Monitoring Of Mechanical Properties Of Appressorium Of Magnaporthe Grisea

This thesis takes the Magnaporthe grisea conidia as the research object,and uses a self-assembly method to modify 1-undecanethiol(1-UDT)on the surface of the gold electrode quartz crystal to make the surface hydrophobic to adhere the Magnaporthe grisea conidia.For the first time,the double resonator quartz crystal microbalance(QCM)technology was used to monitor the dynamic changes of generated force and viscoelasticity during the adhesion and infection of the Magnaporthe grisea conidia,as well as the viscoelastic changes under the inhibition of different concentrations of EGTA.The main test results are as follows:1.A batch of Magnaporthe grisea 110-2 was cultivated and grew well which was used for the experiments,and the selection of the Magnaporthe grisea 110-2media was optimized.The test results showed that when tomato oat media was used for the cultivation of Magnaporthe grisea,the sporulation amount was the best and the sporulation cycle was the shortest.2.8 MHz AT-cut crystals of gold electrodes modified with UDT were used to monitor the dynamic changes in QCM frequency(F)and resistance(R)during the adhesion and spreading of different numbers(0.3’10~4,0.6’10~4,1.2’10~4,1.8’10~4)of Magnaporthe grisea conidia.The test results showed that as the addition of conidia,the QCM F decreased and R increased,indicating that the conidia adhered to the surface of the UDT modified gold electrode very well.Among the four numbers of Magnaporthe grisea conidia tested,12000 conidia induced the largest QCM responses of frequency and resistance.3.For the first time,the double resonator quartz crystal microbalance(QCM)technology was used to monitor and study the dynamic changes of cells-generated surface stress and viscoelasticity during the adhesion and infection of Magnaporthe grisea conidia in real time.The test results demonstrated that the obtained mechanical dynamics curve of the conidia can be divided into five stages,corresponding to the infection process and morphological changes of the conidia observed under the microscope.4.The conidia of Magnaporthe grisea was treated with different concentrations of EGTA inhibitor,and the inhibitory effect on the conidia germination and appressorium formation process was observed.The results showed that under the same concentration,the inhibitory effect of EGTA on conidia appressorium formation of Magnaporthe grisea was significantly higher than that of conidia germination.And the changes in QCM frequency,resistance and cell viscoelastic index(CVI)response of Magnaporthe grisea conidia(about 1.2’10~4)were quantitatively determined by using 8 MHz AT cut quartz crystal gold electrodes under the inhibition of different concentrations of EGTA.The results showed that compared to the control group(without EGTA),with the increase of EGTA concentration,the CVI response became relatively less obvious,indicating that with the increase of EGTA concentration,the inhibition rates of conidia germination and appressorium formation became more significant.