Effect of arsenic on chloroplast ultrastructure and calcium distribution in arsenic hyperaccumulator Pteris vittata L.
This study investigated the impacts of arsenic (As) on the chloroplast ultrastructure and calcium (Ca) distribution in Chinese brake (Pteris vittata L.) mainly by histochemical methods, with an emphasis on the possible function of Ca in As detoxification and accumulation in P. vittata. P. vittata was grown in an artificially contaminated soil added with different concentrations of Na(2)HAsO(4) (0, 100, 300 and 800 mg kg(-1) As dry soil) for 24 weeks in a greenhouse. The addition of As did not affect the chloroplast ultrastructure of young pinna, meanwhile most of the membrane systems of chloroplasts in mature pinna were severely damaged under high As condition. Calcium concentration in the fronds of P. vittata was not significantly affected by the addition of As, but Ca concentration in the mature pinna significantly increased by As addition, consistent with the position appearing As toxicity. When no As was added, most of calcium precipitates distributed around the inner membrane of vacuole. But when the pinna appeared plasmolysis, more calcium precipitates resided outside the cell membrane and bigger particles evenly distributed in the cytoplasm. All the results indicated that Ca had a close relation with As toxicity in P. vittata.
Center for Environmental Remediation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A Datun Road, Beijing 100101, PR China.
Wen-Xue
WX
Li
Tong-Bin
TB
Chen
Ze-Chun
ZC
Huang
Mei
M
Lei
Xiao-Yong
XY
Liao
D001151:Arsenic / Q000378:metabolism / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002736:Chloroplasts / Q000648:ultrastructure*; D032495:Pteris / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism*; D012989:Soil Pollutants / Q000378:metabolism / Q000494:pharmacology
D012989:Soil Pollutants; D001151:Arsenic; D002118:Calcium