THERMAL-ACCLIMATION AND WHOLE-PLANT CARBON BALANCE IN ZOSTERA-MARINA L (EELGRASS)
THERMAL-ACCLIMATION AND WHOLE-PLANT CARBON BALANCE IN ZOSTERA-MARINA L (EELGRASS)
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DOI：
10.1016/0022-0981(89)90197-4
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发表时间：
1989-01-01
影响因子：
2
通讯作者：
ALBERTE, RS
中科院分区：
文献类型：
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作者：
ZIMMERMAN, RC;SMITH, RD;ALBERTE, RS
在 10 和 20 摄氏度下生长植物后，在实验室实验中研究了鳗草大叶藻 (Zostera marina L.) 的热驯化。 C 在 12:12 L:D 方案下持续 21 天。代谢率显示叶子和根对温度的短期反应发生了显着变化。在两个生长温度下测量的生长速率、组织碳水化合物浓度和代谢率在统计上是相同的，表明在这些温度下热驯化基本上完成。当在足够高的 pO2 值下测量以实现呼吸能力速率时，呼吸的热响应 (Q10) 低于之前报告的值，而光合作用的热响应（在低于空气饱和度的 pO2 下测量）与之前的报告相似。根据代谢率数据构建的每日碳预算表明，光合作用平衡碳需求所需的 Hsat 周期可以从 3 小时到 > 12 小时不等，具体取决于净光合作用：呼吸作用 (Pnet:R) 和芽：根的比率。由于 Z. marina 显示出热适应的证据，环境温度的季节性变化可能不会显着影响 Hsat 需求和全植物碳平衡。夏季高温下的快速死亡可能是由于新陈代谢的热破坏而导致的，而内部碳储备对于满足冬季低光照期间的碳需求可能很重要，特别是在高纬度人群中。
Thermal acclimation in eelgrass Zostera marina L. was investigated in laboratory experiments after growing plants at 10 and 20.degree. C for 21 days under a 12:12 L:D regime. Metabolic rates showed significant shifts in short-term response to temperature in leaves and roots. Growth rates, tissue carbohydrate concentrations and metabolic rates measured at the two growth temperatures were statistically identical, indicating that thermal acclimation was essentially complete at these temperatures. When measured at pO2 values high enough to achieve capacity rates of respiration, thermal responses of respiration (Q10) were lower than previously reported while the thermal response of photosynthesis (measured at pO2 below air saturation) was similar to previous reports. Daily C budgets constructed from metabolic rate data indicated that Hsat periods required for photosynthesis to balance C demand can vary from 3 to > 12 h, depending on the ratios of net photosynthesis: respiration (Pnet:R) and shoot:root. Since Z. marina shows evidence of thermal acclimation, seasonal changes in ambient temperature may not significantly affect Hsat requirements and whole-plant C balance. Rapid mortality at high temperatures during summer may result instead from thermal disruption of metabolism while internal C reserves may be important in meeting C demand during winter periods of low light availability, particularly among high-latitude populations.