| Abstract Detail
Photomorphogenesis Smith, Alison M. [2], Street, Ian [1], Shah, Purvi K. [2], Avery, Nathan [2], Neff, Michael M. [2]. SOB3 and ESC are two plant-specific genes involved in seedling development. SOB3 was cloned from an activation tagging screen for suppressors of the long hypocotyl phenotype of a weak phyB allele, phyB-4. SOB3 encodes a nuclear localized single AT-hook containing protein with a second domain of unknown function and is part of a conserved plant specific gene family. sob3-D (suppressor of phyB-4, Dominant) over-expresser seedlings have shorter hypocotyls and as adults, develop significantly larger, rounder leaves, larger flowers and thicker stems than the wild type. The differences in organ size are initially due to cell proliferation as epidermal cell area is similar to the wild type. sob3-D plants have delayed senescence, living twice as long as the wild type and the mutant leaves undergo a two-fold cell expansion after 60 days. SOB3 is most similar at the DNA level to ESCAROLA, identified in an independent activation tagging screen. esc-D plants are also suppressors of the phyB-4 long hypocotyl phenotype and are similar as adults to sob3-D, suggesting that these genes have similar functions. A loss-of-function SOB3 allele (sob3-4) was generated through an EMS intragenic suppressor screen of sob3-D phyB-4 plants. This allele induces a nonsense mutation in the transcript before either of the conserved domains. A similar nonsense allele of ESC (esc-8) was obtained from the Seattle TILLING Project. The sob3-4 esc-8 double mutant has hypocotyls that are less sensitive to multiple fluence rates of white, red, far-red and blue light. sob3-6 (R77>H), a dominant negative missense allele in the AT-hook DNA binding domain suggest this domain is important for SOB3 function. SOB3 and ESC, representatives of a largely uncharacterized gene family, are redundant modulators of the Arabidopsis hypocotyl growth and response to light.
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1 - Washington University, Biology, 1 Brookings Dr. box 1137, St. Louis, Mo, 63130, USA
2 - Washington University, Biology
Keywords:
Arabidopsis
hypocotyl
photomorphogenesis
growth.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P31008
Abstract ID:830 |
