金雀异黄素对蟠桃叶片叶绿素荧光特性和抗氧化酶活性的影响

研究了金雀异黄素(GNT)对‘早蟠桃’叶片色素、碳水化合物、叶绿素荧光特性和抗氧化酶活性的影响。结果表明,40μmol/L GNT可以提高叶片叶绿素a和叶绿素b、淀粉和可溶性糖含量。暗适应以及光照下叶片最大荧光(Fm和Fm′)和可变荧光(Fv和Fv′)下降,但PSⅡ实际光化学效率(ΦPSⅡ)、光化学荧光猝灭系数(qP)、非光化学荧光猝灭系数(NPQ)、表观光合电子传递速率(ETR)和光化学速率(PCR)提高,光合相对限制值(L(PFD))显著下降。就能量分配而言,GNT增加了用于光化学反应部分的光能(Pc)和天线热耗散部分(Hd),同时降低PSⅡ反应中心的过剩激发能耗散(Ex),表明GNT处理具有促进叶绿素荧光光化学猝灭和非光化学猝灭的双重特性。此外,GNT也提高了叶片抗氧化酶的活性。

Effects of Genistein on Chlorophyll Fluorescence Characteristics and Antioxidant Enzymes in Flat Peach Leaves

The leaves of flat peach(Prunus persica var.platycarpa Bailey cv.Zaoshuomi) were used to study the effects of folia spraying of genistein(GNT) on the content of pigment,carbohydrate,chlorophyll fluorescence properties and some antioxidant enzyme activities.The results indicated that 40 μmol/L GNT significantly increased the content of chlorophylls,starch and soluble sugar in the leaves.The kinetics of chlorophyll fluorescence showed that GNT application at 40μmol/L depressed fluorescence quantum yields,including the maximal fluorescence(Fm) and the variable fluorescence(Fv) of leaves at dark,the maximal fluorescence(Fm′) and the variable fluorescence(Fv′) of leaves in light,but increased the actual photochemical efficiency of PSⅡ(ΦPSⅡ),photochemical quenching(qP) and non-photochemical quenching(NPQ),electron transport rate(ETR),photochemical rate(PCR).It was found that energy trapped by PSⅡ reaction centers in GNT-treated leaves was more allocated to photochemistry reaction(Pc) and antennae heat dissipation(Hd),so the excess energy of PSⅡ reaction centers(Ex) was decreased.The measurements of antioxidant enzymes revealed that the effect of GNT treatment on flat peach chlorophyll fluorescence might be related with its promotion on the activities of antioxidant enzymes.