• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Global change biology >Monoterpene emission and monoterpene synthase activities in theMediterranean evergreen oak Quercus ilex L. grown at elevated CO2concentrations
【24h】

Monoterpene emission and monoterpene synthase activities in theMediterranean evergreen oak Quercus ilex L. grown at elevated CO2concentrations

机译：地中海常绿橡树栎（Quercus ilex L.）在较高CO2浓度下生长时的单萜排放和单萜合酶活性

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Monoterpene emissions, monoterpene synthase activities, photosynthesis, fluorescence yield in the dark and drought stress indicators (stomatal conductance and mid-day water potential) were concurrently measured under similar temperature and illumination in current-year leaves of Quercus ilex L. of plants grown in open-top chambers at ambient (350 ppm) and elevated (700 ppm) CO2. The study was undertaken to understand the effect of CO2 on monoterpene biosynthesis, and to predict and parameterize the biogenic emissions at growing CO2 concentrations. The results of the 1998 and 1999 studies show that at elevated CO2, and in the absence of persistent environmental stresses, photosynthesis was stimulated with respect to ambient CO2, but that the emission of the three most abundantly emitted monoterpenes (alpha -pinene, sabinene and beta -pinene) was inhibited by approximately 68%. The enzyme activities of the monoterpene synthases catalysing the formation of the three monoterpenes were also inhibited at elevated CO2 and an excellent relationship was found between monoterpene emission and activity of the corresponding enzyme both at ambient and elevated CO2. Interestingly, however, limonene emission was enhanced in conditions of elevated CO2 as it was also the corresponding synthase. The ratio between enzyme activity and emission of the three main monoterpenes was high (above 20) at ambient CO2 but it was below 10 at elevated CO2 and, for limonene, on both treatments. Our results indicate that the overall emission of monoterpenes at elevated CO2 will be inhibited because of a concurrent, strong down-regulation of monoterpene synthase activities. When the enzyme activity does not change, as for limonene, the high photosynthetic carbon availability at elevated CO2 conditions may even stimulate emission. The results of the 1997 study show that severe and persistent drought, as commonly occurs in the Mediterranean, may inhibit both photosynthesis and monoterpene (a-pinene) emission, particularly at ambient CO2. Thus, emission is probably limited by photosynthetic carbon availability; the effect of elevated CO2 per se is not apparent if drought, and perhaps other environmental stresses, are also present.
机译：在类似温度和光照下，在生长于墨西哥的Quercus ilex L.的当年叶片中，同时测量了黑暗和干旱胁迫指标（气孔导度和中午水势）中的单萜排放，单萜合酶活性，光合作用，荧光产量。在环境（350 ppm）和升高的（700 ppm）CO2下打开顶室。进行该研究以了解CO2对单萜生物合成的影响，并预测和参数化CO2浓度增加时的生物排放。 1998年和1999年的研究结果表明，在CO2升高且没有持续的环境压力的情况下，相对于周围的CO2而言，光合作用受到了刺激，但是，三种排放最丰富的单萜（α-pine烯，sa烯和β-pine烯）被抑制约68％。在升高的CO2下，单萜合酶催化三个单萜形成的酶活性也被抑制，并且在环境和升高的CO2下，单萜的释放与相应酶的活性之间存在极好的关系。然而，有趣的是，在二氧化碳升高的情况下柠檬烯的排放也增加了，因为它也是相应的合酶。三种活性的酶的活性和发射率之间的比率在环境CO2下较高（高于20），但在CO2升高时（对于柠檬烯而言）在两种处理下均低于10。我们的结果表明，由于单萜合酶活性的同时强烈下调，单萜在CO2浓度升高时的总体排放将受到抑制。当酶的活性不变时，例如柠檬烯，在升高的CO2条件下高的光合作用碳利用率甚至可能刺激排放。 1997年研究的结果表明，严重和持续的干旱（通常在地中海地区发生）可能会抑制光合作用和单萜（α-pine烯）的排放，特别是在环境CO2下。因此，排放可能受到光合作用碳可用性的限制。如果还存在干旱和其他环境压力，则二氧化碳本身升高的效果并不明显。

著录项

相似文献

  • 外文文献
  • 中文文献
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号