5-氨基乙酰丙酸处理对低温下西瓜叶片快速叶绿素荧光诱导曲线的影响  

Effect of ALA on Fast Chlorophyll Fluorescence Induction Dynamics of Watermelon Leaves under Chilling Stress

作　　者：孙永平[1] 张治平[1] 徐呈祥[2] 申春苗[1] 高充[1] 汪良驹[1] 

机构地区：[1]南京农业大学园艺学院,南京210095 [2]金陵科技学院园艺学院,南京210038

出　　处：《园艺学报》2009年第5期671-678,共8页Acta Horticulturae Sinica

基　　金：国家自然科学基金项目(30471181)

摘　　要：以西瓜幼苗为材料,利用便携式植物效率仪和JIP-test数据分析方法,研究了5-氨基乙酰丙酸(ALA)处理对4℃低温胁迫中叶片快速叶绿素诱导荧光特性的效应。结果显示,低温胁迫导致叶片快速叶绿素荧光诱导曲线JIP相逐渐降低,而ALA处理可以保持较高的荧光产额。西瓜叶片光合性能指数(PIABS)、捕光性能(PTR)和传递电子性能(PET)随着胁迫时间延长而大幅下降,而ALA处理叶片PIABS、PTR和PET一直保持较高水平。低温胁迫96h后,ALA处理叶片PSⅡ最大光化学效率(φPo)、PSⅡ反应中心吸收光能用于电子传递的量子产额(φEo)以及捕获激子将电子传递到电子传递链QA-下游其他电子受体的概率(Ψo)等,均显著高于对照,而与反应中心关闭有关的荧光参数Mo和Vj均显著低于对照。ALA处理提高低温下西瓜叶片单位受光面积有活性的反应中心数量(RC/CS),几个与PSⅡ反应中心受体侧性能有关的荧光参数包括Fk-j、Fj-i和Fi-p等均明显提高。以上结果证明,ALA处理对低温下西瓜叶片光合作用的促进效应与其提高PSⅡ反应中心受体侧电子传递链受体获得电子的能力有关。Protection of 5-aminolevulinic acid （ALA） on fast chlorophyll fluorescence induction in watermelon （Citrullus lanatus Thunb. Mansfeld） leaves under 4 ℃ low temperature was studied by using a plant efficiency analyzer （PEA） and JIP-test. The results showed that JIP phases of chlorophyll a fluorescence curves in the watermelon leaves decreased during 4 ℃ low temperature stress, whereas much higher fluorescence remained in the leaves treated by ALA. The performance index on an absorption basis （PIABs ） , performance due to the trapping probability （PTR） and performance due to the conversion of excitation energy to electron transport （PET） of watermelon leaves under 4 ℃ low temperature stress were decreased significantly. However, ALA treatment improved PIABS, PTR and PET of watermelon leaves. After low temperature stress for 96 h, ALA treatment increased the maximum quantum yield of PS Ⅱ （φpo）, the quantum yield of electron transport （φEo）, and the efficiency that a trapped exeiton moves an electron into the electron transport chain beyond QA- （ψo） of the watermelon leaves under low temperature stress, while decreased the approximate initial slope of the fluorescence transient （Mo） and relative variable fluorescence intensity at the J-step （ Vj ） greatly, the latter were assumed to be related with closure of reaction centers. ALA treatment increased the density of reaction centers （RC/CS）. And simultaneously, Fk-j , Fj-i and Fi-p, three parameters which were possibly related with the electron acceptability in the aeceptor side of electron transport chain of PS Ⅱ reaction centers were increased greatly in the leaves of ALA treatment. Combined with previous reports, this work proves that ALA improvement on photosynthesis may be correlated with the higher ability of the acceptor side of PS Ⅱ reaction center to transfer electron to downstream under chilling stress condition.

关 键 词：西瓜 5-氨基乙酰丙酸 低温胁迫 快速叶绿素荧光诱导曲线 PSⅡ电子传递链 

分 类 号：S642.2[农业科学—蔬菜学] Q945[农业科学—园艺学]