The article reviews the role of microbial volatile organic compounds (mVOCs) in plant defense mechanisms. mVOCs, produced by various microorganisms, play a crucial role in plant health by promoting growth, activating defense pathways, and inhibiting the growth of phytopathogens. The review highlights the diverse chemical structures of mVOCs, including alcohols, aldehydes, alkenes, and terpenoids, and their interactions with plant defense systems. Key findings include: 1. **Plant Defense Strategies**: Plants use pattern-triggered immunity (PTI) and effector-triggered immunity (ETI) to defend against pathogens. mVOCs can activate these defenses, enhancing plant resistance. 2. **Bacterial Volatile Organic Compounds (bvOCs)**: Bacteria produce bvOCs that can activate plant defense mechanisms through microbe-associated molecular patterns (MAMPs). Examples include 2R,3R-butanediol and dimethyl disulfide, which protect plants against viral and fungal infections, respectively. 3. **Fungal Volatile Organic Compounds (fVOCs)**: Fungi produce fVOCs that can protect plants from phytopathogenic fungi and nematodes. For instance, fVOCs from *Trichoderma* species can induce priming in plants, enhancing their resistance to future infections. 4. **Yeast Volatile Organic Compounds (yVOCs)**: Yeasts produce yVOCs that can inhibit the growth of phytopathogens and protect plants against post-harvest infections. Studies have shown that yVOCs from *Pichia kudriavzevii* and *Hanseniaspora uvarum* can effectively control mold infections in fruits. 5. **Microalgae Volatile Organic Compounds (maVOCs)**: Microalgae produce maVOCs that can stimulate plant growth and activate defense responses. For example, maVOCs from *Chlorella vulgaris* can increase plant biomass and protect against fungal infections. 6. **Oomycete Volatile Organic Compounds (oVOCs)**: Oomycetes, aquatic molds, produce oVOCs that can inhibit the growth of other molds and protect plants. *P. oligandrum* is a notable example, as it can promote plant growth and protect against phytopathogens. The article emphasizes the potential of mVOCs as sustainable alternatives to chemical pesticides, highlighting their ability to activate plant defense mechanisms and reduce environmental pollution. Further research is needed to explore the full potential of mVOCs in agricultural applications.The article reviews the role of microbial volatile organic compounds (mVOCs) in plant defense mechanisms. mVOCs, produced by various microorganisms, play a crucial role in plant health by promoting growth, activating defense pathways, and inhibiting the growth of phytopathogens. The review highlights the diverse chemical structures of mVOCs, including alcohols, aldehydes, alkenes, and terpenoids, and their interactions with plant defense systems. Key findings include: 1. **Plant Defense Strategies**: Plants use pattern-triggered immunity (PTI) and effector-triggered immunity (ETI) to defend against pathogens. mVOCs can activate these defenses, enhancing plant resistance. 2. **Bacterial Volatile Organic Compounds (bvOCs)**: Bacteria produce bvOCs that can activate plant defense mechanisms through microbe-associated molecular patterns (MAMPs). Examples include 2R,3R-butanediol and dimethyl disulfide, which protect plants against viral and fungal infections, respectively. 3. **Fungal Volatile Organic Compounds (fVOCs)**: Fungi produce fVOCs that can protect plants from phytopathogenic fungi and nematodes. For instance, fVOCs from *Trichoderma* species can induce priming in plants, enhancing their resistance to future infections. 4. **Yeast Volatile Organic Compounds (yVOCs)**: Yeasts produce yVOCs that can inhibit the growth of phytopathogens and protect plants against post-harvest infections. Studies have shown that yVOCs from *Pichia kudriavzevii* and *Hanseniaspora uvarum* can effectively control mold infections in fruits. 5. **Microalgae Volatile Organic Compounds (maVOCs)**: Microalgae produce maVOCs that can stimulate plant growth and activate defense responses. For example, maVOCs from *Chlorella vulgaris* can increase plant biomass and protect against fungal infections. 6. **Oomycete Volatile Organic Compounds (oVOCs)**: Oomycetes, aquatic molds, produce oVOCs that can inhibit the growth of other molds and protect plants. *P. oligandrum* is a notable example, as it can promote plant growth and protect against phytopathogens. The article emphasizes the potential of mVOCs as sustainable alternatives to chemical pesticides, highlighting their ability to activate plant defense mechanisms and reduce environmental pollution. Further research is needed to explore the full potential of mVOCs in agricultural applications.