[초청강연] Post-translational regulation of cuticular wax biosynthesis in response to humidity

Post-tranalational regulation of cuticuar wax biosynthesis in
response to humidity and its biological significance

Mi Chung Suh (mcsuh@sogang.ac.kr)

Department of Life Science, Sogang University, Seoul 04107, Republic of Korea

ABSTRACT

During the evolution of land plants, one of the key innovations is the biogenesis of
cuticle covering their aerial surfaces to protect them from terrestrial stresses. The
cuticle is composed of an insoluble polyester, cutin and organic solvent soluble
cuticular waxes. In this presentation, the post-translational regulatory mechanism
underlying cuticular wax biosynthesis in Arabidopsis and an early land plant,
Physcomitrium patens in response to changes in ambient humidity and its biological
significance will be introduced. In Arabidopsis, SMALL AND GLOSSY LEAVES 1
(SAGL1) Kelch repeat F-box protein mediates proteasome-dependent degradation of
ECERIFERUM3 (CER3), a biosynthetic enzyme that is involved in the production of
very long chain alkanes, which are the major wax components. SAGL1, which can be
stabilized under high humidity was observed to regulate the levels of MYC:CER3
proteins in response to humidity changes. In P. Patens, disruption of PpSAGL1 caused
alterations in the levels of wax and cutin molecules, resulting in the inhibition of
gametophore development showing 3D growth. Taken together, the SAGL1-CER3
module negatively regulates cuticular wax biosynthesis in response to changes to
humidity conditions and the post-translational regulatory mechanism contributes to the
maintenance of cuticle integrity for water/gas exchaneges, elected growth, and organ
development and the protection of plants in response to humidity changes.