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

Small peptides produced by plants (SPPs) and microbes (SPMs) function as crucial mediators in plant–rhizosphere microbe interactions, with SPPs facilitating long-distance signaling through extracellular vesicles and SPMs modulating plant immunity and hormone signaling to enhance communication. SPPs may directly alter the rhizosphere microbiomes by modifying microbial gene expression or indirectly by influencing root morphology, exudate release, and immune responses, thus affecting microbial community structure and composition. Leveraging the bidirectional signaling facilitated by SPPs and SPMs between plants and their rhizosphere microbes offers a novel strategy in holobiont engineering, and the potential of exploring transgenic microbes to synthesize small peptides on a large scale merits further investigations. The crucial role of rhizosphere microbes in plant growth and their resilience to environmental stresses underscores the intricate communication between microbes and plants. Plants are equipped with a diverse set of signaling molecules that facilitate communication across different biological kingdoms, although our comprehension of these mechanisms is still evolving. Small peptides produced by plants (SPPs) and microbes (SPMs) play a pivotal role in intracellular signaling and are essential in orchestrating various plant development stages. In this review, we posit that SPPs and SPMs serve as crucial signaling agents for the bidirectional cross-kingdom communication between plants and rhizosphere microbes. We explore several potential mechanistic pathways through which this communication occurs. Additionally, we propose that leveraging small peptides, inspired by plant–rhizosphere microbe interactions, represents an innovative approach in the field of holobiont engineering. [ABSTRACT FROM AUTHOR]