Sandro Augusto Rhoden

Diversity of foliar endophytic fungi from the medicinal plant Sapindus saponaria L . and their localization by scanning electron microscopy

Endophytic fungi inhabit vegetable tissues or organs, without causing them any harm. Endophytes can co-evolve with plant hosts and possess species-specific interactions. They can protect the plant from insect attacks and diseases, and are also able to produce substances of biotechnological interest. In folk medicine, the bark, roots and fruits of Sapindus saponaria is used to produce substances with anxiolytic, astringent, diuretic and expectorant properties, as well as tonics, blood depuratives and cough medicine. This study evaluated the diversity of endophytic fungi present in the leaves of S. saponaria L. and observed the colonization of host plants by endophytes, using light and scanning electron microscopy. We verified that these fungi are found in intercellular and intracellular spaces. The genera of some isolates of S. saponaria were identified mainly by sequencing of ITS region of rDNA and, when possible, also by their microscopic features, as follows: Cochliobolus, Alternaria, Curvularia, Phomopsis, Diaporthe and Phoma. Phylogenetic analysis showed the existence of genetic variability of the genera Phomopsis and Diaporthe and interspecific variation among the Curvularia, Alternaria and Phoma, belonging to family Pleosporaceae.

Endophytic fungi: expanding the arsenal of industrial enzyme producers

Endophytic fungi, mostly belonging to the Ascomycota, are found in the intercellular spaces of the aerial plant parts, particularly in leaf sheaths, sometimes even within the bark and root system without inducing any visual symptoms of their presence. These fungi appear to have a capacity to produce a wide range of enzymes and secondary metabolites exhibiting a variety of biological activities. However, they have been only barely exploited as sources of enzymes of industrial interest. This review emphasizes the suitability and possible advantages of including the endophytic fungi in the screening of new enzyme producing organisms as well as in studies aiming to optimize the production of enzymes through well-known culture processes. Apparently endophytic fungi possess the two types of extracellular enzymatic systems necessary to degrade the vegetal biomass: (1) the hydrolytic system responsible for polysaccharide degradation consisting mainly in xylanases and cellulases; and (2) the unique oxidative ligninolytic system, which degrades lignin and opens phenyl rings, comprises mainly laccases, ligninases and peroxidases. The obvious ability of endophytic fungi to degrade the complex structure of lignocellulose makes them useful in the exploration of the lignocellulosic biomass for the production of fuel ethanol and other value-added commodity chemicals. In addition to this, endophytic fungi may become new sources of industrially useful enzymes such as lipases, amylases and proteases.

Genetic diversity of endophytic fungi from Coffea arabica cv. IAPAR-59 in organic crops

Endophytes are microorganisms that live inside plant tissues throughout its life cycle and during certain phases of development. The endophyte–host relationships can provide benefits to the host, protecting it against attack by insects and diseases. Several studies have demonstrated the diversity of endophytes from Coffea arabica, but few studies in varieties of organic crops. Thus, the objective in this study was to corroborate these reports with knowledge of the endophytic fungi communities in an organic variety of C. arabica L. cultivar IAPAR-59. We identified the endophytic fungi by molecular methods using the ITS1-5.8S-ITS2 region of rDNA and phylogenetic analyses. In the antagonist activity tests, the endophytes were tested against phytopathogens with the evaluation of the kind of interactions between them. Analyses demonstrated a diversity of genera, including: Colletotrichum, Trichoderma, Schizophyllum, Mycosphaerella, Cladosporium, and Cercospora, as well as the first record of the genus Ophiognomonia in C. arabica. The antagonist activity showed reduced growth of the phytopathogenic fungi Glomerella sp., Colletotrichum sp. and Sclerotinia sclerotiorum. The results obtained in this work, with the identification for the first time, of a highly diverse isolated endophytic of the species Ophiognomonia sp. in the coffee plants, is the second report of the detection of these fungi in Brazil. Also, the detection of different isolates with the ability to antagonise pathogens, emphasises the importance of further research, involving the isolation, identification and exploration of endophytes of other genetic varieties of coffee, obtained by breeding programs of this important crop in Brazil.

Toxicity study of the anti-hypertensive agent perindopril on the entomopathogenic fungus Metarhizium anisopliae (Metschnikoff) Sorokin assessed by conidia germination speed parameter

Hypertension is an important vascular disease to the global public health, since it constitutes the principal cause of death from childhood to adulthood. In order to alleviate its symptoms, the treatment is accomplished by anti-hypertensive drugs, among them, is perindopril, an angiotensin-converting enzyme (ACE) inhibitor. The entomopathogenic filamentous fungus Metarhizium anisopliae is widely used for biological control and it has been promising in toxicity studies of substances assessed by conidia germination speed parameter. This study aimed to verify the effect of different concentrations of perindopril on the conidia germination speed of the model fungus M. anisopliae , for detecting a possible toxic effect of this medicament in another eukaryote. Conidia of M. anisopliae were incubated with perindopril in concentrations of 200 and 20 μg/ml at 28°C for 12 h, sampled at 0, 6, 8, 10 and 12 h and analyzed by light microscopy. The frequency of dormant, embedded, bud and germinated conidia was counted. As a result, perindopril in concentrations of 200 and 20 μg/ml increased the germination speed of M. anisopliae conidia , when compared to the negative control (absence of perindopril). It indicates that these two concentrations of perindopril have no toxicity on M. anisopliae , considering the Bayesian analysis. Keywords : Angiotensin-converting enzyme inhibitor, vegetative development, model fungus, entomopathogen, Bayesian analysis. African Journal of Biotechnology Vol. 12(35), pp. 5452-5457+