Investigation of fatty acid biosynthesis and lipid accumulation in walnut kernels using combined transcriptomics and lipidomics analyses

IF 3.9 2区农林科学 Q1 HORTICULTURE

Scientia Horticulturae Pub Date : 2025-06-01 DOI:10.1016/j.scienta.2025.114213

Xuesong Xia , Liying Chen , Zhaohui Hu

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引用次数: 0

Abstract

Walnut (Juglans regia L.) is an important resource for plantial edible oil. In this study, transcriptomics and lipidomics analyses were conducted to investigate the mechanisms underlying the dynamic accumulation of fatty acids and lipid species in kernels of 'Lyuling' walnut cultivar. The total fatty acid composition exhibited an increase in linoleic and oleic acids, alongside a decrease in palmitic and α-linolenic acids. Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) analyses demonstrated that fatty acid biosynthesis was initiated between 25 and 53 days after flowering (DAF), and rapid oil accumulation occurred between approximately 53 and 109 DAF. The dominant genes involved in fatty acid accumulation were identified and analyzed. Linoleic acid was the most abundant in kernel oils, that may be attributed to the considerable expression of gene encoding δ12 fatty acid desaturase (δ12-FAD2). The temporal variations at transcriptional levels of phospholipid:diacylglycerol acyltransferase (PDAT), Phosphatidylcholine: diacylglycerol cholinephosphotransferase (PDCT), and Choline/ethanolamine phosphotransferase (CEPT) demonstrated that diacylglycerol (DAG) derived from PC and PE was critical for triacylglycerol (TAG) synthesis, facilitating the incorporation of fatty acids from phosphatidylcholine (PC) and phosphatidylethanolamine (PE). Lipidomics revealed that TAG (18:1/18:2/18:2), (18:0/18:2/18:3), (18:1/18:1/18:2), and (18:0/18:2/18:2) were the primary nutritional components of ripened walnut oil. Unlike in ordinary oil crops, the major DAG content increased during kernel ripening, enhancing nutritional quality. These findings provide valuable insights for genetic manipulation and molecular markers for fatty acid synthesis in kernels of 'Lyuling' walnut cultivar.

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利用转录组学和脂质组学联合分析核桃核桃仁脂肪酸生物合成和脂质积累

核桃（Juglans regia L.）是重要的植物食用油资源。本研究通过转录组学和脂质组学分析，探讨了‘吕铃’核桃籽粒脂肪酸和脂质物质动态积累的机制。总脂肪酸组成显示亚油酸和油酸增加，棕榈酸和α-亚麻酸减少。基因本体（GO）和京都基因与基因组百科全书（KEGG）分析表明，脂肪酸的生物合成在开花（DAF）后25至53天开始，油脂的快速积累发生在大约53至109 DAF之间。鉴定并分析了脂肪酸积累的显性基因。籽油中亚油酸含量最高，这可能与编码δ12脂肪酸去饱和酶（δ12- fad2）基因的大量表达有关。磷脂：二酰基甘油酰基转移酶（PDAT）、磷脂酰胆碱：二酰基甘油胆碱磷酸转移酶（PDCT）和胆碱/乙醇胺磷酸转移酶（CEPT）转录水平的时间变化表明，来自PC和PE的二酰基甘油（DAG）对三酰基甘油（TAG）的合成至关重要，促进了磷脂酰胆碱（PC）和磷脂酰乙醇胺（PE）脂肪酸的结合。脂质组学结果表明，TAG（18:1/18:2/18:2）、（18:0/18:2/18:3）、（18:1/18:1/18:2）和（18:0/18:2/18:2）是成熟核桃油的主要营养成分。与普通油料作物不同，籽粒成熟过程中主要DAG含量增加，营养品质提高。这些发现为“吕铃”核桃籽粒脂肪酸合成的遗传操作和分子标记提供了有价值的见解。

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来源期刊

Scientia Horticulturae 农林科学-园艺

CiteScore

8.60

自引率

4.70%

发文量

796

审稿时长

47 days

期刊介绍： Scientia Horticulturae is an international journal publishing research related to horticultural crops. Articles in the journal deal with open or protected production of vegetables, fruits, edible fungi and ornamentals under temperate, subtropical and tropical conditions. Papers in related areas (biochemistry, micropropagation, soil science, plant breeding, plant physiology, phytopathology, etc.) are considered, if they contain information of direct significance to horticulture. Papers on the technical aspects of horticulture (engineering, crop processing, storage, transport etc.) are accepted for publication only if they relate directly to the living product. In the case of plantation crops, those yielding a product that may be used fresh (e.g. tropical vegetables, citrus, bananas, and other fruits) will be considered, while those papers describing the processing of the product (e.g. rubber, tobacco, and quinine) will not. The scope of the journal includes all horticultural crops but does not include speciality crops such as, medicinal crops or forestry crops, such as bamboo. Basic molecular studies without any direct application in horticulture will not be considered for this journal.