Tissue-specific synergistic bio-priming of pepper by two Streptomyces species against Phytophthora capsici

Abstract

Among several studied strains, Streptomyces rochei IT20 and S. vinaceusdrappus SS14 showed a high level of inhibitory effect against Phytophthora capsici, the causal agent of pepper blight. The effect of two mentioned superior antagonists, as single or combination treatments, on suppression of stem and fruit blight diseases and reproductive growth promotion was investigated in pepper. To explore the induced plant defense reactions, ROS generation and transcriptional changes of selected genes in leaf and fruit tissues of the plant were evaluated. The plants exposed to the combination of two species responded differently in terms of H 2 O 2 accumulation and expression ratio of GST gene compared to single treatments upon pathogen inoculation. Besides, the increment of shoot length, flowering, and fruit weight were observed in healthy plants compared to control. Likely, these changes depended on the coordinated relationships between PR1, ACCO genes and transcription factors WRKY40 enhanced after pathogen challenge. Our findings indicate that appropriate tissue of the host plant is required for inducing Streptomyces-based priming and relied on the up-regulation of SUS and differential regulation of ethylene-dependent genes. PLOS ONEPLOS ONE | https://doi.org/10.

Investigating Useful Properties of Four Streptomyces Strains Active against Fusarium graminearum Growth and Deoxynivalenol Production on Wheat Grains by qPCR

“…In the present study, the DEF09 strain showed lower but significant inhibition of fungal growth and toxin production, confirming that mechanisms of fungal growth inhibition are active in this strain also on detached grains. Our study identifies peculiarities of each strain that can be exploited for generating complex consortia able to effectively limit the disease [ 58 , 59 ]. Hopefully, future integration of omics analyses of the biocontrol strains may lead to the identification of effective molecules able to block fungal growth and modulate toxin biosynthesis [ 60 ] as well as to the understanding of mechanisms that modulate growth by sensing the fungal neighbor.…”

Streptomyces strains modulate dynamics of soil bacterial communities and their efficacy in disease suppression caused by Phytophthora capsici

“…There is growing evidence that rhizosphere–microbe interactions are modulated by nutrient availability in the soil that bacterial communities act somewhat independently of plants 41 . In particular, the concentration of available P in the soil adjusted the establishment of them 42 or induced plant immunity through PR1 and WRKY40 gene expression which induced salicylic acid‐dependent responses improving resistance against the pathogen 43 . Recent studies also showed that plants with a superior defense and nutrient acquisition, possibly, have specific microbial communities in the rhizosphere, suggesting a close link between plant growth parameters and rhizosphere microbiota functions.…”

Pathogenesis-related protein 10 in resistance to biotic stress: progress in elucidating functions, regulation and modes of action

“…Few studies reported PR-10 down-regulation, which depended on the time and biotic stress assessed ( Figure 4A ; Table S3 ). PR-10 repression was caused by endophytic and mycorrhizal agents, which form mutualistic symbiotic associations with plants ( Johnson et al., 2003 ; Grunwald et al., 2009 ; Mishra et al., 2018 ; Kiani et al., 2021 ), and when more than one PR-10 was evaluated in different genotypes or plant tissues ( Ding et al., 2015 ; Abbasi et al., 2020 ; Irigoyen et al., 2020 ).…”