Development of a new plant defense biostimulant, based on the fungal elicitor AsES, for sustainable crop disease management

CHALFOUN NADIA REGINA; DURMAN SANDRA B.; BUDEGUER FLORENCIA; STENGLEIN SEBASTIÁN A.; BERTANI, ROMINA P.; FILIPPONE MARÍA PAULA; MORETTI ENRIQUE R.; WELIN BJORN; CASTAGNARO ATILIO P.

Varadero

Congreso; Biotecnología Habana 2017: La Biotecnología Agropecuaria en el Siglo XXI; 2017

Centro de Ingeniería Genética y Biotecnología

We present the first member of the Plant Stimulation and Protection Technology (PSP), a new line of bioproducts for sustainable crop production and disease management. This product named PSP1 is based on the subtilisin elicitor AsES, secreted by the strawberry pathogen Acremonium strictum. In an initial step, fungal fermentation conditions were optimized in order to maximize extracellular protein production and to obtain a high defense-eliciting activity, as monitored by reduced anthracnose development in supernatant-treated strawberry plants. Disease protection studies using dilutions of PSP1 indicated that there is a threshold enzymatic activity of AsES needed to induce pathogen defense in strawberry, which seems to be dose-independent. Besides PSP1 is straightforward and economical to produce, effective at low concentrations, stable for months at room temperature, tolerant to exposure to high temperatures, harmless to non-target organisms, easy to handle and apply and provides excellent protection against pathogen attacks. Another important characteristic of PSP1 is its capability to activate disease protection in a broad-range of crop species. In more detail, a foliar application of PSP1 on soybean induced PR1-gene expression up-regulation and protected plants against the late season disease, soybean target spot, caused by Corynespora cassiicola. Furthermore, a double treatment of PSP1 on greenhouse-grown sugarcane plants provided improved protection against bacterial red stripe disease caused by Acidovorax avenae. Likewise, a double foliar application of PSP1 on field-grown wheat plants significantly reduced symptoms of head blight disease, caused by Fusarium graminearum, in experiments with artificial inoculation, manifested in higher yields and an increased germination percentage of seeds collected from treated plants.In summary, these disease protection results demonstrated against both bacterial and fungal pathogens in several important crop species, together with the product characteristics, make PSP1 a very promising ecological candidate for effective and sustainable crop disease management.