cDNA-AFLP analysis of gene expression in hickory (Carya cathayensis) during graft process.

The graft technique is a valid method for propagating plants. A better elucidation of the graft mechanism is helpful in improving the production efficiency and fruit quality in hickory. In this study, cDNA-amplified fragment length polymorphism analysis was used to examine the gene expression in hickory at four time points (at 0, 3, 7 and 14 days) during the graft process. Forty-nine unique genes involved in the graft mechanism were obtained. The expression patterns of these genes were confirmed by real-time reverse transcription-polymerase chain reaction analysis based on 12 selected genes representing different patterns. The 49 genes composed 19 genes of known function, nine genes of unknown function and 21 novel genes. These 19 genes of known functions were involved in the indole-3-acetic acid transport protein, cell cycle, signal transduction, water metabolism, nuclear metabolism, amino acid metabolism, protein metabolism, carbon metabolism and secretion of substances, suggesting that Carya cathayensis Sarg. undergoes a complex metabolism process during the grafting.