Volatile carotenoid cleavage products (VCCPs) are constitutively emitted by Lobaria pulmonaria thalli.
Among VCCPS the retrograde signalling molecule β-cyclocitral (β-CC) has been detected.
VCCPs only represent a fraction less than 1% in the total blend of volatiles.
Emission of VCCPs is less sensitive to stress than any other group of volatiles.
The production of β-CC correlated with the rate of carotenoid loss, but the first was three orders of magnitude smaller.