Study in vitro of the impact of endophytic bacteria isolated from Centella asiatica on the disease incidence caused by the hemibiotrophic fungus Colletotrichum higginsianum

Abstract

Thirty-one endophytic bacteria isolated from healthy leaves of Centella asiatica were screened in vitro for their ability to reduce the growth rate and disease incidence of Colletotrichum higginsianum, a causal agent of anthracnose. Isolates of Cohnella sp., Paenibacillus sp. and Pantoea sp. significantly stimulated the growth rate of C. higginsianum MUCL 44942, while isolates of Achromobacter sp., Acinetobacter sp., Microbacterium sp., Klebsiella sp. and Pseudomonas putida had no influence on this plant pathogen. By contrast, Bacillus subtilis BCA31 and Pseudomonas fluorescens BCA08 caused a marked inhibition of C. higginsianum MUCL 44942 growth by 46 and 82 %, respectively. Cell-free culture filtrates of B. subtilis BCA31 and P. fluorescens BCA08 were found to contain antifungal compounds against C. higginsianum MUCL 44942. Inoculation assays on in vitro-cultured plants of C. asiatica showed that foliar application of B. subtilis BCA31, three days before inoculation with C. higginsianum MUCL 44942, significantly reduced incidence and severity of the disease. The role of endophytic bacteria in maintaining the apparent inactivity of C. higginsianum MUCL 44942 in C. asiatica grown in the wild is discussed.

Isolation, abundance and phylogenetic affiliation of endophytic actinomycetes associated with medicinal plants and screening for their in vitro antimicrobial biosynthetic potential

“…Among 42 endophytic actinomycetes obtained from seven medicinal plants, Streptomyces was the dominant genus ( n = 28, 66.6% of all isolates), a finding consistent with other reports from different hosts showing the dominance of species within the Streptomyces genus (Coombs and Franco, 2003 ; Cao et al, 2004 ). Besides Streptomyces sp., other genera were also reported occasionally from medicinal plants like Microbacterium from Maytenus austroyunnanesis (Qin et al, 2012 ), Leifsonia from Ginseng roots (Qiu et al, 2007 ) and Brevibacterium was isolated from Centella asiatica and Conyza canadensis (Kim et al, 2012 ; Rakotoniriana et al, 2013 ) Therefore, it looks like that these reported rare genera are also able to associate endophytically with various hosts. The Streptomyces genus has an excellent track record for the discovery of secondary metabolites.…”

Comparative Analyses of Phyllosphere Bacterial Communities and Metabolomes in Newly Developed Needles of Cunninghamia lanceolata (Lamb.) Hook. at Four Stages of Stand Growth

“…The total leaf surface area greatly exceeds the terrestrial land area in forest ecosystems. Therefore, plant leaves and needles provide vast habitats for diverse bacteria and fungi, especially foliar endophytic fungi (Saucedo-Garcia et al, 2014 ; Jia et al, 2020 ; Quiring et al, 2020 ; Shahrtash and Brown, 2020 ) and bacteria (Rakotoniriana et al, 2013 ; Yu et al, 2015 ; Carrell et al, 2016 ). Foliar endophytes perform multiple functions (Jia et al, 2020 ) and participate in nutrient uptake (Madhaiyan et al, 2015 ; Moyes et al, 2016 ; Christian et al, 2019 ).…”

Enhanced Tolerance of Chinese Cabbage Seedlings Mediated by Bacillus aryabhattai H26-2 and B. siamensis H30-3 against High Temperature Stress and Fungal Infections

“…B. amyloliquefaciens UCM5113 and its lipopeptide extracts have in vitro antifungal activity against A. brassicicola ( Asari et al, 2017 ). B. subtilis BCA31 and its culture filtrate markedly inhibited in vitro mycelial growth of C. higginsianum ( Rakotoniriana et al, 2013 ). However, no biocontrol has been established on Chinese cabbage plants against the two fungal infections.…”