小麦根圈荧光假单胞菌(Pseudomonas fluorescens)的发光酶基因标记

LuxAB GENES MARKED Pseudomonas fluorescens Xl6 ISOLATED FROM WHEAT RHIZOSPHERE

采用２亲本杂交的方法将Ｔｎ５－ｌｕｘＡＢ标记基因系统成功地转入了分离自小麦根圈的ＰＧＰＲ菌株荧光假单胞菌（Ｐｓｅｕｄｏｍｏｎａｓｆｌｕｏｒｅｓｃｅｎｓ）Ｘｌ６菌株中。与亲本菌株相比，携有发光酶基因ｌｕｘＡＢ的标记菌株Ｘｌ６Ｌ２生理生化特征的变化很小，而且仍保留有在小麦根圈的定殖能力。Ｔｎ５－ｌｕｘＡＢ片段在Ｘｌ６Ｌ２中的稳定性很强，在没有卡那霉素选择压力的情况下，ｌｕｘＡＢ也能稳定表达。即使在４０℃温度下。

Tn5 luxAB gene marker system was sucessfully transfered into a wheat PGPR strain Pseudomonas fluorescens Xl6 with biparental mating. Changes of physiological and biochemcal characteristics of luxAB marked strain Xl6L2 were few compared with its parent strain. Xl6L2 remained good capability of wheat root colonization. Tn5 luxAB genes in Xl6L2 were very stable. Even if there was no Km selective pressure, and could express luciferase activity. Xl6L2 could also emit light at 40℃. It can be used in studying molecular ecology of PGPR in wheat rhizosphere extensively.