不同光强下交替氧化酶基因修饰的两种拟南芥叶片叶绿素荧光特性的变化

Changes of PS Ⅱ chlorophyll fluorescence characteristics in leaves of Arabidopsis thaliana plants with alternative oxidase under different light conditions

关键词:  拟南芥  交替氧化酶  叶绿素荧光参数  不同光强

Key words:  Arabidopsis thaliana  alternative oxidase  chlorophyll fluorescence parameters  different light conditions

摘要:

采用叶绿素荧光测定系统,研究在不同光强下交替氧化酶(alternative oxidase; AOX)基因超表达突变体(XX-2)和野生型(WT)拟南芥(Arabidopsis thaliana)叶片的叶绿素荧光参数的变化。结果表明:两种拟南芥叶片的最大光化学效率(Fv/Fm)没有显著差别; 而不同光强下两种拟南芥叶片的实际光量子效率(Y(II))、光化学猝灭系数(qp)均随光照强度的增加呈下降趋势; 同光强下XX-2叶片的上述参数均高于WT。非光化学猝灭系数(NPQ)与调节型能量耗散的量子产额(Y(NPQ))均随着光照强度的增加呈上升趋势; 同光强下XX-2叶片的NPQ与Y(NPQ)均低于WT。非调节型能量耗散的量子产额(Y(NO))均随光照强度的增加呈下降趋势; 当光强超过165 μmol·m^-2·s^-1后,同光强下XX-2叶片的Y(NO)高于WT; 表观电子传递速率(ETR)随着光照强度的增加均表现出先上升后下降的趋势; 同光强下,XX-2叶片的ETR高于WT。以上结果表明,交替氧化酶超表达体在不同光照条件下具有更加优化的叶绿素荧光性能。

Abstract:

Several chlorophyll fluorescence parameters were investigated under different light conditions(133,165,204,248,297,580,922,1 175,1 465 and 1 855)by a chlorophyll fluorometer of alternative oxidase gene overexpression lines(XX-2)and wild-type(WT)lines of Arabidopsis thaliana plants. The results showed that the parameter of maximal PSII quantum yield(Fv/Fm)didn't have significant change in two type leaves. The parameters of effective PSII quantum yield(Y(II))and coefficient of photochemical quenching(qp)decreased according to the increase of light intensity; the Y(II)and qp of XX-2 leaves increased at the same light intensity compared with WT. The parameters of coefficient of nonphotochemical quenching(NPQ)and quantum yield of regulated energy dissipation[Y(NPQ)]increased with elevation of light intensity; the NPQ and Y(NPQ)of XX-2 leaves declined at the same light intensity compared with WT. The quantum yield of non regulated energy dissipation[Y(NO)] declined with the aggrandizement of light intensity; the Y(NO)of XX-2 leaves decreased at the same light intensity compared with WT in the range of 165-1 855 μmol·m^-2·s^-1. The parameter of electron transport rate increased at the early stage of light treatment,the highest was found at 580 μmol·m^-2·s^-1,then declined according to the increase of light intensity; the ETR of XX-2 leaves increased at the same light intensity compared with WT.