Molecular basis of a shattering resistance boosting global dissemination of soybean
Molecular basis of a shattering resistance boosting global dissemination of soybean
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DOI：
10.1073/pnas.1417282111
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发表时间：
2014-12-16
影响因子：
11.1
通讯作者：
Fujino, Kaien
中科院分区：
文献类型：
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作者：
Funatsuki, Hideyuki;Suzuki, Masaya;Fujino, Kaien
荚果开裂（破碎）对于在荚果中携带种子的野生植物物种的繁殖是必不可少的，但却是豆类和十字花科作物产量损失的主要原因。尽管荚果开裂的自然遗传变异已经并将对植物育种有用，但对作物抗裂性的分子遗传基础知之甚少。因此，我们进行了基于图位的克隆，以揭示一个主要的数量性状位点（QTL）控制大豆荚果开裂。精细定位和互补测试表明，该QTL编码一个类似于dirigent的蛋白，命名为Pdh1。抗碎基因型pdh1的基因有缺陷，有一个提前终止的密码子。功能基因Pdh1在荚果壁富含木质素的厚壁组织中高度表达，尤其是在木质素沉积起始阶段。近等基因系的比较表明，Pdh1通过增加干燥荚壁的扭转来促进荚开裂，这是低湿度下荚开裂的驱动力。一项对大豆种质的调查显示，pdh 1经常在半干旱地区的地方品种中检测到，并已被广泛用于世界主要大豆生产国北美的育种。这些发现指出了一个涉及到分歧蛋白家族的豆荚开裂的新机制，并表明pdh1在全球大豆种植的扩张中发挥了至关重要的作用。此外，pdh 1的直向同源物或具有相同作用的基因可能对作物改良有用。
Pod dehiscence (shattering) is essential for the propagation of wild plant species bearing seeds in pods but is a major cause of yield loss in legume and crucifer crops. Although natural genetic variation in pod dehiscence has been, and will be, useful for plant breeding, little is known about the molecular genetic basis of shattering resistance in crops. Therefore, we performed map-based cloning to unveil a major quantitative trait locus (QTL) controlling pod dehiscence in soybean. Fine mapping and complementation testing revealed that the QTL encodes a dirigent-like protein, designated as Pdh1. The gene for the shattering-resistant genotype, pdh1, was defective, having a premature stop codon. The functional gene, Pdh1, was highly expressed in the lignin-rich inner sclerenchyma of pod walls, especially at the stage of initiation in lignin deposition. Comparisons of near-isogenic lines indicated that Pdh1 promotes pod dehiscence by increasing the torsion of dried pod walls, which serves as a driving force for pod dehiscence under low humidity. A survey of soybean germplasm revealed that pdh1 was frequently detected in landraces from semiarid regions and has been extensively used for breeding in North America, the world's leading soybean producer. These findings point to a new mechanism for pod dehiscence involving the dirigent protein family and suggest that pdh1 has played a crucial role in the global expansion of soybean cultivation. Furthermore, the orthologs of pdh1, or genes with the same role, will possibly be useful for crop improvement.