RESUMO
The diversity and plant growth-promoting ability of fungal endophytes that are associated with five halophytic plant species (Phragmites australis, Suaeda australis, Limonium tetragonum, Suaeda glauca Bunge, and Suaeda maritima) growing in the Buan salt marsh on the west coast of South Korea have been explored. About 188 fungal strains were isolated from these plant samples' roots and were then studied with the use of the internal transcribed spacer (ITS) region (ITS1-5.8S-ITS2). The endophytic fungal strains belonged to 33 genera. Alternaria (18%) and Fusarium (12.8%), of the classes Dothideomycetes and Sordariomycetes, were most rampant in the coastal salt marsh plants. There was a higher diversity in fungal endophytes that are isolated from S. glauca Bunge than in isolates from other coastal salt marsh plants. Plant growth-promoting experiments with the use of Waito-C rice seedlings show that some of the fungal strains could encourage a more efficient growth than others. Furthermore, gibberellins (GAs) GA1, GA3, and GA9 were seen in the Sa-1-4-3 isolate (Acrostalagmus luteoalbus) culture filtrate with a gas chromatography/mass spectrometry.
Assuntos
Alternaria , Endófitos/classificação , Fusarium , Plantas Tolerantes a Sal/microbiologia , Áreas Alagadas , Alternaria/classificação , Alternaria/isolamento & purificação , Ascomicetos/metabolismo , Biodiversidade , DNA Fúngico/genética , Endófitos/isolamento & purificação , Fusarium/classificação , Fusarium/isolamento & purificação , Giberelinas/metabolismo , Oryza/microbiologia , Filogenia , Reguladores de Crescimento de Plantas , Raízes de Plantas/microbiologia , Reação em Cadeia da Polimerase , República da Coreia , Plantas Tolerantes a Sal/crescimento & desenvolvimento , Análise de Sequência de DNA , SimbioseRESUMO
Tricholoma matsutake is an ectomycorrhizal fungus, related with the host of Pinus densiflora. Most of studies on T. matsutake have focused on mycelial growth, genes and genomics, phylogenetics, symbiosis, and immune activity of this strain. T. matsutake is known for its unique fragrance in Eastern Asia. The most major component of its scent is (R)-(-)-1-octen-3-ol and is biosynthesized from the substrate linoleic acid by the sequential reaction of lipoxygenase and peroxide lyase. Here, we report for the first time the biosynthesis of (R)-(-)- 1-octen-3-ol of T. matsutake using the yeast Saccharomyces cerevisiae as a host. In this study, cDNA genes correlated with these reactions were cloned from T. matsutake, and expression studies of theses genes were carried out in the yeast Saccharomyces cerevisiae. The product of these genes expression study was carried out with Western blotting. The biosynthesis of (R)-(-)- 1-octen-3-ol of T. matsutake in recombinant Saccharomyces cerevisiae was subsequently identified with GC-MS chromatography analysis. The biosynthesis of (R)-(-)-1-octen-3-ol with S. cerevisiae represents a significant step forward.
Assuntos
Aldeído Liases/genética , Sistema Enzimático do Citocromo P-450/genética , Expressão Gênica , Lipoxigenase/genética , Octanóis/metabolismo , Saccharomyces cerevisiae/metabolismo , Tricholoma/enzimologia , Tricholoma/genética , Clonagem Molecular , Fermentação , Isoenzimas , Proteínas Recombinantes , Temperatura , Transformação GenéticaRESUMO
Plant growth-promoting endophytic fungi with gibberellin-producing ability were isolated from the roots of Carex kobomugi Ohwi, a common sand-dune plant, and bioassayed for plant growth-promotion. A new strain, Arthrinium phaeospermum KACC43901, promoted growth of waito-c rice and Atriplex gemelinii. Analysis of its culture filtrate showed the presence of bioactive GA(1) (0.5 ng/ml), GA(3) (8.8 ng/ml), GA(4) (4.7 ng/ml) and GA(7) (2.2 ng/ml) along with physiologically inactive GA(5) (0.4 ng/ml), GA(9) (0.6 ng/ml), GA(12) (0.4 ng/ml), GA(15) (0.4 ng/ml), GA(19) (0.9 ng/ml) and GA(24) (1.8 ng/ml). The fungal isolate was identified through sequence homology and phylogenetic analysis of 18S rDNA (internal transcribed region).