牡丹柱枝孢叶斑病(Cylindrocladium canadense)对叶片光合系统功能的影响  

Effect of Infection by Cylindrocladium canadense on Behaviors of Photosystems in Tree Peony Leaves

作　　者：杨德翠[1,2] 刘超[2] 盖树鹏[2] 郑国生[2] 郭平毅[1] 

机构地区：[1]山西农业大学农学院,山西太谷030801 [2]青岛农业大学生命科学学院、山东省高校植物生物技术重点实验室,山东青岛266109

出　　处：《园艺学报》2013年第3期515-522,共8页Acta Horticulturae Sinica

基　　金：山东省农业良种工程重大项目(鲁科农字[2008]167号)

摘　　要：以牡丹(Paeonia suffruticosa)‘藏枝红’为试验材料,通过测定叶绿素荧光快速诱导动力学曲线、820nm光吸收曲线以及气孔交换参数和H2O2含量,研究了柱枝孢叶斑病(Cylindrocladium canadense)对牡丹叶片光合性能和光系统功能的影响。结果显示:在病原菌侵染后,牡丹叶片的净光合速率(Pn)、气孔导度和叶绿素含量均下降,而细胞间隙CO2浓度升高,表明Pn的降低是受非气孔因素的影响。Cylindrocladium canadense的侵染,使H2O2含量显著升高,快速叶绿素荧光诱导动力学曲线形状发生明显改变,Fv/Fm和PIABS均显著下降。PSⅡ供体侧、反应中心和受体侧活性均受到抑制,但PSⅡ受体侧所受抑制比供体侧大。同时,病原菌侵染也使PSⅠ(△I/Io)活性快速下降。由上述研究结果推测:Cylindrocladium canadense的侵染,使H2O2积累增加,对PSⅠ和PSⅡ的功能造成伤害。PSⅠ活性的下降阻碍了PSⅡ向PSⅠ的电子传递,过剩激发能增加,导致ROS增加,抑制D1蛋白的合成,加剧了对PSⅡ伤害,这是其侵染抑制牡丹光合系统的主要原因。In the present study, Effect of infection by Cylindrocladium canadense on behaviors of photosystem Ⅰ （PS I ） and photosystem Ⅱ （PS Ⅱ ） in tree peony （Paeonia suffruticosa ‘Zangzhihong＇ ）leaves was estimated by simultaneously measuring their Chlorophyll fluorescence transient, light absorbance at 820 nm, gas exchange and hydrogen peroxide （H2O2） content. The data showed that the netphotosynthetic rate （Pn）, stomatal conductance and chlorophyll content were significantly decreased compared with that of the control after infection by C. canadense, whereas intercellular CO2 concentrationwas significantly increased. These results indicated that the decreased photosynthesis in infected leaves was resulted from non-stomatal factor. Furthermore, significantly enhanced H2O2 content, reduced Fv/Fmand PIABS, as well as the changed chlorophyll fluorescence transient was also observed in leaves of tree peony infected by C. canadense. The donor sides （Oxygen evolution complex）, reaction centers andacceptor sides of PS Ⅱ were significantly inhibited by C. canadense infection. But the acceptor sides were more suffered than the donor sides. At the same time, the activity of PSI was also significantly reduced.Taken together, the data presented here indicated that C. canadense infection resulted in the accumulation of H2O2, which in turn damaged the functions of PSI and PS II. The decline of PSI activity inhibitedtransportation of electrons from PS Ⅱ to PS Ⅰ, which then led to the accumulation of excessive excitation energy and reactive oxygen species （ROS） . The increased ROS Inhibited synthesis of protein D1,accelerating damage to PS II. It was the main reason for inhibition of photosystems in tree peony leaves after infected by C. canadense.

关 键 词：牡丹 柱枝孢叶斑病 光系统Ⅰ 光系统Ⅱ 活性氧 

分 类 号：S685.11[农业科学—观赏园艺]