Rapid Repression of Maize Invertases by Low Oxygen. Invertase/Sucrose Synthase Balance, Sugar Signaling Potential, and Seedling Survival

DOI PDF 被引用文献7件
  • Ying Zeng
    Plant Molecular and Cellular Biology Program, Horticultural Sciences Department, 1143 Fifield Hall, University of Florida, Gainesville, Florida 32611
  • Yong Wu
    Plant Molecular and Cellular Biology Program, Horticultural Sciences Department, 1143 Fifield Hall, University of Florida, Gainesville, Florida 32611
  • Wayne T. Avigne
    Plant Molecular and Cellular Biology Program, Horticultural Sciences Department, 1143 Fifield Hall, University of Florida, Gainesville, Florida 32611
  • Karen E. Koch
    Plant Molecular and Cellular Biology Program, Horticultural Sciences Department, 1143 Fifield Hall, University of Florida, Gainesville, Florida 32611

抄録

<jats:title>Abstract</jats:title> <jats:p>We show here that invertase gene expression and the invertase-sucrose (Suc) synthase ratio decrease abruptly in response to low oxygen in maize root tips. In addition to aiding in the conservation of carbon and possibly ATP, this response has the potential to directly affect sugar signaling relative to carbon flux. Experiments were motivated by the potential for a reduced invertase/Suc synthase balance to alter the impact of respiratory and/or membrane carbon flux on sugar signaling. Maize (Zea mays L.) seedlings with 5-cm primary roots were exposed to anoxic (0% [v/v] O2), hypoxic (3% [v/v] O2), and aerobic conditions. Rapid repression of theIvr1 and Ivr2 maize invertases by low oxygen was evident in root tips within 3 h at both the transcript and activity levels. The speed and extent of this response increased with the degree of oxygen deprivation and differed with genotypes. This decrease in expression also contrasted markedly to that of other genes for respiratory Suc metabolism, such as Suc synthases, which typically increased or remained constant. Although previous work showed that the contrasting effects of sugars on Suc synthase genes were reflected in their regulation by hypoxia and anoxia, the same was not observed for the differentially sugar-responsive invertases. Theoretically advantageous reductions in the invertase/Suc synthase balance thus resulted. However, where this response was extreme (an Oh43 inbred), total sucrolytic capacity dropped below an apparent minimum and root tip viability was reduced. Paradoxically, only Oh43 seedlings showed survival levels &gt;80% (versus &lt;50%) after extreme, long-term stress, suggesting a possible advantage for multiple means of reducing sink activity. Overall, our results demonstrate a rapid change in the regulation and balance of invertases and Suc synthases that could have an immediate impact on limiting the extent of Suc cleavage and reducing the extent of concomitant, hexose-based sugar signaling under low oxygen.</jats:p>

収録刊行物

  • Plant Physiology

    Plant Physiology 121 (2), 599-608, 1999-10-01

    Oxford University Press (OUP)

被引用文献 (7)*注記

もっと見る

キーワード

詳細情報 詳細情報について

問題の指摘

ページトップへ