Molecular cloning of a PR-5 like protein gene from cherry tomato and analysis of the response of this gene to abiotic stresses.

LePR-5, a putative PR5 like protein gene was amplified from a cherry tomato (Lycopersicon esculentum), which encodes a precursor protein of 250 amino acid residues, and shares high degrees of homology with a number of other PR5 genes. Expression of LePR-5 in different tomato organs was analyzed with Semi-quantitative RT-PCR, showing that LePR-5 expressed at different levels in leaves, stems, roots, flowers and fruits. In addition, expression of LePR-5 under different abiotic stresses was carried out at different time points. Three of the four tested abiotic stimuli, ethophen, salicylic acid and methyl jasmonate, triggered a significant induction of LePR-5 after treatment. However, LePR-5 was weaker induced by abscisic acid than by others. The positive responses of LePR-5 to the three abiotic stimuli suggested that LePR-5 may play an important role in response to abiotic stresses, and it may also be involved in plant defense system against pathogens. In addition, different expression patterns between tomato fruit and seedling suggested that LePR-5 may play a distinctive role in the defensive system protecting tomato fruit and seedling.