title: Stochastic dynamics of actin filaments in guard cells regulating chloroplast localization during stomatal movement.
abstract: Actin filaments and chloroplasts in guard cells play roles in stomatal function. However, detailed actin dynamics vary, and the roles that they play in chloroplast localization during stomatal movement remain to be determined. We examined the dynamics of actin filaments and chloroplast localization in transgenic tobacco expressing green fluorescent protein (GFP)-mouse talin in guard cells by time-lapse imaging. Actin filaments showed sliding, bundling and branching dynamics in moving guard cells. During stomatal movement, long filaments can be severed into small fragments, which can form longer filaments by end-joining activities. With chloroplast movement, actin filaments near chloroplasts showed severing and elongation activity in guard cells during stomatal movement. Cytochalasin B treatment abolished elongation, bundling and branching activities of actin filaments in guard cells, and these changes of actin filaments, and as a result, more chloroplasts were localized at the centre of guard cells. However, chloroplast turning to avoid high light, and sliding of actin fragments near the chloroplast, was unaffected following cytochalasin B treatment in guard cells. We suggest that the sliding dynamics of actin may play roles in chloroplast turning in guard cells. Our results indicate that the stochastic dynamics of actin filaments in guard cells regulate chloroplast localization during stomatal movement.
authors: State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian 271018, China.
authors: Xiu-Ling
authors: XL
authors: Wang
authors: Xin-Qi
authors: XQ
authors: Gao
authors: Xue-Chen
authors: XC
authors: Wang
mesh_terms: D008841:Actin Cytoskeleton / Q000187:drug effects / Q000502:physiology*; D002736:Chloroplasts / Q000378:metabolism*; D003571:Cytochalasin B / Q000494:pharmacology; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics; D054046:Plant Stomata / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000166:cytology; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013269:Stochastic Processes; D016608:Talin / Q000235:genetics / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D016608:Talin; C496077:Tln1 protein, mouse; D049452:Green Fluorescent Proteins; D003571:Cytochalasin B