Wu Baowei, Zhang Xiaoyu, Hu Kunzhi, Zheng Haoyuan, Zhang Siyu, Liu Xiangli, Ma Meng, Zhao Huixian
College of Life Sciences, Northwest A & F University, Yangling, Shaanxi, China.
Front Plant Sci. 2022 Dec 1;13:1014176. doi: 10.3389/fpls.2022.1014176. eCollection 2022.
In wheat production, appropriate flowering time and ideal plant architecture are the prerequisites for high grain yield. Alternative splicing (AS) is a vital process that regulates gene expression at the post-transcriptional level, and AS events in wheat have been found to be closely related to grain-related traits and abiotic stress tolerance. However, AS events and their biological roles in regulating flowering time and plant architecture in wheat remain unclear. In this study, we report that undergoes AS, producing three splicing variants. Molecular characterization of and its splicing variants demonstrated that all three protein isoforms have a conserved NB-ARC domain and a protein kinase domain, but the positions of these two domains and the length of the protein kinase domains are different among them, implying that they may have different three-dimensional structures and therefore have different functions. Further investigations showed that the two splicing variants of and , exhibited different expression patterns during wheat growth and development, while the other one, , was not detected. Subcellular localization demonstrated that TaNAK1.1 was mainly localized in the cytoplasm, while TaNAK1.2 was localized in the nucleus and cytoplasm. Both TaNAK1.1 and TaNAK1.2 exhibit protein kinase activity . Ectopic expression of and in demonstrated that these two splicing variants play opposite roles in regulating flowering time and plant architecture, resulting in different seed yields. positive regulates the transition from vegetative to reproductive growth, plant height, branching number, seed size, and seed yield of , while negatively regulates these traits. Our findings provide new gene resource for regulating flowering time and plant architecture in crop breeding for high grain yield.
在小麦生产中，适宜的开花时间和理想的株型是高产的先决条件。可变剪接（AS）是在转录后水平调节基因表达的重要过程，并且已发现小麦中的AS事件与籽粒相关性状和非生物胁迫耐受性密切相关。然而，AS事件及其在调节小麦开花时间和株型中的生物学作用仍不清楚。在本研究中，我们报道 发生了可变剪接，产生了三种剪接变体。对 及其剪接变体的分子特征分析表明，所有三种蛋白质异构体都具有保守的NB-ARC结构域和蛋白激酶结构域，但这两个结构域的位置以及蛋白激酶结构域的长度在它们之间有所不同，这意味着它们可能具有不同的三维结构，因此具有不同的功能。进一步研究表明， 和 的两种剪接变体在小麦生长发育过程中表现出不同的表达模式，而另一种 未被检测到。亚细胞定位表明，TaNAK1.1主要定位于细胞质中，而TaNAK1.2定位于细胞核和细胞质中。TaNAK1.1和TaNAK1.2均表现出蛋白激酶活性。 和 在 中的异位表达表明，这两种剪接变体在调节开花时间和株型方面发挥相反的作用，从而导致不同的种子产量。 正向调节 从营养生长到生殖生长的转变、株高、分枝数、种子大小和种子产量，而 负向调节这些性状。我们的研究结果为作物高产育种中调节开花时间和株型提供了新的基因资源。
