Department of Biological Sciences, Stanford University, Stanford, California 94305-5020 USA.
Am J Bot. 2001 Mar;88(3):411-8.
Interspecific variation in chloroplast low molecular weight (cLMW) HSP (heat shock protein) expression was examined with respect to phylogeny, species specific leaf area, chlorophyll fluorescence, and mean environmental conditions within species ranges. Eight species of Ceanothus (Rhamnaceae) were heat shocked for 4 h at several different temperatures. Leaf samples were collected immediately after the heat shock, and cLMW HSP expression was quantified using Western blots. At 45°C species from the subgenus Cerastes had significantly greater cLMW HSP expression than species from the subgenus Ceanothus. Specific leaf area was negatively correlated with cLMW HSP expression after the 45°C heat treatment. In addition, chlorophyll fluorescence (F(v)/F(m)) 1 h after the heat shocks was positively correlated with cLMW HSP expression. Contrary to our prediction, there was no correlation between July maximum temperature within species ranges and cLMW HSP expression. These results suggest that evolutionary differentiation in cLMW HSP expression is associated with leaf physiological parameters and related aspects of life history, yet associations between climatic conditions within species ranges and cLMW HSP expression require further study.
针对系统发育、种特异性叶面积、叶绿素荧光和种内环境条件的平均值，研究了质体低分子量（cLMW）热激蛋白（HSP）表达的种间变异性。对 8 种熊果酸（Rhamnaceae）进行了 4 h 的不同温度热休克处理。热休克后立即采集叶片样本，并用 Western blot 定量 cLMW HSP 的表达。在 45°C 时，来自 Cerastes 亚属的物种的 cLMW HSP 表达明显高于 Ceanothus 亚属的物种。经过 45°C 热处理后，种特异性叶面积与 cLMW HSP 表达呈负相关。此外，热休克后 1 h 的叶绿素荧光（F(v)/F(m)）与 cLMW HSP 的表达呈正相关。与我们的预测相反，种内范围的 7 月最高温度与 cLMW HSP 的表达之间没有相关性。这些结果表明，cLMW HSP 表达的进化分化与叶片生理参数和生活史的相关方面有关，但种内范围的气候条件与 cLMW HSP 表达之间的相关性需要进一步研究。
