Fruit set regulating genes are differently expressed after cross-pollination, self-pollination and treatment with plant growth regulators in Malus x domestica cv. 'Jonagold'
Faculty of Sciences. Biology
Acta horticulturae / International Society for Horticultural Science. - 's Gravenhage
, p. 707-713
We report the results from a transcriptome analysis in apple (Malus × domestica) in which cross- and self-pollination conditions were compared with self-pollination combined with indole acetamide (IAM) as a fruit set promoting plant growth regulator (PGR). This analysis yielded a group of genes with differential transcriptional expression patterns at fruit set and early fruit development. A significant part of the identified genes has putative functions in cell division and expansion, cytokinin metabolism and auxin and gibberellin signal transduction. The transcriptional expression pattern of a selection of these genes was studied in more detail by semi-quantitative RT-PCR analysis. In these experiments transcriptional expression patterns were followed from blooming until a month after full bloom for self- and cross-pollination compared to self-pollination combined with either IAM or GA4/7 as fruit set promoting PGR. To validate the results these were compared to the auxin and cytokinin contents of these fruits, pomological parameters and growth curves. Altogether, we identified some interesting genetic expression markers which are very useful tools for further studies of fruit set and early fruit development and how these processes are influenced by the pollination type and the application of commercial plant growth regulators.