| Abstract Detail
Growth and Vegetative Development Bai, Fang [1], DeMason, Darleen [2]. Hormone interactions and regulation of PsPK2:GUS compared to DR5:GUS in Arabidopsis thaliana. The plant hormones auxin, gibberellin and cytokinin play crucial roles during plant growth and development. A putative pea PINOID homolog gene, PsPK2, is positively regulated by auxin and gibberellin, and plays an important role during pea leaf development. Expression of DR5:GUS is an important tool to localize regions of free auxin. In this study, we observed the effects of plant hormones on the expression of PsPK2:GUS compared to DR5:GUS in Arabidopsis, and also examined PINOID gene response to different hormone treatments. GUS expression in Arabidopsis shoots of PsPK2:GUS and DR5:GUS is mainly localized in the stipules, hydothodes, veins, and developing leaves and cotyledons. Unlike DR:GUS, PsPK2:GUS has no expression in the root tips. Both DR5:GUS and PsPK2:GUS are induced by different auxins and are more sensitive to MeIAA, 4-Cl-IAA and NAA than others. In DR5::GUS transformed seedlings, MeIAA+GA3 induction was the strongest followed by MeIAA and MeIAA+BAP. Based on t-Test, GA3 had no significant effect on GUS activity in DR5::GUS transgenic plants compared to the control. In the shoots of PsPK2::GUS transformed plants, all treatments increased GUS activity compared to the control. MeIAA+GA3 induction was the strongest followed by BAP, MeIAA and MeIAA+BAP. All results were significantly different. The combination of auxin and GA results in the higher GUS activity and expression in PsPK2:GUS and DR5:GUS plants than any other treatments, but the enhancement in comparison to auxin or GA alone is neither synergistic nor additive. In conclusion, these results support the hypothesis that auxin, GA and cytokinin positively regulate PsPK2 expression in shoots, but not in roots.
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1 - University of California, Riverside, Dept. of Botany and Plant Sciences, Riverside, CA, 92521, USA
2 - University of California, Riverside, Dept. of Botany and Plant Sciences
Keywords:
PsPK2:GUS
DR5:GUS
auxin
GA
Cytokinin
Hormone
pea
Arabidopsis thaliana.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P26041
Abstract ID:1255 |
