Bcl-2 suppresses activation of VPEs by inhibiting cytosolic Ca²⁺ level with elevated K⁺ efflux in NaCl-induced PCD in rice.
Bcl-2 is one of the most important antiapoptotic members in mammals and prevents many forms of apoptosis in a variety of cell types. Our previous study revealed that overexpression of Bcl-2 significantly suppressed H2O2/NaCl-induced programmed cell death via inhibiting the transcriptional activation of OsVPE2 and OsVPE3 in transgenic rice. However, Ca(2+) and K(+) homeostasis of this process remains largely unknown. In the present study, we investigate whether nonselective cation channels (NSCC) blockers affect Bcl-2 function in rice under salt stress and how Bcl-2 affects ion homeostasis in salt stress-induced PCD. The results showed that overexpression of Bcl-2 significantly decreased transient elevations in the cytosolic Ca(2+) levels, inhibited NaCl-induced K(+) efflux but not H(+) efflux across the plasma membrane, and further suppressed the expression levels of OsVPE2 and OsVPE3, leading to the inhibition of salt-induced PCD and increase of tolerance to salt stress in transgenic rice. During the NaCl-induced PCD, the effects of a NSCC blocker La(3+) on ion homeostasis and VPEs expression in wild-type were similar to the effects of Bcl-2 overexpression in transgenic line. However, a synergistic effect of Bcl-2 and La(3+) was not obviously detectable. Our results suggested that Bcl-2 played an important role in suppression of NaCl-induced PCD by disruption of ion homeostasis, providing an insight into the mechanistic study of plant VPEs, cytosolic Ca(2+) level and K(+) efflux.
Institute of Genetics, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
Yongho
Y
Kim
Institute of Genetics, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
Mingqiang
M
Wang
Institute of Genetics, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
Yu
Y
Bai
Institute of Genetics, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
Zhanghui
Z
Zeng
Institute of Genetics, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
Fu
F
Guo
Institute of Genetics, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
Ning
N
Han
Institute of Genetics, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, College of Life Sciences, Zhejiang University, Hangzhou 310058, China. Electronic address: hwbian@zju.edu.cn.
Hongwu
H
Bian
Institute of Genetics, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
Junhui
J
Wang
College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, China.
Jianwei
J
Pan
Institute of Genetics, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
Muyuan
M
Zhu
D017209:Apoptosis / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism*; D012275:Oryza / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2; D012965:Sodium Chloride / Q000494:pharmacology*
D019253:Proto-Oncogene Proteins c-bcl-2; D012965:Sodium Chloride; D011188:Potassium; D002118:Calcium
Bcl-2; Cytosolic Ca(2+); K(+) efflux; NaCl stress; Programmed cell death; Transgenic rice; Vacuolar processing enzyme