Estimating heat tolerance among plant species by two chlorophyll fluorescence parameters
Estimating heat tolerance among plant species by two chlorophyll fluorescence parameters
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DOI：
10.1007/s11099-005-0070-6
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发表时间：
2005-09
期刊：
影响因子：
2.7
通讯作者：
J. Weng;My Lai
中科院分区：
文献类型：
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作者：
J. Weng;My Lai
利用高温处理前后的F0-T曲线和叶绿素荧光参数比值对8种温带和1种亚热带C3植物以及17种热带C3、C4和CAM植物的耐热性进行了评价。当叶片在黑暗中以约1 °C min− 1的速率加热时，临界温度（Tc）在物种之间变化很大。所有8种温源物种的Tc冬季在40-46 °C之间（平均温度16-19 °C），夏季在32-48 °C之间（平均温度30 °C）。1个亚热带和12个热带C3种的温度范围为25-44 °C和35-48 °C，1个CAM和4个C4种的温度范围分别为41-47和45-46 °C。三种C3草本植物在冬季高温（33/28 °C，昼夜）下驯化10 d，其Tc值上升到接近夏季的测定值。在45 °C下处理20 min，然后在室温下黑暗中放置1 h后，观察到所有温度来源的C3物种以及热带来源的CAM和C4物种的RFv/m（45 °C处理前后的Fv/Fm比值）与Tc之间的显著相关性。然而，热带C3种的F0和Fv/Fm对45 °C处理的敏感性较低，尽管Tc变化较大，但它们的RFv/Fm和Tc之间没有显著相关性。因此，Tc可能不是一个合适的耐热性指标的植物具有广泛的环境适应性。然而，Tc的热带起源C3物种，变化和表现出高可塑性的季节变化和温度处理，出现适合于估计的温度驯化的程度在同一物种。
The heat tolerance of 8 temperate- and 1 subtropical-origin C3species as well as 17 tropical-origin ones, including C3, C4, and CAM species, was estimated using both F0-T curve and the ratio of chlorophyll fluorescence parameters, prior to and after high temperature treatment. When leaves were heated at the rate ofca.1 °C min−1in darkness, the critical temperature (Tc) varied extensively among species. The Tc's of all 8 temperate-origin species ranged between 40–46 °C in winter (mean temperature 16–19 °C), and between 32–48 °C in summer (mean temperatureca.30 °C). Those for 1 subtropical- and 12 tropical-origin C3species ranged between 25–44 °C and 35–48 °C, and for 1 CAM and 4 C4species were 41–47 and 45–46 °C, respectively. Acclimating three C3herbaceous plants at high temperature (33/28 °C, day/night) for 10 d in winter caused their Tc's rising to nearly the values measured in summer. When leaves were exposed to 45 °C for 20 min and then kept at room temperature in darkness for 1 h, a significant correlation between RFv/m(the ratio of Fv/Fmbefore and after 45 °C treatment) and Tcwas observed for all tested temperate-origin C3species as well as tropical-origin CAM and C4species. However, F0and Fv/Fmof the tropical-origin C3species were less sensitive to 45 °C treatment, regardless of a large variation of Tc; thus no significant correlation was found between their RFv/mand Tc. Thus Tcmight not be a suitable index of heat tolerance for plants with wide range of environmental adaptation. Nevertheless, Tc's of tropical origin C3species, varying and showing high plasticity to seasonal changes and temperature treatment, appeared suitable for the estimation of the degree of temperature acclimation in the same species.