Accelerated senescence and enhanced disease resistance in hybrid chlorosis lines derived from interspecific crosses between tetraploid wheat and Aegilops tauschii

ABSTRACT: Hybrid chlorosis, one of the hybrid incompatibilities, has frequently been reported in inter- and intraspecific crosses of allopolyploid wheat. In our previous study, hybrid chlorosis was observed in the wheat triploids between a tetraploid wheat cultivar Langdon and four Ae. tauschii accessions and in their derived synthetic hexaploids. However, the molecular mechanisms underlying hybrid chlorosis are not well understood. Here, we performed cytological and comparative gene expression analyses in leaves to characterize the abnormal growth in wheat synthetics showing mild and severe chlorosis symptom. In addition, disease resistance was comparatively assessed. A number of carbohydrate metabolism- and defense-related genes were markedly up-regulated in the hybrid chlorosis lines, and abnormal chloroplasts were formed in the mesophyll cells before the leaves turned to be yellowish. The mild chlorosis plants showed increased resistance to a wheat blast fungus, although little significant differences of agricultural traits were found between the wild-type and mild chlorosis-showing plants. These observations suggest that the senescence processes might be accelerated in the hybrid chlorosis lines of wheat synthetics. Moreover, the negative effects on biomass can be minimized and the substantial fitness may be obtained under pathogen-polluted conditions in the mild chlorosis-showing wheat synthetics. Expression patterns were compared between a wild-type synthetic wheat line (as a reference) and two hybrid chlorosis-showing hybrid chlorosis lines. Total RNA samples were isolated from the 3-week-old leaf tissues. Two independent experiments were conducted in each line.

ORGANISM(S): Triticum aestivum

SUBMITTER: Shigeo Takumi 

PROVIDER: E-GEOD-59640 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress