title: Superoxide serves as a putative signal molecule for plant cell division: overexpression of CaRLK1 promotes the plant cell cycle via accumulation of O2-and decrease in H2O2.
abstract: Reactive oxygen species (ROS) exert both positive and negative effects on plant growth and development and therefore receive a great deal of attention in current research. A hot pepper, Capsicum annuum receptor-like kinase 1 (CaRLK1) was ectopically expressed in Nicotiana tabacum BY-2 cell and Nicotiana benthamiana plants. This ectopic expression of CaRLK1 enhanced cell division and proliferation in both heterologous systems. Apparently, CaRLK1 is involved in controlling the cell cycle, possibly by inducing expressions of cyclin B1, cyclin D3, cyclin-dependent protein kinase 3, condensin complex subunit 2 and anaphase-promoting complex subunit 11 genes. CaRLK1 overexpression also increased transcript accumulation of NADPH oxidase genes, generation of O2-and catalase (CAT) activity/protein levels. In parallel, it decreased cellular H2O2levels and cell size. Treatment with Tiron or diphenyleneiodonium (DPI) both decreased the cell division rate and O2-concentrations, but increased cellular H2O2levels. Tobacco BY-2 cells overexpressing CaRLK1 were more sensitive to amino-1,2,4-triazole (3-AT), a CAT inhibitor, than control cells, suggesting that the increased H2O2levels may not function as a signal for cell division and proliferation. Overexpression of CaRLK1 stimulated progression of the cell cycle from G0/G1phase into the S phase. It is concluded that the CaRLK1 protein plays a pivotal role in controlling the level of O2-as signaling molecule which promotes cell division, concomitant with a reduction in H2O2by the induction of CAT activity/protein.
authors.affiliation: School of Biological Sciences and Technology, Chonnam National University, Gwangju, South Korea.
authors.forename: Dong Ju
authors.initials: DJ
authors.lastname: Lee
authors.affiliation: School of Biological Sciences and Technology, Chonnam National University, Gwangju, South Korea.
authors.forename: Hyun Jun
authors.initials: HJ
authors.lastname: Choi
authors.affiliation: Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and life Sciences, College of Agriculture & Life Sciences, Seoul National University, Seoul, South Korea.
authors.forename: Mid-Eum
authors.initials: ME
authors.lastname: Moon
authors.affiliation: School of Biological Sciences and Technology, Chonnam National University, Gwangju, South Korea.
authors.forename: Youn-Tae
authors.initials: YT
authors.lastname: Chi
authors.affiliation: School of Biological Sciences and Technology, Chonnam National University, Gwangju, South Korea.
authors.forename: Kon-Young
authors.initials: KY
authors.lastname: Ji
authors.affiliation: Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and life Sciences, College of Agriculture & Life Sciences, Seoul National University, Seoul, South Korea.|Seed Biotechnology Institute, Institute of Green Bio Science and Technology, Pyeongchang Campus, Seoul National University, Pyeongchang, South Korea.
authors.forename: Doil
authors.initials: D
authors.lastname: Choi
mesh_terms: D002212:Capsicum / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D002453:Cell Cycle / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D000066630:Ectopic Gene Expression; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008954:Models, Biological; D019255:NADPH Oxidases / Q000235:genetics; D009861:Onium Compounds / Q000494:pharmacology; D011494:Protein Kinases / Q000235:genetics; D013481:Superoxides / Q000378:metabolism*; D014026:Nicotiana / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D014230:Triazoles / Q000494:pharmacology
chemical_list: D009861:Onium Compounds; D014230:Triazoles; D013481:Superoxides; C045575:1,2,4-triazole; C007517:diphenyleneiodonium; D006861:Hydrogen Peroxide; D019255:NADPH Oxidases; D011494:Protein Kinases