The role of OsPT8 in arsenate uptake and varietal difference in arsenate tolerance in rice.
Arsenic (As) contamination in paddy soil can cause phytotoxicity and elevated As accumulation in rice grain. Rice varieties vary in As uptake and tolerance, but the underlying mechanisms remain unclear. In this study, the aus variety Kasalath was found to be more tolerant to arsenate [As(V)] than the japonica variety Nipponbare, but the two varieties showed similar arsenite [As(III)] tolerance. Nipponbare took up more phosphate (Pi) and As(V) than Kasalath. The expression of genes for Pitransporters or Pihomeostasis regulation was quantified. Nipponbare showed 2- to 3-fold higher expression of the Pitransporter genes OsPT2 and OsPT8 than Kasalath. Two ospt8 mutants were isolated from the Kasalath background and compared with an ospt8 mutant in the Nipponbare background. Mutation in OsPT8 in both backgrounds decreased As(V) uptake by 33-57%, increased As(V) tolerance assayed by root elongation by >100-fold, and abolished the varietal differences in As(V) uptake and tolerance. The results show that OsPT8 plays a key role in As(V) uptake and that As(V) uptake mediated by OsPT8 exerts a profound toxic effect on root elongation. The results also suggest that differential OsPT8 expression explains the varietal differences in As(V) uptake and tolerance between Kasalath and Nipponbare.
State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
Peitong
P
Wang
State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
Wenwen
W
Zhang
State Key Laboratory of Plant Physiology and Biochemistry, College of Life Science, Zhejiang University, Hangzhou 310058, China.
Chuanzao
C
Mao
State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
Guohua
G
Xu
State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China fangjie.zhao@njau.edu.cn.|Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK.
Fang-Jie
0000-0002-0164-169X
FJ
Zhao
D001149:Arsenates / Q000378:metabolism* / Q000633:toxicity; D018053:Arsenites / Q000378:metabolism / Q000633:toxicity; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D017343:Genes, Plant / Q000502:physiology; D009154:Mutation; D012275:Oryza / Q000187:drug effects* / Q000378:metabolism; D028061:Phosphate Transport Proteins / Q000502:physiology*; D010710:Phosphates / Q000378:metabolism; D010940:Plant Proteins / Q000502:physiology*; D018517:Plant Roots / Q000378:metabolism; D018520:Plant Shoots / Q000378:metabolism; D059467:Transcriptome
D001149:Arsenates; D018053:Arsenites; D028061:Phosphate Transport Proteins; D010710:Phosphates; D010940:Plant Proteins; C015001:arsenite; C025657:arsenic acid
Arsenate; arsenate tolerance; arsenate toxicity; arsenic; phosphate transporters; rice.