WRKY42 modulates phosphate homeostasis through regulating phosphate translocation and acquisition in Arabidopsis.
The Arabidopsis (Arabidopsis thaliana) WRKY transcription factor family has more than 70 members, and some of them have been reported to play important roles in plant response to biotic and abiotic stresses. This study shows that WRKY42 regulated phosphate homeostasis in Arabidopsis. The WRKY42-overexpressing lines, similar to the phosphate1 (pho1) mutant, were more sensitive to low-inorganic phosphate (Pi) stress and had lower shoot Pi content compared with wild-type plants. The PHO1 expression was repressed in WRKY42-overexpressing lines and enhanced in the wrky42 wrky6 double mutant. The WRKY42 protein bound to the PHO1 promoter under Pi-sufficient condition, and this binding was abrogated during Pi starvation. These data indicate that WRKY42 modulated Pi translocation by regulating PHO1 expression. Furthermore, overexpression of WRKY42 increased root Pi content and Pi uptake, whereas the wrky42 mutant had lower root Pi content and Pi uptake rate compared with wild-type plants. Under Pi-sufficient condition, WRKY42 positively regulated PHOSPHATE TRANSPORTER1;1 (PHT1;1) expression by binding to the PHT1;1 promoter, and this binding was abolished by low-Pi stress. During Pi starvation, the WRKY42 protein was degraded through the 26S proteasome pathway. Our results showed that AtWRKY42 modulated Pi homeostasis by regulating the expression of PHO1 and PHT1;1 to adapt to environmental changes in Pi availability.
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, National Plant Gene Research Centre (Beijing), Beijing 100193, China.
Tong
T
Su
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, National Plant Gene Research Centre (Beijing), Beijing 100193, China.
Qian
Q
Xu
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, National Plant Gene Research Centre (Beijing), Beijing 100193, China.
Fei-Cui
FC
Zhang
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, National Plant Gene Research Centre (Beijing), Beijing 100193, China.
Yun
Y
Chen
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, National Plant Gene Research Centre (Beijing), Beijing 100193, China.
Li-Qin
LQ
Li
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, National Plant Gene Research Centre (Beijing), Beijing 100193, China.
Wei-Hua
WH
Wu
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, National Plant Gene Research Centre (Beijing), Beijing 100193, China chenyifang@cau.edu.cn.
Yi-Fang
YF
Chen
D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D006706:Homeostasis; D008954:Models, Biological; D009154:Mutation; D010641:Phenotype; D028061:Phosphate Transport Proteins / Q000235:genetics / Q000378:metabolism*; D010710:Phosphates / Q000172:deficiency / Q000378:metabolism*; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D046988:Proteasome Endopeptidase Complex / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000235:genetics / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D029681:Arabidopsis Proteins; C460111:PHO1 protein, Arabidopsis; C520845:PHT1;1 protein, Arabidopsis; D028061:Phosphate Transport Proteins; D010710:Phosphates; D014157:Transcription Factors; C547879:WRKY42 protein, Arabidopsis; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease