奇甜蛋白基因在园艺作物中的表达

奇甜蛋白（thaumatin）是从非洲西部植物katemfe（Thaumatococcus daniellii Benth）中提取得到的几种关系相近的甜味蛋白的统称，其中最主要的为奇甜蛋白Ⅰ和奇甜蛋白Ⅱ。奇甜蛋白不仅甜度高，而且具有低热量、安全无毒以及不易诱发糖尿病等优点。因此，将奇甜蛋白基因转入园艺作物中并使之表达，用以提高可食部分的甜味，有其特别的研究意义。奇甜蛋白基因已先后在马铃薯、梨树、黄瓜、番茄等园艺作物得到表达，但仍有一些问题需要解决。现从奇甜蛋白基因的克隆、测序与表达，转基因果实的安全性检测，甜度的感官评价，甜味遗传特点以及奇甜蛋白抗真菌病害检验等几个方面综述了国内外研究进展，并对今后的研究提出了建议。

Expression of Thaumatin Gene in Horticultural Crops

Thaumatin is a protein which is isolated from the katemfe fruit of west Africa (Thaumatococcus daniellii Benth). Two main forms, thaumatin I and thaumatin II, are known. It is a new sweetener with many advantages such as high sweetness, low calories, no toxicity and nice sweet taste, and especially is suitable for diabetics. The gene for thaumatin has been transferred to horticultural crops in attempts to improve taste. Several research aspects were reviewed in this paper, including thaumatin cDNA cloning and sequencing, expression and inheritance of thaumatin gene in plants, analysis of fruit taste, evaluation of the food safety of genetically modified fruit and transgenic plant tolerance for pathogenic fungus. Some problems in transformation were discussed, and suggestion was given to the future research work of this field.