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Molecular adaptations of H erbaspirillum seropedicae during colonization of the maize rhizosphere
Author(s) -
Balsanelli Eduardo,
TadraSfeir Michelle Z,
Faoro Helisson,
Pankievicz Vânia CS,
Baura Valter A,
Pedrosa Fábio O,
Souza Emanuel M,
Dixon Ray,
Monteiro Rose A
Publication year - 2016
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.12887
Subject(s) - biology , rhizosphere , colonization , biofilm , bacteria , microbiology and biotechnology , polyhydroxybutyrate , mutant , peptidoglycan , chemotaxis , gene , botany , biochemistry , genetics , receptor
Summary Molecular mechanisms of plant recognition and colonization by diazotrophic bacteria are barely understood. H erbaspirillum seropedicae is a Betaproteobacterium capable of colonizing epiphytically and endophytically commercial grasses, to promote plant growth. In this study, we utilized RNA ‐seq to compare the transcriptional profiles of planktonic and maize root‐attached H . seropedicae S m R 1 recovered 1 and 3 days after inoculation. The results indicated that nitrogen metabolism was strongly activated in the rhizosphere and polyhydroxybutyrate storage was mobilized in order to assist the survival of H . seropedicae during the early stages of colonization. Epiphytic cells showed altered transcription levels of several genes associated with polysaccharide biosynthesis, peptidoglycan turnover and outer membrane protein biosynthesis, suggesting reorganization of cell wall envelope components. Specific methyl‐accepting chemotaxis proteins and two‐component systems were differentially expressed between populations over time, suggesting deployment of an extensive bacterial sensory system for adaptation to the plant environment. An insertion mutation inactivating a methyl‐accepting chemosensor induced in planktonic bacteria, decreased chemotaxis towards the plant and attachment to roots. In summary, analysis of mutant strains combined with transcript profiling revealed several molecular adaptations that enable H . seropedicae to sense the plant environment, attach to the root surface and survive during the early stages of maize colonization.