A reciprocal translocation and possible insertion(s) tightly associated with host-specific virulence in Cochliobolus heterostrophus

被引:23
作者
Chang, HR [1 ]
Bronson, CR [1 ]
机构
[1] IOWA STATE UNIV SCI & TECHNOL,DEPT PLANT PATHOL,AMES,IA 50010
关键词
chromosome rearrangement; southern corn leaf blight; pulsed-field electrophoresis; T-toxin; evolution;
D O I
10.1139/g96-070
中图分类号
Q81 [生物工程学(生物技术)]; Q93 [微生物学];
学科分类号
071005 ; 0836 ; 090102 ; 100705 ;
摘要
A reciprocal translocation and one or more apparent insertions are shown to be tightly associated with Tox1, a locus controlling T-toxin production and host-selective virulence in race T of the maize pathogen Cochliobolus heterostrophus. Chromosome arrangements were examined by separating chromosomal DNAs of a variety of Tox+ and Tox- strains by pulsed-field gel electrophoresis and hybridizing with probes known to detect RFLPs genetically linked to Tox1. The existence of the translocation was demonstrated by chromosome hybridization patterns; the existence of the putative insertion(s) was deduced from chromosome migration rates. Both differences in chromosome arrangement were detected between 8 Tox+ and 8 Tox- near-isogenic laboratory strains, suggesting that the differences are tightly linked to Tox1. The reciprocal translocation was also detected between all 7 Tox+ and 8 Tox- field isolates examined, suggesting that the translocation is common in natural populations. The field isolates may also differ by the insertion(s); however, numerous additional chromosome size polymorphisms in the field isolates prevented a firm conclusion. The tight association of the translocation and insertion(s) with T-toxin production suggests that chromosome rearrangements may have been involved in the evolution of race T and Tox1. These genomic differences may be causally related to the previously reported reduced fitness of race T relative to race O on N-cytoplasm maize.
引用
收藏
页码:549 / 557
页数:9
相关论文
共 17 条
[2]   GENETIC-CONTROL AND DISTORTED SEGREGATION OF T-TOXIN PRODUCTION IN FIELD ISOLATES OF COCHLIOBOLUS-HETEROSTROPHUS [J].
BRONSON, CR ;
TAGA, M ;
YODER, OC .
PHYTOPATHOLOGY, 1990, 80 (09) :819-823
[4]  
Daly J., 1982, PLANT INFECTION PHYS, P215
[5]   TRANSVERSE ALTERNATING-FIELD ELECTROPHORESIS AND APPLICATIONS TO MAMMALIAN GENOME MAPPING [J].
GARDINER, K ;
PATTERSON, D .
ELECTROPHORESIS, 1989, 10 (5-6) :296-302
[6]   REDUCED FITNESS ASSOCIATED WITH TOX1 OF COCHLIOBOLUS-HETEROSTROPHUS [J].
KLITTICH, CJR ;
BRONSON, CR .
PHYTOPATHOLOGY, 1986, 76 (12) :1294-1298
[7]  
LEACH J, 1982, J GEN MICROBIOL, V128, P1719
[8]   DOMINANCE AT THE TOX1 LOCUS CONTROLLING T-TOXIN PRODUCTION BY COCHLIOBOLUS-HETEROSTROPHUS [J].
LEACH, J ;
TEGTMEIER, KJ ;
DALY, JM ;
YODER, OC .
PHYSIOLOGICAL PLANT PATHOLOGY, 1982, 21 (03) :327-333
[9]  
LEONARD KJ, 1977, PHYTOPATHOLOGY, V67, P1273, DOI 10.1094/Phyto-67-1273
[10]  
LEONARD KJ, 1987, POPULATIONS PLANT PA, P163