Identification of Genes Differentially Expressed in a Resistant Reaction to Fusarium Oxysporum in Lilium Regale by SSH

Fusarium wilt, caused by the fungal phytopathogen Fusarium oxysporum, is the major disease of lily (Lilium L.). However, the interaction between lily and F. oxysporum is still poorly understood. In order to identify of genes differentially expressed in a resistant reaction to F. oxysporum in L. regale, a rare lily genetic resource with high resistance to F. oxysporum, a cDNA library of L. regale root infected by F. oxysporum was constructed using the method of suppression subtractive hybridization (SSH). In total, 585 unique expressed sequence tags (ESTs) were obtained after sequence analysis of 1101 clones, and homology analysis showed that 342 unique sequences were assigned to no significant homology. On the base of function classification established in model plant, the functional categories of the 243 ESTs which had significant homology with known proteins were assigned, and they were classified into 14 putative cellular functions. The largest group contained genes involved in disease/defense including PR3 (chitinase), PR10, glutathione S-transferase (GST), cytochrome P450, catalase (CAT), peroxidase and so on. Moreover, the signal transduction related genes and important transcription factors participated in defense response against phytopathogens were included in the cDNA library of present study. Briefly, the genes differentially expressed in the resistant reaction to F. oxysporum in L. regale revealed the partial molecular mechanism associated with the resistance of L. regale against F. oxysporum.