串珠镰孢霉硝酸盐还原途径酶的遗传研究

GENETICS OF ENZYMES RELATED TO THE PATHWAY OF NITRATE REDUCTASE IN FUSARIUM MONILIFORME

通过对菌株突变体有性杂交后代的检测方法,对串珠镰孢霉Fusariummoniliforme氮代谢过程中硝酸盐还原途径相关酶基因间关系进行研究。串珠镰孢霉含钼协同因子突变体缺陷型(nitB)与亚硝酸盐还原酶缺陷型突变体(nitC)间的杂交结果显示,在不同的交配群以及在相同交配群不同寄主上的分离菌株中,控制这两种酶的基因有两种类型,并据此提出细胞核基因和细胞质基因共同调控硝酸盐还原途径酶的假说。当杂交后代出现四种表型(nitD:nitB:nitC:wt=1:1:1:1)时,表明这两种酶的遗传受核基因调控,分离时两种基因自由组合;当杂交后代仅有两种表型时,表现为父本表型隐藏,双基因缺陷型(表型同主氮调节基因缺陷型nitD)表型不出现,即母本表现型:野生型为1:1,表明这种遗传类型除受核基因的控制外,还存在细胞质基因的影响。

Studies on the genetic relationship between molybdenum-containing cofactor and nitrite reductase in Fusarium moniliforme were carried out by sexual cross. The results of sexual cross between molybdenum-containing cofactor mutants (nitB) and nitrite reductase mutants (nitC) showed that there were two set of genes to control the enzymes in different mating populations and in the same mating population of the pathogen but on different hosts. It could be hypothesized that nuclear gene and cytogene might co-control the enzymes related to nitrate utilization pathway. If the ratio of segregation is 1:1:1:1 to four different phenotypes (nitD, nitB, nitC, wt), it means that molybdenum-containing cofactor and nitrite reductase were controlled by one set of nuclear gene, when the progenies had only two phenotypes, the male parent phenotype was disappeared, and the ratio of female parent phenotype and wild type was 1:1, indicating that besides nuclear gene, cytogene might be involved in controlling the enzymes.