Harnessing microbial volatiles to replace pesticides and fertilizers

Abstract

Global agricultural systems are under increasing pressure to deliver sufficient, healthy food for a growing population. Seasonal inputs, including synthetic pesticides and fertilizers, are applied to crops to reduce losses by pathogens, and enhance crop biomass, although their production and application can also incur several economic and environmental penalties. New solutions are therefore urgently required to enhance crop yield whilst reducing dependence on these seasonal inputs. Volatile Organic Compounds (VOCs) produced by soil microorganisms may provide alternative, sustainable solutions, due to their ability to inhibit plant pathogens, induce plant resistance against pathogens and enhance plant growth promotion. This review will highlight recent advances in our understanding of the biological activities of microbial VOCs (mVOCs), providing perspectives on research required to develop them into viable alternatives to current unsustainable seasonal inputs. This can identify potential new avenues for mVOC research and stimulate discussion across the academic community and agri-business sector.

Endophytic Bacteria and Essential Oil from Origanum vulgare ssp. vulgare Share Some VOCs with an Antibacterial Activity

“…The ability of these compounds to suppress pathogens and signal to plants proves their potential to be exploited as alternatives to chemical fertilizers and pesticides, which could provide a more sustainable solution as well as have negligible hazardous effects on animals and the environment [ 10 ]. Moreover, recent studies have established that VOCs are able to influence the growth of other bacteria, in a sort of chemical at-a-distance cross-talk [ 11 , 12 , 13 ].…”

The soil crisis: the need to treat as a global health problem and the pivotal role of microbes in prophylaxis and therapy

“…Since monocrops are needed to feed the growing world population, we must counteract their negative impact by (1) reducing the number of crops per season, (2) adopting soil protective practices, like intercropping and alley cropping (Wolz et al, 2018), (3) reducing agrochemical use and replacing with soil-friendlier alternatives, like microbial fertilizers-pesticides, probiotics and agents that boost plant immune responses to pests (e.g. Thomas et al, 2020), (4) reducing mechanized abuse, (5) immediately planting cover plants after harvest, to reduce erosion and provide time and resources for soil diversity to recover between crops, and (6) eliminate stubble burning. ii.…”

Rhizobial Volatiles: Potential New Players in the Complex Interkingdom Signaling With Legumes

“…While the role of BVCs in intermicrobial interactions has only recently been acknowledged, their functions in interkingdom interactions with plants have been known for almost 20 years (reviewed in Sharifi and Ryu, 2018 ; Garbeva and Weisskopf, 2020 ; Thomas et al, 2020 ; Weisskopf et al, 2021 ). Since the seminal contribution by Ryu et al (2003) reporting that volatile blends emitted by two Bacillus species were able to promote growth of Arabidopsis , numerous studies have described the different and relevant effects of BVCs on plants.…”

“…Bacterial volatiles are especially well known for their capacity to increase plant growth and resistance against both biotic and abiotic stresses. These properties could be exploited for the development of eco-friendly solutions in the form of biofertilizers and biopesticides to improve plant health and productivity ( Kanchiswamy et al, 2015 ; Chung et al, 2016 ; Sharifi and Ryu, 2018 ; Garbeva and Weisskopf, 2020 ; Thomas et al, 2020 ).…”