OsMYB2P-1, an R2R3 MYB Transcription Factor, Is Involved in the Regulation of Phosphate-Starvation Responses and Root Architecture in Rice
OsMYB2P-1, an R2R3 MYB Transcription Factor, Is Involved in the Regulation of Phosphate-Starvation Responses and Root Architecture in Rice
复制标题
OsMYB2P-1 是一种 R2R3 MYB 转录因子，参与水稻磷酸盐饥饿反应和根结构的调节
DOI：
10.1104/pp.112.194217
复制
发表时间：
2012-05-01
期刊：
影响因子：
7.4
通讯作者：
Zhang, Wen-Hao
中科院分区：
文献类型：
--
作者：
Dai, Xiaoyan;Wang, Yuanyuan;Zhang, Wen-Hao
通过对水稻基因表达谱的监测，从基因芯片数据中鉴定出一个R2R3 MYB转录因子OsMYB2P-1。幼苗暴露在磷(PI)缺乏的介质中。PI饥饿可诱导OsMYB2P-1的表达。OsMYB2P-1定位于细胞核内，具有转录激活活性。在拟南芥和水稻中过表达OsMYB2P-1提高了水稻对磷饥饿的耐受性，而在水稻中通过RNA干扰抑制OsMYB2P-1使转基因水稻对磷缺乏更加敏感。此外，在PI充足条件下，OsMYB2P-1高表达植株的初生根比野生型植株短，而在缺磷条件下，OsMYB2P-1高表达植株的初生根和不定根长于野生型植株。这些结果表明，OsMYB2P-1可能还与根系构型的调控有关。OsMYB2P-1的过表达导致水稻UDP-磺基喹诺糖合成酶、OsIPS1、OsPAP10、OsmiR399a和OsmiR399j等PI反应基因的表达增加。相反，过表达OsMYB2P-1在PI充足和PI不足的条件下都抑制了OsPHO2的表达。此外，在PI充足的条件下，编码低亲和力PI转运蛋白的OsPT2在OsMYB2P-1高表达的植物中表达上调，而在PI缺乏的条件下，OsMYB2P-1的过表达上调了高亲和力的PI转运蛋白OsPT6、OsPT8和OsPT10的表达，这表明OsMYB2P-1可能在PI转运蛋白的表达调控中起着依赖于PI的调节作用。这些结果表明OsMYB2P-1是一个新的与水稻PI饥饿信号相关的R2R3 MYB转录因子。
An R2R3 MYB transcription factor, OsMYB2P-1, was identified from microarray data by monitoring the expression profile of rice (Oryza sativa ssp. japonica) seedlings exposed to phosphate (Pi)-deficient medium. Expression of OsMYB2P-1 was induced by Pi starvation. OsMYB2P-1 was localized in the nuclei and exhibited transcriptional activation activity. Overexpression of OsMYB2P-1 in Arabidopsis (Arabidopsis thaliana) and rice enhanced tolerance to Pi starvation, while suppression of OsMYB2P-1 by RNA interference in rice rendered the transgenic rice more sensitive to Pi deficiency. Furthermore, primary roots of OsMYB2P-1-overexpressing plants were shorter than those in wild-type plants under Pi-sufficient conditions, while primary roots and adventitious roots of OsMYB2P-1-overexpressing plants were longer than those of wild-type plants under Pi-deficient conditions. These results suggest that OsMYB2P-1 may also be associated with the regulation of root system architecture. Overexpression of OsMYB2P-1 led to greater expression of Pi-responsive genes such as Oryza sativa UDP-sulfoquinovose synthase, OsIPS1, OsPAP10, OsmiR399a, and OsmiR399j. In contrast, overexpression of OsMYB2P-1 suppressed the expression of OsPHO2 under both Pi-sufficient and Pi-deficient conditions. Moreover, expression of OsPT2, which encodes a low-affinity Pi transporter, was up-regulated in OsMYB2P-1-overexpressing plants under Pi-sufficient conditions, whereas expression of the high-affinity Pi transporters OsPT6, OsPT8, and OsPT10 was up-regulated by overexpression of OsMYB2P-1 under Pi-deficient conditions, suggesting that OsMYB2P-1 may act as a Pi-dependent regulator in controlling the expression of Pi transporters. These findings demonstrate that OsMYB2P-1 is a novel R2R3 MYB transcriptional factor associated with Pi starvation signaling in rice.