Plantactinospora sonchi sp nov., an actinobacterium isolated from the leaves of common sowthistle (Sonchus oleraceus L.)

A novel actinobacterium, designated strain NEAU-QY2(T), was isolated from the leaves of Sonchus oleraceus L. specimen, collected from Wuchang, Heilongjiang Province, China. A polyphasic study was carried out to establish the taxonomic position of this strain. The organism formed single spores with rough surfaces on substrate mycelia. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NEAU-QY2(T) belonged to the genus Plantactinospora and formed a monophyletic Glade with its closest related strains Plantactinospora endophytica YIM 68255(T) (99.2 % 16S rRNA gene sequence similarity), Plantactinospora veratri NEAU-FHS4(T) (98.8 %) and Plantactinospora mayteni YIM 61359(T) (98.7 %), an association that was supported by a bootstrap value of 90 % in the neighbour joining tree and also recovered with the maximum-likelihood algorithm. However, DNA DNA hybridization values between strain NEAU-QY2(T) and the three closely related strains were below 70 %. With reference to phenotypic characteristics, phylogenetic data and DNA DNA hybridization results, strain NEAU-QY2(T) was distinguished from closely related strains and is classified as representing a novel species of the genus Plantactinospora, for which the name Plantactinospora sonchi sp. nov. is proposed. The type strain is NEAU-QY2(T) (=CGMCC 4.7216(T)=JCM 30345(T)).