Poster: Late and Moved Abstracts

Abs # 1000: Functional Analysis of the Spermidine Synthase Promoter in Arabidopsis thaliana

Presenter:	Minocha, Subhash C, sminocha@christa.unh.edu
Authors	Minocha, Subhash C (A)   Rice, Charles  (A)   Bezold, Todd  (A)   Tiberghein, Katherine  (A)
Affiliations:	(A): University Of New Hampshire

Polyamines (putrescine, spermidine, and spermine) are involved in a variety of cellular functions and are found in all living cells. Their biosynthesis is regulated by the enzymes: arginine decarboxylase, ornithine decarboxylase, S-adenosylmethionine decarboxylase, spermidine synthase and spermine synthase. The expression pattern of two spermidine synthase (spds) genes was studied in different parts of the Arabidopsis plant at different developmental stages during its entire life cycle, using the approach of promoter-reporter fusion. The results show that: (1) the two genes are expressed to a different extent in different cells at different stages of development; (2) spds is expressed in almost all parts of the plant, although the expression is greater in younger tissues; (3) the expression of spds is localized more in the vascular region than other tissues in a given organ. This is consistent with a role for spermidine as a source of H₂O₂ (through its oxidation) for lignin polymerization. This research will complement our current research on the study of the expression pattern of all key genes involved in polyamine metabolism (the ‘polyaminome’) in Arabidopsis, which is in line with the NSF Arabidopsis 2010 Project, aimed at analyzing the expression and function of all genes in this model plant. The results of the study will also enable us to alter the developmental pattern of a plant or its ability to tolerate abiotic stress through genetic engineering approaches. Supported by the UNH-Undergraduate Research Opportunities Program (UROP), The Plant Biology Conrad Fund, and the NH Agricultural Experiment Station.