Ohyama Ami, Tominaga Rumi, Toriba Taiyo, Tanaka Wakana
School of Applied Biological Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8528, Japan.
School of Applied Biological Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8528, Japan; Graduate School of Integrated Sciences for Life, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8528, Japan.
J Plant Physiol. 2022 Mar;270:153634. doi: 10.1016/j.jplph.2022.153634. Epub 2022 Feb 2.
D-type cyclins (CYCDs) are involved in a wide range of biological processes, as one of the major regulators of cell cycle activity. In Arabidopsis (Arabidopsis thaliana), three members of CYCD3 subgroup genes play important roles in plant development such as leaf development and branch formation. In rice (Oryza sativa), there is only one gene (OsCYCD3;1) belonging to the CYCD3 subgroup; its function is unknown. In this study, in order to elucidate the function of OsCYCD3;1, we generated knockout mutants of the gene and conducted developmental analysis. The knockout mutants showed a significantly reduced number of branches compared with a wild type, suggesting that OsCYCD3;1 promotes branch formation. Histological analysis showed that the activities of the axillary meristem and the shoot apical meristem (SAM) were compromised in these mutant plants. Our results suggest that OsCYCD3;1 promotes branch formation, probably by regulating cell division to maintain the activities of the axillary meristem and the SAM.
D型细胞周期蛋白（CYCDs）作为细胞周期活动的主要调节因子之一，参与了广泛的生物学过程。在拟南芥中，CYCD3亚组基因的三个成员在植物发育过程中发挥重要作用，如叶片发育和分枝形成。在水稻中，属于CYCD3亚组的基因只有一个（OsCYCD3;1），其功能尚不清楚。在本研究中，为了阐明OsCYCD3;1的功能，我们构建了该基因的敲除突变体并进行了发育分析。与野生型相比，敲除突变体的分枝数量显著减少，这表明OsCYCD3;1促进分枝形成。组织学分析表明，这些突变植株的腋生分生组织和茎尖分生组织（SAM）的活性受到损害。我们的结果表明，OsCYCD3;1可能通过调节细胞分裂来维持腋生分生组织和SAM的活性，从而促进分枝形成。
