Idioblasts and peltate hairs as distribution networks for water absorbed
by the leaves of Capparis odoratissima
- Juan Losada,
- Miriam Diaz,
- Noel Holbrook
Abstract
Capparis odoratissima is a tree species native to semi-arid environments
of the northern coast of South America where low soil water availability
coexists with frequent nighttime fog. A previous study showed that water
applied to leaf surfaces enhanced leaf hydration, photosynthesis, and
growth, but the mechanisms of foliar water uptake are unknown. Here we
combine detailed anatomical evaluations with water and dye uptake
experiments in the laboratory, and use immunolocalization of pectin and
arabinogalactan protein epitopes to characterize water uptake pathways
in leaves. Abaxially, the leaves of C. odoratissima are covered with
peltate hairs, while the adaxial surfaces are glabrous. Both surfaces
are able to absorb condensed water, but the lower surface has higher
rates of water uptake. Numerous idioblasts connect the adaxial leaf
surface and the abaxial peltate hairs, both of which contain hygroscopic
substances such as arabinogalactan proteins and pectins. The highly
specialized anatomy of the leaves of C odoratissima fulfills the dual
function of minimizing water loss when stomata are closed, while
maintaining the ability to absorb liquid water. Cell-wall related
hygroscopic compounds in the peltate hairs and idioblasts create a
network of microchannels that maintain leaf hydration and promote water
uptake.21 Sep 2020Submitted to Plant, Cell & Environment 22 Sep 2020Submission Checks Completed
22 Sep 2020Assigned to Editor
27 Sep 2020Reviewer(s) Assigned
27 Oct 2020Review(s) Completed, Editorial Evaluation Pending
01 Nov 2020Editorial Decision: Revise Minor
11 Nov 20201st Revision Received
11 Nov 2020Submission Checks Completed
11 Nov 2020Assigned to Editor
17 Nov 2020Reviewer(s) Assigned
11 Dec 2020Review(s) Completed, Editorial Evaluation Pending
12 Dec 2020Editorial Decision: Accept