Small peptides: novel targets for modulating plant–rhizosphere microbe interactions

Specialized metabolism plays a central role in how plants cope with both biotic and abiotic stresses in order to survive and reproduce within dynamic and challenging environments. One recently circumscribed class of plant-specific, ribosomally synthesized and post-translationally modified peptides are the burpitides, which are characterized by the installation of distinct sidechain macrocycles by enzymes known as burpitide cyclases. While they are found across many plant families and exhibit diverse bioactivities, little is known about their evolution or how new variants arise. Here we present the discovery of a new burpitide cyclase, resurrected from a defunct pseudogene from the model organism Nicotiana attenuata, the coyote tobacco. By repairing the pseudogene ΨNatBURP2 and expressing it heterologously in Nicotiana benthamiana, we successfully reconstituted its original enzymatic activity. As an autocatalytic peptide cyclase, it installs a unique C-C bond between the tyrosine side chain and a specific backbone a-carbon of a heptapeptide core motif, resulting in the burpitide dubbed "nanamin." Despite its pseudogenization in N. attenuata, we found that the closely related species, N. clevelandii, retains the wild-type gene and produces nanamins. Phylogenetic analyses and targeted mutagenesis experiments reveal that this chemotype must have evolved from the duplication and neofunctionalization of a more promiscuous ancestral gene. This work highlights how novel peptide chemotypes may rapidly emerge and disappear in plants, while expanding the molecular toolkit for engineering novel peptides with applications in agriculture and drug discovery.

show abstract

Managing tomato bacterial wilt through pathogen suppression and host resistance augmentation using microbial peptide

Tiwari,

Bhojiya,

Jain

et al. 2024

Front. Microbiol.

View full text Add to dashboard Cite

The increasing health and environmental risks associated with synthetic chemical pesticides necessitate the exploration of safer, sustainable alternatives for plant protection. This study investigates a novel biosynthesized antimicrobial peptide (AMP) from Lactiplantibacillus argentoratensis strain IT, identified as the amino acid chain PRKGSVAKDVLPDPVYNSKLVTRLINHLMIDGKRG, for its efficacy in controlling bacterial wilt (BW) disease in tomato (Solanum lycopersicum) caused by Ralstonia solanacearum. Our research demonstrates that foliar application of this AMP at a concentration of 200 ppm significantly reduces disease incidence by 49.3% and disease severity by 45.8%. Scanning electron microscopy revealed severe morphological disruptions in the bacterial cells upon exposure to the AMP. Additionally, the AMP enhanced host resistance by elevating defense enzyme activities, leading to notable improvements in plant morphology, including a 95.5% increase in plant length, a 20.1% increase in biomass, and a 96.69% increase in root length. This bifunctional AMP provides dual protection by exerting direct antimicrobial activity against the pathogen and eliciting plant defense mechanisms. These findings underscore the potential of this biologically sourced AMP as a natural agent for combating plant diseases and promoting growth in tomato crops. To the best of our knowledge, this is the first study to demonstrate the use of a foliar spray application of a biosynthesized microbial peptide as biocontrol agent against R. solanacearum. This interaction not only highlights its biocontrol efficacy but also its role in promoting the growth of Solanum lycopersicum thereby increasing overall agricultural yield.

show abstract

Small peptides: novel targets for modulating plant–rhizosphere microbe interactions

Cited by 5 publications

References 97 publications

Transcriptomic insights into the potential impacts of flavonoids and nodule-specific cysteine-rich peptides on nitrogen fixation in Vicia villosa and Vicia sativa

Transcriptomic insights into the potential impacts of flavonoids and nodule-specific cysteine-rich peptides on nitrogen fixation in Vicia villosa and Vicia sativa

The emergence and loss of cyclic peptides inNicotianailluminate dynamics and mechanisms of plant metabolic evolution

Managing tomato bacterial wilt through pathogen suppression and host resistance augmentation using microbial peptide

Contact Info

Product

Resources

About