小麦与叶锈菌互作过程中H2O2的时空分布特点及其功能分析

H2O2 is an important signaling molecule in plants. Previous work in our lab have been proved through the experiment of pharmacology that H2O2 outbreak is associated with programmed cell death of host cells infected by leaf rust. To further explore the spatial and temporal distribution and the source of H2O2 during the interaction between Triticum aestivum and Puccinia triticina, we used DAB, CeCl3 to mark H2O2 and observed it through optical microscopy and transmission electron microscopy. The results showed that H2O2 mainly distributed on sub-stomatal vesicles , haustorial mother cell and haustorium, within the host cell which infected by leaf rust and on the health mesophyll cell plasma membrane arounding the infected site in the incompatible combination at early stage. But in the compatible combination, H2O2 mainly concentrated on the guard cells of infection point. So,we gusee that H2O2 generated during the interaction sourced mainly from the host cell membrane and wall. At the earlier stage of interaction, H2O2 might play a major role in inducing the host cells to produce a series of defensive response. At the later stage of interaction, H2O2 directly involved in the killing effect on leaf rust and the promoting effect on host cells to produce HR, while as a signal could induce neighboring HR cells to produce defensive reactions.