Relationship between the Ni hyperaccumulator Alyssum murale and the parasitic plant Orobanche nowackiana from serpentines in Albania

Abstract

AbstractOrobanche nowackiana Markgr. is the only parasitic flowering plant in Europe which is an obligate serpentinophyte. This plant parasitizes the Ni hyperaccumulator Alyssum murale Waldst. & Kit. which grows in many areas including serpentine slopes of Mt. Komjan (Albania). The aims of the study were to investigate this host/parasite relationship from a biogeochemical point of view in order to evaluate: (1) the metal accumulation in different parts of the parasite and host plants and (2) the effect of Orobanche infection on host growth. Soil and plant samples of A. murale and O. nowackiana were analyzed for elemental concentrations after acid digestion using inductively coupled plasma atomic emission spectrometry (Ca, Mg, Fe, Ni, Cr, Co, Zn, Cu, Mn, Na, Al), colorimetry (for N and P), and flame photometry (for K). Individuals of A. murale, both infected and healthy, showed slight differences in their composition of essential elements (N, P, K) and of some micronutrients. The parasite had higher P, K, Na, and lower N, Ca, Mg, Ni, Zn, Co, Mn and Al concentrations than the host. Orobanche nowackiana is a Ni accumulator with 299 mg kg−1 in the leaves. Hyperaccumulation of Ni by A. murale did not prevent attack by O. nowackiana. After infection there was a decline in Ni concentration and the dry weight of all organs of the host, thus reducing the biomass yield and consequently Ni phytoextraction yield of A. murale. This infection could be a potential threat to the use of A. murale for Ni agromining.