| Abstract Detail
Photomorphogenesis Spiro, Mark [1], Barnett, Judith [2], Fries, Carol [2], Mauskapf, Adam [2]. Characterization of the det30/her1 constitutive-photomorphogenic mutant of Ceratopteris richardii reveals a cryptochrome-dependent, antheridiogen-independent mechanism that promotes male sexual determination. We have characterized the photobiology and developmental phenotype of the det30/her1, constitutive photomorphogenic, mutant of Ceratopteris richardii. det30 (formerly germ4) was originally identified in a screen of EMS-treated her1 spores (Cooke et al., 1995, Int J Plant Sci 156: 367-373). The her1 mutation confers antheridiogen insensitivity allowing for investigation of the independent effect of light on sexual development. In the light both her1 and det30/her1 gametophytes develop entirely as heart-shaped hermaphrodites. In the dark her1 grows as highly-elongated, primarily-asexual, multiseriate filaments; whereas, det30/her1 grows as short, broad prothalli that possess antheridia, but not archegonia. Dark-grown det30/her1 undergoes continual antheridiogenesis to form ≥30 antheridia per gametophyte, resulting in differentiation of the meristem and promotion of male sexual determination. After prolonged dark culture det30/her1 gametophytes lose the ability to develop as hermaphrodites when transferred to light, but under similar conditions her1 gametophytes retain this ability. Treatment of her1 with prolonged, low-irradiance (0.1-0.5 µEm-2s-1) blue light phenocopies det30/her1 producing gametophytes with decreased cell elongation, increased prothallus width, and numerous antheridia. Red light inhibits antheridiogenesis. Our findings suggests that DET30 acts as a repressor of cryptochrome signaling and that cryptochrome promotes an antheridiogen-independent mechanism for stimulating antheridiogenesis and male sexual determination that is inhibited by phytochrome.
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1 - Bucknell University, Biology Department, Lewisburg, PA, 17855
2 - Bucknell University, Biology Department
Keywords:
Ceratopteris richardii
Fern
photomorphogenesis
cryptochrome.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P31017
Abstract ID:1900 |
