Comparative microarray analysis of programmed cell death induced by proteasome malfunction and hypersensitive response in plants.
Programmed cell death (PCD) plays a pivotal role in the elimination of injured or unwanted cells during diverse physiological and developmental conditions in organisms. However in contrast to the animal system, signaling pathways and molecular mechanism of PCD are largely unknown in plants. We previously reported that silencing of NbPAF encoding the alpha6 subunit of 20S proteasome by virus-induced gene silencing activated programmed cell death in plants by inactivating proteasome function. In this study, we analyzed global gene expression profile of PCD induced by suppression of NbPAF expression, in comparison with that of hypersensitive response (HR)-induced PCD, using a cDNA microarray representing 4685 hot pepper genes. HR is a well-characterized PCD program in plants, which occurs in response to pathogen infection. The microarray analyses identified 247 genes whose gene expression was differentially modulated during PCD activated by NbPAF depletion or HR. Most of the genes that were up-regulated during the NbPAF-mediated PCD, including the ubiquitin/proteasome pathway-related genes, were down-regulated during HR cell death. In contrast, transcription of many defense-related genes, transcription factor genes, and photosynthesis-related genes remained unchanged or repressed during NbPAF-mediated PCD, while it was highly induced during HR cell death. Only a small number of genes including antioxidant-related genes and proteases were found to be up-regulated during induction of PCD by both proteasome inactivation and HR. Based on these results, these two PCD pathways appear to be differentially regulated, but some overlapping mechanism exists, which involves core regulators of plant PCD.
BioNanotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-333, Republic of Korea.
Moonil
M
Kim
Sanghyeob
S
Lee
Kyoungsook
K
Park
Eun-Ju
EJ
Jeong
Choong-Min
CM
Ryu
Doil
D
Choi
Hyun-Sook
HS
Pai
D017209:Apoptosis / Q000235:genetics* / Q000502:physiology; D002212:Capsicum / Q000235:genetics; D015536:Down-Regulation / Q000235:genetics; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D020411:Oligonucleotide Array Sequence Analysis; D018384:Oxidative Stress / Q000235:genetics; D010802:Phylogeny; D046988:Proteasome Endopeptidase Complex / Q000235:genetics* / Q000502:physiology; D015398:Signal Transduction / Q000235:genetics; D014026:Nicotiana / Q000166:cytology* / Q000201:enzymology* / Q000235:genetics*; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics; D015854:Up-Regulation / Q000235:genetics
D014157:Transcription Factors; D046988:Proteasome Endopeptidase Complex