study of sut1، chi3 and cyp1 genes expression in tomato parasitized by broomrape (orobanche aegyptica)

broomrape (orobanche aegyptica) is an obligate root parasite causing yield losses in large number of crops such as tomato, sunflower, cucumber, tobacco. in tropical and mediterranean countries from europe, africa and asia. several methods have been suggested for control of this parasite, but most of them are expensive and ineffective. for the efficient control, a better understanding of its interaction with host plant characterization of resistance mechanisms at molecular level is required, the expression of genes encoding chitinase, cysteine proteinase and succrose transporter in response to orobanche aegyptica was studied in a tolerant and sensetive tomatos cultivars by realtime pcr method. results showed that the genes were up-regulated in early stage of infection. two species also showed different expression in succrose transporter and cysteine proteinase, but the same expression was observed for chitinase gene. the behaviour pattern of two genotypes showed that defence activity of tomato started at early hours of infection and the resistant genotype responses were earlier than sensetive genotype to signal of invasion. results also indicated that protease enzymes can be one of the important tools of plants for preventing the penetration and connection of parasite to its root.