Differential gene expression in chestnut buds following infestation by gall-wasp (Dryocosmus kuriphilus Yasumatsu, Hymenoptera: Cynipidae)

The chestnut gall-wasp Dryocosmus kuriphilus Yasumatsu, an insect native to China, was found in 2002 for the first time in North western Italy (Cuneo province). The cynipid causes the development of galls on leaves, sprouts and inflorescences, due to the feeding activity of larvae. Complete resistance to D. kuriphilus was recently found in the hybrid Bouche de Bètizac (C. sativa × C. crenata) and the genetic bases regulating this resistance are being investigated. Accessions of the cultivars Marrone (susceptible) and Bouche de Bétizac (resistant) were subjected to an intensive attack of D. kuriphilus, with the purpose of getting infested buds to be examined at different stages of development of larvae. At budburst and just afterwards (March-April) buds were collected for the extraction and isolation of mRNA. cDNA was obtained by reverse transcription and analysed using the differential display technique. Differentially expressed bands were cloned, sequenced and blasted with sequences deposited in NCBI and TIGR databases; putative genes involved in resistant response and larva nourishing were identified.