Antimicrobial Activity Against Phytopathogens and Inhibitory Activity on Solanine in Potatoes of the Endophytic Bacteria Isolated From Potato Tubers

Abstract

As an important global crop, the potato ( Solanum tuberosum L.) contains the endotoxin solanine that leads to human poisoning and major economic losses. Poisoning symptoms and even acute poisoning may occur when the content of solanine in potatoes exceeds 200 mg/kg. In addition, potatoes are susceptible to some pathogenic bacteria, including Streptomyces scabies and Erwinia carotovora subsp. atroseptica (Van Hall) dye, which can cause potato scab and potato blackleg disease, respectively. In this study, 37 culturable endophytic bacteria strains were obtained from potato tubers based on the culture-dependent method. Results indicated that nine strains showed antimicrobial activity against at least one pathogen by antimicrobial activity screening and 23 strains showed inhibitory activity on solanine in potato tubers. Among them, strain P-NA2-14 ( Bacillus megaterium NBRC 15308 T , 99.31%) showed not only better antimicrobial activity against both the two indicator pathogens, but also the best inhibitory activity on solanine, which was proved to be a potential biocontrol bacterium. Meanwhile, the relationship between the distribution of the endophytic bacterial community and the content of solanine in potato tubers was studied by Illumina-based analysis, indicating that the distribution of the endophytic bacterial community was obviously influenced by the content of solanine. The results showed a new insight into the relationship between plant secondary metabolites and endophytic bacteria in potato tubers and provided potential new technical support for the biological control of potato storage.

Analysis of Endophytic Bacterial Diversity From Different Dendrobium Stems and Discovery of an Endophyte Produced Dendrobine-Type Sesquiterpenoid Alkaloids

“…In other words, the rarefaction curves showed that the sequencing work was relatively comprehensive in covering the bacterial diversity, as the curves tended to approach saturation, indicating that the selected sequence data adequately reflected the bacterial abundance of these samples. The alpha-diversity analyses, including Shannon, Sobs, Simpson, Chao, Ace, and Coverage, were used to detect the distribution of endophytic microbial composition on OTU level and estimated the endophytic community complexity ( Liu J. M. et al, 2020 ; Supplementary Table 2 ). The lower Simpson index value but higher Shannon index of group J10_15cm indicated greater community diversity.…”

“…The raw reads were stored in the Sequence Read Archive of the National Center for Biotechnology Information (NCBI) database. Sequencing data were processed and analyzed according to the method in Liu J. M. et al (2020) ( Supplementary Figure 3 ).…”

“…As the unique component of Dendrobium , 26 dendrobine-type sesquiterpenoid alkaloids (DSAs) have been isolated and identified from Dendrobium to date ( Li et al, 2019 ; Liu J. M. et al, 2020 ; Yin et al, 2020 ). DSAs show significant activity in protecting hepatic injury, improving brain function, protecting acute cerebral ischemia injury, antitumor, anti-cataract, and anti-influenza A virus ( Wang and Ren, 2015 ; Li R. C. et al, 2017 ; Li et al, 2019 ; Ci et al, 2020 ).…”

Molecular Host-Nematode Interactions and Tuber Development

“…CIPC ([isopropyl-N-(3-chlorophenyl) carbamate) is particularly important as a sprout suppressant for potatoes during storage. However, CIPC has been proven not to be safe for humans and the environment in recent years [101]. Therefore, alternate sprout suppressant approaches, for example constant ethylene supplement, could be used to suppress post-harvest sprouting [102].…”

Applications of bacterial endophytes and their advanced identification methodologies

“…It was reported that endophytic bacteria colonized through plant tissue into vegetative and reproductive organs of plants. Plants with prior inoculation with endophytes reduce the diseases of fungal, viral, and bacteria and prevent insects and nematodes attack [52][53][54].…”