Transcriptome profiling of cotton-bollworm larvae fed on transgenic hpa1Xoo cotton leaves by the application of silkworm 23K oligo microarray

To analyse the resistance of harpin(Xoo)-expressing transgenic cotton T-34 plants to cotton-bollworm (Helicoverpa armigera), bioassays and the silkworm genome-wide microarray were employed. The global transcriptomic level was used to compare the H. armigera larvae fed on T-34 leaves (LFT-34) with larvae fed on leaves of the untransformed cotton line Z35 (LFZ35). The development of LFT-34 was slowed, eventually leading to larval death. The microarray data indicated that 872 genes in LFT-34 were totally deregulated, comparing to their expression in LFZ35. All the preferentially expressed genes were classified into 13 biological functions and were involved in 96 biological pathways. These results indicated that harpin(Xoo) confers T-34 with resistance to H. armigera and influences multiple metabolic pathways in the larvae. Hpa1(Xoo), as a new genetic resource, provides primary evidence for breeding cotton that is resistant to cotton bollworm. The results also showed that the silkworm 70-mer oligo microarray can be used as a new approach to analyse the global transcriptional expression of H. armigera and its interaction with plants.