Molecular identification of a major quantitative trait locus, qLTG3-1, controlling low-temperature germinability in rice
Molecular identification of a major quantitative trait locus, qLTG3-1, controlling low-temperature germinability in rice
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DOI：
10.1073/pnas.0805303105
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发表时间：
2008-08-26
影响因子：
11.1
通讯作者：
Yano, Masahiro
中科院分区：
文献类型：
--
作者：
Fujino, Kenji;Sekiguchi, Hiroshi;Yano, Masahiro
作物对非生物胁迫的耐受性是一个重要的农艺性状，受多个基因控制，这些基因被称为数量性状基因座（QTL）。这些QTL的鉴定不仅有助于理解植物生物学，而且有助于植物育种，以实现世界各地稳定的作物生产。在此之前，我们定位了三个控制发芽期低温耐受性（称为低温发芽力）的QTL。为了了解这些QTL之一，qLTG 3 -1（3号染色体上的低温发芽性的数量性状位点）的分子基础，进行了基于图位的克隆，该QTL被证明是由未知功能的蛋白质编码。QTL qLTG 3 -1在种子萌发过程中的胚中强烈表达。在种子萌发前和萌发过程中，β-葡萄糖醛酸苷酶染色在覆盖胚的组织中的特异性定位，所述组织涉及覆盖胚芽鞘的上胚层和种皮的糊粉层。qLTG 3 -1的表达与覆盖胚胎的组织的空泡化密切相关。这可能导致组织弱化，导致胚芽鞘生长潜力的机械阻力降低。这些现象与双子叶植物种子萌发的模式系统十分相似，表明双子叶植物和单子叶植物的种子萌发模式都是保守的。
Tolerance to abiotic stress is an important agronomic trait in crops and is controlled by many genes, which are called quantitative trait loci (QTLs). Identification of these QTLs will contribute not only to the understanding of plant biology but also for plant breeding, to achieve stable crop production around the world. Previously, we mapped three QTLs controlling low-temperature tolerance at the germination stage (called low-temperature germinability). To understand the molecular basis of one of these QTLs, qLTG3-1 (quantitative trait locus for low-temperature germinability on chromosome 3), map-based cloning was performed, and this QTL was shown to be encoded by a protein of unknown function. The QTL qLTG3-1 is strongly expressed in the embryo during seed germination. Before and during seed germination, specific localization of beta-glucuronidase staining in the tissues covering the embryo, which involved the epiblast covering the coleoptile and the aleurone layer of the seed coat, was observed. Expression of qLTG3-1 was tightly associated with vacuolation of the tissues covering the embryo. This may cause tissue weakening, resulting in reduction of the mechanical resistance to the growth potential of the coleoptile. These phenomena are quite similar to the model system of seed germination presented by dicot plants, suggesting that this model may be conserved in both dicot and monocot plants.