Gu Houwen, Zhang Kunming, Chen Jie, Gull Sadia, Chen Chuyan, Hou Yafei, Li Xiangbo, Miao Jun, Zhou Yong, Liang Guohua
Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education, Yangzhou University, Yangzhou, 225009, China.
Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, 225009, Jiangsu, China.
Rice (N Y). 2022 Sep 6;15(1):47. doi: 10.1186/s12284-022-00593-1.
The initiation of flowering in cereals is a critical process influenced by environmental and endogenous signals. Flowering Locus T-like (FT-like) genes encode the main signals for flowering. Of the 13 FT-like genes in the rice genome, Hd3a/OsFTL2 and RFT1/OsFTL3 have been extensively studied and revealed to be critical for flowering. In this study, a rice FT-like gene, OsFTL4, was functionally characterized. Specifically, osftl4 mutants were generated using a CRISPR/Cas9 system. Compared with the wild-type control (Guangluai 4), the osftl4-1 and osftl4-2 mutants flowered 9.6 and 5.8 days earlier under natural long-day and short-day conditions, respectively. Additionally, OsFTL4 was mainly expressed in the vascular tissue, with the resulting OsFTL4 protein localized in both the nucleus and cytoplasm. Furthermore, OsFTL4 was observed to compete with Hd3a for the interaction with multiple 14-3-3 proteins. An analysis of the effects of simulated drought stress suggested that silencing OsFTL4 enhances drought tolerance by decreasing stomatal conductance and water loss. These results indicate that OsFTL4 helps integrate the flowering process and the drought response in rice.
谷类作物开花的起始是一个受环境和内源信号影响的关键过程。成花素类似物（FT-like）基因编码开花的主要信号。在水稻基因组的13个FT-like基因中，Hd3a/OsFTL2和RFT1/OsFTL3已被广泛研究，并显示对开花至关重要。在本研究中，对一个水稻FT-like基因OsFTL4进行了功能鉴定。具体而言，使用CRISPR/Cas9系统构建了osftl4突变体。与野生型对照（广陆矮4号）相比，osftl4-1和osftl4-2突变体在自然长日照和短日照条件下分别提前9.6天和5.8天开花。此外，OsFTL4主要在维管组织中表达，产生的OsFTL4蛋白定位于细胞核和细胞质中。此外，观察到OsFTL4与Hd3a竞争与多种14-3-3蛋白的相互作用。模拟干旱胁迫效应分析表明，沉默OsFTL4可通过降低气孔导度和水分流失增强耐旱性。这些结果表明，OsFTL4有助于整合水稻的开花过程和干旱响应。
