Zhang Songlin, Wang Li, Yao Jin, Wu Na, Ahmad Bilal, van Nocker Steve, Wu Jiuyun, Abudureheman Riziwangguli, Li Zhi, Wang Xiping
State Key Laboratory of Crop Stress Biology in Arid Areas, College of Horticulture, Northwest A&F University, Yangling, Shaanxi 712100, China.
Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Northwest A&F University, Yangling, Shaanxi 712100, China.
Hortic Res. 2023 Apr 13;10(6):uhad070. doi: 10.1093/hr/uhad070. eCollection 2023 Jun.
Seedless grapes are increasingly popular throughout the world, and the development of seedless varieties is a major breeding goal. In this study, we demonstrate an essential role for the grapevine MADS-box gene in morphogenesis of the ovule. We found that mRNA accumulated in the ovules of a seeded cultivar, 'Red Globe', throughout the course of ovule and seed development, especially within the integument/seed coat. In contrast, in the seedless cultivar 'Thompson Seedless', was expressed only weakly in ovules, and this was associated with increased levels of histone H3 lysine 27 trimethylation (H3K27me3) within the promoter region RNAi-mediated transient suppression of expression in 'Red Globe' led to reduced seed size associated with inhibition of episperm and endosperm cell development. Heterologous overexpression of in transgenic tomatoes interfered with sepal development and resulted in smaller fruit but did not obviously affect seed size. Assays in yeast cells showed that is subject to regulation by the transcription factor , and that VvMADS28 could interact with the Type I/ Mβ MADS-domain protein VvMADS5. Moreover, through DNA-affinity purification-sequencing (DAP-seq), we found that VvMADS28 protein specifically binds to the promoter of the grapevine () gene, suggesting that maintenance of the VvMADS28-VvMADS5 dimer and expression homeostasis influences seed development. Taken together, our results provide insight into regulatory mechanisms of ovule and seed development associated with .
无核葡萄在全球越来越受欢迎，培育无核品种是主要的育种目标。在本研究中，我们证明了葡萄MADS-box基因在胚珠形态发生中起重要作用。我们发现，在有核品种‘红地球’的胚珠中，mRNA在胚珠和种子发育的整个过程中积累，尤其是在内珠被/种皮中。相比之下，在无核品种‘汤普森无核’中，该基因在胚珠中仅微弱表达，这与该基因启动子区域组蛋白H3赖氨酸27三甲基化（H3K27me3）水平升高有关。RNAi介导的对‘红地球’中该基因表达的瞬时抑制导致种子大小减小，这与珠被和胚乳细胞发育受抑制有关。在转基因番茄中对该基因进行异源过表达会干扰萼片发育，导致果实变小，但对种子大小没有明显影响。酵母细胞试验表明，该基因受转录因子调控，且VvMADS28可与I型/Mβ MADS结构域蛋白VvMADS5相互作用。此外，通过DNA亲和纯化测序（DAP-seq），我们发现VvMADS28蛋白特异性结合葡萄（）基因的启动子，这表明维持VvMADS28-VvMADS5二聚体和该基因表达稳态会影响种子发育。综上所述，我们的研究结果为与该基因相关的胚珠和种子发育调控机制提供了见解。
