Sorghum wax chemistry data

Virtually all land plants are coated in a cuticle, a waxy polyester that
prevents nonstomatal water loss and is important for heat and drought
tolerance. Here, we describe a likely genetic basis for a divergence in
cuticular wax chemistry between Sorghum bicolor, a drought tolerant crop
widely cultivated in hot climates, and its close relative Zea mays
(maize). Combining chemical analyses, heterologous expression, and
comparative genomics, we reveal that: 1) sorghum and maize leaf waxes are
similar at the juvenile stage but, after the juvenile-to-adult transition,
sorghum leaf waxes are rich in triterpenoids that are absent from maize;
2) biosynthesis of the majority of sorghum leaf triterpenoids is mediated
by a gene that maize and sorghum both inherited from a common ancestor but
that is only functionally maintained in sorghum; and 3) sorghum leaf
triterpenoids accumulate in a spatial pattern that was previously shown to
strengthen the cuticle and decrease water loss at high temperatures. These
findings uncover the possibility for resurrection of a cuticular
triterpenoid-synthesizing gene in maize that could create a more
heat-tolerant water barrier on the plant’s leaf surfaces. They also
provide a fundamental understanding of sorghum leaf waxes that will inform
efforts to divert surface carbon to intracellular storage for bioenergy
and bioproduct innovations.