The successful history of A. brasilense Az39 in Agriculture. A metadata analysis.

RODRÍGUEZ, BELÉN; NIEVAS, SOFÍA; LÓPEZ, GASTÓN; MOLINA, ROMINA; CONIGLIO, ANAHÍ; MORA, VERÓNICA; CASSÁN FABRICIO

Viena

Congreso; miCROPe 2019 International Symposium. Microbe-assisted crop production. Opportunities, challenges and needs.; 2019

miCROPe

Azospirillum is one of the most studied bacterial genera in the last 60years; However, the history of the appearance of biological products formulatedwith this bacterium began in the 1980s, but intensified in the last 20 years inArgentina, Brazil and the rest of South America. In the case of Argentina, A. brasilense Az39 is the strain that has been recommended for more than40 years for the production of biofertilizers for wheat, sorghum, corn andsoybean (co-inoculation). This strain has demonstrated a great capacity topromote plant growth with average yield increases greater than 10.0% and asuccess rate higher than 70% in different crops in thousand experiments.Despite the immense amount of information available at the agronomic level,until a few years ago very little was known about the molecular basis thatdetermined the ability of this strain to promote plant growth. In 2012, the Laboratorio de Fisiología Vegetaly de la Interacción Planta-Microorganismo of the Universidad Nacional de Río Cuarto conformed an internationalconsortium with the aim to analyze the genome sequence of A. brasilense Az39 and B. japonicum E109, two of the most used strainsfor biofertilizer production in South America. Using a combined sequencingstrategy, it was established that the Az39 genome has a size of 7.39 Mpbdistributed in 6 replicons [1 chromosome, 3 chromides and 2 plasmids]. Throughthe use of comparative bioinformatics tools, numerous genes and putativeproteins involved in the expression of plant growth promotion mechanisms and otherrelated with the rhizosphere lifestyle were identified. The decoding of thisinformation has provided a solid basis for the elucidation of new mechanisms ofinteraction and growth promotion, as well as some specific components thatwould determine the agronomic success of this microorganism. In thispresentation we will address some of the new biological models recentlyidentified for this bacterium and how they affect their rhizosphere lifestyle.