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Title: | 番茄Bwr12基因座內12g520與12g550參與防禦反應之
機制研究 Study on the mechanisms underlying tomato innate immunity mediated by 12g520 and 12g550 in Bwr12 locus |
Authors: | Ching-Jung Lin 林靖容 |
Advisor: | 鄭秋萍 |
Keyword: | 青枯病,青枯病菌,數量性狀位點,H7996,LRR,RLP,PTI, Bacterial wilt,Ralstonia solanacearum,QTL,Hawaii 7996,LRR,RLP,PTI, |
Publication Year : | 2018 |
Degree: | 碩士 |
Abstract: | 青枯病是由細菌Ralstonia solanacearum (Rs)引起之土壤性維管束病害,造成全球許多重要經濟作物之嚴重損失卻無有效化學防治方法,因此抗病育種對於控制病情極為重要。目前穩定的番茄抗青枯病品系Hawaii 7996 (H7996)之多個QTL雖已定位,然而其抗病分子機制與主導之抗病基因仍未知。我們先前研究顯示H7996具有強烈pathogen-associated molecular patterns (PAMP)-triggered immunity (PTI),而且主導Rs phylotype I之抗性之QTL Bwr12及其上兩個基因 (12g520、12g550) 參與其中。本研究旨在進一步探討H7996、12g520及12g550在防禦反應之特性與相關訊息傳導路徑。施用訊息傳遞抑制劑之試驗顯示細胞質鈣離子累積、mitogen-activated protein kinase (MAPK) 傳導及NADPH oxidase參與H7996之PTI誘導反應。蛋白質定位結果顯示12g520應座落於植物細胞膜,12g550則可能座落於植物細胞膜及細胞核。功能性遺傳學與基因表現特性等分析結果顯示12g520與12g550在番茄與菸草PTI反應與抵抗多種病原細菌之抗病反應中為正向調控者,且細胞質鈣離子累積、MAPK傳導及NADPH oxidase參與12g520與12g550調控之PTI反應。酵母菌雙雜交與雙分子螢光互補試驗結果顯示12g520在未誘導PTI之狀況下可能不會與細胞膜上已知之PTI重要成員SlFLS2、SlSERK3A或SlSERK3B有交互作用,而12g550也可能不會與NADPH oxidase SlWFI1或SlRboh1有交互作用。預期本研究有助於提供番茄抗青枯病與廣效抗病性之關鍵訊息,未來可進一步搜尋其可能作用蛋白與其上下游關係以釐清其作用機制。 Bacterial wilt (BW), caused by Ralstonia solanacearum (Rs), is a devastating disease of many crops, and breeding for durable resistance is urgent and important for disease control. Tomato cultivar Hawaii 7996 (H7996) is a readily stable resistance source for BW control. Although various BW-resistance-associated quantitative trait loci (QTLs) have been mapped on H7996 chromosomes, the involved molecular mechanisms and the gene identities remain undetermined. Our previous studies showed that H7996 possesses strong PTI responses, and the major QTL associated with the H7996 resistance against Rs phylotype I strains, namely Bwr12, and two Bwr12–associated genes (12g520、12g550) are positively involved in PTI. This study aimed to investigate nature of H7996 and 12g520/12g550-mediated PTI responses and the involved signaling transduction pathways. The results of inhibitor treatment revealed the involvement of calcium influx, mitogen-activated protein kinase (MAPK) cascades and NADPH oxidase in H7996-mediated PTI responses. Transient expression assay suggested that 12g520 localizes on plasma membrane of Nicotiana benthamiana (Nb), while 12g550 might localize in plasma membrane and nucleus. Functional genetic studies and transcriptional expression analyses revealed positive roles of 12g520 and 12g550 in PTI and defense against distinct pathogens, and the involvement of calcium influx, MAPK cascades and NADPH oxidase in 12g520- and 12g550-mediated PTI responses. In addition, under normal conditions, the yeast-two-hybrid and bimolecular fluorescence complementation (BiFC) assays suggested that 12g520 might not directly interact with SlSERK3A, SlSERK3B or SlFLS2, and that 12g550 might not directly interact with tomato NADPH oxidases SlWFI1 and SlRboh1. These results along with future studies are projected to shed light on H7996 defense mechanisms. Further identification of interacting proteins and possible functional relationships would help elucidate the underlying regulatory mechanisms for their functions. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/7630 |
DOI: | 10.6342/NTU201800323 |
Fulltext Rights: | 同意授權(全球公開) |
metadata.dc.date.embargo-lift: | 2028-12-31 |
Appears in Collections: | 植物科學研究所 |
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ntu-107-1.pdf Until 2028-12-31 | 9.52 MB | Adobe PDF |
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