Expression of ACC oxidase promoter-GUS fusions in tomato and Nicotiana plumbaginifolia regulated by developmental and environmental stimuli
Expression of ACC oxidase promoter-GUS fusions in tomato and Nicotiana plumbaginifolia regulated by developmental and environmental stimuli
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DOI：
10.1046/j.1365-313x.1997.12040731.x
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发表时间：
1997-10-01
期刊：
影响因子：
7.2
通讯作者：
Grierson, D
中科院分区：
文献类型：
--
作者：
Blume, B;Grierson, D
ACC氧化酶催化植物激素乙烯生物合成的最后一步，由番茄中的一个小的多基因家族编码，包括三个成员，LEACO 1，LEACO 2和LEACO 3。LEACO 1是在成熟、叶片衰老和受伤期间表达的主要基因（巴里等人，1996）。为了研究ACC氧化酶基因表达的转录调控，构建了β-葡萄糖醛酸酶报告基因与97 bp的5' UTR加上124、396和1825 bp的5'未转录LEACO 1序列之间的嵌合融合体，并将其导入番茄（Mill cv. Ailsa克雷格）和烟草（Nicotiana plumbaginifolia）。对转基因番茄的分析表明，含有LEACO 1基因的核苷酸-124至+97的区域足以在果实成熟期间赋予GUS活性的显著增加，尽管在非常低的速度下。396和1825 bp的LEACO 1上游序列的融合导致在已知伴随有增强的乙烯产生的情况下GUS表达的强烈和特异性诱导。报告基因的表达是类似的内源LEACO 1基因，主要增加，特别是在果实成熟，衰老和脱落的叶子，并在较小程度上，花。对转基因N.白花丹植物证实了在番茄叶和花中检测到的LEACO 1启动子活性的模式。报告基因的表达也诱导受伤后，乙烯处理，和病原体感染。组织化学分析表明，本地化的GUS活性在果皮的成熟果实，衰老的叶柄和未受精的花朵，并在伤口部位的剥离区。这些结果表明，ACC氧化酶的调节在转录水平上在广泛的细胞类型在不同的发育阶段，并响应于几个外部刺激。
The enzyme ACC oxidase, catalysing the last step in the biosynthesis of the plant hormone ethylene, is encoded by a small multigene family in tomato, comprising three members, LEACO1, LEACO2 and LEACO3. LEACO1 is the major gene expressed during ripening, leaf senescence, and wounding (Barry et al. 1996). To investigate the transcriptional regulation of ACC oxidase gene expression, chimeric fusions between the beta-glucuronidase reporter gene and 97 bp of 5' UTR plus 124, 396 and 1825 bp, respectively, of 5' untranscribed LEACO1 sequence were constructed and introduced into Lycopersicon esculentum (Mill cv. Ailsa Craig) and Nicotiana plumbaginifolia. Analysis of transgenic tomatoes indicated that the region containing nucleotides -124 to +97 of the LEACO1 gene is sufficient to confer a marked increase in GUS activity during fruit ripening, albeit at very low revels. Fusion of 396 and 1825 bp of LEACO1 upstream sequence resulted in strong and specific induction of GUS expression in situations known to be accompanied by enhanced ethylene production. Reporter gene expression was similar to that of the endogenous LEACO1 gene, with major increases especially during fruit ripening, senescence and abscission of leaves and, to a lesser extent, of flowers. Analysis of transgenic N. plumbaginifolia plants confirmed the pattern of LEACO1 promoter activity detected in tomato leaves and flowers. Reporter gene expression was also induced following wounding, treatment with ethylene, and pathogen infection. Histochemical analysis illustrated localized GUS activity in the pericarp of ripening fruit, abscission zones of senescent petioles and unfertilized flowers, and at wound sites. These results demonstrate that ACC oxidase is regulated at the transcriptional level in a wide range of cell types at different developmental stages and in response to several external stimuli.