Draft genome sequence of multitrait plant growth-promoting Bacillus sp. strain RZ2MS9

Plant growth-promoting rhizobacteria (PGPR) are able to colonize plant rhizosphere and improve plant growth through several direct and indirect mechanisms (1), which makes them good candidates for use as biofertilizers. Members of the genus Bacillus are often reported as PGPR because of multiple traits that promote plant growth, for instance, the ability to fix nitrogen (2), produce hormones like indole acetic-acid (IAA), solubilize phosphate, and suppress pathogen growth (3). The rhizobacterium Bacillus sp. strain RZ2MS9 was isolated in Brazil from the rhizosphere of guarana, a typical tropical plant, and was identified as Bacillus thuringiensis by multi-locus sequence type (MLST) analysis. On in vitro tests, this strain was able to produce 67.40 _g IAA/ml, solubilize phosphate, produce siderophore, and fix nitrogen. The strain promoted the growth of maize (Zea mays) and soybean (Glycine max) in an experiment conducted in greenhouse conditions, suggesting that it can be used in a broad range of hosts, which is a greatly desired feature in biofertilizer development (B. D. Batista, submitted for publication). The draft genome sequence of the strain presented here will be useful to explore its genomic features as a multitrait PGPR

Draft genome sequence of Burkholderia ambifaria RZ2MS16, a plant growth-promoting rhizobacterium isolated from guarana, a tropical plant

Burkholderia ambifaria strain RZ2MS16 was isolated from the rhizosphere of Amazon guarana in Brazil. This bacterium exhibits a remarkable capacity to promote the growth of corn and soybean. Here, we report the draft genome sequence of RZ2MS16 and some genes related to multiple traits involved in plant growth promotion

Isolation and enzyme bioprospection of endopytic bacteria associated with plants of Brazilian mangrove ecosystem

The mangrove ecosystem is a coastal tropical biome located in the transition zone between land and sea that is characterized by periodic flooding, which confers unique and specific environmental conditions on this biome. In these ecosystems, the vegetation is dominated by a particular group of plant species that provide a unique environment harboring diverse groups of microorganisms, including the endophytic microorganisms that are the focus of this study. Because of their intimate association with plants, endophytic microorganisms could be explored for biotechnologically significant products, such as enzymes, proteins, antibiotics and others. Here, we isolated endophytic microorganisms from two mangrove species, Rhizophora mangle and Avicennia nitida, that are found in streams in two mangrove systems in Bertioga and Cananéia, Brazil. Bacillus was the most frequently isolated genus, comprising 42% of the species isolated from Cananéia and 28% of the species from Bertioga. However, other common endophytic genera such as Pantoea, Curtobacterium and Enterobacter were also found. After identifying the isolates, the bacterial communities were evaluated for enzyme production. Protease activity was observed in 75% of the isolates, while endoglucanase activity occurred in 62% of the isolates. Bacillus showed the highest activity rates for amylase and esterase and endoglucanase. To our knowledge, this is the first reported diversity analysis performed on endophytic bacteria obtained from the branches of mangrove trees and the first overview of the specific enzymes produced by different bacterial genera. This work contributes to our knowledge of the microorganisms and enzymes present in mangrove ecosystems

An Interspecies Signaling System Mediated by Fusaric Acid Has Parallel Effects on Antifungal Metabolite Production by Pseudomonas protegens Strain Pf-5 and Antibiosis of Fusarium spp.

Pseudomonas protegens strain Pf-5 is a rhizosphere bacterium that suppresses soilborne plant diseases and produces at least seven different secondary metabolites with antifungal properties. We derived mutants of Pf-5 with single and multiple mutations in biosynthesis genes for seven antifungal metabolites: 2,4-diacetylphoroglucinol (DAPG), pyrrolnitrin, pyoluteorin, hydrogen cyanide, rhizoxin, orfamide A, and toxoflavin. These mutants were tested for inhibition of the pathogens Fusarium verticillioides and Fusarium oxysporum f. sp. pisi. Rhizoxin, pyrrolnitrin, and DAPG were found to be primarily responsible for fungal antagonism by Pf-5. Previously, other workers showed that the mycotoxin fusaric acid, which is produced by many Fusarium species, including F. verticillioides, inhibited the production of DAPG by Pseudomonas spp. In this study, amendment of culture media with fusaric acid decreased DAPG production, increased pyoluteorin production, and had no consistent influence on pyrrolnitrin or orfamide A production by Pf-5. Fusaric acid also altered the transcription of biosynthetic genes, indicating that the mycotoxin influenced antibiotic production by Pf-5 at the transcriptional level. Addition of fusaric acid to the culture medium reduced antibiosis of F. verticillioides by Pf-5 and derivative strains that produce DAPG but had no effect on antibiosis by Pf-5 derivatives that suppressed F. verticillioides due to pyrrolnitrin or rhizoxin production. Our results demonstrated the importance of three compounds, rhizoxin, pyrrolnitrin, and DAPG, in suppression of Fusarium spp. by Pf-5 and confirmed that an interspecies signaling system mediated by fusaric acid had parallel effects on antifungal metabolite production and antibiosis by the bacterial biological control organism

Diversity and biotechnological potential of plant-associated endophytic bacteria

Endophytes are microorganisms that inhabit the interior of plant tissues without harming their hosts. This definition includes internal colonists with apparently neutral behavior, symbionts and bacteria that migrate between the surface and the inside of the plant during their endophytic phase. The utilization of endophytes for biotechnological purposes has increased recently, especially in pest and disease control and in plant growth promotion. Endophytic bacteria promote plant growth in three major ways: they synthesize particular compounds that are useful for the plants, facilitate the uptake of certain nutrients from the soil, and control or prevent diseases (biological control). Growth promotion mediated by endophytic bacteria occurs via several mechanisms: the production of vital enzymes; the production of hormones such as auxin (indoleacetic acid [IAA]); symbiotic nitrogen fixation; antagonism against phytopathogens via the production of siderophores, chitinases or antibiotics and the solubilization and mineralization of nutrients, particularly insoluble mineral phosphates. The interactions between endophytes and plants can promote plant health and play a significant role in low-input sustainable agriculture for both food and nonfood crops. An understanding of the mechanisms enabling these endophytes to interact with plants is essential for realizing the biotechnological potential of these microorganisms

Molecular variability and genetic relationship among Brazilian strains of the sugarcane smut fungus

Sporisorium scitamineum is the fungus that causes sugarcane smut disease. Despite of the importance of sugarcane for Brazilian agribusiness and the persistence of the pathogen in most cropping areas, genetic variation studies are still missing for Brazilian isolates. In this study, sets of isolates were analyzed using two molecular markers (AFLP and telRFLP) and ITS sequencing. Twenty-two whips were collected from symptomatic plants in cultivated sugarcane fields of Brazil. A total of 41 haploid strains of compatible mating types were selected from individual teliospores and used for molecular genetic analyses. telRFLP and ITS analyses were expanded to six Argentine isolates, where the sugarcane smut was first recorded in America. Genetic relationship among strains suggests the human-mediated dispersal of S. scitamineum within the Brazilian territory and between the two neighboring countries. Two genetically distinct groups were defined by the combined analysis of AFLP and telRFLP. The opposite mating-type strains derived from single teliospores were clustered together into these main groups, but had not always identical haplotypes. telRFLP markers analyzed over two generations of selfing and controlled outcrossing confirmed the potential for emergence of new variants and occurrence of recombination, which are relevant events for evolution of virulence and environmental adaptation.Fil: Benevenuto, Juliana. Universidade de Sao Paulo; BrasilFil: Longatto, Daniel P.. Universidade de Sao Paulo; BrasilFil: Reis, Gislaine V.. Universidade de Sao Paulo; BrasilFil: Mielnichuk, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Palhares, Alessandra C.. Universidade de Sao Paulo; BrasilFil: Carvalho, Giselle. Universidade de Sao Paulo; BrasilFil: Saito, Suzane. Universidade de Sao Paulo; BrasilFil: Quecine, Maria C.. Universidade de Sao Paulo; BrasilFil: Sanguino, Alvaro. Agencia Paulista de Tecnologia Dos Agronegocios; BrasilFil: Vieira, Maria Lucia C.. Universidade de Sao Paulo; BrasilFil: Camargo, Luis Eduardo A.. Universidade de Sao Paulo; BrasilFil: Creste, Silvana. Agencia Paulista de Tecnologia Dos Agronegocios; BrasilFil: Monteiro-Vitorello, Claudia B.. Universidade de Sao Paulo; Brasi

Describing the unexplored microorganisms associated with guarana : a typical tropical plant

In Amazon rainforest, guarana (Paullinia cupana) is a typical tropical plant with valuable pharmaceutical, economic, and social importance, especially for Brazil, which is the only commercial producer of guarana. Despite its importance and exclusive origins, knowledge regarding the microbial community associated with guarana is incipient. The microorganisms associated with this plant were only recently determined, and they were nearly unexplored until 2010 when two research groups from São Paulo and Amazonas States joined in an unprecedented project to explore the guarana microbiome. The main goal of the project was to find a biological control for Colletotrichum, the causal agent of guarana anthracnose, which is an important disease that severely affects the culture. Due to the huge diversity found in the microbial community associated with guarana, the project has extended beyond its original purpose, and other biotechnological applications have been found for these new microorganisms. From the collection of fungi and bacteria (endophytic and epiphytic, culturable and unculturable) that were obtained from different ecological niches of guarana, several studies have been conducted aimed at different applications, especially focusing on the control of plant pathogens, the promotion of plant growth, and the discovery of new compounds

Beneficial microorganisms associated with sugarcane crops : the green gold for clean energy

Sugarcane is currently the economic basis of more than 100 countries, planted on over 25 million hectares worldwide. It has been considered one of the most promising crops for generating clean and renewable energy and is expected to become the second largest energy source in the world by 2030. The global production of this crop is continuously growing, mostly because of the rising consumption of sugar and ethanol. Increases in both crop area plantations and yield are occurring to meet the growing demand. As sugarcane plants establish associations with a great diversity of microorganisms during their life cycle, the use of beneficial fungi and bacteria as a complementary tool to improve plant yield has arisen as a powerful option to meet the current needs to increase productivity and sustainability. However, despite the economic importance of sugarcane, knowledge regarding the microbial community associated with this crop is still limited, as there is still a lack of information on the real diversity and roles of fungal and bacterial species. Current knowledge on sugarcane mycobiota has revealed Epicoccum, Trichoderma, and arbuscular mycorrhizae fungi as the main beneficial fungal agents with high potential for use as microbial-based biostimulants, leading to positive effects that include growth promotion, plant protection, stress resistance, and improved nutrient acquisition. The most studied plant growth-promoting bacteria (PGPB) associated with sugarcane include representatives of the genera Beijerinckia, Gluconacetobacter, Herbaspirillum, Burkholderia, and Azospirillum. The most significant effect obtained from the interaction of sugarcane with these PGPBs is the reduction of chemical nitrogen fertilizers, as these bacteria are able to convert atmospheric nitrogen into an available source, ammonium. Therefore, the use of microbial inoculants should be maximized in crop production, as there is strong evidence that sugarcane plants are able to grow more efficiently by establishing interactions with beneficial microorganisms. This chapter presents an overview on sugarcane production worldwide and gathers the main information about fungi and bacteria described as beneficial to sugarcane, as well as recent data on its complex microbiome

Antagonistic activity of fungi from anthracnose lesions on Paullinia cupana against Colletotrichum sp.

Anthracnose is a cosmopolitan disease caused by Colletotrichum spp. that affects many crops worldwide. Observations have shown that anthracnose leaf lesions may be colonized by several non-pathogenic microorganisms. The relationship of these microorganisms with the pathogen as well as their potential as biocontrol agents is not well known. Guarana (Paullinia cupana Mart. var. sorbilis) is a typical native Amazon crop with unknown microbial diversity. Guarana productivity has been reduced by a fungal disease caused by Colletotrichum sp. In this study, we isolated 15 fungi from guarana anthracnose leaf lesions that belong to five genera: Fusarium, Phomopsis, Leptosphaeria, Microdochium and Pestalotiopsis. Four isolates from the Fusarium sp. (C6 and C10), Pestalotiopsis sp. (C3), and Microdochium sp. (P7) consistently inhibited anthracnose fungal growth in vitro. Except for the Microdochium sp. (P7), these isolates were also able to inhibit the growth of the pathogen in in vivo assays using detached guarana leaves. Some mechanisms related to the growth inhibition of this pathogen were studied. Fusarium sp. (C6) produced chitinases; Fusarium sp. (C6, C10) and Pestalotiopsis sp. (C3) produced antagonistic volatile organic compounds. These three isolates also inhibited the growth of Fusarium spp., a pathogen of several plant species, suggesting their potential broad range of growth inhibition of other phytopathogens

QuecineInterspeciesSignalingSystem.pdf

Pseudomonas protegens strain Pf-5 is a rhizosphere bacterium that suppresses soilborne plant diseases and produces at least seven different secondary metabolites with antifungal properties. We derived mutants of Pf-5 with single and multiple mutations in biosynthesis genes for seven antifungal metabolites: 2,4-diacetylphoroglucinol (DAPG), pyrrolnitrin, pyoluteorin, hydrogen cyanide, rhizoxin, orfamide A, and toxoflavin. These mutants were tested for inhibition of the pathogens Fusarium verticillioides and Fusarium oxysporum f. sp. pisi. Rhizoxin, pyrrolnitrin, and DAPG were found to be primarily responsible for fungal antagonism by Pf-5. Previously, other workers showed that the mycotoxin fusaric acid, which is produced by many Fusarium species, including F. verticillioides, inhibited the production of DAPG by Pseudomonas spp. In this study, amendment of culture media with fusaric acid decreased DAPG production, increased pyoluteorin production, and had no consistent influence on pyrrolnitrin or orfamide A production by Pf-5. Fusaric acid also altered the transcription of biosynthetic genes, indicating that the mycotoxin influenced antibiotic production by Pf-5 at the transcriptional level. Addition of fusaric acid to the culture medium reduced antibiosis of F. verticillioides by Pf-5 and derivative strains that produce DAPG but had no effect on antibiosis by Pf-5 derivatives that suppressed F. verticillioides due to pyrrolnitrin or rhizoxin production. Our results demonstrated the importance of three compounds, rhizoxin, pyrrolnitrin, and DAPG, in suppression of Fusarium spp. by Pf-5 and confirmed that an interspecies signaling system mediated by fusaric acid had parallel effects on antifungal metabolite production and antibiosis by the bacterial biological control organism