Plant Genome II Conference
Town & Country Conference Center, San Diego, CA, January, 1994.
PG-II: EVOLUTION OF DIVERSE PATTERNS OF ACTIN GENE REGULATION IN
HIGHER PLANTS
EVOLUTION OF DIVERSE PATTERNS OF ACTIN GENE REGULATION IN
HIGHER PLANTS
Richard Meagher, John McDowell, Shurong Huang, Yong-Quiang An and
Elizabeth McKinny, Department of Genetics, University of Georgia,
Athens, GA 30602
Plant actins are involved in several fundamental processes
essential to growth and development, including positioning of the
division plane, cell elongation, programming cell wall
development, and cytoplasmic streaming. Plants contain ancient
and highly diverse actin gene families. The plant proteins have
three times more charged residue variation than animal actin
families. Arabidopsis thaliana has nine functional actin genes
and one pseudogene which make up six ancient subfamilies. The
ACT1/3 subfamily is strongly expressed in leaf, root, and floral
primordia and in late pollen development. The ACT2/8 subfamily
is expressed constitutively throughout development with the
exception of the pollen sack, carpel, hypocotyl and seed coat.
The ACT4/12 subfamily is expressed late in pollen development and
in root cap. ACT7 is expressed strongly in all tissues of the
seedling and developing inflorescence with the exception of the
carpel body. ACT11 is strongly expressed in early floral
development, most notably the carpel body and developing embryos.
Initial data suggest that the gene family encoding the actin
binding protein, profilin, is also large, diverse, and
differentially expressed. We propose that several actin
subsystems arose concomitant with the macroevolution of new
organs and tissues early in plant evolution.
Return to Previous Page or Intl-PAG Homepage