Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: 1/12/2010
Publication Date: 1/15/2010
Citation: Varanasi, V., Rudell Jr, D.R., Mattheis, J.P., Zhu, Y. 2010. The role of cultivar-specific expression patterns of MdACS3 gene on apple fruit ripening and quality. Plant and Animal Genome Conference. N/A.
Technical Abstract: Ethylene plays an important role in diverse physiological and developmental processes of plants. In apple, two ethylene biosynthesis genes, MdACS1 and MdACS3, are expressed in fruit tissues. While MdACS1 expresses at late ripening stages, expression of MdACS3 can be detected as early as 6 weeks before commercial maturity. Different expression levels of MdACS3 were observed between two apple cultivars with equivalent maturity from our early study. The objective of this study was to characterize MdACS3 expression in relation to cultivar-specific apple fruit ripening and quality by quantitative RT-PCR. Among 14 apple cultivars investigated, two different expression patterns of MdACS3 gene were observed, i.e. steadily-increasing with high level expression, and low level expression with a transient peak. These expression patterns appear to correlate with fruit ripening season and firmness at commercial maturity. For example, “Sunrise” with highest levels of MdACS3 expression had the lowest firmness and with early ripening season; while “Pink Lady” with very low levels of MdACS3 expression showed the highest firmness and with late ripening season. Unlike MdACS1, the expression of MdACS3 is not inhibited or delayed by the treatment of ethylene action inhibitor 1-MCP, but rather expression increased slightly after 1-MCP treatment. The relationship between MdACS3 expression patterns and the timing of MdACS1 activation after 1-MCP treatment, the time-window for postharvest management and postharvest fruit storability are under investigation.