Wang Xiqing, Yan Wen, Real Núria, Jia Yunhe, Fu Yongkai, Zhang Xuejun, You Haibo, Cai Yi, Liu Bin
Horticultural Branch of Heilongjiang Academy of Agricultural Sciences, Harbin, China.
Center for Research in Vegetable Engineering Technology of Heilongjiang, Harbin, China.
Front Plant Sci. 2024 Jul 16;15:1394724. doi: 10.3389/fpls.2024.1394724. eCollection 2024.
Seed size (SS) constitutes a pivotal trait in watermelon breeding. In this study, we present findings from an examination of two watermelon accessions, namely, BW85 and F211. Seeds from BW85 exhibited a significant enlargement compared to those of F211 at 13 days after pollination (DAP), with the maximal disparity in seed length and width manifesting at 17 DAP. A comprehensive study involving both metabolic and transcriptomic analyses indicated a significant enrichment of the ubiquinone and other terpenoid-quinone biosynthesis KEGG pathways. To detect the genetic region governing seed size, a BSA-seq analysis was conducted utilizing the F (BW85 × F211) population, which resulted in the identification of two adjacent QTLs, namely, and , located on chromosomes 6. spanned from Chr06:4847169 to Chr06:5163486, encompassing 33 genes, while ranged from Chr06:5379337 to Chr06:5419136, which included only one gene. Among these genes, 11 exhibited a significant differential expression between BW85 and F211 according to transcriptomic analysis. Notably, three genes (, , and ) presented a differential expression at both 13 and 17 DAP. Through annotation, was identified as a ubiquitin-conjugating enzyme E2, playing a role in the ubiquitin pathway that mediates seed size control. Taken together, our results provide a novel candidate gene influencing the seed size in watermelon, shedding light on the mechanism underlying seed development.
种子大小（SS）是西瓜育种中的一个关键性状。在本研究中，我们展示了对两个西瓜种质BW85和F211进行检测的结果。与授粉后13天（DAP）的F211种子相比，BW85的种子显著增大，种子长度和宽度的最大差异出现在17 DAP。一项综合了代谢和转录组分析的研究表明，泛醌和其他萜类醌生物合成KEGG途径显著富集。为了检测控制种子大小的遗传区域，利用F（BW85×F211）群体进行了全基因组重测序分析（BSA-seq），结果在6号染色体上鉴定出两个相邻的数量性状位点（QTL），即 和 。 跨度为Chr06:4847169至Chr06:5163486，包含33个基因，而 范围为Chr06:5379337至Chr06:5419136，仅包含一个基因。在这些基因中，根据转录组分析，有11个在BW85和F211之间表现出显著差异表达。值得注意的是，三个基因（ 、 和 ）在13和17 DAP时均表现出差异表达。通过注释， 被鉴定为一种泛素结合酶E2，在介导种子大小控制的泛素途径中发挥作用。综上所述，我们的结果提供了一个影响西瓜种子大小的新候选基因，揭示了种子发育的潜在机制。
