Seed dormancy is closely related to pre-harvest sprouting resistance. Both plant hormone abscisic acid (ABA) and DELAY OF GERMINATION 1 (DOG1) protein are key regulators of seed dormancy. Their relationship is well reported in Arabidopsis, but little is known in rice. Here, we show that a quantitative trait locus, qSd-1-1 contributes significantly to seed dormancy differences between the strongly dormant indica variety N22 and non-dormant japonica variety Nanjing35. It encodes a DOG1-like protein named OsDOG1L-3 with homology to Arabidopsis DOG1. There were evident promoter and expression differences in OsDOG1L-3 between N22 and Nanjing35, and overexpression or introduction of the N22 OsDOG1L-3 allele in Nanjing35 enhanced its seed dormancy. OsDOG1L-3 expression was positively correlated with seed dormancy and induced by ABA. OsbZIP75 and OsbZIP78 bound directly with the promoter of OsDOG1L-3 to induce its expression. Overexpression of OsbZIP75 increased OsDOG1L-3 protein abundance and promoted seed dormancy. OsDOG1L-3 upregulated expression of ABA-related genes and increased ABA content. We propose that the N22 OsDOG1L-3 allele is a candidate gene for the seed dormancy in QTL qSd-1-1, and that it participates in the ABA pathway to establish seed dormancy in rice.

中文翻译：

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OsDOG1L-3通过脱落酸途径调控水稻种子休眠

种子休眠与收获前抗萌发性密切相关。植物激素脱落酸 (ABA) 和延迟发芽 1 (DOG1) 蛋白都是种子休眠的关键调节剂。它们的关系在拟南芥中得到了很好的报道，但在水稻中却鲜为人知。在这里，我们表明数量性状基因座 qSd-1-1 对强休眠籼稻品种 N22 和非休眠粳稻品种南京 35 之间的种子休眠差异有显着影响。它编码一种名为 OsDOG1L-3 的 DOG1 样蛋白，与拟南芥 DOG1 具有同源性。N22与南京35之间OsDOG1L-3的启动子和表达差异明显，南京35中N22 OsDOG1L-3等位基因的过表达或引入增强了其种子休眠。OsDOG1L-3 的表达与种子休眠呈正相关，并由 ABA 诱导。OsbZIP75 和 OsbZIP78 直接与 OsDOG1L-3 的启动子结合以诱导其表达。OsbZIP75 的过表达增加了 OsDOG1L-3 蛋白丰度并促进了种子休眠。OsDOG1L-3 上调 ABA 相关基因的表达并增加 ABA 含量。我们提出 N22 OsDOG1L-3 等位基因是 QTL qSd-1-1 种子休眠的候选基因，它参与 ABA 途径以在水稻中建立种子休眠。