胜肽 flg22 對於阿拉伯芥氣孔發育之研究

Study on the effects of flg22 in Arabidopsis stomatal development

高子萱(Tzu-Hsuan Kao)

指導教授 ： 楊健志

國立臺灣大學/生命科學院/生化科技學系/碩士(2018年)

https://doi.org/10.6342/NTU201803218

摘要

Flg22為源自於細菌鞭毛之22個胺基酸的保守胜肽片段。Flg22會引發阿拉伯芥的PTI反應 (Pathogen-associated molecular pattern triggered immunity)；阿拉伯芥以flg22短期處理一小時的條件下，即可啟動植物防禦機制，包括：促使氣孔關閉以避免病原菌入侵，抑制根生長，脂質累積及誘導致病相關基因表現等現象。為進一步探索flg22是否對其他植物發育過程亦具調控作用。本研究分析flg22處理後對阿拉伯芥氣孔發育之影響。Flg22 長期處理十天後，觀察阿拉伯芥根生長受到抑制，顯示本實驗使用之化學合成的 flg22 具有生物活性。阿拉伯芥經不同濃度flg22 (0.05 μM, 0.1 μM, 1 μM, 5 μM, 10 μM) 的長期處理下，都有部分氣孔其分佈違反「一個細胞間隔」之發育原則，且處理組的氣孔指數相較於控制組有下降的趨勢。此外，參與阿拉伯芥氣孔發育過程之主要調控轉錄因子在flg22處理下，基因表現量也有所改變。基於以上結果推論以 flg22 長期處理植植株後，flg22會藉由調控氣孔發育相關的轉錄因子之表現，進而影響阿拉伯芥的氣孔發育，導致氣孔指數的下降，並改變其分佈。

關鍵字

阿拉伯芥 ； 氣孔發育 ； 胜? ； flg22

並列摘要

Flg22, a 22-amino-acid peptide derived from flagellin, is known to activate the pattern triggered immunity (PTI) in Arabidopsis. With the short-term treatment of flg22 for 1 hr, the defense system of Arabidopsis is triggered including stomatal closure to prevent pathogen invasion. The effects of long-term treatment of flg22 for 7 to 14 days in Arabidopsis are root growth inhibition, callose deposition and expression of pathogenesis related genes. The effect of flg22 in regulating plant development was investigated in this study. Stomatal development is one of the indicators in response to environment change. Arabidopsis was treated with flg22 for 3 days to observe if flg22 affected stomatal development in this study. In this research, the bioactivity of synthetic flg22 was demonstrated by inhibiting the root growth of wild type (WT). Some of the stomata in WT treated with flg22 showed irregular patterning which “one-cell spacing rule” was not strictly followed. The stomatal index decreased in a dose-dependent manner in WT treated with flg22. The expression levels of those master regulator genes and their interacting partners in stomatal development was changed in WT treated with flg22. In this study, flg22 was proposed to play roles in stomatal development by regulating the transcript levels of master regulators that leads to the decreased stomatal density and impaired stomatal patterning.

Keywords:
Arabidopsis; stomatal development; peptide; flg22

並列關鍵字

Arabidopsis ； stomatal development ； peptide ； flg22

參考文獻

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