【摘要】 独脚金内酯是新发现的起源于类胡萝卜素生物合成途径的信号分子,调控着植物生长发育中的各种生理过程。为了解独脚金内酯及其信号途径对植物光合特性的影响,以拟南芥Arabidopsis thaliana独脚金内酯合成突变体max1和信号突变体max2为材料,测定叶片的光合色素质量分数及叶绿素荧光特性。结果发现:max1突变体与max2突变体在光合荧光特性存在明显的差异。max1叶绿素质量分数较野生型并没有显著降低,但叶绿素a/b发生了变化,max1突变体叶绿素初始荧光Fo和Y（NO）显著高于野生型,但F_v/F_m,Y（Ⅱ）,qP等荧光参数较野生型并没有显著变化。快速光响应曲线发现max1突变体在强光下的ETR,Y（Ⅱ）和QNP等参数低于野生型。而max2突变体叶片的叶绿素a和叶绿素b质量分数显著低于野生型（P<0.05）,叶绿素荧光参数F_v/F_m,Y（Ⅱ）,qP等光化学参数也显著降低,但Q_NP,q_N等光保护参数显著升高（P<0.05）。这些结果说明独脚金内酯可能参与了调控植物光合对环境的适应,而其信号传导蛋白MAX2则可能对植物光系统的建成具有基础作用。更多还原

【Abstract】 Strigolactones are a class of carotenoid-derived compounds and play as novel signaling molecules to regulate various processes of growth and development in plant. For understanding the roles of strigolactone and its signaling protein in plant photosynthesis, we measured the contents of photosynthetic pigments and chlorophyll fluorescence parameters in the leaves of strigolactone biosynthesis mutant max1, strigolactone insensitive mutants max2 and wild type of Arabidopsis thaliana, and the results showed that features of photosynthetic fluorescence are obvious differences in max1 and max2 mutants. The contents of chlorophyll and values of photochemical-related parameters weren’t significantly decreased in max1 mutant, but ratio of content of chlorophyll a to chlorophyll b was reduced and the value of minimal fluorescence(Fo) and Y(NO) were increased than WT plant. Furthermore, rapid light-response curve of PSⅡ chlorophyll fluorescence parameters showed that the value of electron transport rate through PSⅡ(ETR), Y(Ⅱ) and QNPin max1 mutant is lower than WT under intensive light. However, in max2 mutant, the contents of chlorophyll and values of photochemical-related parameters including maximum quantum efficiency of PSⅡ photochemistry(F_v/F_m), actual photochemical rate of PSⅡ[Y(Ⅱ)] and photochemical dissipation(qP) are significantly lower than WT(P<0.05), while the values of photoprotection-related parameters, such as nonphotochemical quenching(QNP) and non-photochemical dissipation(qN), are significantly higher than WT(P<0.05). These results demonstrated that strigolactone are possibly involved in modulating photosynthesis adaptability in response to environmental cues, and MAX2 protein has specific roles in plant photosystem and photosynthesis that different with strigolactone, which possibly participates in regulation of structure of photosystem of plant.更多还原