title: The actin-related Protein2/3 complex regulates mitochondrial-associated calcium signaling during salt stress in Arabidopsis.
abstract: Microfilament and Ca(2+) dynamics play important roles in stress signaling in plants. Through genetic screening of Arabidopsis thaliana mutants that are defective in stress-induced increases in cytosolic Ca(2+) ([Ca(2+)]cyt), we identified Actin-Related Protein2 (Arp2) as a regulator of [Ca(2+)]cyt in response to salt stress. Plants lacking Arp2 or other proteins in the Arp2/3 complex exhibited enhanced salt-induced increases in [Ca(2+)]cyt, decreased mitochondria movement, and hypersensitivity to salt. In addition, mitochondria aggregated, the mitochondrial permeability transition pore opened, and mitochondrial membrane potential Ψm was impaired in the arp2 mutant, and these changes were associated with salt-induced cell death. When opening of the enhanced mitochondrial permeability transition pore was blocked or increases in [Ca(2+)]cyt were prevented, the salt-sensitive phenotype of the arp2 mutant was partially rescued. These results indicate that the Arp2/3 complex regulates mitochondrial-dependent Ca(2+) signaling in response to salt stress.
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhao
authors.forename: Zhen
authors.initials: Z
authors.lastname: Pan
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiaolu
authors.initials: X
authors.lastname: Qu
authors.forename: Yuguo
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yongqing
authors.initials: Y
authors.lastname: Yang
authors.forename: Xiangning
authors.initials: X
authors.lastname: Jiang
authors.forename: Shanjin
authors.initials: S
authors.lastname: Huang
authors.forename: Ming
authors.initials: M
authors.lastname: Yuan
authors.forename: Karen S
authors.initials: KS
authors.lastname: Schumaker
authors.forename: Yan
authors.initials: Y
authors.lastname: Guo
mesh_terms: D051377:Actin-Related Protein 2 / Q000235:genetics / Q000378:metabolism*; D051376:Actin-Related Protein 2-3 Complex / Q000378:metabolism*; D051378:Actin-Related Protein 3 / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D020013:Calcium Signaling; D003600:Cytosol / Q000378:metabolism; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D030821:Plants, Genetically Modified; D055049:Salt Tolerance / Q000502:physiology; D013312:Stress, Physiological
chemical_list: C512742:ARP2 protein, Arabidopsis; D051377:Actin-Related Protein 2; D051376:Actin-Related Protein 2-3 Complex; D051378:Actin-Related Protein 3; D029681:Arabidopsis Proteins; C478027:DIS1 protein, Arabidopsis