Transport properties of the mung bean (Vigna radiata) non‐aerial hypocotyl membrane: permselectivity to hydrophilic compounds. Issue 1 (12th June 2013)

• Record Type: Journal Article
• Authors: Aponte, John; Baur, Peter
• Is Part Of: Pest management science. Volume 70:Issue 1(2014:Jan.)
• Page Start: 148
• Page End: 155
• Publication Date: 2013-06-12
• Subjects: Pests -- Control -- Periodicals; Pesticides -- Periodicals; 632.9
• DOI: 10.1002/ps.3540
• Languages: English
• ISSNs: 1526-498X

Abstract

<abstract abstract-type="main" id="ps3540-abs-0001"> <title>Abstract</title> <sec id="ps3540-sec-0001" sec-type="section"> <title>Background</title> <p id="ps3540-para-0001"> <bold>Aerial plant surfaces are covered by a lipophilic cuticular membrane (CM) that restricts the transport of water and small solutes. Non‐aerial tissues do not exhibit such a barrier. Recent data have shown that large relative to CM hydrophilic agrochemicals were able to pass at high rates through the non‐aerial coleoptile.</bold> </p> </sec> <sec id="ps3540-sec-0002" sec-type="section"> <title>Results</title> <p id="ps3540-para-0002"> <bold>A moderately large hydrophilic solute like PEG 1000 with a mean molar volume of 782 cm<sup>3</sup> mol<sup>−1</sup> was rejected by the non‐aerial hypocotyl. Uptake of smaller solutes like urea (46.5 cm<sup>3</sup> mol<sup>−1</sup>) was fast and with 99% after 1 day. Cut‐off size estimations suggest a pore size diameter below 1.5 nm.</bold> </p> </sec> <sec id="ps3540-sec-0003" sec-type="section"> <title>Conclusion</title> <p id="ps3540-para-0003"> <bold>Aerial and non‐aerial CM differ largely in their absolute barrier properties. This difference is related to the absence of embedded cuticular waxes in the non‐aerial hypocotyl membrane, which make the CM physically dense and cause low solubility of hydrophilic solutes. The free volume for diffusion at the interface of the non‐aerial hypocotyl cuticle to the environment is much larger resulting in higher penetration rates. It is suggested that diffusion through the non‐aerial hypocotyl does not proceed in a real channel system with continuous aqueous phase but is more like transport through a filter with restricted diffusion in the pore openings. © 2013 Society of Chemical Industry</bold> </p> </sec> </abstract>