Kong Shuyao, Zhu Mingyuan, Scarpin M Regina, Pan David, Jia Longfei, Martinez Ryan E, Alamos Simon, Vadde Batthula Vijaya Lakshmi, Garcia Hernan G, Qian Shu-Bing, Brunkard Jacob O, Roeder Adrienne H K
Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA; Section of Plant Biology, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USA.
Laboratory of Genetics, University of Wisconsin, Madison, WI 53706, USA.
Dev Cell. 2024 Dec 2;59(23):3141-3160.e7. doi: 10.1016/j.devcel.2024.08.010. Epub 2024 Sep 20.
Robustness is the invariant development of phenotype despite environmental changes and genetic perturbations. In the Arabidopsis flower bud, four sepals robustly initiate and grow to a constant size to enclose and protect the inner floral organs. We previously characterized the mutant development-related myb-like 1 (drmy1), where 3-5 sepals initiate variably and grow to different sizes, compromising their protective function. The molecular mechanism underlying this loss of robustness was unclear. Here, we show that drmy1 has reduced TARGET OF RAPAMYCIN (TOR) activity, ribosomal content, and translation. Translation reduction decreases the protein level of ARABIDOPSIS RESPONSE REGULATOR7 (ARR7) and ARABIDOPSIS HISTIDINE PHOSPHOTRANSFER PROTEIN 6 (AHP6), two cytokinin-signaling inhibitors that are normally rapidly produced before sepal initiation. The resultant upregulation of cytokinin signaling disrupts robust auxin patterning and sepal initiation. Our work shows that the homeostasis of translation, a ubiquitous cellular process, is crucial for the robust spatiotemporal patterning of organogenesis.
稳健性是指尽管存在环境变化和基因扰动，表型仍能稳定发育。在拟南芥花芽中，四个萼片稳健地起始并生长到恒定大小，以包裹和保护内部花器官。我们之前对与突变体发育相关的类myb1（drmy1）进行了表征，在该突变体中，3 - 5个萼片起始数量可变且生长到不同大小，损害了它们的保护功能。这种稳健性丧失背后的分子机制尚不清楚。在这里，我们表明drmy1具有降低的雷帕霉素靶蛋白（TOR）活性、核糖体含量和翻译水平。翻译水平降低会降低拟南芥响应调节因子7（ARR7）和拟南芥组氨酸磷酸转移蛋白6（AHP6）的蛋白质水平，这两种细胞分裂素信号抑制剂通常在萼片起始之前迅速产生。由此导致的细胞分裂素信号上调会破坏稳健的生长素模式和萼片起始。我们的工作表明，翻译的稳态作为一种普遍存在的细胞过程，对于器官发生的稳健时空模式形成至关重要。
