This article demonstrates the stability window of sporopollenin under laboratory simulated diagenetic conditions. We show that sporopollenin is resistant to chemical alteration when subject to low-to-moderate diagenetic conditions, maintaining its original aliphatic:phenolic co-polymer configuration. Under the most extreme of conditions tested here we show that the co-polymer configuration begins to defunctionalise and reploymerise to be replaced in-situ by a predominantly aliphatic polymeric structure, including aliphatic components significantly shorter than originally were present in the starting material. The outcome of this study shows that fossil sporopollenin may still retain its original chemical composition, even after being subjected to diagenesis. Such a finding opens the door for investigating deeper time chemical composition of sporopollenin and environmentally-influenced variations in sporopollenin structure, beyond that currently achieved.
A growing body of evidence suggests that plants alter their chemical composition in relation to the amount of incoming solar radiation (“insolation“) they are exposed to during life. Chemical changes are induced in order to provide protection against the deleterious effects of ultraviolet (UV) radiation; a relatively small, but important component of the total solar spectrum. UV radiation is linked with a range of detrimental biological effects, primarily stemming from damaged DNA. As sessile organisms, plants need to employ various mitigation mechanisms to prevent/reduce damage induced by UV radiation. Such mechanisms include effective DNA repair pathways, physiological adaptations, and UV-absorbing compounds. It is this last mechanism, UV-absorbing compounds (UACs), that is discussed here.
Lycopodium spore chemistry can be divided into two distinct groups; aliphatic components and phenolic components.