Dicarboxylate Transporters of Azospirillum brasilense Sp7 Play an Important Role in the Colonization of Finger Millet (Eleusine coracana) Roots.
Mol Plant Microbe Interact
; 32(7): 828-840, 2019 Jul.
Article
in En
| MEDLINE
| ID: mdl-30688544
ABSTRACT
Azospirillum brasilense is a plant growth-promoting bacterium that colonizes the roots of a large number of plants, including C3 and C4 grasses. Malate has been used as a preferred source of carbon for the enrichment and isolation Azospirillum spp., but the genes involved in their transport and utilization are not yet characterized. In this study, we investigated the role of the two types of dicarboxylate transporters (DctP and DctA) of A. brasilense in their ability to colonize and promote growth of the roots of a C4 grass. We found that DctP protein was distinctly upregulated in A. brasilense grown with malate as sole carbon source. Inactivation of dctP in A. brasilense led to a drastic reduction in its ability to grow on dicarboxylates and form cell aggregates. Inactivation of dctA, however, showed a marginal reduction in growth and flocculation. The growth and nitrogen fixation of a dctP and dctA double mutant of A. brasilense were severely compromised. We have shown here that DctPQM and DctA transporters play a major and a minor role in the transport of C4-dicarboxylates in A. brasilense, respectively. Studies on inoculation of the seedlings of a C4 grass, Eleusine corcana, with A. brasilense and its dicarboxylate transport mutants revealed that dicarboxylate transporters are required by A. brasilense for an efficient colonization of plant roots and their growth.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Azospirillum brasilense
/
Dicarboxylic Acid Transporters
/
Eleusine
Country/Region as subject:
America do sul
/
Brasil
Language:
En
Journal:
Mol Plant Microbe Interact
Journal subject:
BIOLOGIA MOLECULAR
/
BOTANICA
/
MICROBIOLOGIA
Year:
2019
Document type:
Article
Affiliation country:
India