Activation of MKK9-MPK3/MPK6 enhances phosphate acquisition in Arabidopsis thaliana
Activation of MKK9-MPK3/MPK6 enhances phosphate acquisition in Arabidopsis thaliana
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DOI：
10.1111/nph.12872
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发表时间：
2014-09-01
期刊：
影响因子：
9.4
通讯作者：
Ren, Dongtao
中科院分区：
文献类型：
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作者：
Lei, Lei;Li, Yuan;Ren, Dongtao
尽管土壤中含有丰富的磷，但很少有磷酸盐（Pi）可供植物使用。植物通常经历低Pi（LP）胁迫。利用凝胶内激酶测定法，我们测定了拟南芥幼苗在LP和Pi充足（Murashige and Skoog，MS）条件下MPK 3和MPK 6的活性。利用MKK 9突变体、转基因突变体和杂交突变体，分析了MPK 3和MPK 6在调节幼苗磷胁迫反应中的功能。还筛选了MKK 9下游组分-MPK 3/MPK 6对Pi反应的调节。LP处理激活了MPK 3和MPK 6。在LP和MS条件下，mpk 3和mpk 6幼苗对Pi的吸收和积累均低于野生型，MKK 9-MPK 3/MPK 6的激活诱导了Pi吸收相关基因的转录，促进了Pi的吸收和积累，而其激活则抑制了花青素生物合成相关基因的转录和花青素的积累; WRKY 75在调控植物体内Pi和花色素苷的积累以及Pi获得相关基因和花色素苷生物合成基因的转录时，位于MKK 9-MPK 3/MPK 6的下游，表明MKK 9-MPK 3/MPK 6级联是植物体内Pi信号通路的一部分。
Despite the abundance of phosphorus in soil, very little is available as phosphate (Pi) for plants. Plants often experience low Pi (LP) stress. Intensive studies have been conducted to reveal the mechanism used by plants to deal with LP; however, Pi sensing and signal transduction pathways are not fully understood.Using in-gel kinase assays, we determined the activities of MPK3 and MPK6 in Arabidopsis thaliana seedlings under both LP and Pi-sufficient (Murashige and Skoog, MS) conditions. Using MKK9 mutant transgenic and crossed mutants, we analyzed the functions of MPK3 and MPK6 in regulating Pi responses of seedlings. The regulation of Pi responses by downstream components of MKK9-MPK3/MPK6 was also screened.LP treatment activated MPK3 and MPK6. Under both LP and MS conditions, mpk3 and mpk6 seedlings took up and accumulated less Pi than the wild-type; activation of MKK9-MPK3/MPK6 in transgenic seedlings induced the transcription of Pi acquisition-related genes and enhanced Pi uptake and accumulation, whereas its activation suppressed the transcription of anthocyanin biosynthetic genes and anthocyanin accumulation; WRKY75 was downstream of MKK9-MPK3/MPK6 when regulating the accumulation of Pi and anthocyanin, and the transcription of Pi acquisition-related and anthocyanin biosynthetic genes.These results suggest that the MKK9-MPK3/MPK6 cascade is part of the Pi signaling pathway in plants.