Abstract
Tobacco SIPK and WIPK appeared to be activated in response to various stimuli, salicylic acid, wounding and TMV infection, etc. We adopted agroinfiltration method on tobacco leaves to investigate the stress-activated MAP kinases. Suspension of agrobacterium was infiltrated into tobacco leaves to result in transient expression of GST-SIPK and GST-WIPK. Protein expression and activation of GST-fused MAP kinases in agroinfiltrated leaves were detected by western blot with an anti-GST antibody and in-gel kinase assay, respectively.
After irradiation of ultra-violet ray on tobacco intact leaves, protein kinases with the relative molecular mass of 45-48KDa similar to those of SIPK and WIPK were activated. Furthermore, activations of GST-SIPK and GST-WIPK in the infiltrated leaves are also observed.
These results suggest that SIPK and WIPK are involved in stress signaling in tobacco under UV irradiation. Further investigation of mechanism of the stress signaling is in progress.
