The effect of three hosts on the metabolic profiles of Cuscuta campestris

Cuscuta spp. is a stem holoparasite with a wide host range that causes major damage to crops. Cuscuta seedlings are thread-like, and after contacting hosts plants, they form initial haustoria that penetrate the host to absorb water and nutrients. This enables the parasite to disperse to other plants and to rapidly develop their reproductive organs. The aims of the research were: (i) to define the metabolic differences between C. campestris` three organs, flower, stem and haustoria; and (ii) to gain more knowledge of the effect of three hosts on the parasite`s metabolic profile. The parasite`s organs were collected from three hosts: Heliotropium hirsutissimum, Polygonum equisetiforme and Amaranthus viridis. The results showed differences between the three organs: flowers had high levels of free amino acids compared to the other organs, whereas the stems showed higher contents of sugars. However, while the levels of the metabolites did not significantly alter in flowers obtained from the three hosts, the levels of TCA cycle metabolites, sugars and sugars acids were found to be significantly altered between the three hosts in the stems, and much less in the haustoria. The observation that the hosts do not significantly alter the metabolites in the flower suggests that they control the levels of their metabolites, unlike the other organs. Further studies are required to understand this regulation, and to reveal which metabolites are taken from the host and which are synthesized by the parasite.