Author:
Hirsch A M,Bang M,Ausubel F M
Abstract
Ineffective alfalfa nodules formed by Rhizobium meliloti nif::Tn5 mutants were examined by light and electron microscopy. R. meliloti nifH::Tn5 mutants formed nodules that were similar in structure to wild-type nodules except that nifH- bacteroids accumulated a compact, electron-dense body. In contrast to nodules induced by wild type and nifH mutants, nifDK- R. meliloti mutants induced nodules which contained numerous starch grains and prematurely senescent bacteroids. In addition, meristematic activity in nifDK- nodules ceased significantly earlier than in nifH- nodules. All mutant nodules exhibited elevated levels of rough endoplasmic reticulum and Golgi membranes compared to wild-type nodule cells. These elevated levels may reflect either a response to nitrogen starvation in the ineffective nodules or an abnormal synthesis and export of nodule-specific proteins during later developmental stages.
Publisher
American Society for Microbiology
Subject
Molecular Biology,Microbiology
Reference32 articles.
1. Induction and expression of nodule-specific host genes in effective and ineffective root nodules of soybean;Augur S.;Biochemistry,1981
2. Ultrastructure of soybean nodules. II. Deterioration of the symbiosis in ineffective nodules;Bassett B.;Can. J. Bot.,1977
3. The structure of "ineffective;Chen H. K.;Proc. R. Soc. London Ser. B.,1940
4. The Fuelgen-like osmium-ammine reaction as a tool to investigate chromatin structure in thin sections;Derezini M.;J. Ultrastruct. Res.,1982
5. Structural studies of alfalfa roots infected with nodulation mutants of Rhizobium meliloti;Hirsch A. M.;J. Bacteriol.,1982
Cited by
120 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献