PDF(Pubmed)
Abstract：
Reducing plant height (PH) is one of the core contents of the \"Green Revolution\", which began in the 1960s in wheat. A number of 27 reduced-height (Rht) genes have been identified and a great number of quantitative trait loci (QTLs) for PH have been mapped on all 21 chromosomes. Nonetheless, only several genes regulated PH have been cloned. In this study, we found the interval of QTL QPh-1B included an EST-SSR marker swes1079. According to the sequence of swes1079, we cloned the TaOSCA1.4 gene. We developed a CAPS marker to analyze the variation across a natural population. The result showed that the PH was significantly different between the two haplotypes of TaOSCA1.4-1B under most of the 12 environments and the average values of irrigation and rainfed conditions. This result further demonstrated that TaOSCA1.4 was associated with PH. Then, we validated the TaOSCA1.4 via RNAi technology. The average PHs of the wild-type (WT), RNAi lines 1 (Ri-1) and 2 (Ri-2) were 94.6, 83.6 and 79.2 cm, respectively, with significant differences between the WT and Ri-1 and Ri-2. This result indicated that the TaOSCA1.4 gene controls PH. TaOSCA1.4 is a constitutively expressed gene and its protein localizes to the cell membrane. TaOSCA1.4 gene is a member of the OSCA gene family, which regulates intracellular Ca2+ concentration. We hypothesized that knock down mutants of TaOSCA1.4 gene reduced regulatory ability of Ca2+, thus reducing the PH. Furthermore, the cell lengths of the knock down mutants are not significantly different than that of WT. We speculate that TaOSCA1.4 gene is not directly associated with gibberellin (GA), which should be a novel mechanism for a wheat Rht gene.
摘要：
降低株高(PH)是“绿色革命”的核心内容之一,始于1960年代的小麦。已鉴定出27个高度降低（Rht）基因，并且已在所有21条染色体上定位了大量PH的数量性状基因座（QTL）。尽管如此，只克隆了几个调节PH的基因。在这项研究中,我们发现QTLQPh-1B的间隔包括EST-SSR标记swes1079。根据swes1079的序列，我们克隆了TaOSCA1.4基因。我们开发了一个CAPS标记来分析整个自然种群的变异。结果表明，在12种环境中的大多数环境以及灌溉和雨养条件的平均值下，TaOSCA1.4-1B的两种单倍型之间的PH存在显着差异。该结果进一步证明TaOSCA1.4与PH相关。然后，我们通过RNAi技术验证了TaOSCA1.4。野生型(WT)的平均PH，RNAi品系1(Ri-1)和2(Ri-2)分别为94.6、83.6和79.2cm,分别,WT与Ri-1和Ri-2之间存在显著差异。该结果表明TaOSCA1.4基因控制PH。TaOSCA1.4是组成型表达基因,其蛋白定位于细胞膜。TaOSCA1.4基因是OSCA基因家族中的一员,它调节细胞内Ca2+浓度。我们假设TaOSCA1.4基因的敲低突变体降低了Ca2+的调节能力,从而降低PH。此外，敲除突变体的细胞长度与WT的细胞长度没有显著差异。我们推测TaOSCA1.4基因与赤霉素(GA)不直接相关,这应该是小麦Rht基因的新机制。
