Differential expression analysis of genes related to graft union healing in Pyrus ussuriensis Maxim by cDNA-AFLP

- Construction of a micro-graft technique in pear.
- Isolation of the graft union healing related genes in pear.
- Preliminary analysis of molecular mechanism of graft-union healing in pear.

The purpose of the present study was to understand the molecular mechanisms during the graft union healing process. In the present study, cDNA-amplified fragment length polymorphism (cDNA-AFLP) analysis was used to examine gene expression in Pyrus ussuriensis Maxim micro-grafting plantlets at four time points (at 0, 4, 7, and 11 days) during grafting tissue healing process. Twenty-six transcript-derived fragments (TDFs) involved in the graft healing mechanism were successfully obtained, which comprised 14 genes of known function, 9 genes of unknown function, and 3 novel genes. These 14 genes of known functions were involved in the functions of kinase, carbohydrate metabolism, protein metabolism, nuclear metabolism, cell activity and development, energy, and others. The expression analysis of 3 TDFs by qPCR showed that the results analyzed by cDNA-AFLP were basically reliable. These results suggest that P. ussuriensis undergoes complex metabolic processes during the graft union healing process. Detailed characterization of the genes involved in the specific process can help us uncover the molecular mechanisms for the healing process in plants.