Characterization and cloning of SMALL GRAIN 4, a novel DWARF11 allele that affects brassinosteroid biosynthesis in rice
Characterization and cloning of SMALL GRAIN 4, a novel DWARF11 allele that affects brassinosteroid biosynthesis in rice
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DOI：
10.1007/s11434-015-0798-8
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发表时间：
2015-05-01
期刊：
影响因子：
18.9
通讯作者：
Qian, Qian
中科院分区：
文献类型：
--
作者：
Shi, Zhenyuan;Rao, Yuchun;Qian, Qian
油菜素内酯（BRs）是调节植物发育和生理的重要激素。BR的相关研究取得了实质性进展，特别是越来越多的参与BR生物合成的新基因被发现。在这里，我们描述了一个与br相关的水稻突变体，小粒4 (sg4)，从粳稻品种Nipponbare的愈伤组织培养中获得。该突变体表现出深绿色、皱褶状直立叶片和小圆粒等多种表型。它高于野生型，不同于大多数BR和赤霉素相关突变体。遗传分析表明，突变型受单隐性基因座控制。利用图谱克隆技术，在1100个F-2隐性个体中对该基因进行了90.7 kb的精细定位。在这段时间内共发现11个开放阅读框，其中只有1个在5'UTR区有8 bp插入。功能互补测试显示，矮人11等位基因LOC_Os04g39430是sg4突变表型的答案。对BR的组织特异性反应和BR生物合成基因表达水平的降低表明，sg4是一个弱BR缺陷突变体。这些结果有助于更全面地了解sg4的生理作用。
Brassinosteroids (BRs) are important hormones that regulate plant development and physiology. Substantial progresses have been made in BR-related studies, and especially an increasing number of new genes involved in BR biosynthesis have been identified. Here, we characterize a BR-related rice mutant, small grain 4 (sg4), obtained from callus culture of japonica cultivar Nipponbare. This mutant showed multiple phenotypes such as dark green, rugose erect leaves and small round grains. It was higher than the wild type, different from the majority of BR- and gibberellin-related mutants. Genetic analysis showed that the mutant phenotypes are controlled by a single recessive locus. The gene was fine-mapped to a 90.7-kb interval with 1,100 F-2 recessive individuals by means of map-based cloning. Totally 11 open reading frames were found in this interval, only one of which was detected with an 8-bp insertion in the 5'UTR region by sequencing. Functional complementation test revealed that a DWARF11 allele, LOC_Os04g39430, is answer for the mutant phenotype of sg4. Tissue-specific response to BR and decreased expression levels of BR biosynthetic genes suggest that sg4 is a weak BR-deficient mutant. These results are beneficial to understanding the physiological action of sg4 in a more comprehensive way.