Mutations in the F-box gene LARGER PANICLE improve the panicle architecture and enhance the grain yield in rice
Mutations in the F-box gene LARGER PANICLE improve the panicle architecture and enhance the grain yield in rice
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F-box 基因 LARGER PANICLE 突变可改善水稻的穗结构并提高籽粒产量
DOI：
10.1111/j.1467-7652.2011.00610.x
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发表时间：
2011-12-01
影响因子：
13.8
通讯作者：
Cheng, Zhukuan
中科院分区：
文献类型：
--
作者：
Li, Ming;Tang, Ding;Cheng, Zhukuan
穗型结构是直接影响水稻产量的重要农艺性状之一。我们在此报告了两个等位基因大穗(LP)突变体的深入特征，它们显示出显著增加的穗大小以及改善的植株结构。形态分析表明，两个突变体的花序分枝特别是一次分枝较多，籽粒较多。此外，突变株也表现出比野生型更强的抗倒伏能力。突变体的单株籽粒产量也有所提高，表明突变体在水稻育种中具有潜在的高产潜力。基于图谱的克隆表明，较大的穗(LP)编码一个含有Kelch重复序列的F-box蛋白。RNA原位杂交研究表明，Lp在分支原始区表达丰富。亚细胞定位分析表明，Lp是一种内质网定位蛋白，提示Lp可能参与内质网相关蛋白的降解。通过酵母双杂交和双分子荧光互补分析，我们证实Lp是一个F-box蛋白，并且能够以依赖于F-box结构域的方式与水稻Skp1类蛋白相互作用。实时定量聚合酶链式反应结果表明，突变株中编码细胞分裂素氧化酶/脱氢酶的OsCKX2基因表达明显下调，提示LP可能参与了植物组织中细胞分裂素水平的调节。这些结果表明，LP在植物结构调控中起着重要作用，尤其是对穗部结构的调控，因此是粮食生产植物遗传改良的良好靶点。
Panicle architecture is one of the most important agronomical traits that directly contribute to grain yield in rice (Oryza sativa L.). We report herein an in-depth characterization of two allelic larger panicle (lp) mutants that show significantly increased panicle size as well as improved plant architecture. Morphological analyses reveal that panicles of two mutants produced more inflorescence branches, especially the primary branches, and contained more grains. Moreover, mutant plants also display more lodging resistance than the wild type. The grain yield per plant in mutants is also increased, suggesting that mutant plants have useful potential for high grain yield in rice breeding. Map-based cloning reveals that LARGER PANICLE (LP) encodes a Kelch repeat-containing F-box protein. RNA in situ hybridization studies display that LP expression was enriched in the branch primordial region. Subcellular localization analyses demonstrate that LP is an endoplasmic reticulum (ER) localized protein, suggesting that LP might be involved in ER-associated protein degradation (ERAD). Using yeast two-hybrid assay and bimolecular fluorescence complementation analysis, we confirm that LP is an F-box protein and could interact with rice SKP1-like protein in an F-box domain-dependent manner. Quantitative real-time PCR results show that OsCKX2, which encodes cytokinin oxidase/dehydrogenase, is down-regulated evidently in mutants, implying that LP might be involved in modulating cytokinin level in plant tissues. These results suggest that LP plays an important role in regulating plant architecture, particularly in regulating panicle architecture, thereby representing promising targets for genetic improvement of grain production plants.