Agrobacterium-Mediated Transformation of Diaporthe schini Endophytes Associated with Vitis labrusca L. and Its Antagonistic Activity Against Grapevine Phytopathogens.

Fungus-caused diseases are among the greatest losses in grapevine culture. Biological control of pathogens by endophytes may be used to decrease fungicide application rates and environmental impacts. Previously, Diaporthe sp. B46-64 and C27-07 were highlighted as antagonists of grapevine phytopathogens. Herein, molecular multigene (ITS-TUB-TEF1) identification and phylogenetic analysis allowed the identification of these endophytes as belonging to Diaporthe schini species. Agrobacterium tumefaciens-mediated transformation was employed for obtaining 14 stable and traceable gfp- or DsRed-expressing transformants, with high transformation efficiency: 96% for the pFAT-GFP plasmid and 98% for pCAM-DsRed plasmid. Transformants were resistant to hygromycin B with gene hph confirmed by polymerase chain reaction and proved to be mitotically stable, expressing the fluorescent phenotype, with morphological differences in the colonies when compared with wild strains. In vitro antagonism tests revealed an increased antagonistic activity of some transformant strains. The current genetic transformation of D. schini mediated by A. tumefaciens proved to be an efficient technique within the randomized insertion of reporter genes for the monitoring of the strain in the environment.

Mangrove endophyte promotes reforestation tree (Acacia polyphylla) growth

ABSTRACT Mangroves are ecosystems located in the transition zone between land and sea that serve as a potential source of biotechnological resources. Brazil's extensive coast contains one of the largest mangrove forests in the world (encompassing an area of 25,000 km2 along all the coast). Endophytic bacteria were isolated from the following three plant species: Rhizophora mangle, Laguncularia racemosa and Avicennia nitida. A large number of these isolates, 115 in total, were evaluated for their ability to fix nitrogen and solubilize phosphorous. Bacteria that tested positive for both of these tests were examined further to determine their level of indole acetic acid production. Two strains with high indole acetic acid production were selected for use as inoculants for reforestation trees, and then the growth of the plants was evaluated under field conditions. The bacterium Pseudomonas fluorescens (strain MCR1.10) had a low phosphorus solubilization index, while this index was higher in the other strain used, Enterobacter sp. (strain MCR1.48). We used the reforestation tree Acacia polyphylla. The results indicate that inoculation with the MCR1.48 endophyte increases Acacia polyphylla shoot dry mass, demonstrating that this strain effectively promotes the plant's growth and fitness, which can be used in the seedling production of this tree. Therefore, we successfully screened the biotechnological potential of endophyte isolates from mangrove, with a focus on plant growth promotion, and selected a strain able to provide limited nutrients and hormones for in plant growth.

Mangrove endophyte promotes reforestation tree (Acacia polyphylla) growth.

Mangroves are ecosystems located in the transition zone between land and sea that serve as a potential source of biotechnological resources. Brazil's extensive coast contains one of the largest mangrove forests in the world (encompassing an area of 25,000km2 along all the coast). Endophytic bacteria were isolated from the following three plant species: Rhizophora mangle, Laguncularia racemosa and Avicennia nitida. A large number of these isolates, 115 in total, were evaluated for their ability to fix nitrogen and solubilize phosphorous. Bacteria that tested positive for both of these tests were examined further to determine their level of indole acetic acid production. Two strains with high indole acetic acid production were selected for use as inoculants for reforestation trees, and then the growth of the plants was evaluated under field conditions. The bacterium Pseudomonas fluorescens (strain MCR1.10) had a low phosphorus solubilization index, while this index was higher in the other strain used, Enterobacter sp. (strain MCR1.48). We used the reforestation tree Acacia polyphylla. The results indicate that inoculation with the MCR1.48 endophyte increases Acacia polyphylla shoot dry mass, demonstrating that this strain effectively promotes the plant's growth and fitness, which can be used in the seedling production of this tree. Therefore, we successfully screened the biotechnological potential of endophyte isolates from mangrove, with a focus on plant growth promotion, and selected a strain able to provide limited nutrients and hormones for in plant growth.