title: Knockdown of OsPAO and OsRCCR1 cause different plant death phenotypes in rice.
abstract: Pheophorbide a oxygenase (PAO) and red chlorophyll catabolite reductase (RCCR) catalyze key steps in chlorophyll degradation by opening the porphyrin macrocycle of pheophorbide a and forming the primary non-photoreactive fluorescent chlorophyll catabolite. These genes strongly participate in senescence and reportedly involved in plants' responses to physical wounding and pathogens. In this report, a single PAO gene (OsPAO) and two RCCR genes (OsRCCR1 and OsRCCR2) have been isolated from rice. Expression analysis by semi-quantitative PCR or quantitative real-time PCR showed that OsRCCR1 transcripts were much more abundant than OsRCCR2, and all of these genes were upregulated during senescence and following wound treatment. RNA interference knockdown of OsPAO led to pheophorbide a accumulation in leaves (especially dark-induced senescent leaves) and leaf death from regeneration stage onwards, even transgenic plants inviability after transplantation. While, knockdown of OsRCCR1 resulted in lesion-mimic spots generation in older leaves which died off early in the transgenic plants. These results suggest that OsPAO and OsRCCR1 play key roles in senescence and are involved in wound responses.
authors.affiliation: Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, PR China.
authors.forename: Yongyan
authors.initials: Y
authors.lastname: Tang
authors.forename: Meiru
authors.initials: M
authors.lastname: Li
authors.forename: Yaping
authors.initials: Y
authors.lastname: Chen
authors.forename: Pingzhi
authors.initials: P
authors.lastname: Wu
authors.forename: Guojiang
authors.initials: G
authors.lastname: Wu
authors.forename: Huawu
authors.initials: H
authors.lastname: Jiang
mesh_terms: D000595:Amino Acid Sequence; D016923:Cell Death; D002734:Chlorophyll / Q000031:analogs & derivatives / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D009928:Organ Specificity; D012275:Oryza / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D010105:Oxygenases / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D010802:Phylogeny; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D018547:Plant Stems / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics; D018749:RNA, Plant / Q000235:genetics; D012639:Seeds / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D016415:Sequence Alignment; D015854:Up-Regulation / Q000235:genetics
chemical_list: D010940:Plant Proteins; D012333:RNA, Messenger; D018749:RNA, Plant; D002734:Chlorophyll; D010088:Oxidoreductases; D010105:Oxygenases; C112915:pheide a oxygenase; C580943:RCCR1 protein, rice; C580944:RCCR2 protein, rice; C032623:pheophorbide a