SlMBP22 overexpression in tomato affects flower morphology and fruit development
SlMBP22 overexpression in tomato affects flower morphology and fruit development
复制标题
SlMBP22在番茄中的过度表达影响花形态和果实发育
DOI：
10.1016/j.jplph.2022.153687
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发表时间：
2022-04-01
影响因子：
4.3
通讯作者：
Chen, Guoping
中科院分区：
文献类型：
--
作者：
Li, Fenfen;Jia, Yanhua;Chen, Guoping
MADS结构域转录因子是被子植物花和果实发育的关键调控因子。B-sister（B-s）基因作为MADS-box亚家族的成员，在种子植物生殖器官的进化过程中发挥着重要作用。然而，它们对水果作物如番茄（Solanum lycopersicum）生殖发育的影响仍不清楚。在这里，我们发现SlMBP 22过表达（SlMBP 22-OE）导致花形态的相当大的改变，并影响几个花同源异型基因的表达水平。通过酵母双杂交（Y2 H）和双分子荧光互补（BiFC）测定的进一步分析表明，SlMBP 22分别与A类蛋白MACROCALYX（MC）和SEPALLATA（SEP）花同源异型蛋白TM 5和TM 29形成二聚体。此外，花粉活力和异花受精试验表明，雌性生殖发育的缺陷是导致在强过表达转基因植物中观察到的不育表型的原因。轻度过表达的转基因果实由于细胞扩增减少而表现出尺寸减小，而不是细胞分裂受损。此外，SlMBP 22在番茄中的过表达不仅影响原花色素（PA）的积累，而且改变种子休眠。总之，这些发现可能为番茄花和果实发育中Bs MADS盒基因的知识提供新的见解。
MADS-domain transcription factors have been identified as key regulators involved in proper flower and fruit development in angiosperms. As members of the MADS-box subfamily, B-sister (B-s) genes have been observed to play an important role during the evolution of the reproductive organs in seed plants. However, their effects on reproductive development in fruit crops, such as tomato (Solanum lycopersicum), remain unclear. Here, we found that SlMBP22 overexpression (SlMBP22-OE) resulted in considerable alterations in floral morphology and affected the expression levels of several floral homeotic genes. Further analysis by yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays demonstrated that SlMBP22 forms dimers with class A protein MACROCALYX (MC) and SEPALLATA (SEP) floral homeotic proteins TM5 and TM29, respectively. In addition, pollen viability and cross-fertilization assays suggested that the defect in female reproductive development was responsible for the infertility phenotype observed in the strong overexpression transgenic plants. Transgenic fruits with mild overexpression exhibited reduced size as a result of reduced cell expansion, rather than impaired cell division. Additionally, SlMBP22 overexpression in tomato not only affected proanthocyanidin (PA) accumulation but also altered seed dormancy. Taken together, these findings may provide new insights into the knowledge of Bs MADS-box genes in flower and fruit development in tomato.