An Arabidopsis mutant of inositol pentakisphosphate 2-kinase AtIPK1 displays reduced arsenate tolerance.
Arsenate [As(V)] toxicity is considered to be derived from similarities in the chemical properties of As(V) and phosphate (Pi). An Arabidopsis thaliana mutant of inositol pentakisphosphate 2-kinase (AtIPK1), atipk1-1, has previously exhibited lower level of phytate and higher level of Pi, relative to wild-type (WT). Here, atipk1-1 displayed hypersensitivity to As(V) stress and less As(V) uptake when compared to WT. Overexpression of AtIPK1 controlled by the CaMV 35S promoter partially rescued the As(V)-sensitive phenotype of atipk1-1. When compared to control Pi status, addition of Pi enhanced As(V) tolerance of both WT and atipk1-1 plants, while the arsenic concentration was less reduced in the latter genotype. Despite the higher Pi level in atipk1-1 than did WT plants, the mutant suffered more severe Pi starvation under Pi limitation stress, indicating that Pi homeostasis was altered in the mutant. Gene expression analysis of WT and atipk1-1 plants showed the diverse effect of As(V) stress on Pi starvation-dependent regulation of Pi-responsive genes. Our study suggested that a particular mechanism of As(V) toxicity existed in atipk1-1 mutant, and may offer new insights into the interactions between Pi homeostasis and As(V) detoxification in plants.
Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
Yang-Yang
YY
Sun
Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
Wen-Zhong
WZ
Xu
Hunan Provincial Key Laboratory of Phytohormones and Growth and Development, Hunan Agricultural University, Changsha, 410128, China.
Li
L
Wu
Hunan Provincial Key Laboratory of Phytohormones and Growth and Development, Hunan Agricultural University, Changsha, 410128, China.
Ruo-Zhong
RZ
Wang
Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
Zhen-Yan
ZY
He
Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
Mi
M
Ma
D000222:Adaptation, Physiological / Q000187:drug effects; D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology* / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001149:Arsenates / Q000633:toxicity*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D009154:Mutation / Q000235:genetics*; D010641:Phenotype; D010710:Phosphates / Q000378:metabolism; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism*; D013312:Stress, Physiological / Q000187:drug effects; D014158:Transcription, Genetic / Q000187:drug effects
D029681:Arabidopsis Proteins; D001149:Arsenates; D010710:Phosphates; D017853:Phosphotransferases (Alcohol Group Acceptor); C508906:inositol 1,3,4,5,6-pentakisphosphate 2-kinase, Arabidopsis; C025657:arsenic acid
Arabidopsis; AtIPK1; arsenate; phosphate; phosphate homeostasis