Poster: Temperature responses

Abs # 117: Gene expression during cold treatment and recovery process in Pachysandra terminalis

Presenter:	Zhou, Suping , zhoutsu@yahoo.com
Authors	Zhou, Suping  (A)   Sauve, Roger J (A)   Abudullah, Abudullah  (A)
Affiliations:	(A): Tennessee State University

Low and freezing temperatures during the growing season cause annual yield losses and crop failures in the US and limit crop production Worldwide. The understanding of the antifreeze mechanism in plant species that tolerate sporadic freezing temperatures is necessary for the development of strategies to minimize losses due to low temperature fluctuation. The objective of this experiment was to identify genes in Pachysandra terminalis that are regulated by low temperature fluctuations. Plants maintained at 25C for 30 d were subjected to the following treatments: 5C for 24h followed by 0.5C 24h and returned to 25C for 12h. The total RNA was extracted from leaf tissues and genes with different transcriptions were identified using cDNA differential display (mRNA image kit, Genehunter, Nashville). Those with different expression levels after temperature treatments were cloned onto PCR-Trap cloning vector and confirmed by colony hybridization and reverse-northern dot blot using probes synthesized from the total RNA of cold treated leaf tissues. DNA sequence analysis and database search (NCBI, nr and est) results showed that the genes up-regulated following cold treatments shared good homology with protein phosphatase, cab, gad1, and with other genes induced by other abiotic and biotic stresses. However, most gene fragments isolated from P. terminalis had no high homology with reported sequences in the database. While P. terminalis’ molecular response mechanism to environmental stresses is similar to other plants, our data suggest that it may have unique differences.