Wei Gang, Yu Wenjing, Chen Xinlong, Yun Han, Wang Tongming, Wang Nan, Zhang Ting, He Guanghua
Chongqing Key Laboratory of Crop Molecular Improvement, Rice Research Institute, Academy of Agricultural Sciences, College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China.
Integrative Science Center of Germplasm Creation in Western China (Chongqing) Science City, College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China.
Plants (Basel). 2025 May 27;14(11):1627. doi: 10.3390/plants14111627.
The growth of young roots is crucial for the development and yield of rice. However, the molecular mechanisms underlying young rice root development remain unclear. Our research indicates that the rice B-type cytokinin response regulator factor negatively regulates the development of young rice roots. is highly expressed in the root meristematic zone of young rice roots. In transgenic lines overexpressing , the lengths of primary roots and adventitious roots, as well as the corresponding root meristematic zone lengths, are significantly reduced. This is due to a decrease in both the number and size of longitudinal cells in the root meristematic zone. On the one hand, can inhibit root apical cell division and reduce the number of longitudinal cells in the root meristematic zone by affecting the auxin synthesis and transport pathways. On the other hand, ORR3 may directly activate the transcription of cell wall metabolism-related genes, thereby restricting the size of cells in the root meristematic zone. In summary, negatively regulates rice young root growth by responding to cytokinin signals to influence auxin signal transduction and cell wall metabolism pathways, thereby negatively regulating the number and size of cells in the root meristematic zone.
幼根的生长对水稻的发育和产量至关重要。然而，水稻幼根发育的分子机制仍不清楚。我们的研究表明，水稻B型细胞分裂素响应调节因子对水稻幼根的发育起负调控作用。它在水稻幼根的根分生区高度表达。在过表达该因子的转基因株系中，主根和不定根的长度以及相应的根分生区长度均显著缩短。这是由于根分生区纵向细胞的数量和大小均减少。一方面，该因子可通过影响生长素合成和运输途径来抑制根尖细胞分裂并减少根分生区纵向细胞的数量。另一方面，ORR3可能直接激活细胞壁代谢相关基因的转录，从而限制根分生区细胞的大小。总之，该因子通过响应细胞分裂素信号来影响生长素信号转导和细胞壁代谢途径，从而对水稻幼根生长起负调控作用，进而负调控根分生区细胞的数量和大小。
