A bacterial endophyte from apoplast fluids protects canola plants from different phytopathogens via antibiosis and induction of host resistance

ROMERO F.M.; ROSSI F.R.; GARRIZ A.; CARRASCO SORLI, P.; RUIZ O.A.

PHYTOPATHOLOGY

AMER PHYTOPATHOLOGICAL SOC

Lugar: NEW YORK; Año: 2019 vol. 109 p. 332 - 342

0031-949X

Endophytic bacteria colonize inner plant tissues andthrive at the apoplast, which is considered its main reservoir. Since thisniche is the place where the main molecular events take place between beneficial and pathogenic microorganisms, the aim ofthis work was to characterize culturable endophytic bacteria from apoplasticfluids obtained from field-grown canola leaves and analyse their potential forbiological control of diseases caused by different pathogenic bacteria such as Xanthomonas campestris, Sclerotiniasclerotiorum or Leptosphaeriamaculans. Dual culture analysis indicated that three isolates (Apo8, Apo11and Apo12) were able to inhibit the growth of all three phytopathogens.Sequencing of the 16S rRNA gene of these isolates revealed that they areclosely related to Pseudomonasviridiflava. One of the isolates, Apo11, was able to diminish the propagationof X. campestris in whole plantsassays. At the same time, Apo11 inoculation reduced the necrotic lesionsprovoked by S. sclerotiorum on canolaleaves. This protective effect might be due either to the induction ofresistance in the host mediated by salicylic or jasmonic acid or to theproduction of compounds with antimicrobial activity. At the same time, Apo11inoculation promoted canola plant growth. Thus, the isolate characterized inthis work has several desirable characteristics which make it a potentialcandidate for the formulation of biotechnological products to control plantdiseases and to promote plant growth.