Agrobacterium-mediated transformation of Guignardia citricarpa: an efficient tool to gene transfer and random mutagenesis.

Guignardia citricarpa is the causal agent of Citrus Black Spot (CBS), an important disease in Citriculture. Due to the expressive value of this activity worldwide, especially in Brazil, understanding more about the functioning of this fungus is of utmost relevance, making possible the elucidation of its infection mechanisms, and providing tools to control CBS. This work describes for the first time an efficient and successful methodology for genetic transformation of G.

Species diversity of culturable endophytic fungi from Brazilian mangrove forests.

This study aimed to perform a comparative analysis of the diversity of endophytic fungal communities isolated from the leaves and branches of Rhizophora mangle, Avicennia schaueriana and Laguncularia racemosa trees inhabiting two mangroves in the state of São Paulo, Brazil [Cananeia and Bertioga (oil spill-affected and unaffected)] in the summer and winter. Three hundred and forty-three fungi were identified by sequencing the ITS1-5.8S-ITS2 region of rDNA.

Endophytic fungi from the Amazonian plant Paullinia cupana and from Olea europaea isolated using cassava as an alternative starch media source.

Endophytic fungi live inside plants, apparently do not cause any harm to their hosts and may play important roles in defense and growth promotion. Fungal growth is a routine practice at microbiological laboratories, and the Potato Dextrose Agar (PDA) is the most frequently used medium because it is a rich source of starch. However, the production of potatoes in some regions of the world can be costly.

3-hydroxypropionic acid as an antibacterial agent from endophytic fungi Diaporthe phaseolorum.

Endophytic fungi are considered a rich source of active compounds resulting from their secondary metabolism. Fungi from marine environment grow in a habitat with unique conditions that can contribute to the activation of metabolic pathways of synthesis of different unknown molecules. The production of these compounds may support the adaptation and survival of the fungi in the marine ecosystem.

Genetic transformation of Diaporthe phaseolorum, an endophytic fungus found in mangrove forests, mediated by Agrobacterium tumefaciens.

We describe the genetic transformation of the mycelial tissue of Diaporthe phaseolorum, an endophytic fungus isolated from the mangrove species Laguncularia racemosa, using Agrobacterium tumefaciens-mediated transformation (ATMT). ATMT uses both the hygromycin B resistant (hph) gene and green fluorescent protein as the selection agents. The T-DNA integration into the fungal genome was assessed by both PCR and Southern blotting.

Limited vegetative compatibility as a cause of somatic recombination in Trichoderma pseudokoningii.

With the aim of a better characterization of the somatic recombination process in Trichoderma pseudokoningii, a progeny from crossings between T. pseudokoningii strains contrasting for auxotroph markers was characterized by RAPD markers and PFGE (electrophoretic karyotype). Cytological studies of the conidia, conidiogenesis and heterokaryotic colonies were also performed.

Specific plant induced biofilm formation in Methylobacterium species.

Two endophytic strains of Methylobacterium spp. were used to evaluate biofilm formation on sugarcane roots and on inert wooden sticks. Results show that biofilm formation is variable and that plant surface and possibly root exudates have a role in Methylobacterium spp.

Disparity between Multilocus Enzyme Electrophoresis, Microsatellite Markers and Pulsed-Field Gel Electrophoresis in epidemiological tracking of Candida albicans.

Various molecular systems are available for epidemiological, genetic, evolutionary, taxonomic and systematic studies of innumerable fungal infections, especially those caused by the opportunistic pathogen C. albicans. A total of 75 independent oral isolates were selected in order to compare Multilocus Enzyme Electrophoresis (MLEE), Electrophoretic Karyotyping (EK) and Microsatellite Markers (Simple Sequence Repeats - SSRs), in their abilities to differentiate and group C.

Culturable endophytic filamentous fungi from leaves of transgenic imidazolinone-tolerant sugarcane and its non-transgenic isolines.

The diversity of endophytic filamentous fungi from leaves of transgenic imidazolinone-tolerant sugarcane plants and its isoline was evaluated by cultivation followed by amplified rDNA restriction analysis (ARDRA) of randomly selected strains. Transgenic and non-transgenic cultivars and their crop management (herbicide application or manual weed control) were used to assess the possible non-target effects of genetically modified sugarcane on the fungal endophytic community. A total of 14 ARDRA haplotypes were identified in the endophytic community of sugarcane.

Cytological characterization of an Aspergillus Nidulans mutant from a strain with chromosomic duplication.

A development mutant, named V103, was obtained spontaneously from the A strain of A. nidulans. The A strain contains a duplicated segment of chromosome I that has undergone translocation to chromosome II (I II).

Evaluation of GFP tag as a screening reporter in directed evolution of a hyperthermophilic beta-glucosidase.

By applying a directed evolution methodology specific enzymatic characteristics can be enhanced, but to select mutants of interest from a large mutant bank, this approach requires high throughput screening and facile selection. To facilitate such primary screening of enhanced clones, an expression system was tested that uses a green fluorescent protein (GFP) tag from Aequorea victoria linked to the enzyme of interest. As GFP's fluorescence is readily measured, and as there is a 1:1 molar correlation between the target protein and GFP, the concept proposed was to determine whether GFP could facilitate primary screening of error-prone PCR (EPP) clones.

Transgenic tobacco revealing altered bacterial diversity in the rhizosphere during early plant development.

The rhizosphere constitutes a complex niche that may be exploited by a wide variety of bacteria. Bacterium-plant interactions in this niche can be influenced by factors such as the expression of heterologous genes in the plant. The objective of this work was to describe the bacterial communities associated with the rhizosphere and rhizoplane regions of tobacco plants, and to compare communities from transgenic tobacco lines (CAB1, CAB2 and TRP) with those found in wild-type (WT) plants.

Diversity of cultivated endophytic bacteria from sugarcane: genetic and biochemical characterization of Burkholderia cepacia complex isolates.

Bacteria were isolated from the rhizosphere and from inside the roots and stems of sugarcane plants grown in the field in Brazil. Endophytic bacteria were found in both the roots and the stems of sugarcane plants, with a significantly higher density in the roots. Many of the cultivated endophytic bacteria were shown to produce the plant growth hormone indoleacetic acid, and this trait was more frequently found among bacteria from the stem.

PCR method for the detection of potential ochratoxin-producing Aspergillus species in coffee beans.

Ochratoxin A (OA) is a nephrotoxic and carcinogenic mycotoxin that has been found in cereal and food commodities. Currently, Aspergillus carbonarius, A. niger and A.

Isolation and characterization of soybean-associated bacteria and their potential for plant growth promotion.

Endophytic and epiphytic bacteria were isolated from two soybean cultivars (Foscarin and Cristalina). Significant differences were observed in bacterial population densities in relation to season of isolation, soybean growth phase and the tissues from which the isolates were obtained. The isolates were identified by partial 16S rDNA sequence analysis, with most of the isolates belonging to the Pseudomonaceae, Burkholderiacea and Enterobacteriaceae groups.

Molecular characterization of a beta-1,4-endoglucanase from an endophytic Bacillus pumilus strain.

Endophytes comprise mainly microorganisms that colonize inner plant tissues, often living with the host in a symbiotic manner. Several ecological roles have been assigned to endophytic fungi and bacteria, such as antibiosis to phytopathogenic agents and plant growth promotion. Nowadays, endophytes are viewed as a new source of genes, proteins and biochemical compounds that may be used to improve industrial processes.