Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/25/2008
Publication Date: 6/26/2008
Citation: Campbell, M.A., Deweerd, J., Suttle, J.C. 2008. Gene Expression Profiles of Potato Tuber Meristems Treated with Compounds that Prolong and Repress the Dormant State [abstract.] American Society of Plant Biologists Annual Meeting, June 26 - July 1, 2008, Merida, Mexico. Abstract # P06013. ASPB CDROM. Interpretive Summary:
Technical Abstract: The prevention sprouting is of significant economic importance and is often accomplished with chemical applications such as chloropropham (CIPC). The mechanism of action for CIPC is that of a mitotic inhibitor and herbicide but additional products that suppress sprout growth by alternate modes would have significant commercial application. The compound 1,4-dimethylnaphthalene (DMN) represents a new class of sprout inhibitor of unknown mechanism. In this study we examine gene expression using a TIGR cDNA microarray in potato tubers treated with bromoethane (BE), a compound that breaks dormancy, and the sprout inhibitors CIPC and DMN in order to ascertain the transcriptional profiles elicted by these compounds. BE and normal dormancy cessation resulted in similar expression profiles particularly in a decrease of the abscisic acid (ABA) inducible transcripts in the RD22 class and in the increase in transcripts encoding for members of the oxoglutarate-dependent family. Cluster analysis of arrays examining gene expression in dormant, nondormant, CIPC, and DMN treated tuber tissues showed that the dormant and DMN resulted in a profiles with the greatest similarity followed by CIPC treated tissues suggesting that DMN may function by prolonging the dormant state. It was also demonstrated that more cDNAs were specifically down-regulated in DMN treated tissues then up-regulated implying that suppression of transcriptional activity is more common to DMN exposure. In comparison to CIPC, and the nondormant state, few cDNAs were up-regulated exclusively by DMN. ABA analysis did not support the hypothesis that DMN extends dormancy. Levels of ABA were highest in dormant meristems and declined to the same extent in meristems isolated from non-dormant, CIPC- , and DMN-treated tubers.