Key Laboratory of Plant Resources, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, China.
Int J Mol Sci. 2022 Oct 19;23(20):12520. doi: 10.3390/ijms232012520.
Seeds directly determine the survival and population size of woody plants, but the genetic basis of seed weight in woody plants remain poorly explored. To identify genetic variations and candidate genes responsible for seed weight in natural woody populations, we investigated the hundred-seed weight of 198 paper mulberry individuals from different areas. Our results showed that the hundred-seed weight of paper mulberry was significantly associated with the bioclimatic variables of sampling sites, which increased from south to north along the latitudinal-temperature gradient. Using 2,414,978 high-quality SNPs from re-sequencing data, the genome-wide association analysis of the hundred-seed weight was performed under three models, which identified 148, 19 and 12 associated genes, respectively. Among them, 25 candidate genes were directly hit by the significant SNPs, including the WRKY transcription factor, fatty acid desaturase, F-box protein, etc. Most importantly, we identified three crucial genetic variations in the coding regions of candidate genes (, and ), and significant differences in the hundred-seed weight were detected among the individuals carrying different genotypes. Further analysis revealed that encoding a fatty acid desaturase (FAD) might be a key factor affecting the seed weight and local climate adaptation of woody plants. Furthermore, the genome-wide investigation and expression analysis of genes were performed, and the results suggested that widely expressed in various tissues and responded to multiple phytohormone and stress treatments. Overall, our study identifies valuable genetic variations and candidate genes, and provides a better understanding of the genetic basis of seed weight in woody plants.
种子直接决定木本植物的生存和种群大小，但木本植物种子重量的遗传基础仍未得到充分探索。为了鉴定与自然木本种群种子重量相关的遗传变异和候选基因，我们调查了来自不同地区的 198 个桑树个体的百粒重。我们的研究结果表明，桑树的百粒重与采样地点的生物气候变量显著相关，这些变量沿纬度-温度梯度从南向北增加。利用重测序数据中的 2414978 个高质量 SNP，我们在三个模型下对百粒重进行了全基因组关联分析，分别鉴定出 148、19 和 12 个相关基因。其中，25 个候选基因直接被显著 SNP 命中，包括 WRKY 转录因子、脂肪酸去饱和酶、F-box 蛋白等。最重要的是，我们在候选基因的编码区鉴定出三个关键的遗传变异（ 、 和 ），并在携带不同基因型的个体中检测到百粒重的显著差异。进一步的分析表明，编码脂肪酸去饱和酶（FAD）的 可能是影响种子重量和木本植物局部气候适应的关键因素。此外，我们还对 基因进行了全基因组调查和表达分析，结果表明 广泛表达于各种组织，并对多种植物激素和胁迫处理有响应。总的来说，我们的研究确定了有价值的遗传变异和候选基因，为理解木本植物种子重量的遗传基础提供了更好的认识。
