Proteomics study during root knot nematode (Meloidogyne incognita) infection in tomato (Solanum lycopersicum L.)

Abstract

Tomato (Solanum lycopersicum L., 2n=2x=24) is an important vegetable for human consumption because of its enriched nutritional composition that provide the basic body nutritional requirements. Tomato (S. lycopersicum L.) is affected by various diseases caused mainly by fungi, bacteria and nematodes. Root-knot nematodes (Meloidogyne spp.) found to be very fatal infective agents and cause severe yield loses. The present investigation was undertaken to enhance understanding regarding proteome changes that takes place in the tomato seedlings under root knot biotic stress. Two tomato cultivars AT 3 (Susceptible) and SL 120 (Resistant) grown under sterile and root knot nematode (3000 J2 stage larvae per plant) inoculated soil were used for proteomics study during root knot nematode (Meloidogyne incognita) infection in tomato (S. lycopersicum L.). Isozyme analysis for polyphenol oxidase (PPO), peroxidase (POX) and catalse (CAT) revealed one cultivar specific isoform of PPO while two stress induced isoform of POX. The characterization of root proteins by SDS-PAGE had indicated that number of bands had increased in both the cultivars upon transition from control to stress environment and resistant cultivar had shown more number of bands as compare to susceptible cultivar. Protein profiling through 2-D gel electrophoresis had shown total of 506 protein spots out of which 166 proteins were found to be differentially expressed in both the cultivars (susceptible and resistant) under both the conditions (control and diseased). Overall 26 proteins were found to be specifically expressed in resistant cultivar (SL 120) only and absent in susceptible one (AT 3) under both control and diseased conditions, 29 proteins seemed to be differentially expressed under diseased conditions in susceptible cultivar AT 3 and were totally absent in AT 3 (Control). These proteins can be considered as promising candidates for identification markers in the screening of resistant genotype against the root knot nematode.