| Autor: |
Staal, Jens, Kaliff, Maria, Bohman, Svante, Dixelius, Christina |
| Předmět: |
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| Zdroj: |
Plant Journal; Apr2006, Vol. 46 Issue 2, p218-230, 13p |
| Abstrakt: |
In a cross between the two resistant accessions Col-0 and L er-0, a 15:1 segregation was found in F2, suggesting the presence of unlinked resistance loci to Leptosphaeria maculans. One hundred Col-4 × L er-0, and 50 L er-2 × Cvi-1 recombinant inbred lines, and seven susceptible L er-0 × Ws-0 F2 progenies were examined to identify the two loci. Resistance in Col-4, Ws-0 and Cvi-1 ( RLM1) was mapped to the marker m305 on chromosome 1. Col-4 × L er-0 and L er-2 × Cvi-1 mapping populations located RLM2L er on the same arm of chromosome 4. A tight physical location of RLM2 was established through near-isogenic lines. This region was found to correspond to an ancient duplication event between the RLM1 and RLM2 loci. Two independent T-DNA mutants in a TIR-NB-LRR R gene (At1g64070) displayed susceptibility, and L. maculans susceptible mutant phenotypes were confirmed to be allelic for rlm1 in F1 after crosses with susceptible rlm1L er rlm2Col plants. Complementation of rlm1L er rlm2Col with the genomic Col-0 sequence of At1g64070 conferred resistance. In addition, two T-DNA mutants in a neighbouring homologous TIR-NB-LRR gene (At1g63880) displayed moderate susceptibility to L. maculans. Sequence analysis revealed that At1g64070 was truncated by a premature stop codon, and that At1g63880 was absent in L er-0. RNA interference confirmed that L er-0 resistance is dependent on genes structurally related to RLM1. Camalexin was identified as a quantitative co-dominant resistance factor of Col-0 origin, but independent of RLM1. RLM1/RLM2 resistance was, however, found to require RAR1 and partially HSP90.1. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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