Pollination

Terpene

Bacteria

Biology

Gene

Pollinator

Horticulture

Terpenoid

Microorganism

Gynoecium

Petunia

Fumigation

Stamen

Pollen

Botany

Genetics

Biochemistry

Nature Chemical Biology

Plants synthesize volatile organic compounds (VOCs) to attract pollinators and beneficial microorganisms, to defend themselves against herbivores and pathogens, and for plant-plant communication. In general, VOCs accumulate in and are emitted from the tissue of their biosynthesis. However, using biochemical and reverse genetic approaches, we demonstrate a new physiological phenomenon: inter-organ aerial transport of VOCs via natural fumigation. Before petunia flowers open, a tube-specific terpene synthase produces sesquiterpenes, which are released inside the buds and then accumulate in the stigma, potentially defending the developing stigma from pathogens. These VOCs also affect reproductive organ development and seed yield, which are previously unknown functions of terpenoid compounds. Bioactive sesquiterpenes accumulating in petunia stigmas are synthesized in the floral tube and then transported to the pistil via natural fumigation within the internal airspace of the developing flower.

Natural fumigation as a mechanism for volatile transport between flower organs