Cd^(2+)胁迫对银芽柳PSⅡ叶绿素荧光光响应曲线的影响  

Rapid light-response curves of PSⅡ chlorophyll fluorescence parameters in leaves of Salix leucopithecia subjected to cadmium-ion stress

作　　者：钱永强[1] 周晓星[1] 韩蕾[1] 孙振元[1] 巨关升[1] 

机构地区：[1]中国林业科学研究院林业研究所/林木遗传育种国家重点实验室/国家林业局林木培育重点实验室,北京100091

出　　处：《生态学报》2011年第20期6134-6142,共9页Acta Ecologica Sinica

基　　金：中央级公益性科研院所基本科研业务费专项资金(ZD200916;RIF2010-07)

摘　　要：以盆栽银芽柳为材料,利用MINI-IMAGING-PAM荧光成像测定系统,研究了Cd2+胁迫下叶片叶绿素荧光参数的变化及其光响应曲线。结果表明,初始荧光Fo与最大荧光Fm随着Cd2+浓度的增大而呈现先升后降的趋势,Fo与Fm在200 mg/LCd2+处理4周时达到最高值,400 mg/LCd2+处理则显著下降;PSⅡ最大光化学效率(Fv/Fm)与PSⅡ潜在光化学效率(Fv/Fo)显著受Cd2+胁迫抑制,但随Cd2+浓度的增加呈先降后升的变化趋势。Cd2+胁迫下各叶绿素荧光参数的光响应结果表明,PSⅡ实际光量子效率Y(Ⅱ)、荧光淬灭系数(qP)随光化光强度的增加呈下降趋势,而同光强下高浓度Cd2+使Y(Ⅱ)与(qP)显著降低;PSⅡ调节性能量耗散的量子产额Y(NPQ)、非光化学淬灭系数(qN)与表观电子传递速率(ETR)则随着光强增加呈上升趋势,同光强下高浓度Cd2+处理显著提高Y(NPQ)、qN与ETR。Cd2+胁迫下,PSⅡ非调节性能量耗散的量子产额Y(NO)稳定在较低水平,同光强下Y(NO)随Cd2+浓度增加略有提高。说明,银芽柳通过调节PSⅡ反应中心开放程度与活性,对Cd2+胁迫表现出较强的耐性,高浓度Cd2+胁迫导致PSⅡ反应中心关闭或不可逆失活,表现出光抑制。Heavy metals in soil affect the growth,development,and multiplication of plants.Meanwhile,the plants which survive in environment contaminated by heavy metals have mechanisms to tolerate heavy metals.Fluorescence-based photosynthetic activity of leaves plays an important role in adaptation to heavy metal conditions,such as Cd2＋.In this paper,the effects of Cd2＋ on rapid light-response curves of photochemical and non-photochemical chlorophyll fluorescence quenching parameters including dark fluorescence yield（Fo）,maximal fluorescence yield（Fm）,maximal PSⅡ quantum yield（Fv/Fm）,and latent PSⅡ quantum yield（Fv/Fo） of Salix leucopithecia were investigated under different concentrations of Cd2＋ solutions（0,50,100,200,400 mg/L） by MINI-IMAGING-PAM Chlorophyll Fluorometer. The results showed that Fo and Fm present trend of first increased and then decreased,and the two parameters reached the maximum when Salix leucopithecia were subjected to 200 mg/L Cd2＋ solution after four weeks.The Fv/Fm declined significantly under cadmium-bearing solution,but it was higher in the same Cd2＋ solution after four weeks than after two weeks.The Fv/Fm rebounded slightly in 200 mg/L Cd2＋ condition after two weeks and then dropped to the minimum in the same condition after four weeks.Fv/Fo was also inhibited significantly by Cd2＋ stress,and showed the similar trend with the changes of Fv/Fm. The rapid light-response curves of chlorophyll fluorescence parameters were also measured at various light intensities（0,20,60,100,300,500,600,800,1000,and 1200μmol · m-2 · s-1）.The effective PS Ⅱ quantum yield（Y（Ⅱ）） and coefficient of photochemical quenching（qP） decreased with the increase of light intensity.The Y（Ⅱ） and qP declined significantly subjected to high concentration of Cd2＋ solution compared with low concentration under the same light intensity.The parameters of quantum yield of regulated energy dissipation（Y（NPQ））,coefficient of nonphotochemical quenching（qN）,

关 键 词：银芽柳 叶绿素荧光 镉离子胁迫 快速光响应曲线 

分 类 号：X173[环境科学与工程—环境科学]