Jasmonic and salicylic acid induction during the interaction of Bacillus methylotrophicus RC 218 and Fusarium graminearum on wheat spikes under greenhouse conditions.

PALAZZINI J.M; YERKOVICH, N; FUMERO, V.; TORRES A.M.; CHULZE, S.N

Foz de Iguazu

Congreso; 11th International Congress of Plan Molecular Biology,.; 2015

Species within the Fusarium graminearum complex are the main pathogens causing Fusarium head blight (FHB), a devastating disease of wheat and barley worldwide. Bacillus methylotrophicus RC 218 has been previously characterized as a biocontrol agent to control FHB and deoxynivalenol accumulation. The aim of the present study was: -to evaluate the effect of B. methylotrophicus RC 218 (Bmet), F. graminearum (Fgram) and their interaction, on the induction of the phytohormones salicylic (SA) and jasmonic acid (JA) at different period times after challenging wheat spikes. The plant hormones were measured by HPLC-MS/MS. The production of JA was induced after Fgram inoculation at 48 and 72 h, meanwhile JA was reduced when compared to the co-inoculated treatment. No differences in JA or SA induction were observed Bmet treatment and the control. Under the Fgram treatment, SA production was early induced at 12h and after this period, SA decreased to the basal levels. Under co-inoculation treatment levels of SA and JA were similar to the control. In general, early induction of SA was observed under the Fgram treatment, as it was shown for initial FHB basal resistance, meanwhile the late induction of JA reveals a defense state against necrotrophic pathogens such as F. graminearum. It is possible that the biocontrol agent B. methylotrophicus RC 218 had reduced the pathogen activity and, therefore, the plant response.