RRC ID 6461
Author Mizuno N, Hosogi N, Park P, Takumi S.
Title Hypersensitive response-like reaction is associated with hybrid necrosis in interspecific crosses between tetraploid wheat and Aegilops tauschii coss.
Journal PLoS One
Abstract BACKGROUND:Hybrid speciation is classified into homoploid and polyploid based on ploidy level. Common wheat is an allohexaploid species that originated from a naturally occurring interploidy cross between tetraploid wheat and diploid wild wheat Aegilops tauschii Coss. Aegilops tauschii provides wide naturally occurring genetic variation. Sometimes its triploid hybrids with tetraploid wheat show the following four types of hybrid growth abnormalities: types II and III hybrid necrosis, hybrid chlorosis, and severe growth abortion. The growth abnormalities in the triploid hybrids could act as postzygotic hybridization barriers to prevent formation of hexaploid wheat.
METHODOLOGY/PRINCIPAL FINDINGS:Here, we report on the geographical and phylogenetic distribution of Ae. tauschii accessions inducing the hybrid growth abnormalities and showed that they are widely distributed across growth habitats in Ae. tauschii. Molecular and cytological characterization of the type III necrosis phenotype was performed. The hybrid abnormality causing accessions were widely distributed across growth habitats in Ae. tauschii. Transcriptome analysis showed that a number of defense-related genes such as pathogenesis-related genes were highly up-regulated in the type III necrosis lines. Transmission electron microscope observation revealed that cell death occurred accompanied by generation of reactive oxygen species in leaves undergoing type III necrosis. The reduction of photosynthetic activity occurred prior to the appearance of necrotic symptoms on the leaves exhibiting hybrid necrosis.
CONCLUSIONS/SIGNIFICANCE:Taking these results together strongly suggests that an autoimmune response might be triggered by intergenomic incompatibility between the tetraploid wheat and Ae. tauschii genomes in type III necrosis, and that genetically programmed cell death could be regarded as a hypersensitive response-like cell death similar to that observed in Arabidopsis intraspecific and Nicotiana interspecific hybrids. Only Ae. tauschii accessions without such inhibiting factors could be candidates for the D-genome donor for the present hexaploid wheat.
Volume 5(6)
Pages e11326
Published 2010-6-25
DOI 10.1371/journal.pone.0011326
PMID 20593003
PMC PMC2892878
MeSH Genes, Plant Hybridization, Genetic* Necrosis Photosynthesis Polyploidy* Triticum / genetics Triticum / growth & development Triticum / physiology*
IF 2.74
Times Cited 44
Wheat KU-2154 KU-2068 KU-2087 KU-2122 KU-2144 KU-2145 KU-2152 KU-2157 KU-20-8 KU-2069 KU-2078 KU-2083 KU-2111 KU-2118 KU-2124 KU-2126 KU-2155 KU-2156 KU-20-1 KU-2088 KU-2096 KU-2100 KU-2110 KU-2160 KU-2074 KU-2075 KU-2076 KU-2077 KU-2079 KU-2080 KU-2090 KU-2091 KU-2092 KU-2093 KU-2097 KU-2098 KU-2101 KU-2102 KU-2103 KU-2104 KU-2105 KU-2106 KU-2108 KU-2158 KU-2159 KU-20-6 KU-2001 KU-2003 KU-2136 KU-2132