Community Structure of Endophytic Actinobacteria in a New Zealand Native Medicinal Plant Pseudowintera colorata (Horopito) and Their Influence on Plant Growth
The role of plant endophytic Actinobacteria remains poorly understood with no reports of these communities in New Zealand native plants. This first investigation of endophytic Actinobacteria in New Zealand targeted the culturally significant medicinal shrub Pseudowintera colorata (horopito) as a model plant. Community analysis in plant tissues collected from ten geographically distinct sites showed that tissue type had the strongest influence on diversity and richness of endophytic Actinobacteria. More denaturing gradient gel electrophoresis (DGGE) bands were obtained from stems (n = 18) compared to roots (n = 13). Sequencing analysis of the major bands (n = 20) identified them as uncultured bacteria, Streptomyces sp. and Angustibacter peucedani. Using two Actinobacteria-specific media, nine isolates were recovered from surface-sterilised P. colorata tissues. This was approximately 12% of the total taxa and correlated well with culturable numbers in international studies. In vitro analysis of the functionality of these strains showed that Streptomyces sp. PRY2RB2 inhibited all the tested phytopathogenic fungi (n = 4), Streptomyces sp. UKCW/B and Nocardia sp. TP1BA1B solubilised phosphate and produced siderophores. The functionality of the phosphate solubilising strains (n = 2) in vivo was investigated by inoculation of P. colorata seedlings. After 4 months, the mean shoot height of seedlings treated with Nocardia sp. TP1BA1B was 1.65× longer, had higher shoot dry weight (1.6×) and number of internodes (1.67×) compared to control. This study identified for the first time a key group of endophytic Actinobacteria that are likely to be important in the ecology of New Zealand flora.
KeywordsPlant-microbe interaction Phytopathogens Growth promotion Microbial communities
isolate from Paringa Forest root sample
isolate from Paringa Forest root sample
denaturing gradient gel electrophoresis
isolate from Taihape Scenic Reserve stem sample
The authors thank Lincoln University for funding this research and New Zealand Department of Conservation (DOC) for permission to collect samples. The first author (NP) was funded through NZAID Commonwealth scholarship administered by the New Zealand Ministry of Foreign Affairs and Trade (MFAT).
- 4.Brooker SG, Cambie RC, Cooper RC (1987) New Zealand medicinal plants. Heinemann publishers, Auckland, p 268Google Scholar
- 12.Ernawati M, Solihin DD, Lestari Y (2015) Community structures of endophytic Actinobacteria from medicinal plant Centella asiatica L. urban-based on metagenomics approach. Int. J Pharm Sci 8:292–297Google Scholar
- 30.Passari AK, Mishra VK, Saikia R, Gupta VK, Singh BP (2015) Isolation, abundance and phylogenetic affiliation of endophytic actinomycetes associated with medicinal plants and screening for their in vitro antimicrobial biosynthetic potential. Front Microbiol 6:273CrossRefPubMedPubMedCentralGoogle Scholar
- 35.Qin S, Zhang YJ, Yuan B, Xu PY, Xing K, Wang J, Jiang JH (2014) Isolation of ACC deaminase-producing habitat-adapted symbiotic bacteria associated with halophyte Limonium sinense (Girard) Kuntze and evaluating their plant growth- promoting activity under salt stress. Plant Soil 374:753–766CrossRefGoogle Scholar
- 38.Rungin S, Indananda C, Suttiviriya P, Kruasuwan W, Jaemsaeng R, Thamchaipenet A (2012) Plant growth enhancing effects by a siderophore- producing endophytic streptomycete isolated from a Thai jasmine rice plant (Oryza sativa L. cv. KDML105). Antonie Leeuwenhoek 102:463–472CrossRefPubMedGoogle Scholar
- 39.Salam N, Khieu T-N, Liu M-J, Vu T-T, Chu-Ky S, Quanch N-T et al (2017) Endophytic Actinobacteria associated with Dracaena cochinchinensis Lour.: isolation, diversity, and their cytotoxic activities. BioMed Res Int Article ID 1308563, 11 pagesGoogle Scholar
- 43.Sun Og L, Ja Choi G, Ho Choi Y, Soo Jang K, Park D-J, Kim C-J, Kim J-C (2008) Isolation and characterization of endophytic Actinomycetes from Chinese cabbage roots as antagonists to Plasmodiophora brassicae. J Microbiol Biotechnol 18:1741–1746Google Scholar