13 research outputs found
Conservation and Diversity of Seed Associated Endophytes in Zea across Boundaries of Evolution, Ethnography and Ecology
Endophytes are non-pathogenic microbes living inside plants. We asked whether endophytic species were conserved in the agriculturally important plant genus Zea as it became domesticated from its wild ancestors (teosinte) to modern maize (corn) and moved from Mexico to Canada. Kernels from populations of four different teosintes and 10 different maize varieties were screened for endophytic bacteria by culturing, cloning and DNA fingerprinting using terminal restriction fragment length polymorphism (TRFLP) of 16S rDNA. Principle component analysis of TRFLP data showed that seed endophyte community composition varied in relation to plant host phylogeny. However, there was a core microbiota of endophytes that was conserved in Zea seeds across boundaries of evolution, ethnography and ecology. The majority of seed endophytes in the wild ancestor persist today in domesticated maize, though ancient selection against the hard fruitcase surrounding seeds may have altered the abundance of endophytes. Four TRFLP signals including two predicted to represent Clostridium and Paenibacillus species were conserved across all Zea genotypes, while culturing showed that Enterobacter, Methylobacteria, Pantoea and Pseudomonas species were widespread, with γ-proteobacteria being the prevalent class. Twenty-six different genera were cultured, and these were evaluated for their ability to stimulate plant growth, grow on nitrogen-free media, solubilize phosphate, sequester iron, secrete RNAse, antagonize pathogens, catabolize the precursor of ethylene, produce auxin and acetoin/butanediol. Of these traits, phosphate solubilization and production of acetoin/butanediol were the most commonly observed. An isolate from the giant Mexican landrace Mixteco, with 100% identity to Burkholderia phytofirmans, significantly promoted shoot potato biomass. GFP tagging and maize stem injection confirmed that several seed endophytes could spread systemically through the plant. One seed isolate, Enterobacter asburiae, was able to exit the root and colonize the rhizosphere. Conservation and diversity in Zea-microbe relationships are discussed in the context of ecology, crop domestication, selection and migration
Biological control of Heterodera glycines by spore-forming plant growth-promoting rhizobacteria (PGPR) on soybean
Analysis of endophytic bacterial community composition by 16S rDNA clone library in Achnatherum inebrians
Use of Plant-Associated Bacillus Strains as Biofertilizers and Biocontrol Agents in Agriculture
Structural characteristics and plant-beneficial effects of bacteria colonizing the shoots of field grown conventional and genetically modified T4-lysozyme producing potatoes
Endophytic bacteria isolated from Angleton pasture (Dichantium aristatum, Benth) in Sucre Department, Colombia
Interactions between plants and beneficial Pseudomonas spp.: exploiting bacterial traits for crop protection
23 pagesSpecific strains of fluorescent Pseudomonas
spp. inhabit the environment surrounding plant roots and some even the root interior. Introducing such bacterial strains to plant roots can lead to increased plant growth, usually due to suppression of plant pathogenic microorganisms. We review the
modes of action and traits of these beneficial Pseudomonas bacteria involved in disease suppression. The complex regulation of biological control traits in relation to the functioning in the root environment is discussed. Understanding the complexity
of the interactions is instrumental in the
exploitation of beneficial Pseudomonas spp. in controlling
plant diseases.Peer reviewe