Background

Proper organ development is pivotal for normal rice growth and production. Many genes are involved in this process, and these genes provide a basis for rice breeding.

Objective

To identify a novel mutation causing developmental defects in rice.

Methods

The phenotype of a rice mutant, stunted sterile (ss), identified from the japonica rice cultivar Samkwang treated with N-methyl-N-nitrosourea, was characterized, including anatomical and pollen activity analyses. A genetic analysis and fine mapping were performed to identify a candidate locus, followed by a sequence analysis to determine the causal mutation for the phenotype.

Results

Compared with wild-type plants, the mutant exhibited a 34% reduction in height, 46% reduction in flag leaf width, and complete panicle sterility. Cell proliferation in the leaf and pollen viability were significantly inhibited in the mutant. The mutant phenotypes were controlled by a single recessive gene that was fine-mapped to an 84 kb region between two SNP markers on the short arm of chromosome 5. A candidate gene analysis determined that the mutant carries an 11 bp insertion in the coding region of LOC_Os05g03550, which encodes a protein containing two SANT domains, resulting in a premature termination codon before the conserved domain.

Conclusions

We identified a novel rice gene, Stunted sterile, involved in the regulation of various developmental processes. Our findings improve our understanding of the role of chromatin remodeling in organ development and have implications for breeding owing to the broad effects of the gene on plant growth.

中文翻译：

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水稻发育迟缓的无菌（ss）突变体的鉴定和表征。

背景

适当的器官发育对于正常的水稻生长和生产至关重要。该过程涉及许多基因，这些基因为水稻育种提供了基础。

目的

鉴定导致水稻发育缺陷的新突变。

方法

从用N-甲基-N-亚硝基脲处理过的粳稻品种Samkwang中鉴定出的水稻突变体，发育迟缓的不育（ss）表型，包括解剖和花粉活性分析。进行了遗传分析和精细作图以鉴定候选基因座，然后进行序列分析以确定表型的因果突变。

结果

与野生型植物相比，该突变体的株高降低了34％，旗叶宽度降低了46％，穗完全不育。在突变体中，叶片中的细胞增殖和花粉活力被显着抑制。突变体的表型受单个隐性基因控制，该隐性基因被精细映射到5号染色体短臂上两个SNP标记之间的84 kb区域。候选基因分析确定该突变体在cDNA的编码区中插入11 bp LOC_Os05g03550，其编码包含两个SANT结构域的蛋白质，导致在保守结构域之前出现过早的终止密码子。

结论

我们确定了一个新的水稻基因，特技不育，参与各种发育过程的调控。我们的发现提高了我们对染色质重塑在器官发育中的作用的理解，并且由于该基因对植物生长的广泛影响而对育种具有影响。