Interaction between the rhizobacteria Beijerinckia and Brevibacillus and sugarcane calluses

• Grant number: 13/14821-6
• Support Opportunities: Research Grants - Visiting Researcher Grant - International
• Duration: January 15, 2014 - April 14, 2014
• Field of knowledge: Biological Sciences - Microbiology - Biology and Physiology of Microorganisms
• Principal Investigator: Heloiza Ramos Barbosa
• Grantee: Heloiza Ramos Barbosa
• Visiting researcher: Teresa de los Milagros Orbera Raton
• Visiting researcher institution: Universidad de Oriente, Cuba
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The purpose of this work is the association of diazotrophic rhizobacteria isolated from both sugarcane soil (Brevibacillus) and Cerrado soil (Beijerinckia) with calluses of sugarcane The goal is to determine what kind of interactions with these microorganisms develop plants: beneficial, pathogenic or neutral.. Rhizobacteria may be plant growth promoters and in the case of these bacteria under study, some of these characteristics were determined after their isolation. Beijerinckia showed a high ability to reduce acetylene, characterized therefore by high nitrogenase activity Moreover, the genus Brevibacillus is a producer of phytohormones such as indoleacetic acid and ethylene. The paper proposes a co-culture of callus of sugarcane with one of both bacteria and also co-cultures with both bacteria and callus. These studies have shown advantageous because it can be fully developed in vitro. The proposed model also allows measures of defense responses of plant cells. The co-cultures will be performed in liquid medium. The measures to be determined will be: Bacterial growth as Colony Forming Units, nitrogenase activity by acetylene reduction assay, the dosage of the protein content of the callus, the production of ethylene and indoleacetic acid and plant defense responses: reactive species oxygen and nitric oxide. Results of similar tests conducted with different endophytic bacteria were quite interesting, because the growth of some bacteria was stimulated by callus, other were partially inhibited and others, were killed. It was also observed that the bacteria whose growth was stimulated by the callus should transfer fixed nitrogen to plant cells, since there is an increased protein content of the callus that were cultivated in medium lacking N-combined. This work aims for the future, a proposal for possible inoculants to sugarcane, for evaluating the interaction between bacteria isolated from sugarcane and sugarcane cells, the possibility of getting success with such inoculants will be great. (AU)