RT Journal Article
SR Electronic
T1 The molecular structure of plant sporopollenin
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 415612
DO 10.1101/415612
A1 Li, Fu-Shuang
A1 Phyo, Pyae
A1 Jacobowitz, Joseph
A1 Hong, Mei
A1 Weng, Jing-Ke
YR 2018
UL http://biorxiv.org/content/early/2018/09/12/415612.abstract
AB Sporopollenin is a ubiquitous and extremely chemically inert biopolymer that constitutes the outer wall of all land-plant spores and pollen grains. Sporopollenin protects the vulnerable plant gametes against a wide range of environmental assaults, and is considered as a prerequisite for the migration of early plants onto land. Despite its importance, the chemical structure of plant sporopollenin has remained elusive. Using a newly developed thioacidolysis degradative method together with state-of-the-art solid-state NMR techniques, we determined the detailed molecular structure of pine sporopollenin. We show that pine sporopollenin is primarily composed of aliphatic-polyketide-derived polyvinyl alcohol units and 7-O-p-coumaroylated C16 aliphatic units, crosslinked through a distinctive m-dioxane moiety featuring an acetal. Naringenin was also identified as a minor component of pine sporopollenin. This discovery answers the long-standing question about the chemical makeup of plant sporopollenin, laying the foundation for future investigations of sporopollenin biosynthesis and for design of new biomimetic polymers with desirable inert properties.