Calcium- and ROS-mediated defence responses in BY2 tobacco cells by nonpathogenic Streptomyces sp

Abstract

Aims: The early molecular events underlying the elicitation of plant defence reactions by Gram‐positive bacteria are relatively unknown. In plants, calcium and reactive oxygen species are commonly involved as cellular messengers of a wide range of biotic stimuli from pathogenic to symbiotic bacteria. In the present work, we checked whether nonpathogenic Streptomyces sp. strains could induce early signalling events leading to defence responses in BY2 tobacco cell suspensions. Methods and Results: We have demonstrated that nonpathogenic Streptomyces sp. OE7 strain induced a cytosolic Ca2+ increase and a biphasic oxidative burst in the upstream signalling events, leading to defence responses in BY2 tobacco cell suspensions. Streptomyces sp. OE7 also elicited delayed intracellular free scopoletin production and programmed cell death. In agreement with scopoletin production, OE7 induced accumulation of PAL transcripts and increased accumulation of transcripts of EREBP1 and AOX genes that are known to be regulated by the jasmonate/ethylene pathway. Transcript levels of PR1b and NIMIN2α, both salicylic acid pathway–linked genes, were not modified. Moreover, Streptomyces sp. OE7 culture filtrates could reduce Pectobacterium carotovorum‐ and Pectobacterium atrosepticum‐induced death of BY2 cells and soft rot on potato slices. Conclusions: New insights are thus provided into the interaction mechanisms between Streptomyces sp. and plants; Streptomyces sp. could be sensed by plant cells, and through cytosolic Ca2+ changes and the generation of reactive oxygen species, defence responses were induced. Significance and Impact of the Study: These induced defence responses appeared to participate in attenuating Pectobacterium‐induced diseases in plants. Thus, Streptomyces sp. OE7 could be a biocontrol agent against Pectobacterium sp.

Infection of a tomato cell culture by Phytophthora infestans; a versatile tool to study Phytophthora-host interactions

“…In other studies, treatments with MAMPs such as chitin, induced defense responses in Msk8 cells [ 37 ]. Furthermore, culture filtrates from P. infestans and a species of the bacterium Streptomyces induced changes in pH in potato cells and ROS production in BY-2 cells, respectively [ 17 , 23 ].…”

“…as biocontrol agent against Pectobacterium spp. [ 17 ]. Another example is the use of Arabidopsis cell suspension cultures for transcriptomic analysis with a focus on phosphoinositide-dependent phospholipase C (PI-PLC) regulated gene expression [ 18 ].…”

Potential of Bioremediation and PGP Traits in Streptomyces as Strategies for Bio-Reclamation of Salt-Affected Soils for Agriculture

“…In some cases, bacteria can act in a vaccine-like fashion, eliciting non-specific plant defense mechanisms. This effect provides the host with resistance against pathogens via different mechanisms along the plant infection cycle [122][123][124]. Additionally, the use of some strains in the production of insecticides renders and environmentally friendly approach to control pests and disease without the application of synthetic compounds [99,102].…”

The potential of antagonistic moroccan Streptomyces isolates for the biological control of damping‐off disease of pea (Pisum sativum L.) caused by Aphanomyces euteiches

“…Approximately 80% of the known commercial antibiotics used in medicine and agriculture have initially been isolated from actinobacteria, and especially from strains of genus Streptomyces (Sanglier, Haag, Huck, & Fehr, ), that proved to be a rich source of antibiotics. Furthermore, Streptomyces have been reported in several studies as biological control and showed potential to control a wide range of plant pathogenic bacteria, fungi and oomycetes by producing diverse bioactive substances (Baz, Lahbabi, et al, ; Baz, Tran, et al, ; Errakhi, Lebrihi, & Barakate, ; Goudjal, Zamoum, Sabaou, Mathieu, & Zitouni, ; Samri et al, ). These bacteria like many other microorganisms can also promote plant growth by producing phytohormones (Goudjal et al, ), by improved phosphate mobilization (Hamdali, Hafidi, Virolle, & Ouhdouch, ) and by production of siderophores for iron acquisition (Macagnan, Romeiro, Pomella, & Souza, ).…”