臭氧对玉簪叶片近轴侧和远轴侧伤害的比较

Comparation of Injury on Leaf Adaxial and Abaxial Sides in Hosta plantaginea Induced by Ozone

为探讨臭氧(O3)是否伤害叶片远轴侧以及对与近轴侧和远轴侧伤害的异同,以玉簪为材料通过显微观察、叶绿素荧光诱导动力学和气体交换等技术研究了该问题。叶片形态和显微观察表明,200μg·kg-1 O3处理10 d后玉簪叶片近轴侧表面和叶肉组织呈现明显伤害症状,而远轴侧在300μg·kg-1 O3条件下也发生明显伤害。O3处理显著改变了叶片近轴侧和远轴侧荧光诱导动力学曲线的形状;尽管两侧荧光诱导动力学曲线的K、J和I点相对荧光产量均增加,但仅近轴侧K点的相对荧光上升幅度更加明显。此外,O3处理下玉簪叶片的光合速率和叶绿素含量均下降,相对电导率和膜脂过氧化程度大幅增加。鉴于显微观察和荧光诱导动力学的测定结果,我们认为O3能够同时伤害玉簪叶片近轴侧和远轴侧叶肉组织,并就臭氧对玉簪叶片两侧的伤害机制进行了比较和讨论。

In order to explore the comparation of injury on leaf adaxial and abaxial sides in Hosta plantaginea induced by ozone,micro-observation,chlorophyll fluorescent,gas exchange characteristics and chlorophyll content were studied in H.plantaginea seedlings under various ozone levels.Our micro-observation showed that injury symptoms on leaf adaxial side were induced by 10 days ozone treatment（200 μg·kg^（-1））,however,the injury on leaf abaxial side was observed only when ozone concentration reached 300 μg·kg^（-1）.In the presence of ozone,the shapes of polyphasic rise of fluorescence transient both in the two sides were greatly changed.Further analysis revealed that ozone induced pronounced K,J and I steps both on adaxial and abaxial sides of H.plantaginea leaves.Moreover,the enhancement of K step on adaxial side was more significant than that on abaxial side.Additionally,we also noticed that ozone induced the decrease in photosynthetic rate and chlorophyll content,while REC and MDA increase under various ozone treatments.According to micro-observation and the polyphasic rise of fluorescence transient,we thought that ozone can injure the both side of H.plantaginea leaves.The potential mechanisms were also discussed in this study.