Chang Weixia, Chen Yanyan, Xie Peisi, Diao Xin, Yao Xiaohua, Chang Jun, Zhang Chengcai, Cai Zongwei
State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong 999077, China.
State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding of Zhejiang Province, Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China.
Food Chem. 2025 Mar 1;467:142368. doi: 10.1016/j.foodchem.2024.142368. Epub 2024 Dec 4.
Pecan (Carya illinoinensis) is a globally important nut crop, yet the processes of lipid biosynthesis and spatial lipid distribution within its embryo remain poorly understood. This study employed UHPLC-MS/MS and MALDI-MSI to profile lipids in developing pecan embryos, identifying 401 lipid molecules, including a high abundance of glycerolipids (148) and glycerophospholipids (144). Differential diacylglycerols showed gradual uptrends, highlighting their role in synthesizing glycerolipids and glycerophospholipids. Unsaturated fatty acids, especially oleic, linoleic, and linolenic acids, were enriched in triacylglycerols, diacylglycerols, phosphatidylethanolamines, and phosphatidylcholines. MALDI-MSI revealed the spatial distribution of phosphatidic acid (PA), phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylinositol (PI), suggesting heterogeneous lipid distribution within embryos. The proportion of linoleic and linolenic acids is higher in the kernel coat, whereas the proportion of oleic acid is relatively higher in the cotyledons. Differences in lipid content were also observed between the inner and outer cotyledons. This study provides the first comprehensive map of lipid distribution in pecan embryos, offering new insights into lipid metabolism regulation.
山核桃（Carya illinoinensis）是一种全球重要的坚果作物，然而其胚胎内脂质生物合成过程和脂质空间分布仍知之甚少。本研究采用超高效液相色谱-串联质谱法（UHPLC-MS/MS）和基质辅助激光解吸电离质谱成像（MALDI-MSI）对发育中的山核桃胚胎中的脂质进行分析，鉴定出401种脂质分子，其中包括大量的甘油脂（148种）和甘油磷脂（144种）。差异二酰甘油呈现逐渐上升趋势，突出了它们在合成甘油脂和甘油磷脂中的作用。不饱和脂肪酸，尤其是油酸、亚油酸和亚麻酸，在三酰甘油、二酰甘油、磷脂酰乙醇胺和磷脂酰胆碱中含量丰富。MALDI-MSI揭示了磷脂酸（PA）、磷脂酰胆碱（PC）、磷脂酰乙醇胺（PE）和磷脂酰肌醇（PI）的空间分布，表明胚胎内脂质分布不均。种皮中亚油酸和亚麻酸的比例较高，而子叶中油酸的比例相对较高。在内子叶和外子叶之间也观察到脂质含量的差异。本研究提供了首张山核桃胚胎脂质分布的综合图谱，为脂质代谢调控提供了新的见解。
