中文摘要：

最近研究证明,在叶绿体中超表达甲基营养菌固定甲醛关键酶HPS-PHI的融合蛋白（由rmpAB基因编码）是提高转基因天竺葵代谢和吸收甲醛（HCHO）的一个有效策略。以rmpAB转化模式观赏植物矮牵牛,经基因组PCR分析确认5个转基因株系,RT-PCR检测结果表明rmpAB基因在这5个株系的叶片中可以正常转录。选取3个转录水平高的株系进行Western分析,结果证明融合蛋白HPS-PHI能在这3个转基因株系的叶片中表达,表达的融合蛋白HPS-PHI有生物学活性,酶活性最高的株系（P26）是野生型的2.5倍。经检测,3个转基因株系对液体甲醛的吸收速率均高于野生型。用P26株系进行H14 CHO标记试验,结果证实融合蛋白HPS-PHI的超表达也增强矮牵牛同化HCHO的能力。在含有7、10mmol.L-1甲醛的MS培养基上,P26的生长优势很明显,气体HCHO处理也观察到类似的结果,表明转基因矮牵牛HCHO抗性增强。证明应用该策略提高转基因观赏植物代谢和吸收HCHO的能力具有可行性。

英文摘要：

A recent study demonstrated that over-expression of the fused protein HPS-PHI（encoding by the rmpAB gene）,the key enzyme of formaldehyde（HCHO）-fixation in methyl bacteria,in chloroplasts to install a photosynthetic HCHO-fixation pathway as a bypass of the Calvin cycle is an effective strategy to elevate HCHO-absorption ability and HCHO-metabolism capacity of transgenic Geranium.In order to verify the feasibility of this strategy,the rmpAB gene was used to transform the model ornamental plant petunia in this study.Five transgenic lines were verified by genomic PCR analysis.RT-PCR analysis indicated that rmpAB gene was transcribed normally in all of the five transgenic lines,but the transcriptional level was varied in different lines.The three lines with high transcriptional level were selected for Western analysis.The results showed that the fused HPS-PHI protein was expressed in the leaves of the three transgenic lines.Measurements for enzyme activity suggested that the expressed fused HPS-PHI protein had biological activity.The HPS-PHI activity of the highest expression line（P26） was 2.5 folds of that in the wild-type（WT）.The analysis for liquid HCHO-absorption capacity of the three transgenic lines showed that the absorption rates of these transgenic lines were all higher than that of the WT line,suggesting that over-expression of the HPS-PHI fusion protein improved the HCHO-absorption rate of transgenic petunia.H14CHO tracer experiment with P26 line confirmed that transgenic plants assimilated more HCHO into the insoluble fraction of the plants than WT plants.When grown on MS medium with 7 or 10 mmol·L-1 HCHO or exposed to gaseous HCHO,the shoots of P26 line showed better growth than WT.This suggested that the transgenic petunia had a higher HCHO-tolerance than WT.These results verified again the feasibility of applying this strategy to enhance the ability of transgenic ornamental plants to uptake and assimilate HCHO.