Paolo Dario, Rotasperti Lisa, Schnittger Arp, Masiero Simona, Colombo Lucia, Mizzotti Chiara
Dipartimento di BioScienze, Università degli Studi di Milano, 20133 Milano, Italy.
Abteilung für Entwicklungsbiologie, Institut für Pflanzenforschung und Mikrobiologie, Universität Hamburg, 22609 Hamburg, Germany.
Plants (Basel). 2021 Jan 20;10(2):192. doi: 10.3390/plants10020192.
Seed size is the result of complex molecular networks controlling the development of the seed coat (of maternal origin) and the two fertilization products, the embryo and the endosperm. In this study we characterized the role of MADS-domain transcription factor SEEDSTICK (STK) in seed size control. STK is known to regulate the differentiation of the seed coat as well as the structural and mechanical properties of cell walls in developing seeds. In particular, we further characterized mutant seeds. Genetic evidence (reciprocal crosses) of the inheritance of the small-seed phenotype, together with the provided analysis of cell division activity (flow cytometry), demonstrate that STK acts in the earlier phases of seed development as a maternal activator of growth. Moreover, we describe a molecular mechanism underlying this activity by reporting how STK positively regulates cell cycle progression via directly activating the expression of , a key regulator of the cell cycle. Altogether, our results unveil a new genetic network active in the maternal control of seed size in .
种子大小是由复杂的分子网络控制种皮（母本来源）以及两个受精产物——胚和胚乳发育的结果。在本研究中，我们对MADS结构域转录因子种子柄（STK）在控制种子大小中的作用进行了表征。已知STK可调节种皮的分化以及发育中种子细胞壁的结构和机械特性。特别是，我们进一步对突变种子进行了表征。小种子表型遗传的遗传证据（正反交），连同所提供的细胞分裂活性分析（流式细胞术）表明，STK在种子发育的早期阶段作为生长的母本激活因子发挥作用。此外，我们通过报告STK如何通过直接激活细胞周期的关键调节因子的表达来正向调节细胞周期进程，描述了这种活性背后的分子机制。总之，我们的结果揭示了一个在种子大小的母本控制中活跃的新遗传网络。
