a Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences , Central China Normal University , Wuhan , China.
b Cell Biology and Plant Biochemistry , Regensburg Center for Biochemistry, University of Regensburg , Regensburg , Germany.
Plant Signal Behav. 2019;14(5):e1588664. doi: 10.1080/15592324.2019.1588664. Epub 2019 Mar 8.
Post-translational modification of proteins by small ubiquitin-like modifier (SUMO) plays essential roles in a large variety of cellular and developmental processes. While SUMO conjugation to target proteins has been reported in numerous studies in animals and human, and partly also in the model plant Arabidopsis, little is known about the specific roles of SUMO in crop plants. Here, we report about the maize SUMO family and show that the highly conserved core isoform SUMO1 predominately locates to the nucleus where it marks euchromatin rather than heterochromatin. Moreover, SUMO1 is especially present in nuclei of small dividing cells. Strong overexpression of SUMO1 caused a severe dwarf phenotype and abnormalities in floral organ structures. Defects in anther development and female gametogenesis occurred similar to null-mutant phenotypes reported in Arabidopsis. Taken together, these studies imply that precise and fine-tuned conjugation of the highly conserved plant SUMO1 isoform to target proteins is required for vegetative and reproductive development. Mis-regulation by overexpression or knock-out is deleterious, strongly affecting fertility in both dicots and monocots, including the crop plant maize.
蛋白质的翻译后修饰由小泛素样修饰物（SUMO）完成，它在多种细胞和发育过程中起着至关重要的作用。虽然 SUMO 与靶蛋白的连接已在动物和人类的大量研究中，以及在模式植物拟南芥中部分得到证实，但 SUMO 在作物中的具体作用却知之甚少。在这里，我们报告了玉米 SUMO 家族，并表明高度保守的核心同工型 SUMO1 主要位于细胞核中，它标记常染色质而不是异染色质。此外，SUMO1 特别存在于小分裂细胞的核中。SUMO1 的过表达导致严重的矮化表型和花器官结构异常。与拟南芥中报道的 null 突变表型相似，花药发育和雌性配子体发生缺陷。总之，这些研究表明，高度保守的植物 SUMO1 同工型与靶蛋白的精确和精细的连接对于营养和生殖发育是必需的。过表达或敲除的失调是有害的，会严重影响包括玉米在内的双子叶植物和单子叶植物的育性。
