tailieunhanh - báo cáo khoa học: " The elicitation of a systemic resistance by Pseudomonas putida BTP1 in tomato involves the stimulation of two lipoxygenase isoforms"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: The elicitation of a systemic resistance by Pseudomonas putida BTP1 in tomato involves the stimulation of two lipoxygenase isoforms | Mariutto et al. BMC Plant Biology 2011 11 29 http 1471-2229 11 29 BMC Plant Biology RESEARCH ARTICLE Open Access The elicitation of a systemic resistance by Pseudomonas putida BTP1 in tomato involves the stimulation of two lipoxygenase isoforms I f- f-z-s 1 f E r 1 A 11 V l h1 11 1 f A l r A I m 2 h r I Diir II1 I Iz z V4 h f r X z t n3 Martin Mariutto i-ranceime Duby AKram Adam Charlotte Bureau Marie-Laure Fauconnier Marc Ongena Philippe Thonart2 3 Jacques Dommes1 Abstract Background Some non-pathogenic rhizobacteria called Plant Growth Promoting Rhizobacteria PGPR possess the capacity to induce in plant defense mechanisms effective against pathogens. Precedent studies showed the ability of Pseudomonas putida BTP1 to induce PGPR-mediated resistance termed ISR Induced Systemic Resistance in different plant species. Despite extensive works molecular defense mechanisms involved in ISR are less well understood that in the case of pathogen induced systemic acquired resistance. Results We analyzed the activities of phenylalanine ammonia-lyase PAL and lipoxygenase LOX Key enzymes of the phenylpropanoid and oxylipin pathways respectively in tomato treated or not with P. putida BTP1. The bacterial treatment did not stimulate PAL activity and linoleate-consuming LOX activities. Linolenate-consuming LOX activity on the contrary was significantly stimulated in P. putida BTP1-inoculated plants before and two days after infection by B. cinerea. This stimulation is due to the increase of transcription level of two isoforms of LOX TomLoxD and TomLoxF a newly identified LOX gene. We showed that recombinant TomLOXF preferentially consumes linolenic acid and produces 13-derivative of fatty acids. After challenging with B. cinerea the increase of transcription of these two LOX genes and higher linolenic acid-consuming LOX activity were associated with a more rapid accumulation of free 13-hydroperoxy-octadecatrienoic and 13-hydroxy-octadecatrienoic acids two .