Over-expression of mitochondrial heat shock protein 70 suppresses programmed cell death in rice.
In this study, we identified and functionally characterized the mitochondrial heat shock protein 70 (mtHsp70). Over-expression of mtHsp70 suppressed heat- and H(2)O(2)-induced programmed cell death (PCD) in rice protoplasts, as reflected by higher cell viability, decreased DNA laddering and chromatin condensation. Mitochondrial membrane potential (Δψ(m)) after heat shock was destroyed gradually in protoplasts, but mtHsp70 over-expression showed higher Δψ(m) relative to the vector control cells, and partially inhibited cytochrome c release from mitochondria to cytosol. Heat treatment also significantly increased reactive oxygen species (ROS) generation, a phenomenon not observed in protoplasts over-expressing mtHsp70. Together, these results suggest that mtHsp70 may suppress PCD in rice protoplasts by maintaining mitochondrial Δψ(m) and inhibiting the amplification of ROS.
College of Life Science, Nanjing Agricultural University, Nanjing, Jiangsu, China.
Yaocheng
Y
Qi
Hongjuan
H
Wang
Yu
Y
Zou
Cheng
C
Liu
Yanqi
Y
Liu
Ying
Y
Wang
Wei
W
Zhang
D017209:Apoptosis; D015153:Blotting, Western; D002470:Cell Survival; D002843:Chromatin / Q000378:metabolism; D053938:DNA Fragmentation; D018506:Gene Expression Regulation, Plant; D018840:HSP70 Heat-Shock Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D006358:Hot Temperature; D006861:Hydrogen Peroxide / Q000494:pharmacology; D020287:In Situ Nick-End Labeling; D053078:Membrane Potential, Mitochondrial; D008856:Microscopy, Fluorescence; D012275:Oryza / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D016877:Oxidants / Q000494:pharmacology; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011523:Protoplasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
D002843:Chromatin; D018840:HSP70 Heat-Shock Proteins; D016877:Oxidants; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide