Quantification and tracking of niche colonization of the Bacillus amyloliquefaciens GB03 in Arugula (Eruca sativa) in defense against Plutella xylostella and Spodoptera frugiperda

• Grant number: 16/17952-2
• Support type: Scholarships in Brazil - Doctorate
• Effective date (Start): February 01, 2017
• Effective date (End): January 31, 2020
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: José Maurício Simões Bento
• Grantee: Rafaela Cristina dos Santos
• Home Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated scholarship(s): 18/16581-6 - Linking Beneficial Soil Bacteria in the Rhizosphere with Gene Induction in Arugula, BE.EP.DR

Abstract

This study aims to understand the mechanisms involved in the interaction of Bacillus amyloquefaciens GB03 (PGPR) and Arugula (Eruca sativa), and the response of this plant-microorganism to damage caused by an expert insect (diamondback moth) and other general (Trichoplusia ni) of brassicas. For this, will be performed transformation of the B. amyloquefaciens GB03 by inserting of the pBC16 plasmid with the gene gfp (green fluorescent protein), which will be used to screen B. amyloquefaciens GB03 in rhizosphere and in the plant. Right after the transformation, the rocket seeds are inoculated with a suspension of B. amyloquefaciens GB03 and maintained in a greenhouse for a period of sixty days. Larvae of Plutella xylostella and T. ni third instar will be made for the induction of plants for 24 h. It will then be collected volatiles of these plants for eight hours. Subsequently, the rhizosphere DNA extraction will be performed, Arugula endophytic and also the gut of P. xylostella and T. ni to access the structure of the bacterial community present in these ecosystems. In addition, the gfp gene is quantified via qPCR (rhizosphere, endophytic and intestine of insects) and trace B. amyloquefaciens GB03 inside the roots will be done by scanning electron microscopy to check the settlement niche in the plant. In addition, the glucosinolate content analyzes will be performed on arugula plants and phytohormones tests, in order to better understand the mechanisms involved in the studied interactions. Interactions involving beneficial microorganisms living in soil, plants and shoots of insects are quite complex, and there is a lack of strategies to facilitate the monitoring of PGPR on the ground. The understanding of this interaction still poorly understood, so this work will bring new information that will help in the elucidation of various issues on the use of PGPR in the field and the use of B. amyloquefaciens GB03 as biocontrol agent in the management of insect pests.