Efficient use of energy in anoxia‐tolerant plants with focus on germinating rice seedlings. Issue 1 (4th December 2014)

• Record Type: Journal Article
• Authors: Atwell, Brian J.; Greenway, Hank; Colmer, Timothy D.
• Is Part Of: New phytologist. Volume 206:Issue 1(2015)
• Page Start: 36
• Page End: 56
• Publication Date: 2014-12-04
• Subjects: Botany -- Periodicals; 580
• DOI: 10.1111/nph.13173
• Languages: English
• ISSNs: 0028-646X

Abstract

<abstract abstract-type="main" id="nph13173-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="nph13173-sec-0001" sec-type="opening"> <p> <table-wrap position="anchor" orientation="portrait"> <table width="100%" border="1"> <colgroup span="1"> <col span="1" /> <col span="1" /> <col span="1" /> </colgroup> <tbody> <tr> <td align="left" rowspan="1" colspan="1"> </td> <td align="left" rowspan="1" colspan="1"> <xref ref-type="link" rid="nph13173-sec-1001" /> </td> <td align="left" rowspan="1" colspan="1">36</td> </tr> <tr> <td align="left" rowspan="1" colspan="1">I.</td> <td align="left" rowspan="1" colspan="1"> <xref ref-type="link" rid="nph13173-sec-0002">I.</xref> </td> <td align="left" rowspan="1" colspan="1">36</td> </tr> <tr> <td align="left" rowspan="1" colspan="1">II.</td> <td align="left" rowspan="1" colspan="1"> <xref ref-type="link" rid="nph13173-sec-0003">II.</xref> </td> <td align="left" rowspan="1" colspan="1">37</td> </tr> <tr> <td align="left" rowspan="1" colspan="1">III.</td> <td align="left" rowspan="1" colspan="1"> <xref ref-type="link" rid="nph13173-sec-0014">III.</xref> </td> <td align="left" rowspan="1" colspan="1">44</td> </tr> <tr> <td align="left" rowspan="1" colspan="1">IV.</td> <td align="left" rowspan="1" colspan="1"> <xref ref-type="link" rid="nph13173-sec-0025">IV.</xref> </td> <td align="left" rowspan="1" colspan="1">49</td> </tr> <tr> <td align="left" rowspan="1" colspan="1">V.</td> <td align="left" rowspan="1" colspan="1"> <xref ref-type="link" rid="nph13173-sec-0035">V.</xref> </td> <td align="left" rowspan="1" colspan="1">53</td> </tr> <tr> <td align="left" rowspan="1" colspan="1"> </td> <td align="left" rowspan="1" colspan="1"> <xref ref-type="link" rid="nph13173-sec-0036" /> </td> <td align="left" rowspan="1" colspan="1">54</td> </tr> <tr> <td align="left" rowspan="1" colspan="1"> </td> <td align="left" rowspan="1" colspan="1"> <xref ref-type="link" rid="nph13173-bibl-0001">References</xref> </td> <td align="left" rowspan="1" colspan="1">55</td> </tr> </tbody> </table> </table-wrap> </p> </sec> <sec id="nph13173-sec-1001" sec-type="section"> <title>Summary</title> <p>Anoxia tolerance in plants is distinguished by direction of the sparse supply of energy to processes crucial to cell maintenance and sometimes to growth, as in rice seedlings. In anoxic rice coleoptiles energy is used to synthesise proteins, take up K<sup>+</sup>, synthesise cell walls and lipids, and in cell maintenance. Maintenance of electrochemical H<sup>+</sup> gradients across the tonoplast and plasma membrane is crucial for solute compartmentation and thus survival. These gradients sustain some H<sup>+</sup>‐solute cotransport and regulate cytoplasmic pH. Pyrophosphate (PP<sub>i</sub>), the alternative energy donor to ATP, allows direction of energy to the vacuolar H<sup>+</sup>‐PP<sub>i</sub>ase, sustaining H<sup>+</sup> gradients across the tonoplast. When energy production is critically low, operation of a biochemical pHstat allows H<sup>+</sup>‐solute cotransport across plasma membranes to continue for at least for 18 h. In active (e.g. growing) cells, PP<sub>i</sub> produced during substantial polymer synthesis allows conversion of PP<sub>i</sub> to ATP by PP<sub>i</sub>‐phosphofructokinase (PFK). In quiescent cells with little polymer synthesis and associated PP<sub>i</sub> formation, the PP<sub>i</sub> required by the vacuolar H<sup>+</sup>‐PP<sub>i</sub>ase and UDPG pyrophosphorylase involved in sucrose mobilisation via sucrose synthase might be produced by conversion of ATP to PP<sub>i</sub> through reversible glycolytic enzymes, presumably pyruvate orthophosphate dikinase. These hypotheses need testing with species characterised by contrasting anoxia tolerance.</p> </sec> </abstract>