Pseudomonas fluorescens Pf0-1 showed positive chemotactic responses toward 20 commonly-occurring l-amino acids. Genomic analysis revealed that P. fluorescens Pf0-1 possesses three genes (Pfl01_0124, Pfl01_0354, and Pfl01_4431) homologous to the Pseudomonas aeruginosa PAO1 pctA gene, which has been identified as a chemotaxis sensory protein for amino acids. When Pf01_4431, Pfl01_0124, and Pfl01_...

Arbuscular mycorrhizas (AM) are widespread, ancient endosymbiotic associations that contribute significantly to soil nutrient uptake in plants. We have previously shown that initial fungal penetration of the host root is mediated via a specialized cytoplasmic assembly called the prepenetration apparatus (PPA), which directs AM hyphae through the epidermis (Genre et al., 2005). In vivo confocal ...

The excellent-root-colonizing Pseudomonas fluorescens WCS365 was selected previously as the parental strain for the isolation of mutants impaired in root colonization. Transposon mutagenesis of WCS365 and testing for root colonization resulted in the isolation of mutant strain PCL1201, which is approximately 100-fold impaired in competitive tomato root colonization. In this manuscript, we provi...

The effect of root exudates from non-mycorrhizal and mycorrhizal cucumber (Cucumis sativus L.) plants colonized by one of three arbuscular mycorrhizal fungi (Gigaspora rosea Nicolson & Schenck, Glomus intraradices Smith & Schenck, or Glomus mosseae (Nicolson & Gerdemann) Gerd. & Trappe) on hyphal growth of Gi. rosea and G. intraradices in axenic culture and on root colonization by G. mosseae in...

Theobroma cacao (cacao) is cultivated in tropical climates and is exposed to drought stress. The impact of the endophytic fungus Trichoderma hamatum isolate DIS 219b on cacao's response to drought was studied. Colonization by DIS 219b delayed drought-induced changes in stomatal conductance, net photosynthesis, and green fluorescence emissions. The altered expression of 19 expressed sequence tag...

The main objectives of the current study were to investigate effect arbuscular mycorrhizal fungi (AMF) and nano-iron chelate fertilizer under water deficit conditions on grain yield, root colonization, leaf chlorophyll concentration, oil percentage, fatty acid profile Lallemantia species. experiment was carried out as a factorial based complete randomized block design consisting three factors i...

To test direct and indirect effects of glomalin, mycorrhizal hyphae, and roots on aggregate stability, perspex pots separated by 37-μm nylon mesh in the middle were used to form root-free hyphae and root/hyphae chambers, where trifoliate orange (Poncirus trifoliata) seedlings were colonized by Funneliformis mosseae or Paraglomus occultum in the root/hyphae chamber. Both fungal species induced s...

Root colonization of plants with certain rhizobacteria, such as Pseudomonas chlororaphis O6, induces tolerance to biotic and abiotic stresses. Tolerance to drought was correlated with reduced water loss in P. chlororaphis O6-colonized plants and with stomatal closure, indicated by size of stomatal aperture and percentage of closed stomata. Stomatal closure and drought resistance were mediated b...

We studied the production of xyloglucanase enzymes of leguminous roots in the presence of Rhizobium and arbuscularmycorrhizal (AM) fungi. The AM fungus Glomus mosseae and Sinorhizobium meliloti GR4 for alfalfa, Rhizobium leguminosarum bv. viceae Rlv 13 for pea, R. leguminosarum bv. trifolii 2152 for clover, R. tropici CIAT 899 for bean and Mesorrhizobium mediterraneum USDA 3392 for chickpea. Th...

The mutualism pattern of the dark septate endophyte (DSE) Harpophora oryzae in rice roots and its biocontrol potential in rice blast disease caused by Magnaporthe oryzae were investigated. Fluorescent protein-expressing H. oryzae was used to monitor the colonization pattern. Hyphae invaded from the epidermis to the inner cortex, but not into the root stele. Fungal colonization increased with ro...