美国杜克大学Pablo Szekely和Cara M. Winter共同合作，近期取得重要工作进展。他们研究提出，SHR和SCR在细胞周期早期协调根系的形成和生长。相关研究成果2024年1月31日在线发表于《自然》杂志上。

据介绍，在多细胞生物的发育过程中，精确控制细胞分裂对于正常的模式和生长至关重要。产生新组织模式的形成性分裂与促进生长的增殖性分裂之间的协调尚不清楚。SHORTROT（SHR）和SCARECROW（SCR）是在拟南芥根系干细胞生态位中形成分裂所需的转录因子。

研究人员发现SHR和SCR在细胞周期早期的水平决定了分裂平面的方向，导致形成性或增殖性细胞分裂。研究人员使用4D定量、长期和频繁（每15分钟一次，持续48小时）光片和共聚焦显微镜来探测活根的单个细胞内SHR和SCR串联的动力学。通过SHR诱导系统直接控制它们的动力学，研究人员能够挑战现有的SHR-SCR基因调控网络的双稳态模型，并确定对拯救SHR突变体的形成性分裂至关重要的关键特征。SHR和SCR动力学与双稳态系统的预期行为不一致，形成分裂只需要细胞周期早期出现的低瞬态水平。

总之，这些结果揭示了一种发育调节因子直接协调模式和生长的独特机制。

附：英文原文

Title: SHR and SCR coordinate root patterning and growth early in the cell cycle

Author: Winter, Cara M., Szekely, Pablo, Popov, Vladimir, Belcher, Heather, Carter, Raina, Jones, Matthew, Fraser, Scott E., Truong, Thai V., Benfey, Philip N.

Issue&Volume: 2024-01-31

Abstract: Precise control of cell division is essential for proper patterning and growth during the development of multicellular organisms. Coordination of formative divisions that generate new tissue patterns with proliferative divisions that promote growth is poorly understood. SHORTROOT (SHR) and SCARECROW (SCR) are transcription factors that are required for formative divisions in the stem cell niche of Arabidopsis roots1,2. Here we show that levels of SHR and SCR early in the cell cycle determine the orientation of the division plane, resulting in either formative or proliferative cell division. We used 4D quantitative, long-term and frequent (every 15min for up to 48h) light sheet and confocal microscopy to probe the dynamics of SHR and SCR in tandem within single cells of living roots. Directly controlling their dynamics with an SHR induction system enabled us to challenge an existing bistable model3 of the SHR–SCR gene-regulatory network and to identify key features that are essential for rescue of formative divisions in shr mutants. SHR and SCR kinetics do not align with the expected behaviour of a bistable system, and only low transient levels, present early in the cell cycle, are required for formative divisions. These results reveal an uncharacterized mechanism by which developmental regulators directly coordinate patterning and growth.

DOI: 10.1038/s41586-023-06971-z

Source: https://www.nature.com/articles/s41586-023-06971-z