多种植物物种中鉴定编码GPAT的基因，对于解析其参与不同代谢通路与生理功能的机制至关重要。本研究针对植物GPAT家族开展了全基因组水平与进化分析。在所研究的所有藻类与植物物种中均成功鉴定到GPAT基因。系统发育分析结果显示，这些基因可划分为3个主要进化枝。其中进化枝I（GPAT9）与进化枝II（可溶性GPAT）涵盖了来自藻类与植物的GPAT成员，而进化枝III（GPAT1-8）仅包含植物特有的GPAT，这类酶参与角质或木栓质的生物合成。植物GPAT的基因结构与表达模式与系统发育进化枝的划分高度吻合，表明其进化特征可直接反映功能特性。综上，本研究结果为植物GPAT家族的进化历程提供了重要见解，并为探索这类基因功能分化背后的进化机制提供了新的研究思路。