| Summary: | 碩士 === 國立屏東科技大學 === 植物醫學系所 === 103 === Bacterial soft rot disease was an important disease worldwide. It has been proven that transferring plant ferredoxin-like protein (pflp) to various crops was able to control bacterial soft rot disease. PFLP-mediated resistance against bacterial soft rot pathogen was associated with the intensification of PAMP-triggered immunity (PTI), but its effect on intracellular signaling was still unknown. Thus, this study will discuss what effect on PTI signaling by PFLP in PFLP-intensified resistance to bacterial soft rot disease. Firstly, it was confirmed PFLP could improve the response of PTI, including rapid H2O2 generation and callose deposition in Arabidopsis upon the existence of PFLP and flagellin (FliC). Subsequently, the results also exhibited that PFLP intensified rapid generation of H2O2, callose deposition, accumulation of H2O2, and hypersensitive response (HR) while the existence of the conserved amino acid of bacterial flagellin, flg22Pst. In addition, PFLP increased the expression of AtrbohD transcripts when flg22Pst was used as an elicitor. To gain more insight about whether PFLP-intensified PTI are related to MAPK and CDPK pathway, results indicated PFLP could intensify flg22Pst-induced MAPK pathway, but only prolong flg22Pst-induced CDPK pathway based on mRNA transcripts of marker genes, FRK1 and PHI1 in MAPK pathway and CDPK pathway, respectively. The data also revealed that the increasing expression of these two genes may be due to PFLP-intensified activities of MAPK and CDPK. To understand if PFLP-intensified callose deposition is related to MAPK pathway, results showed that PFLP intensified flg22Pst-induced callose deposition in mkk5, and mpk6 plants, implying PFLP could intensify flg22Pst-induced callose deposition and MAPK pathway, simultaneously. The data indicated PFLP-intensified resistance is reduced in mekk1, mkk5, and mpk6 plants after inoculation with Pectobacterium carotovorum subsp. carotovorum Ecc17. Besides, PFLP also intensified flg22Pst-induced salicylic acid pathway and jasmonic acid/ethylene pathway based on increasing marker gene expression of PR1 and PDF1.2, respectively. These results suggested that PFLP could intensified multiple defense signalings. According to the above results, PFLP-intensified resistance to P. carotovorum subsp. carotovorum Ecc17 may be associated with multiple PTI signaling, and MAPK pathway plays the key role in PFLP-intensified resistanceified resistance.
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