Primary metabolic profiling of Egyptian broomrape (Phelipanche aegyptiaca) compared to its host tomato roots

Broomrape (Phelipanche aegyptiaca) is a root holoparasitic plant considered among the most destructive agricultural weeds worldwide. In order to acquire more knowledge about the metabolism of broomrape and its interaction with its tomato host, we performed primary metabolic profiling using GCMS analysis for the early developmental stage of the parasite and of infected and non-infected roots. The analysis revealed that out of 59 metabolites detected, the levels of 37 significantly increased in the parasite while the levels of 10 significantly decreased compared to the infected roots. In addition, the analysis showed that the levels of total protein in the albumin fraction, reducing sugars (representing starch) and total phenols increased by 9.8-, 4.6- and 3.3-fold, respectively, in the parasite compared to the roots. These changes suggest that P. aegyptiaca has its own metabolism that differs significantly in its regulation from those found in their host. In addition, the results have shown that the levels of most of the metabolites in the infected roots were similar to levels detected in the non-infected roots, except for seven metabolites whose levels increased in the infected versus the non-infected roots. This suggests that the parasite did not significantly affect the host primary metabolic pathways.