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Original Research ARTICLE Provisionally accepted The full-text will be published soon. Notify me

Front. Plant Sci. | doi: 10.3389/fpls.2019.01499

Guard-Cell Hexokinase Increases Water-Use Efficiency under Normal and Drought Conditions

 Gilor Kelly1, Aiman Egbaria1, Belal Khamaisi1,  Nitsan Lugassi1, Ziv Attia2,  Menachem Moshelion2 and  David Granot1*
  • 1Institute of Plant Sciences, Agricultural Research Organization, Volcani Center, Israel
  • 2The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, Israel

Water is a limiting resource for many land plants. Most of the water taken up by plants is lost to the atmosphere through the stomata, which are adjustable pores on the leaf surface that allow for gas exchange between the plant and the atmosphere. Modulating stomatal activity might be an effective way to reduce plants’ water consumption and enhance their productivity under normal, as well as water-limiting conditions. Our recent discovery of stomatal regulation by sugars that is mediated by guard-cell hexokinase (HXK), a sugar-sensing enzyme, has raised the possibility that HXK might be used to increase plant water-use efficiency (WUE; i.e., carbon gain per unit of water). We show here that transgenic tomato and Arabidopsis plants with increased expression of HXK in their guard cells (GCHXK plants) exhibit reduced transpiration and improved WUE without any negative effects on growth under normal conditions, as well as improved performance under limited-water conditions. Our results demonstrate that exclusive expression of HXK in guard cells is an effective tool for improving WUE, and plant performance under drought.

Keywords: guard cells, water-use efficiency, transpiration, Hexokinase, Photosynthesis

Received: 16 Apr 2019; Accepted: 29 Oct 2019.

Copyright: © 2019 Kelly, Egbaria, Khamaisi, Lugassi, Attia, Moshelion and Granot. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Dr. David Granot, Institute of Plant Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, Central District, Israel, granot@agri.gov.il