Plant-associated microorganisms are considered a key determinant of plant health and growth. However, little information is available regarding the composition and ecological function of the roots' and leaves' bacterial microbiota of halophytes. Here, using both culture-dependent and culture-independent techniques, we characterized the bacterial communities of the roots and leaves as well as the rhizosphere and bulk soils of the coastal halophyte in Jiangsu Province, China. We identified 49 representative bacterial strains belonging to 17 genera across all samples, with as the most dominant genus. All isolates showed multiple potential plant growth promotion traits and tolerated a high concentration of NaCl and a wide pH range. Interestingly, further inoculation experiments showed that the strain KLBMP 5180 isolated from root tissue significantly promoted host growth under NaCl stress. Indeed, KLBMP 5180 inoculation increased the concentrations of total chlorophyll, proline, antioxidative enzymes, flavonoids, K, and Ca in the leaves; the concentrations of malondialdehyde (MDA) and Na were reduced. A transcriptome analysis identified 1,359 and 328 differentially expressed genes (DEGs) in inoculated seedlings treated with 0 and 250 mM NaCl, respectively. We found that pathways related to phenylpropanoid and flavonoid biosynthesis and ion transport and metabolism might play more important roles in host salt stress tolerance induced by KLBMP 5180 inoculation compared to that in noninoculated leaves. Our results provide novel insights into the complex composition and function of the bacterial microbiota of the coastal halophyte and suggest that halophytes might recruit specific bacteria to enhance their tolerance of harsh environments. Halophytes are important coastal plants often used for the remediation of saline coastal soils. is well known for its medical properties and phytoremediation of saline soils. However, excessive exploitation and utilization have made the wild resource endangered. The use of endophytic and rhizosphere bacteria may be one of the suitable ways to solve the problem. This study was undertaken to develop approaches to improve the growth of using endophytes. The application of actinobacterial endophytes ameliorated salt stress damage of the host via complex physiological and molecular mechanisms. The results also highlight the potential of using habitat-adapted, symbiotic, indigenous endophytic bacteria to enhance the growth and ameliorate abiotic stress damage of host plants growing in special habitats.
A novel actinobacterium, designated KLBMP 5180T, was isolated from the surface-sterilized root of a coastal halophyte, Limonium sinense, collected from the city of Lianyungang, Jiangsu Province, eastern China. The isolate was Gram-stain-positive, aerobic and non-motile. The components of the cell-wall peptidoglycan were lysine, glutamic acid and alanine. The predominant menaquinone was MK-9. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, one unknown phospholipid, one unidentified glycolipid and two unidentified lipids. anteiso-C15 : 0 and iso-C16 : 0 were the major cellular fatty acids. The DNA G+C content of strain KLBMP 5180T was 60.0 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain KLBMP 5180T belongs to the genus Glutamicibacter and was related most closely to Glutamicibacter nicotianae DSM 20123T (99.3 % similarity), Glutamicibacterarilaitensis Re117T (99.3 %) and Glutamicibacter mysorens LMG 16219T (99.1 %); similarity to other type strains of the genus Glutamicibacter was lower than 98.5 %. However, DNA-DNA relatedness values between strain KLBMP 5180T, G . nicotianae DSM 20123T, G. arilaitensis Re117T and G. mysorens LMG 16219T were 47.5±2.6, 51.3±3.1 and 41.2±4.3 %, respectively. The combination of DNA-DNA hybridization, phylogenetic, phenotypic and chemotaxonomic data supported the suggestion that strain KLBMP 5180T represents a novel species of the genus Glutamicibacter, for which the name Glutamicibacterhalophytocola sp. nov. is proposed. The type strain is KLBMP 5180T (=DSM 101718T=KCTC 39692T).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.