苜蓿中华根瘤菌042BM noeAB基因的转录调控

Transcriptional regulation ofnoeAB fromSinorhizobium meliloti 042BM

对苜蓿中华根瘤菌(Sinorhizobiummeliloti) 0 4 2BMnoeAB基因的表达调控进行研究。结果发现,葫芦巴碱不能使noeAB的表达水平提高,证明它们的转录不受nodD2的调控。当nodD3和syrM同时存在时,noeAB的表达水平没有明显的变化,表明它们也不受nodD3 syrM系统的调控。在FY基本培养基上,毛地黄黄酮的诱导使noeAB基因的表达水平提高16倍,而在不添加该诱导物的TY培养基上,noeAB基因的表达水平也能够提高30倍以上,说明noeAB是受nodD1控制的,但除受毛地黄黄酮诱导外。

The expression regulation ofS.meliloti 042BMnoeAB was studied. The results showed that trigonelline could not elevate the level ofnoeAB expression, which indicated that these genes are not regulated bynodD2. Since association ofnodD3 andsyrM could not change the level of the genes expression, they aren't also controlled bynodD3-syrM system. However, induction of luteolin resulted in 16 times increase ofnoeAB expression, which indicated thatnoeAB was regulated bynodD1. Most interestingly, more than 30 times increase in its expression was observed on TY medium without any flavonoid. Thus, it was suggested thatnoeAB may be controlled by other unknown factors.