• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Plant and Soil >Response of root respiration and root exudation to alterations in root C supply and demand in wheat.
【24h】

Response of root respiration and root exudation to alterations in root C supply and demand in wheat.

机译：小麦根系呼吸和根系分泌物对根系碳供求变化的响应。

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

Rising atmospheric CO2 concentrations have highlighted the importance of being able to understand and predict C fluxes in plant-soil systems. We investigated the responses of the two fluxes contributing to below-ground efflux of plant root-dependent CO2, root respiration and rhizomicrobial respiration of root exudates. Wheat (Triticum aestivum L., var. Consort) plants were grown in hydroponics at 20 degrees C, pulse-labelled with 14CO2 and subjected to two regimes of temperature and light (12 h photoperiod or darkness at either 15 degrees C or 25 degrees C), to alter plant C supply and demand. Root respiration was increased by temperature with a Q10 of 1.6. Root exudation was, in itself, unaltered by temperature, however, it was reduced when C supply to the roots was reduced and demand for C for respiration was increased by elevated temperature. The rate of exudation responded much more rapidly to the restriction of C input than did respiration and was approximately four times more sensitive to the decline in C supply than respiration. Although temporal responses of exudation and respiration were treatment dependent, at the end of the experimental period (2 days) the relative proportion of C lost by the two processes was conserved despite differences in the magnitude of total root C loss. Approximately 77% of total C and 67% of 14C lost from roots was accounted for by root respiration. The ratio of exudate specific activity to CO2 specific activity converged to a common value for all treatments of 2, suggesting that exudates and respired CO2 were not composed of C of the same age. The results suggest that the contributions of root and rhizomicrobial respiration to root-dependent below-ground respiration are conserved and highlight the dangers in estimating short-term respiration and exudation only from measurements of labelled C. The differences in responses over time and in the age of C lost may ultimately prove useful in improving estimates of root and rhizomicrobial respiration..
机译：大气中CO2浓度的不断提高凸显了能够理解和预测植物-土壤系统中C通量的重要性。我们调查了两种通量对植物根系依赖的二氧化碳地下释放，根系呼吸作用和根系分泌物的根际微生物呼吸作用的响应。小麦（Triticum aestivum L.，var。Consort）植物在20°C的水培法中生长，用14CO2脉冲标记，并在15°C或25°C的温度和光照（12 h光照或黑暗）两种条件下），以更改工厂C的供求关系。温度使根呼吸增加，Q10为1.6。根系分泌物本身并不受温度的影响，但是，当根系中的碳供应减少并且温度升高时，对呼吸作用的碳的需求会增加。与呼吸作用相比，渗出速率对碳输入限制的响应要快得多，对碳供应下降的敏感性比呼吸快约四倍。尽管渗出和呼吸的时间响应取决于治疗，但在实验期（2天）结束时，尽管总根部C损失量存在差异，但两个过程中C损失的相对比例仍得以保留。根部呼吸造成了根部总碳损失的77％和14C损失的67％。所有治疗方法2的渗出液比活性与CO2比活性之比均收敛于一个共同值，表明渗出液和呼吸的CO2并非由同一年龄的C组成。结果表明，根和根际微生物呼吸对依赖根的地下呼吸的贡献得到了保留，并突出了仅通过测量标记的C来估计短期呼吸和渗出的危险。随着时间和年龄的变化，反应的差异损失的C量最终可能被证明有助于改善对根和根际微生物呼吸的估计。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
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