Idioblasts and peltate hairs as distribution networks for water absorbed by xerophilous leaves.

Autor: Losada JM; Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Málaga, Spain.; Department of Organismic and Evolutionary Biology, Cambridge, Massachusetts, USA.; Arnold Arboretum of Harvard University, Boston, Massachusetts, USA., Díaz M; Centro de Investigaciones en Ecología y Zonas Áridas (CIEZA), Universidad Nacional Experimental Francisco de Miranda, Coro, Venezuela., Holbrook NM; Department of Organismic and Evolutionary Biology, Cambridge, Massachusetts, USA.; Arnold Arboretum of Harvard University, Boston, Massachusetts, USA.
Jazyk: angličtina
Zdroj: Plant, cell & environment [Plant Cell Environ] 2021 May; Vol. 44 (5), pp. 1346-1360. Date of Electronic Publication: 2021 Jan 05.
DOI: 10.1111/pce.13985
Abstrakt: Capparis odoratissima is a tree species native to semi-arid environments of South America where low soil water availability coexists with frequent night-time 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 abaxial surface has higher rates of water uptake. Thousands of idioblasts per cm 2 , a higher density than stomata, 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 fulfils 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.
(© 2020 John Wiley & Sons Ltd.)
Databáze: MEDLINE
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