欢迎访问林业科学,今天是

林业科学 ›› 2008, Vol. 44 ›› Issue (12): 28-34.doi: 10.11707/j.1001-7488.20081205

• 论文 • 上一篇    下一篇

温度对银杏光系统 Ⅱ 光抑制的影响

任士福 王梅 高志奎 史保胜 戈晓立   

  1. (河北农业大学 保定071001)
  • 收稿日期:2007-10-31 修回日期:1900-01-01 出版日期:2008-12-25 发布日期:2008-12-25

Effects of Temperature on Photosystem Ⅱ Photoinhibition in Ginkgo

Ren Shifu,Wang Mei,Gao Zhikui,Shi Baosheng,Ge Xiaoli   

  1. (Hebei Agriculture University Baoding 071001)
  • Received:2007-10-31 Revised:1900-01-01 Online:2008-12-25 Published:2008-12-25

摘要: 摘 要:以银杏叶片为试材,在不同温度下采用连续激发式植物效率仪PEA测试强光照射对快速叶绿素荧光诱导动力学参数的影响,利用CIRAS-2型便携式光合系统进行光合光转化效率LCE的光强响应测试。结果表明:银杏光抑制不仅呈现光强剂量效应,而且呈现温度剂量效应。当光强超过约1 000 μmol m-2s-1时银杏LCE最低,为较严重的光抑制过程。在25 ℃常温下超过1 000 μmol m-2s-1光强照射20 min时银杏Fv/Fm下降加快;15 ℃以下低温和35 ℃以上高温均会使Fv/Fm进一步降低;而且热胁迫比冷胁迫的光抑制程度更大,因为25~45 ℃下Fv / Fm的直线回归斜率/kheat/比5~20 ℃的 / k chilling / 增大了15.4%。5~10 ℃的低温强光引起银杏叶片热耗散 DIo / RC略微增加,而35 ℃以上高温强光会导致热耗散DIo / RC剧增。冷胁迫会降低PSⅡ反应中心数目,但是热胁迫会使之降低更多。冷热胁迫下强光引起的光抑制( Fv / Fm )与PSⅡ反应中心数目 RC / CSo 或 RC / ABS 与之间高度正相关。因此,PSⅡ的异质性即PSⅡ反应中心的可逆失活是冷热胁迫下光合机构发生光抑制的保护机制。

关键词: 关键词:冷胁迫, 热胁迫, 叶绿素荧光参数, 光系统Ⅱ, 光抑制, 银杏

Abstract: Abstract: A fast chlorophyll transient fluorescence and its dynamic parameters were measured by a PEA (Plant Efficiency Analyzer from Hansatech), in the leaves of Ginkgo ( Ginkgo biloba ) after illumination of strong light with chilling stress or heat stress, respectively. In addition, a response of light on LCE (light conversion efficiency of photosynthesis) was measured by a CIRAS-2 of the portable photosynthesis systems. The results indicated that photoinhibition in leaves of Ginkgo showed a dosage effect of not only the light intensity but also the temperature. LCE was lowest and showed more serious photoinhibition over about 1 000 μmol m-2s-1 PAR (photosynthetic available radiation). At 25 ℃, Fv / Fm in the leaves of Ginkgo showed accelerating decline after illuminating for 20 min at PAR 1 000 μmol m-2s-1 or more on the leaf of Ginkgo, and the Fv / Fm showed more serious decline at low temperature of 15 ℃ or lower and high temperature of 35 ℃ higher. Meanwhile, photoinhibition exhibited more serious when treated by chilling stress than by heat stress, because absolute value of the slope of linear regression equation ( kheat ) between Fv / Fm and temperature form 25 ℃ to 45 ℃ increased 15.4% than absolute value of kchilling from 20 ℃ to 5 ℃. The strong light caused a modest little increase of energy dissipation DIo /RC at chilling stress of 5~10 ℃, but a sharp increase of that at heat stress of 35 ℃ or higher 35 ℃. Density of PS Ⅱreaction centers decreased at chilling stress, but it decreased more serious at heat stress than at chilling stress. There were remarkable correlations between photoinhibition ( Fv / Fm ) caused by strong light at chilling stress and heat stress and density of PS Ⅱreaction centers ( RC/CSo or RC/ABS ). Therefore, the heterogeneity of PSⅡ, i.e. reversible inactivation of PSⅡ reaction center, is protection mechanism on photoinhibition of the photosynthesis apparatus.

Key words: Key words: chilling stress, heat stress, chlorophyll fluorescence parameter, photosystem Ⅱ, photoinhibition, ginkgo