title: Arabidopsis ACT11 modifies actin turnover to promote pollen germination and maintain the normal rate of tube growth.
abstract: Actin is an ancient conserved protein that is encoded by multiple isovariants in multicellular organisms. There are eight functional actin genes in the Arabidopsis genome, and the precise function and mechanism of action of each isovariant remain poorly understood. Here, we report the characterization of ACT11, a reproductive actin isovariant. Our studies reveal that loss of function of ACT11 causes a delay in pollen germination, but enhances pollen tube growth. Cytological analysis revealed that the amount of filamentous actin decreased, and the rate of actin turnover increased in act11 pollen. Convergence of actin filaments upon the germination aperture was impaired in act11 pollen, consistent with the observed delay of germination. Reduction of actin dynamics with jasplakinolide suppressed the germination and tube growth phenotypes in act11 pollen, suggesting that the underlying mechanisms involve an increase in actin dynamics. Thus, we demonstrate that ACT11 is required to maintain the rate of actin turnover in order to promote pollen germination and maintain the normal rate of pollen tube growth.
authors.affiliation: Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Chang
authors.affiliation: Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.|Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China.|National Center for Plant Gene Research, Beijing, 100101, China.
authors.forename: Shanjin
authors.initials: S
authors.lastname: Huang
mesh_terms: D000199:Actins / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000254:growth & development*; D011058:Pollen / Q000254:growth & development*
chemical_list: D000199:Actins
keywords: actin cytoskeleton; actin turnover; isovariant dynamics; pollen germination; pollen tube growth