德達松乾旱誘導基因lp3之所在位置與生理機制分析

Analysis and Localization of the Water-Deficit Stress-Induced Gene (lp3)

王昭泰(Jau-Tay Wang)

《明道學術論壇》 3卷2期 (2007/12) Pp. 49-59

https://doi.org/10.6953/MJ.200712.0049

摘要

LP3是一種與ASR（離層酸ABA，逆境Stress與果實成熟Ripening）蛋白類似的乾旱誘導的蛋白質。它與ASR假設性蛋白的相似度，C端比N端來得高。本研究的目的是在研究LP3蛋白質的功能及lp3啟動子對水分逆境及其他逆境所產生的反應。β-葡糖醛酸糖酶基因(uidA, GUS)在繼代的轉基因煙草(T0)的表現上，以lp3啓動子－GUS基因的質體構築下，使用聚乙烯甘油(PEG)、離層酸(ABA)、甲基茉莉酸鹽(MeJa)及離層酸的抑制劑fluridione (Flu)進行檢測。GUS基因表現實驗中發現激勃素(GA3)、二氯苯氧乙酸(2,4-D)、硝酸銀、益收生長素（ethephon；乙烯釋放劑）等，處理後發現，GUS基因沒有反應。含有lp3啟動子－GUS基因的質體構築的T1幼苗，在種子發芽後，約表現40天的GUS活性（40天後就失去活性）。當5-azacytidine （DNA甲基化抑制劑）加入培養基內，GUS基因活性又會恢復，顯示煙草發育性的調節機制與基因的靜默，包含基因的甲基化。在轉基因煙草的研究中，LP3蛋白位於細胞核內，受到乾旱的誘導，並且顯示受到植物發育的影響調節。

關鍵字

煙草 ； 乾旱逆境WDS ； 離層酸ABA ； 聚乙烯甘油PEG ； 離層酸的抑制劑fluridione ； lp3基因 ； 甲基化 ； ASR離層酸ABA，逆境Stress與果實成熟Ripening

並列摘要

LP3 is a water-deficit-induced protein, which is highly homologous to ASR (ABA, stress and ripening) proteins. Homology was found in the C-terminal region of the putative LP3 protein while lower homologies were found in the N-terminal region. The goal of this study was to investigate the function of the LP3 protein and the mechanism of the lp3 promoter in response to water-deficit stress (WDS) and other stresses. In regenerated transgenic tobacco (T0), expression of b-glucuronidase (GUS) from the lp3 promoter-GUS construct was observed in polyethylene glycol (PEG), abscisic acid (ABA), methyl-jasmonate (MeJa), and fluridone (Flu) treatments. GUS expression was not observed following gibberellin (GA3), 2-methyl-4-dichlorophenoxy acetic acid (2, 4-D), silver nitrate, or ethephon (ethylene releasing agent) treatments. Germinated T1 seedlings containing the lp3 promoter-GUS construct exhibited GUS activity up to 40 days postgermination. Expression could be restored when 5-azacytidine was included in the culture media, indicative of a developmentally regulated silencing mechanism involving methylation. In transgenic tobacco, the LP3 protein localized in the cell nucleus was induced by WDS and appeared to be developmentally regulated.

並列關鍵字

Tobacco ； Water-deficit stress WDS ； Abscisic acid ABA ； Polyethylene glycol PEG ； Fluridone ； lp3 gene ； Methylation ； ASR ABA, Stress and Ripening