IAA production of Neotyphodium sincium EHA-1-Roegneria kamoji complex
【摘要】：正Endophytic fungi-grass symbiotum base on either endophyte can synthesize or induce the host plant to produce various kinds of secondary metabolites(De Battista Bacon 1990). These secondary metabolites,such as alkaloids and plant hormones usually benefit to plant survival,growth and reproduction.We detected IAA concentrations of culture filtrates,cell free macerates of Neotyphodium sincium EHA-1 by ELISA and HPLC,and report here that indole-3-acetic acid(IAA) accumulation in culture media.N.sincium EHA-1 synthesizing IAA even no tryptophan(Trp),precursor of IAA was added exogenously into the culture(Ji 2002). These indicated this isolate can produce plant hormone de novo.In Trp presence conditions, highest concentration of 47.08 mg/g dry mycelium was recorded in IAA production tests.When IAA was extracted from aerial tissue of Roegneria kamoji EI and EF plants and analyzed by HPLC,higher concentration of IAA was detected in EI plants comparing with that of EF plants. This phenomenon was recognized on plants in period of heading stage and flowering stage respectively.These suggested that IAA biosynthesis in fungal cells may have a certain contribution in total IAA level within Chinese Roegneria-Neotyphodium symbiotum.