Auxin production and plant growth promotion by sp. nov. from the rhizoplane of leafless Seidenf. orchid.

The strains of the genus , with more than 150 species, inhabit diverse environments; plant-associated bacteria reveal their plant growth-promoting activities due to a number of beneficial characteristics. Through the performance of diverse techniques and methods, including isolation of a novel strain from the aerial roots of leafless epiphytic orchid, Seidenf., its morphological and biochemical characterization, chemotaxonomy, phylogenetic and genome analysis, as well as bioassays and estimation of its auxin production capacity, a novel strain of ET2 is described.

Complete genome sequence of new sp. strain ET2, isolated from roots of leafless orchid.

Whole-genome sequence of ET2 strain, isolated from the roots of leafless orchid, constitutes a single circular chromosome of 3,604,840 bp (69.44% G + C content). BLAST+-based average nucleotide identity (ANIb) and digital DNA-DNA hybridization values indicate that ET2 may be a novel species.

Cyanobacterial Root Associations of Leafless Epiphytic Orchids.

The leafless orchids are rare epiphytic plants with extremely reduced leaves, and their aerial roots adopted for photosynthesis. The beneficial plant-microbial interactions contribute significantly to host nutrition, fitness, and growth. However, there are no data available on the bacterial associations, inhabiting leafless orchids.

Megasporogenesis, megagametogenesis, and embryogenesis in Dendrobium nobile (Orchidaceae).

The orchid reproductive strategy, including the formation of numerous tiny seeds, is achieved by the elimination of some stages in the early plant embryogenesis. In this study, we documented in detail the formation of the maternal tissues (the nucellus and integuments), the structures of female gametophyte (megaspores, chalazal nuclei, synergids, polar nuclei), and embryonic structures in Dendrobium nobile. The ovary is unilocular, and the ovule primordia are formed in the placenta before the pollination.

Comparative "Omics" of the Fusarium fujikuroi Species Complex Highlights Differences in Genetic Potential and Metabolite Synthesis.

Species of the Fusarium fujikuroi species complex (FFC) cause a wide spectrum of often devastating diseases on diverse agricultural crops, including coffee, fig, mango, maize, rice, and sugarcane. Although species within the FFC are difficult to distinguish by morphology, and their genes often share 90% sequence similarity, they can differ in host plant specificity and life style. FFC species can also produce structurally diverse secondary metabolites (SMs), including the mycotoxins fumonisins, fusarins, fusaric acid, and beauvericin, and the phytohormones gibberellins, auxins, and cytokinins.

The biotransformation of brewer's spent grain into biogas by anaerobic microbial communities.

The present study reports on the biotransformation of the brewer's spent grain (BSG) in co-digestion with Jerusalem artichoke (JA, Helianthus tuberosus L.) phytomass by thermophilic (+55 °C) and mesophilic (+30 °C) anaerobic methanogenic communities. BSG is a by-product of the beer-brewing process generated in large amounts, in which utilization provokes a negative effect on the environment.

Asymbiotic in vitro seed propagation of Dendrobium.

The ability to germinate orchids from seeds in vitro presents a useful and viable method for the propagation of valuable germplasm, maintaining the genetic heterogeneity inherent in seeds. Given the ornamental and medicinal importance of many species within the genus Dendrobium, this review explores in vitro techniques for their asymbiotic seed germination. The influence of abiotic factors (such as temperature and light), methods of sterilization, composition of basal media, and supplementation with organic additives and plant growth regulators are discussed in context to achieve successful seed germination, protocorm formation, and further seedling growth and development.

Symbiotic in vitro seed propagation of Dendrobium: fungal and bacterial partners and their influence on plant growth and development.

The genus Dendrobium is one of the largest genera of the Orchidaceae Juss. family, although some of its members are the most threatened today. The reason why many species face a vulnerable or endangered status is primarily because of anthropogenic interference in natural habitats and commercial overexploitation.

Production of gibberellic acids by an orchid-associated Fusarium proliferatum strain.

The rice pathogen Fusarium fujikuroi is well known for its ability to produce the plant hormones gibberellins (GAs). However, the majority of closely related Fusarium species is unable to produce GAs although the GA gene cluster is present in their genomes. In this study, we analyzed five orchid-associated Fusarium isolates for their capacity to produce GAs.

Orchid-associated bacteria produce indole-3-acetic acid, promote seed germination, and increase their microbial yield in response to exogenous auxin.

Germination of orchid seeds is a complex process. In this paper we focus on interactions between the host-plant and its bacterial partners via indole-3-acetic acid (IAA). Originally isolated from the roots of the epiphytic orchid Dendrobium moschatum, the strains of Rhizobium, Microbacterium, Sphingomonas, and Mycobacterium genera were among the most active IAA producers.

Bacteria associated with orchid roots and microbial production of auxin.

Associative bacteria of terrestrial (Paphiopedilum appletonianum) and epiphytic (Pholidota articulata) tropical orchids were investigated. Microbial community of epiphytic plant differed from that of the terrestrial one. Streptomyces, Bacillus, Pseudomonas, Burkholderia, Erwinia and Nocardia strains populated Paphiopedilum roots, whereas Pseudomonas, Flavobacterium, Stenotrophomonas, Pantoea, Chryseobacterium, Bacillus, Agrobacterium, Erwinia, Burkholderia and Paracoccus strains colonized Pholidota roots.