Jing You, Wenbo Chen, Zhifeng He, Yan Xiang, XinFang Zhang, Mi Wei, RuHui Wu, Wenqiang Shen, Jun Zhang, QianNan Duan, Guanghua He, Yunfeng Li, Ting Zhang
Rice Research Institute, Key Laboratory of Application and Safety Control of Genetically Modified Crops, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715 China.
Physiol Mol Biol Plants. 2023 Mar;29(3):335-347. doi: 10.1007/s12298-023-01297-6. Epub 2023 Mar 23.
In grass, the lemma is a unique floral organ structure that directly determines grain size and yield. Despite a great deal of research on grain enlargement caused by changes in glume cells, the importance of normal development of the glume for normal grain development has been poorly studied. In this study, we investigated a rice spikelet mutant, (), which developed florets with a slightly degenerated or rod-like lemma. More importantly, also showed a significant reduction in grain length and width, seed setting rate, and 1000-grain weight, which led to a reduction in yield. The results indicate that the mutation of the gene further affects rice grain yield. Map-based cloning shows a single-nucleotide substitution from T to A within , causing an amino acid mutation of Leu-34 to His-34 in the mutant. Compared with the wild type, the expression of in was significantly reduced, which might be caused by single base substitution. In addition, the expression level of in was lower than that of the wild type. RT-qPCR results show that the expression of some floral organ identity genes was changed, which indicates that the gene regulates lemma development by modulating the expression of these genes. The present results suggest that the normal expression of is necessary for the formation of lemma and the normal development of grain morphology and therefore has an important effect on the yield.
The online version contains supplementary material available at 10.1007/s12298-023-01297-6.
在禾本科植物中，外稃是一种独特的花器官结构，直接决定谷粒大小和产量。尽管对颖壳细胞变化引起的谷粒增大进行了大量研究，但对于颖壳正常发育对谷粒正常发育的重要性研究较少。在本研究中，我们调查了一个水稻小穗突变体（），其发育出的小花外稃略有退化或呈棒状。更重要的是，该突变体还表现出谷粒长度和宽度、结实率以及千粒重显著降低，导致产量下降。结果表明，基因的突变进一步影响水稻产量。基于图谱的克隆显示，基因内发生了从T到A的单核苷酸替换，导致突变体中第34位氨基酸由亮氨酸突变为组氨酸。与野生型相比，突变体中该基因的表达显著降低，这可能是由单碱基替换引起的。此外，突变体中该基因的表达水平低于野生型。RT-qPCR结果表明，一些花器官特征基因的表达发生了变化，这表明该基因通过调节这些基因的表达来调控外稃发育。目前的结果表明，该基因的正常表达对于外稃的形成以及谷粒形态的正常发育是必要的，因此对产量有重要影响。
在线版本包含可在10.1007/s12298-023-01297-6获取的补充材料。
