Linking Beneficial Soil Bacteria in the Rhizosphere with Gene Induction in Arugula

Abstract

Bacillus amyloliquefaciens GB03 is an important plant growth promoting rhizobacterium (PGPR) that was shown to promote growth and biotic and abiotic stress tolerance in Arabidopsis thaliana, as well as, genes involved in these interactions have been identified. Although, the understanding about mechanisms involved in the relations that GB03 participates, in general, the PGPR monitoring is an obstacle to the use of this inoculants. Green fluorescent protein (GFP) markers have been used to understand how PGPR acts on the soil. This study aims the GB03 colonization mapping and quantification in arugula (Eruca sativa) roots and rizosphere, by pNKGFP plasmid insertion that contains a green fluorescent protein and by the use of RT-PCR technique. This is the first report about the use of GFP technique in GB03 mapping. Thus, arugula plants will be protected or exposed to diamondback moth (Plutella xylostella) damage, in order to verify if insect feeding stress may cause changes in GB03 arugula colonization. Furthermore, this proposal aims to estimate arugula plants physiological parameters that could be improved with GB03 inoculation, as well as, check if GB03 colonization has influence in glucosinolate synthesis in Plutella xylostella presence or absence and determine if primers applied in identification of genes envolved in Arabidopsis glucosinolates synthesis could be applied in arugula. Thus, we wish with this proposal improve the understanding about the mechanisms envolved in GB03 interactions and we hope that this study can help in PGPR future researches and become the use of these inoculants in field more consistent.