Volatile signaling in innate immunity

Volatile signaling in innate immunity

Well known for their role in plant-to-plant communication in plant-insect interactions, we recently associated plant volatile organic compounds (VOCs) with innate immunity and more specifically SAR. Emissions of the volatile monoterpenes α-pinene, β-pinene, and camphene were induced during infection and essential for SAR. Importantly, plant-to-plant communication experiments revealed an essential role of monoterpenes in plant-to-plant propagation of innate immune signals (Riedlmeier et al., 2017, Plant Cell 29: 1440). Our ongoing work suggests that plant-to-plant innate immune signal relay also functions between plants of different lineages (e.g. spruce to Arabidopsis), suggesting that monoterpenes act as ecologically relevant infochemicals propagating stress-induced signals throughout plant populations in natural and possibly also agricultural ecosystems. Current work in the group aims to unravel the potential of such signaling mechanisms for future crop protection strategies.

Figure 2 ‚Plant-to-plant SAR‘ – spruce needles emit signals that enhance Arabidopsis immunity to Pseudomonas syringae. Wild type (wt) Arabidopsis plants were incubated in vacuum dessicators either alone or in the presence of 4 or 8 spruce needles. Subsequently, the plants were infected with Pseudomonas syringae pathovar tomato (Pst). The resulting Pst titers are shown at 4 days post-inoculation. The data indicate that spruce needles, which are high monoterpene emitters, emit infochemicals that enhance Arabidopsis resistance to Pst. Figure was adapted from Riedlmeier et al., 2017, Plant Cell 29: 1440-1459.