1. Foliar water and solute absorption: an update.
- Author
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Fernández, Victoria, Gil‐Pelegrín, Eustaquio, and Eichert, Thomas
- Subjects
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ABSORPTION of water in plants , *PLANT cuticle , *PLANT surfaces , *ABSORPTION , *CROPS - Abstract
SUMMARY: The absorption of water and solutes by plant leaves has been recognised since more than two centuries. Given the polar nature of water and solutes, the mechanisms of foliar uptake have been proposed to be similar for water and electrolytes, including nutrient solutions. Research efforts since the 19th century focussed on characterising the properties of cuticles and applying foliar sprays to crop plants as a tool for improving crop nutrition. This was accompanied by the development of hundreds of studies aimed at characterising the chemical and structural nature of plant cuticles from different species and the mechanisms of cuticular and, to a lower extent, stomatal penetration of water and solutes. The processes involved are complex and will be affected by multiple environmental, physico‐chemical and physiological factors which are only partially clear to date. During the last decades, the body of evidence that water transport across leaf surfaces of native species may contribute to water balances (absorption and loss) at an ecosystem level has grown. Given the potential importance of foliar water absorption for many plant species and ecosystems as shown in recent studies, the aim of this review is to first integrate current knowledge on plant surface composition, structure, wettability and physico‐chemical interactions with surface‐deposited matter. The different mechanisms of foliar absorption of water and electrolytes and experimental procedures for tracing the uptake process are discussed before posing several outstanding questions which should be tackled in future studies. Significance Statement: Foliar water and solute absorption has been investigated since more than one century, with focus on the permeability of agrochemical sprays and increasing attention on foliar water uptake of natural ecosystems worldwide. Analysing foliar water and solute interactions with plant surfaces and their transport to the leaf interior is, however, prone to experimental artefacts and scientific misinterpretations, due to the structural and chemical complexity of plant surfaces and the nano‐, micro‐ and macro‐scale levels. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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