Developmental and Structural Section
Healy, Rosaria , Palmer, Reid G. , Horner, Harry T. .
Multicellular secretory trichome development on perennial and annual soybean gynoecia.
MULTICELLULAR secretory trichomes occur on gynoecia of wild perennial Glycine tomentella, and on the wild annual G. soja, and annual cultivars of G. max. This trichome is similar in all taxa examined, with usually 5 to 6 linearly arranged cells. These trichomes are located along the gynoecium from the base of the ovary to the base of the style, and sometimes along the style as in G. tomentella. They begin developing at least 2 days prior to anthesis, and new trichomes continue to form up through the young seed pod stage. During secretion, the apical 2 to 4 cells have prominent Golgi bodies with large vesicles, and the endoplasmic reticulum has enlarged lumens. Both organelles appear to be involved in the production of an unknown secretory product. The basal 2 to 3 cells become highly vacuolate, and their cytoplasm is nearly devoid of Golgi bodies and extensive endoplasmic reticulum. Secretion begins with the exudation of a product between the plasmalemma and the primary wall. Continued secretion builds up between the primary wall and an outer special, non-cuticularized wall that covers the entire trichome. This latter wall separates from the primary walls of the apical cells. The secretory product is ultimately exuded to the outside, and is visible along the outer surfaces of the secreting trichome and adjacent gynoecium epidermis. Secretion appears to be more common in the perennial than in the annual species examined. These results are compared with similar-looking trichomes on vegetative soybean leaves in an unrelated earlier study.
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1 - Iowa State University, Department of Genetics, Development & Cell Biology, Bessey Microscopy Facility, 3A Bessey Hall, Ames, Iowa, 50011-1020, USA
2 - Iowa State University, USDA ARS CICGR and Agronomy, Ames, Iowa, 50011, USA
Presentation Type: Oral Paper:Papers for Sections
Location: 303/Bell Memorial Union
Date: Wednesday, August 2nd, 2006
Time: 11:00 AM