Identification of up-regulated genes in tea leaves under mild infestation of green leafhopper

Transcriptional changes accompany induced resistance of plants against insect feeding, and monitoring transcriptional reorganization triggered in response to herbivory is an essential step for deciphering the molecular basis of the resistance. To isolate up-regulated genes in tea leaves under mild infestation of green leafhopper (Empoasca vitis Gothe), a subtractive cDNA library was constructed using the suppression subtractive hybridization strategy. Subsequent differential screening, DNA sequencing analyses, and real-time PCR analyses identified 21 unique genes up-regulated by leafhopper feeding from the library. Among the genes likely to be directly involved in defense, those encoding pathogen-related protein and type 2 ribosome-inactivating protein were found in the subtractive library. In addition, genes involved in the CBL (calcineurin B-like)-CIPK (CBL-interacting protein kinases) pathway, cell wall fortification, secondary metabolite synthesis, water transport, and oxidative stress protection were identified in our experiment. Besides, a number of genes that have not been previously associated with defense responses against insects were isolated. (C) 2011 Elsevier B.V. All rights reserved.