MERISTEM ACTIVITYLESS(MAL) is involved in root development through maintenance of meristem size in rice
MERISTEM ACTIVITYLESS(MAL) is involved in root development through maintenance of meristem size in rice
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MERISTEM ACTIVITYLESS (MAL) 通过维持水稻分生组织大小参与根部发育
DOI：
10.1007/s11103-020-01053-4
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发表时间：
2020-09-12
影响因子：
5.1
通讯作者：
Zhao, Yu
中科院分区：
文献类型：
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作者：
Jiang, Wei;Zhou, Shaoli;Zhao, Yu
水稻分生组织（MERISTEM activitless， MAL）是一个含有RING-H2指结构域（RFD）的基因，通过细胞分裂素信号介导根原基形成后，调控分生组织细胞的活力。RING-H2指域（RFD）家族基因在植物发育和生物/非生物胁迫响应中发挥着多种作用。水稻MERISTEM actiyless （MAL）基因位于RING-H2指结构域（RFD）中，其n端有一个跨膜结构域，c端有一个C3H2C3锌指结构域。为了阐明MAL的生理和分子功能，我们通过RNA干扰产生MAL基因敲低的转基因植株。MAL rna干扰（MRi）转基因植株表现出冠根长度短、冠根数少、细胞分裂率低的表型。在MAL表达的根分生组织中，分裂率较低。此外，转录组数据显示，细胞壁大分子代谢相关基因和氧化还原相关基因在MAL RNAi细胞系中富集。这些差异表达基因（DEGs）大多是由外源性细胞分裂素诱导的。因此，我们认为MAL作为一种新的调控因子，在根原始形成开始后，通过细胞分裂素信号和活性氧（ROS）介导，在分生组织中维持细胞活力方面起着重要作用。
Rice MERISTEM ACTIVITYLESS (MAL), a RING-H2 finger domain (RFD)-containing gene, regulates meristem cell viability after the initiation of root primordia mediated by cytokinin signaling. Genes in the RING-H2 finger domain (RFD) family play various roles during plant development and in biotic/abiotic stress responses. Rice gene MERISTEM ACTIVITYLESS (MAL), being contained in the RING-H2 finger domain (RFD), is characterized by a transmembrane domain at the N-terminal and a C3H2C3 zinc finger domain at the C-terminal. To elucidate the physiological and molecular functions of MAL, we generated MAL knockdown transgenic plants by RNA interference. MAL RNA-interfered (MRi) transgenic plants exhibited a phenotype with shorter crown root length and lower crown root number, accompanied by a lower cell division rate. The low division rate was observed in the root meristem exactly where MAL was expressed. Furthermore, transcriptome data revealed that cell wall macromolecule metabolism-related genes and redox-related genes were enriched in MAL RNAi lines. Most of these differentially expressed genes (DEGs) were induced by exogenous cytokinin. Hence, we conclude that MAL, as a novel regulatory factor, plays a major role in maintaining cell viability in the meristem after the initiation of root primordial formation, mediated by cytokinin signaling and reactive oxygen species (ROS).