Functional nonequivalency of actin isovariants in Arabidopsis

被引:95
作者
Kandasamy, MK [1 ]
McKinney, EC [1 ]
Meagher, RB [1 ]
机构
[1] Univ Georgia, Dept Genet, Athens, GA 30602 USA
关键词
D O I
10.1091/mbc.01-07-0342
中图分类号
Q2 [细胞生物学];
学科分类号
071009 ; 090102 ;
摘要
Plants encode at least two ancient and divergent classes of actin, reproductive and vegetative, and each class produces several subclasses of actin isovariants. To gain insight into the functional significance of the actin isovariants, we generated transgenic Arnbidopsis lines that expressed a reproductive actin, ACT1, under the control of the regulatory sequences of a vegetative actin gene, ACT2. In the wild-type plants, ACT1 is predominantly expressed in the mature pollen, growing pollen tubes, and ovules, whereas ACT2 is constitutively and strongly expressed in all vegetative tissues and organs, but not in pollen. Misexpression of ACT1 in vegetative tissues causes dwarfing of plants and altered morphology of most organs, and the effects are in direct proportion to protein expression levels. Similar overexpression of ACT2 has little effect. Immunolocalization of actin in leaf cells from transgenic plants with highest levels of ACT1 protein revealed massive polymerization, bundling, and reorganization of actin filaments. This phenomenon suggests that misexpression of ACT1 isovariant in vegetative tissues affects the dynamics of actin and actin-associated proteins, in turn disrupting the organization of actin cytoskeleton and normal development of plants.
引用
收藏
页码:251 / 261
页数:11
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共 35 条
  • [21] McDowell JM, 1996, GENETICS, V142, P587
  • [22] The arabidopsis ACT7 actin gene is expressed in rapidly developing tissues and responds to several external stimuli
    McDowell, JM
    An, YQ
    Huang, SR
    McKinney, EC
    Meagher, RB
    [J]. PLANT PHYSIOLOGY, 1996, 111 (03) : 699 - 711
  • [23] SEQUENCE-BASED IDENTIFICATION OF T-DNA INSERTION MUTATIONS IN ARABIDOPSIS - ACTIN MUTANTS ACT2-1 AND ACT4-1
    MCKINNEY, EC
    ALI, N
    TRAUT, A
    FELDMANN, KA
    BELOSTOTSKY, DA
    MCDOWELL, JM
    MEAGHER, RB
    [J]. PLANT JOURNAL, 1995, 8 (04) : 613 - 622
  • [24] Isovariant dynamics expand and buffer the responses of complex systems: The diverse plant actin gene family
    Meagher, RB
    McKinney, EC
    Kandasamy, MK
    [J]. PLANT CELL, 1999, 11 (06) : 995 - 1005
  • [25] The evolution of new structures - clues from plant cytoskeletal genes
    Meagher, RB
    McKinney, EC
    Vitale, AV
    [J]. TRENDS IN GENETICS, 1999, 15 (07) : 278 - 284
  • [26] MEAGHER RB, 1994, ARABIDOPSIS, P1049
  • [27] MEAGHER RB, 2000, DYNAMIC FRAMEWORK MU, P3
  • [28] ECTOPIC EXPRESSION OF THE FLORAL HOMEOTIC GENE AGAMOUS IN TRANSGENIC ARABIDOPSIS PLANTS ALTERS FLORAL ORGAN IDENTITY
    MIZUKAMI, Y
    MA, H
    [J]. CELL, 1992, 71 (01) : 119 - 131
  • [29] Nick P, 1999, PLANT BIOLOGY, V1, P169, DOI 10.1111/j.1438-8677.1999.tb00240.x
  • [30] Genomics, the cytoskeleton and motility
    Pollard, TD
    [J]. NATURE, 2001, 409 (6822) : 842 - 843