College of Forestry, Northwest A & F University, Yangling, Shaanxi, 712100, China.
Shaanxi Walnut Engineering Technology Research Center, Yangling, Shaanxi, 712100, China.
BMC Plant Biol. 2024 Sep 4;24(1):828. doi: 10.1186/s12870-024-05546-y.
Walnut is an oilseed tree species and an ecologically important woody tree species that is rich in oil and nutrients. In light of differences in the lipid content, fatty acid composition and key genes expression patterns in different walnut varieties, the key gene regulatory networks for lipid biosynthesis in different varieties of walnuts were intensively investigated.
The kernels of two walnut varieties, 'Xilin 3' (X3) and 'Xiangling' (XL) were sampled at 60, 90, and 120 days post-anthesis (DPA) to construct 18 cDNA libraries, and the candidate genes related to oil synthesis were identified via sequencing and expression analysis. A total of 106 differentially expressed genes associated with fatty acid biosynthesis, fatty acid elongation, unsaturated fatty acid biosynthesis, triglyceride assembly, and oil body storage were selected from the transcriptomes. Weighted gene co-expression network analysis (WGCNA), correlation analysis and quantitative validation confirmed the key role of the FAD3 (109002248) gene in lipid synthesis in different varieties.
These results provide valuable resources for future investigations and new insights into genes related to oil accumulation and lipid metabolism in walnut seed kernels. The findings will also aid future molecular studies and ongoing efforts to genetically improve walnut.
核桃是一种含油的树种，也是一种生态上重要的木本树种，富含油脂和营养物质。鉴于不同核桃品种的脂质含量、脂肪酸组成和关键基因表达模式的差异，对不同品种核桃中脂质生物合成的关键基因调控网络进行了深入研究。
从‘西林 3 号’（X3）和‘香玲’（XL）两个核桃品种的核仁中分别在授粉后 60、90 和 120 天取样，构建了 18 个 cDNA 文库，通过测序和表达分析鉴定了与油合成相关的候选基因。从转录组中总共选择了 106 个与脂肪酸生物合成、脂肪酸伸长、不饱和脂肪酸生物合成、甘油三酯组装和油体储存相关的差异表达基因。加权基因共表达网络分析（WGCNA）、相关性分析和定量验证证实了 FAD3（109002248）基因在不同品种脂质合成中的关键作用。
这些结果为未来的研究提供了有价值的资源，并为核桃种子中与油脂积累和脂质代谢相关的基因提供了新的见解。这些发现也将有助于未来的分子研究和正在进行的核桃遗传改良工作。
