Shen Feng, Zhang He, Wan Miaomiao, Yang Yanzhi, Kuang Zheng, Xiao Liang, Zuo Daqing, Li Zhan, Qin Genji, Li Lei
Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences in Weifang, Shandong, China.
School of Advanced Agricultural Sciences and School of Life Sciences, Peking University, Beijing, China.
Nat Commun. 2025 May 2;16(1):4108. doi: 10.1038/s41467-025-59336-7.
In plants, endoreplication, the process where nuclear DNA replicates in the absence of mitosis, and remodeling of the primary cell walls are both coupled with cell expansion. However, the mechanisms by which these two processes coordinate to determine cell size remain largely elusive. Here, employing the tcpΔ7 septuple mutant disabling seven of the eight CIN-TCP transcription factors in Arabidopsis, we find that hindered endoreplication progression in tcpΔ7 whereby ploidy increases from 8 C to beyond is correlated with an increase in cell wall pectin. CIN-TCPs transcriptionally activate POLYGALACTURONASE LIKE 1 (PGL1), which encodes a polygalacturonase downregulating both abundance and molecular mass of pectin polymers. Genetic analysis of PGL1 in both the wild type and tcpΔ7 backgrounds confirm that pectin reduction promotes endocycle progression and cell enlargement. Collectively, these findings reveal a critical role of pectin in regulating endoreplication, providing insights in the understanding of cell growth and organ development in plants.
在植物中，核内复制（即细胞核DNA在无有丝分裂的情况下进行复制的过程）和初生细胞壁的重塑都与细胞扩张相关联。然而，这两个过程如何协同作用以决定细胞大小的机制在很大程度上仍不清楚。在这里，我们利用tcpΔ7七重突变体（该突变体使拟南芥中八个CIN-TCP转录因子中的七个失活），发现tcpΔ7中核内复制进程受阻，即倍性从8C增加到更高水平，这与细胞壁果胶的增加相关。CIN-TCP转录激活多聚半乳糖醛酸酶样1（PGL1），PGL1编码一种多聚半乳糖醛酸酶，可下调果胶聚合物的丰度和分子量。在野生型和tcpΔ7背景下对PGL1进行的遗传分析证实，果胶减少促进了内复制周期进程和细胞增大。总的来说，这些发现揭示了果胶在调节核内复制中的关键作用，为理解植物细胞生长和器官发育提供了见解。
