|Varanasi, Vijaya - Washington State University|
|Zheng, Ping - Washington State University|
|Main, Dorrie - Washington State University|
Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 6/18/2009
Publication Date: 7/1/2009
Citation: Zhu, Y., Varanasi, V., Zheng, P., Main, D., Curry, E.A., Mattheis, J.P. 2009. Transcriptomic analysis of apple fruit ripening and texture attributes. American Society of Plant Biologists Annual Meeting. N/A.
Technical Abstract: Molecular events regulating cultivar-specific apple fruit ripening and sensory quality are largely unknown. Such knowledge is essential for genomic-assisted apple breeding and postharvest quality management. The ripening behavior and texture attributes of two apple cultivars, ‘Pink Lady’ and ‘Honeycrisp’, vary greatly. In this study, transcriptomic analysis and scanning electronic microscopic examination, combined with systematic physiological characterization were carried out. Substantial differences of crispness and firmness in fruit cortex were observed using Digi-test and other physiological approaches. SEM images of fruit cortex tissues with similar maturity suggest that the cell wall thickness, rather than cell density, cell size and inter-cell space, may contribute to the observed firmness and crispness phenotype. A 50-70-mer isothermal oligonucleotides representing 23,997 unigenes and duplex 190,135 cross-hybridization-free features, was manufactured on a Nimblegen array platform. The developmental stage- and cultivar-specific expression profiling analysis indicated that genes in functional groups of cell wall metabolism (both degradation and biosynthesis), hormonal metabolism and response (including auxin, ethylene, gibberellin and brassinosteroid) and transcription factors (such as NAC and WRKY families) as well as components in signal transduction and secondary metabolism related pathways showed distinct expression patterns between cultivars and during ripening. In many cases, genes in same functional group were regulated in a similar fashion (up- or down-regulated), however, different gene family members or possible allelotypes were regulated differentially between cultivars, likely reflecting the high heterozygosity and allotetroploidy nature of apple.