IFEVA   02662
INSTITUTO DE INVESTIGACIONES FISIOLOGICAS Y ECOLOGICAS VINCULADAS A LA AGRICULTURA
Unidad Ejecutora - UE
artículos
Título:
Maize leaf epiphytic bacteria diversity patterns are genetically correlated with resistance to fungal pathogen infection
Autor/es:
BALINT-KURTI P; SIMMONS SJ; BLUM JE; BALLARÉ CL; STAPLETON AE
Revista:
MOLECULAR PLANT-MICROBE INTERACTIONS
Editorial:
AMER PHYTOPATHOLOGICAL SOC
Referencias:
Año: 2010 vol. 23 p. 473 - 484
ISSN:
0894-0282
Resumen:
Plant leaves host a specific set of microbial epiphytes. Plant
genetic and solar UV-B radiation effects on the diversity of
the phyllosphere were examined by measuring epiphytic
bacterial ribosomal DNA diversity in a maize recombinant
inbred (RI) mapping population. Several chromosomal
quantitative trait loci (QTL) with significant effects on bacterial
diversity were identified, some of which had effects
only in the presence of UV-B radiation and others that had
effects both with and without UV-B. Candidate genes with
allele-specific effects were mapped to the bacterial diversity
chromosomal regions. A glutamate decarboxylase candidate
gene was located at a UV-Bspecific chromosomal
locus, and in a comparison between two RI lines with
contrasting bacterial diversity phenotypes, high bacterial
diversity was associated with high levels of glutamate decarboxylase
enzyme activity, a component of the gamma-aminobutyric
acid (GABA) pathway. The bacterial diversity
loci exhibited a significant overlap with loci connected with
Southern leaf blight (SLB) susceptibility in the field. A
SLB-resistant inbred genotype had less beta bacterial diversity,
and antibiotic treatment of inbreds increased this
diversity. These results suggest that the GABA pathway is
genetically associated with phyllosphere bacterial diversity.
Furthermore, the colocalization of QTL between low bacterial
diversity and fungal blightresistance and the increase
in beta diversity in antibiotic-treated leaves suggest that occupation
of leaf habitats by a particular set of suppressive
bacteria may restrict phyllosphere bacterial variability and
increase resistance to fungal infection.