Volatile Organic Compounds

This week we will look briefly at one well known form of plant communication; volatile organic compounds, (VOCs). Some plants respond to herbivory by releasing chemical cues. Many plants do this to prepare themselves for the onset attack on other parts of their structure. This means they can release a volatile organic compound at the site that is under attack in an effor to deter predation. A nearby branch can detect the compound and begin to increase its production of the same compound (Karban et al. 2014).

Similarly, separate individuals have the ability to detect these chemicals and they too can coordinate their system to increase their own defence.  In one particular study, sagebrush and wild tobacco plants were grown in close proximity to each other. The sagebrush leaves were clipped and began to release a volatile signal ( methyl jasmonate).  Some of the wild tobacco plants were exposed to the air filled with the VOCs emitted by the sagebrush. The exposure induced the wild tobacco to produce a chemical defence ( polyphenol oxidase). Subsequently, these wild tobacco plants significantly reduced the level of leaf damage caused by grasshoppers and cutworms. (Karban et al. 2000).

Figure 1. Levels of VOCs (polyphenol oxidase) activity for tobacco plants near clipped or unclipped sagebrush. (Karban et al. 2000).

The outcome of this adaptation has been demonstrated to increase fitness for the emitting plant in cases where it has emitted to prepare other parts of its own structure for attack. With intra - plant communication, it has been shown to increase fitness in the same regard. It has also been found that lima beans exposed to VOCs were able to defend existing leaves against herbivory to a greater degree than the controls in the experiment. They were also able to produce more new leaves than the controls after exposure. (Kost & Heli , 2006). Further research may identify more ways in which plants can benefit from this form of communication.


Karban, R., Baldwin, I.T., Baxter,K.J., Laue, G., Felton, G.W. 2000. Communication between plants: induced resistance in wild tobacco plants following clipping of neighboring sagebrush. Oecologia. 125, 1: 66 – 71.

Karban, R., Louie, H.Y., Edwards, K.F. 2014. Volatile communication between plants that affects herbivory: a meta – analyses. Ecology Letters. 17: 44 – 52.

Kost, C., Heli, M. 2006. Herbivore-induced plant volatiles induce an indirect defense in neighboring plants. Journal of Ecology, 94: 619 – 628.