Genetic variation in ZmKW1 contributes to kernel weight and size in dent corn and popcorn
Genetic variation in ZmKW1 contributes to kernel weight and size in dent corn and popcorn
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DOI：
10.1111/pbi.14279
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发表时间：
2024-01-01
影响因子：
13.8
通讯作者：
Li，Yuling
中科院分区：
文献类型：
--
作者：
Zhang，Long;Fu，Miaomiao;Li，Yuling
籽粒重量是影响玉米产量的关键因素。在天然自交系中，爆米花籽粒明显比凹陷玉米粒小，籽粒重量受多个遗传位点控制，差异很大。在这里，我们描述了1号染色体上的一个主要数量性状基因座，负责控制籽粒重量(QKW1)和籽粒大小。QKW1基因座编码一个含有7个缺失结构域的蛋白质，具有E3泛素连接酶活性，从胚乳顶端到中部显著表达。通过ZmKW1基因编辑证实了qKW1的存在和功能，其中ZmKW1的突变显著增加了籽粒重量，与籽粒大小的变化一致，而过表达的ZmKW1则相反。ZmKW1通过减少胚乳细胞的数量和大小，影响胚乳的灌浆，对籽粒重量和大小起负调控作用。值得注意的是，爆米花等位基因qKW1N和凹陷玉米等位基因qKW1编码相同的蛋白质；然而，启动子活性的差异是由于在qKW1N启动子中插入了Indel-1346序列，导致了比qKW1D更高的表达水平，从而导致爆米花和凹陷玉米籽粒之间的籽粒重量和大小的差异。对ZmKW12.8 kb启动子区域的连锁不平衡分析表明，ZmKW1有两种不同的单倍型。我们的结果为凹陷玉米和爆米花的籽粒发育和产量调控的潜在机制提供了洞察力，特别是泛素化调节系统的作用。
Kernel weight is a critical factor that essentially affects maize (Zea mays) yield. In natural inbred lines, popcorn kernels exhibit overtly smaller sizes compared to dent corn kernels, and kernel weight, which is controlled by multiple genetic loci, varies widely. Here, we characterized a major quantitative trait locus on chromosome 1, responsible for controlling kernel weight (qKW1) and size. TheqKW1locus encodes a protein containing a seven in absentia domain with E3 ubiquitin ligase activity, expressed prominently from the top to the middle region of the endosperm. The presence and function ofqKW1were confirmed throughZmKW1gene editing, where the mutations inZmKW1within dent corn significantly increased kernel weight, consistent with alterations in kernel size, while overexpression ofZmKW1had the opposite effect.ZmKW1acts as a negative regulator of kernel weight and size by reducing both the number and size of the endosperm cells and impacting endosperm filling. Notably, the popcorn alleleqKW1Nand the dent corn alleleqKW1Dencode identical proteins; however, the differences in promoter activity arise due to the insertion of an Indel‐1346 sequence in theqKW1Npromoter, resulting in higher expression levels compared toqKW1D, thus contributing to the variation in kernel weight and size between popcorn and dent corn kernels. Linkage disequilibrium analysis of the 2.8 kb promoter region ofZmKW1in a dataset comprising 111 maize association panels identified two distinct haplotypes. Our results provide insight into the mechanisms underlying kernel development and yield regulation in dent corn and popcorn, with a specific focus on the role of the ubiquitination system.