Wang Gui-Luan, Zhang Chun-Ling, Huo He-Qiang, Sun Xiao-Shuai, Zhang Ya-Li, Hao Yu-Jin, You Chun-Xiang
State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Taian, Shandong, China.
Mid-Florida Research and Education Center, University of Florida, Institute of Food and Agricultural Sciences, Apopka, FL, United States.
Front Plant Sci. 2022 Apr 15;13:836935. doi: 10.3389/fpls.2022.836935. eCollection 2022.
Plant growth and organ size putatively associated with crop yield are regulated by a complex network of genes including ones for controlling cell proliferation. The gene was first identified in tomatoes and reported to govern fruit size variation through controlling cell division. In this study, we isolated a putative ortholog of the tomato gene from apple, (). Our functional analysis showed that may control fruit size and root growth. MdCNR8 was mediated by the SUMO E3 ligase MdSIZ1, and SUMOylation of MdCNR8 at residue-Lys39 promoted the translocation of MdCNR8 from plasma membrane to the nucleus. The effect of in inhibiting root elongation could be completely counteracted by the coexpression of . Moreover, the lower cell proliferation of apple calli due to silencing MdSIZ1 could be rescued by silencing MdCNR8. Collectively, our results showed that the MdSIZ1-mediated SUMOylation is required for the fulfillment of MdCNR8 in regulating cell proliferation to control plant organ size. This regulatory interaction between and will facilitate understanding the mechanism underlying the regulation of organ size.
与作物产量相关的植物生长和器官大小受包括控制细胞增殖相关基因在内的复杂基因网络调控。该基因最初在番茄中被鉴定出来，并报道其通过控制细胞分裂来调控果实大小变异。在本研究中，我们从苹果中分离出了番茄该基因的一个假定直系同源基因，即MdCNR8。我们的功能分析表明，MdCNR8可能控制果实大小和根系生长。MdCNR8由SUMO E3连接酶MdSIZ1介导，MdCNR8第39位赖氨酸残基处的SUMO化促进了MdCNR8从质膜向细胞核的转运。MdCNR8抑制根系伸长的作用可通过与MdSIZ1共表达而完全抵消。此外，由于沉默MdSIZ1导致的苹果愈伤组织细胞增殖降低可通过沉默MdCNR8得到挽救。总体而言，我们的结果表明，MdSIZ1介导的SUMO化是MdCNR8调控细胞增殖以控制植物器官大小所必需的。MdCNR8与MdSIZ1之间的这种调控相互作用将有助于理解器官大小调控的潜在机制。
