Bates Philip D, Shockey Jay
Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USA.
United States Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, LA 70124, USA.
Plant Physiol. 2025 Feb 7;197(2). doi: 10.1093/plphys/kiae658.
Plant lipids represent a fascinating field of scientific study, in part due to a stark dichotomy in the limited fatty acid (FA) composition of cellular membrane lipids vs the huge diversity of FAs that can accumulate in triacylglycerols (TAGs), the main component of seed storage oils. With few exceptions, the strict chemical, structural, and biophysical roles imposed on membrane lipids since the dawn of life have constrained their FA composition to predominantly lengths of 16-18 carbons and containing 0-3 methylene-interrupted carbon-carbon double bonds in cis-configuration. However, over 450 "unusual" FA structures can be found in seed oils of different plants, and we are just beginning to understand the metabolic mechanisms required to produce and maintain this dichotomy. Here we review the current state of plant lipid research, specifically addressing the knowledge gaps in membrane and storage lipid synthesis from 3 angles: pathway fluxes including newly discovered TAG remodeling, key acyltransferase substrate selectivities, and the possible roles of "metabolons."
植物脂质是一个引人入胜的科学研究领域，部分原因在于细胞膜脂质中有限的脂肪酸（FA）组成与可积累在三酰甘油（TAGs）中的大量不同脂肪酸之间形成了鲜明的二分法，而TAGs是种子贮藏油的主要成分。除了少数例外，自生命起源以来，细胞膜脂质所承担的严格化学、结构和生物物理作用将其脂肪酸组成限制为主要是16 - 18个碳的长度，且含有0 - 3个顺式构型的亚甲基间隔碳 - 碳双键。然而，在不同植物的种子油中可以发现超过450种“异常”的脂肪酸结构，而我们才刚刚开始了解产生和维持这种二分法所需的代谢机制。在这里，我们综述了植物脂质研究的现状，特别从三个角度探讨了膜脂和贮藏脂合成方面的知识空白：包括新发现的TAG重塑在内的途径通量、关键酰基转移酶的底物选择性以及“代谢体”的可能作用。
