RESISTANCE TO NODULATION OF CV AFGHANISTAN PEAS IS OVERCOME BY NODX, WHICH MEDIATES AN O-ACETYLATION OF THE RHIZOBIUM-LEGUMINOSARUM LIPO-OLIGOSACCHARIDE NODULATION FACTOR
RESISTANCE TO NODULATION OF CV AFGHANISTAN PEAS IS OVERCOME BY NODX, WHICH MEDIATES AN O-ACETYLATION OF THE RHIZOBIUM-LEGUMINOSARUM LIPO-OLIGOSACCHARIDE NODULATION FACTOR
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DOI：
10.1111/j.1365-2958.1993.tb01961.x
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发表时间：
1993-10-01
影响因子：
3.6
通讯作者：
DOWNIE, JA
中科院分区：
文献类型：
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作者：
FIRMIN, JL;WILSON, KE;DOWNIE, JA
豌豆根瘤菌生物变种中只有部分菌株能有效地侵染豌豆品种。阿富汗，它携带一个隐性等位基因，阻止了大多数西方分离的R。I.蚕豆其中一株（TOM）能使cv.阿富汗豌豆有一个基因（p3 X），需要克服抗干旱。菌株TOM产生的脂寡糖促凝因子的量显著低于其他R.这种效应似乎是由于较低水平的nod基因诱导。这些因子与其它R.蚕豆乳杆菌菌株，因为它们由四个或五个β 1 -4连接的N-乙酰基葡萄糖胺残基的低聚物组成，其中末端非还原葡萄糖胺携带O-乙酰基和C18：4或C18：1 N-酰基。但TOM株产生的一个趋化因子与其它菌株不同。I. viciae，因为它在还原性N-乙酰葡糖胺残基的C-6上携带O-乙酰基。这种乙酰化是NodX依赖性的，并且五聚体形成因子在还原性N-乙酰葡糖胺残基上被乙酰化，而四聚体形成因子不是。尽管BRL基因产物也是O-乙酰基转移酶（它使末端非还原葡糖胺的C-6 O-乙酰化），但这两种乙酰基转移酶的氨基酸序列之间几乎没有相似性。
Only some strains of Rhizobium leguminosarum biovar viciae can efficiently nodulate varieties of peas such as cv. Afghanistan, which carry a recessive allele that blocks efficient nodulation by most western isolates of R. I. viciae. One strain (TOM) which can nodulate cv. Afghanistan peas has a gene (nodX) that is required to overcome the nodulation resistance. Strain TOM makes significantly lower amounts of lipo-oligosaccharide nodulation factors than other strains of R. L viciae and this effect appears to be due to lower levels of nod gene induction. These nodulation factors are similar to those from other R. L viciae strains in that they consist of an oligomer of four or five beta1-4-linked N-acetylglucosamine residues in which the terminal non-reducing glucosamine carries an O-acetyl group and a C18:4 or C18:1 N-acyl group. However, one of the nodulation factors made by strain TOM differs from the factors made by other strains of R. I. viciae in that it carries an O-acetyl group on the C-6 of the reducing N-acetylglucosamine residue. This acetylation is NodX-dependent and the pentameric nodulation factor is acetylated on the reducing N-acetylglucosamine residue whereas the tetrameric nodulation factor is not. Although the nodL gene product is also an O-acetyl transferase (it O-acetylates the C-6 of the terminal non-reducing glucosamine), there is very little similarity between the amino acid sequences of these two acetyl transferases.