GDA-lipase1 (CaGL1) contributes to wound stress resistance by modulation of CaPR-4 expression in hot pepper

A full length cDNA clone encoding Capsicum annuum GDSL-lipase 1 (CaGL1) was isolated by microarray analysis. The expression of CaGL1 was triggered by methyl jasmonic acid (MeJA), an important signal in abiotic/biotic stress response. However, the expression of this gene was not increased by the application of salicylic acid (SA) or ethylene treatment. And, local/systemic Wounding stimuli resulted in rapid accumulation of CaGL1 mRNA. However, CaGL1 was not specifically induced during the hypersensitive response upon Tobacco mosaic virus (TMV) inoculation. By using a virus-induced gene silencing (VIGS)-based reverse genetic approach, it was observed that the suppression of CaGL1 attenuates the expression of Capsicum annuum pathogenesis-related protein 4 (CaPR-4) during wound stress. However, the CaPR-4 transcript level induced by TMV was not regulated by CaGL1 expression. These results indicate that CaGL1 may be involved in signaling pathway of MeJA and/or the wound responses through CaPR-4 expression modulation. (c) 2008 Elsevier Inc. All rights reserved.