阿拉伯芥凝集素受體激酶A4.1是細菌誘發之基本性免疫作用中的正向調控者

The Arabidopsis Legume-Like Lectin Receptor Kinase A4.1 is a Positive Regulator of the Bacterial-Induced PAMP-Triggered Immunity

簡志丞(Chih-Cheng Chien)

指導教授 ： 金洛仁

國立臺灣大學/生命科學院/植物科學研究所/碩士(2009年)

https://doi.org/10.6342/NTU.2009.10179

摘要

植物最初是對於表面病原菌特定分子標誌(pathogen-associated molecular patterns, PAMPs)的感知(perception)來辨認病原菌的入侵，對於病原菌入侵的感應會引發植物中的PAMP誘導免疫反應(PAMP-triggered immunity, PTI)。本論文報導阿拉伯芥中一個凝集素受體激酶A4.1(Lectin receptor kinase A4.1, LecRKA4.1)在植物抗病反應中扮演之角色。LecRKA4.1的T-DNA插入突變株lecrka4.1-1對於半活體寄生型(hemi-biotrophic)的細菌性斑點病病原菌(Pseudomonas syringae pv tomato DC3000)與死體寄生型(necrotrophic)的細菌性軟腐病病原菌(Erwinia carotovora subsp. carotovora)較感病。然而，lecrka4.1-1對於真菌性灰黴病病原菌(Botrytis cinerea)和卵菌性黃葉病病原菌(Hyaloperonospora parasitica)的抗病性卻與野生株Col-0相似。我們的分析資料也顯示lecrka4.1-1在被細菌感染後，其PTI標的基因(例如FRK1和WRKY53)的轉錄活性有缺陷。於互補實驗中，在突變株的背景下大量表現LecRKA4.1可以回復PTI標的基因的轉錄活性，也可以回復此植株對於細菌性入侵的抗病性。此外，LecRKA4.1大量表現的植株對於PTI標的基因擁有很高的基礎轉錄活性(basal transcriptional level)與持續性的表現。由此結果可以推論對於細菌引發的PAMP誘導免疫反應，LecRKA4.1扮演一個正向的調節因子。

關鍵字

阿拉伯芥 ； 細菌性斑點病菌 ； 細菌性軟腐病菌 ； 灰黴病菌 ； 卵菌性黃葉病菌 ； 凝集素受體激酶細菌 ； 病原菌特定分子標誌 ； PAMP誘導免疫反應

並列摘要

Plants initially sense microbial pathogens through perception of pathogen-associated molecular patterns (PAMPs) by pattern-recognition receptors located on the cell surface. Recognition leads to the activation of PAMP-triggered immunity (PTI). Here, we characterize the function of the lectin receptor kinase A 4.1 (LecRKA4.1) in the Arabidopsis response to pathogens. A LecRK4.1 T-DNA knock-out line (lecrka4.1-1) was found to be highly susceptible to the hemi-biotrophic Pseudomonas syringae pv tomato (Pst) DC3000 and the necrotrophic Erwinia carotovora subsp. carotovora (Ecc) bacteria. However, lecrka4.1-1demonstrated a normal response to Botrytis cinerea and Hyaloperonospora parasitica, a fungal and oomycete pathogen, respectively. Our data also show that lecrka4.1 is deficient in the transcriptional activation of PAMP-triggered immunity (PTI) marker genes such as FRK1 and WRKY53 after bacteria inoculations. Over-expression of LecRKA4.1 in lecrka4.1-1 background restored PTI activation and resistance to bacterial microbes to a wild type level. In addition, the basal transcriptional level of PTI marker genes was found to be constitutively activated in super over-expressing lines. We propose that LecRK4.1 is a positive regulator of bacterial-induced PTI.

並列關鍵字

Arabidopsis ； Pseudomonas syringae ； Erwinia carotovora ； Botrytis cinerea ； Hyaloperonospora parasitica ； lectin receptor kinase ； bacteria ； PAMP ； PAMP-triggered immunity

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