C4 Bacterial Volatiles Improve Plant Health

Abstract

Plant growth-promoting rhizobacteria (PGPR) associated with plant roots can trigger plant growth promotion and induced systemic resistance. Several bacterial determinants including cell-wall components and secreted compounds have been identified to date. Here, we review a group of low-molecular-weight volatile compounds released by PGPR, which improve plant health, mostly by protecting plants against pathogen attack under greenhouse and field conditions. We particularly focus on C4 bacterial volatile compounds (BVCs), such as 2,3-butanediol and acetoin, which have been shown to activate the plant immune response and to promote plant growth at the molecular level as well as in large-scale field applications. We also disc/ uss the potential applications, metabolic engineering, and large-scale fermentation of C4 BVCs. The C4 bacterial volatiles act as airborne signals and therefore represent a new type of biocontrol agent. Further advances in the encapsulation procedure, together with the development of standards and guidelines, will promote the application of C4 volatiles in the field.

Isolation and identification of antagonistic Bacillus amyloliquefaciens HSE-12 and its effects on peanut growth and rhizosphere microbial community

“…Table 1 lists the compounds with biocontrol and probiotic effects, of which acetoin, 2,3-butanediol and N-methyl-N-nitroso-Ethanamine, were the first three major VOCs. 2,3-butanediol and acetoin were known to promote plant growth, antagonise fungi, induce resistance and improve plant tolerance ( Wu et al, 2019 ; Silva Dias et al, 2021 ); ethanol inhibits Staphylococcus aureus and Streptococcus pyogenes ( Rajendran et al, 2013 ); 2-nonanone, 3-methyl-2-pentanone, 5-methyl-2-hexanone and linalool have been shown to inhibit the growth of pathogenic bacteria ( Li et al, 2015 ; Hou et al, 2021 ; Teliban et al, 2021 ).…”

Agronomic efficiency and genome mining analysis of the wheat-biostimulant rhizospheric bacterium Pseudomonas pergaminensis sp. nov. strain 1008T

“…However, the capacity to induce systemic resistance cannot be discarded for strain 1008, as typical general elicitors of ISR like LPS, flagella and siderophores of the pyoverdine type ( Pieterse et al, 2014 ) are structural and functional components of strain 1008 ( Figure 1 , Supplementary Figure 2 , and Supplementary Table 8 ). Furthermore, the genome of strain 1008 encodes genes for the production of the volatile compounds 2,3-butanediol and acetoin ( Figure 3 and Supplementary Table 8 ), which are also elicitors of ISR ( Pieterse et al, 2014 ; Silva Dias et al, 2021 ). In addition, it has been recently proposed that certain plant-beneficial rhizobacteria may engage into a feedback loop.…”

Bacterial volatile organic compounds induce adverse ultrastructural changes and DNA damage to the sugarcane pathogenic fungus Thielaviopsis ethacetica

“…Therefore, investments in agricultural biotechnology are necessary, and plant growth‐promoting bacteria (PGPB) play a fundamental role in revolutionizing agriculture. PGPBs have several mechanisms that promote plant growth and health (Ryu et al ., 2020; Silva Dias et al ., 2021); among them, we highlight the production of volatile organic compounds (VOCs), which are small molecules of a lipophilic nature derived from a wide range of biosynthetic pathways and have a low boiling point and high vapour pressure (Lemfack et al ., 2014).…”