Jia Sha-Sha, Ren Xin-Yu, Tong Man-Ni, Jiang Si-Yao, Zhang Chang-Quan, Liu Qiao-Quan, Li Qian-Feng
Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Zhongshan Biological Breeding Laboratory/Key Laboratory of Plant Functional Genomics of the Ministry of Education, Agricultural College of Yangzhou University, Yangzhou 225009, China.
Co-Innovation Center for Modern Production Technology of Grain Crops of Jiangsu Province/Jiangsu Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou 225009, China.
Plants (Basel). 2024 Dec 18;13(24):3538. doi: 10.3390/plants13243538.
The Aux/IAA family proteins, key components of the auxin signaling pathway, are plant-specific transcription factors with important roles in regulating a wide range of plant growth and developmental events. The family genes have been extensively studied in Arabidopsis. However, most of the family genes in rice have not been functionally studied. Only two genes have been reported to be involved in the regulation of rice grain size. Grain size is a key factor affecting both rice yield and quality. Therefore, we selected an unreported member, , based on bioinformatics analysis to investigate its potential role in grain size control. Our study showed that was constitutively expressed in all tissues tested and that the encoding protein was nuclear localized. The mutants were then generated using CRISPR/Cas9 gene editing. Agronomic trait analyses showed that the mutation significantly increased rice grain length and weight, but had no significant effect on plant height, number of tillers, flag leaf length and width. In addition, the chalkiness of the mutant seeds also increased, but their eating and cooking quality (ECQ) was not altered. Finally, seed germination analysis showed that knocking out slightly suppressed rice seed germination. These results suggest that may specifically regulate rice seed-related traits, such as grain shape, rice chalkiness and seed germination. This study not only enriched the functional study of the genes and the auxin signaling pathway in rice, but also provided valuable genetic resources for breeding elite rice varieties.
生长素/吲哚乙酸（Aux/IAA）家族蛋白是生长素信号通路的关键组成部分，是植物特有的转录因子，在调控多种植物生长和发育过程中发挥着重要作用。该家族基因在拟南芥中已得到广泛研究。然而，水稻中大多数该家族基因尚未进行功能研究。仅有两个该家族基因被报道参与水稻粒型调控。粒型是影响水稻产量和品质的关键因素。因此，我们基于生物信息学分析选择了一个未报道的该家族成员OsIAA25，来研究其在粒型控制中的潜在作用。我们的研究表明，OsIAA25在所有测试组织中组成型表达，其编码蛋白定位于细胞核。然后利用CRISPR/Cas9基因编辑技术构建了OsIAA25突变体。农艺性状分析表明，OsIAA25突变显著增加了水稻粒长和粒重，但对株高、分蘖数、剑叶长度和宽度没有显著影响。此外，OsIAA25突变体种子的垩白度也增加了，但其食味品质（ECQ）未改变。最后，种子萌发分析表明，敲除OsIAA25略微抑制了水稻种子萌发。这些结果表明，OsIAA25可能特异性调控水稻种子相关性状，如粒型、水稻垩白度和种子萌发。本研究不仅丰富了水稻中OsIAA基因和生长素信号通路的功能研究，也为培育优良水稻品种提供了宝贵的遗传资源。
