The changes of morphological and physiological characteristics in hemiparasiticMonochasma savatieribefore and after attachment to the host plant

Background Monochasma savatieriis an endangered hemiparasitic medicinal plant with a variety of antioxidant, antimicrobial and anti-inflammatory properties. Despite the urgent need to understand the parasitic biology ofM. savatieri, parasite-host associations have long been neglected in studies ofM. savatieri. Methods We conducted a pot cultivation experiment to analyze changes in the growth traits, physiological performance and anatomical structures ofM. savatierigrown with the potential hostGardenia jasminoidesE., before and after the establishment of the parasite-host association. Results Prior to the establishment of the parasite-host association, the presence of the host had no significant effect on the maximum root length, leaf indexes or total dry weight ofM. savatieriseedlings, but had significant positive effect on seedling height, number of roots or number of haustoria. When it was continuously grown without a host,M. savatierigrowth was rather slow. The establishment of the parasite-host association enhanced the growth ofM. savatieri, and higher levels of photosynthetic pigments, increased antioxidant enzyme activity and lower malondialdehyde accumulation were observed inM. savatieriwith an established parasite-host association. Furthermore, an analysis of the anatomical structures ofM. savatierishowed that the establishment of the parasite-host association enabled better development of the seedling vegetative organs than that in seedlings without parasite-host associations. Conclusions Our study demonstrates the physiological and anatomical changes that occurred inM. savatieriafter connection with a host and suggests that the enhanced growth and development ofM. savatieriwere highly dependent on the parasite-host association.