caa a22 4500 477132359 CHVBK 20180405111707.0 cr unu---uuuuu 170330e19970901xx s 000 0 eng 10.1023/A:1018339425355 doi (NATIONALLICENCE)springer-10.1023/A:1018339425355 Zinc resistance in Neurospora crassa [Elektronische Daten] [V.S.K.V. Rama Rao, C.H. Wilson, P. Maruthi Mohan] Three non-identical Zn-resistant strains of Neurospora crassa have been isolated. ZNR-1 and ZNR-2 strains were obtained after repeated subculturing of wild type N. crassa on Zn-containing agar media (8mM and 16mM), while ZNR-3 was isolated after mutagenesis with diethyl sulfate, followed by selection on Zn agar plates (16mM). All three ZNR strains showed two- to threefold resistance to Zn in liquid media when compared with the wild type. However, growth measured by hyphal elongation clearly distinguished between the resistant strains (ZNR-3>ZNR-2>ZNR-1⋙wild). The ZNR-2 and ZNR-3 strains were also cross-resistant to Co, while ZNR-2 alone was cross-resistant to Cu. Both Mg and Fe reversed the growth inhibition caused by Zn; Mg by suppression of Zn uptake and Fe without affecting the same. Assay of catalase, iron-binding siderophores and glutathione in Zn toxicity revealed significant increases in catalase and glutathione levels in the ZNR-2 strain when compared with the wild type. Kinetics of Zn uptake by preformed mycelia showed a rapid initial phase of uptake followed by a slower phase. The rates of Zn uptake measured after leaching surface-bound metal with EDTA revealed that ZNR strains have significantly reduced Zn uptake rates when compared with the wild type. The overall data suggest a partial transport block for Zn uptake as the major mechanism for resistance in ZNR strains. Genetic analysis of ZNR strains showed that in the ZNR-3 strain the znr locus maps close to the mating type locus (mt) of N. crassa LG I, while that of ZNR-1 and ZNR-2 is linked to LG IV associated with chromosomal aberration. Chapman and Hall, 1997 linkage nationallicence Neurospora crassa nationallicence resistance nationallicence uptake nationallicence zinc nationallicence Rama Rao V.S.K.V. Department of Biochemistry, Osmania University, Hyderabad, India aut Wilson C.H. Fungal Genetics Stock Center, The University of Kansas Medical Center, Kansas City, USA aut Maruthi Mohan P. Department of Biochemistry, Osmania University, Hyderabad, India aut Biometals Kluwer Academic Publishers 10/3(1997-09-01), 147-156 0966-0844 10:3<147 1997 10 10534 https://doi.org/10.1023/A:1018339425355 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1018339425355 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Rama Rao V.S.K.V. Department of Biochemistry, Osmania University, Hyderabad, India aut NATIONALLICENCE 700 1- Wilson C.H. Fungal Genetics Stock Center, The University of Kansas Medical Center, Kansas City, USA aut NATIONALLICENCE 700 1- Maruthi Mohan P. Department of Biochemistry, Osmania University, Hyderabad, India aut NATIONALLICENCE 773 0- Biometals Kluwer Academic Publishers 10/3(1997-09-01), 147-156 0966-0844 10:3<147 1997 10 10534 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer