BioProject

Bud mutation (bud sport) is mutation occurred in one branch in a tree and the mutant branch shows different phenotype from normal branches. More...

Bud mutation (bud sport) is mutation occurred in one branch in a tree and the mutant branch shows different phenotype from normal branches. Because bud mutation occurs in a part of plant body, genomic backgrounds of mutant branch and normal branches are the same, except some mutations. Therefore bud mutants are ideal material to identify key genes for important traits of crops. We studied ‘Giant Laf’, a bud mutant setting large fruit, which generated spontaneously in European pear ‘La France’ tree. In ‘Giant Laf’, increase of cell size and DNA reduplication occurred specifically in fruit flesh. The DNA reduplication in ‘Giant Laf’ was observed at 1 week before full bloom stage. This suggested that DNA reduplication observed in ‘Giant Laf’ fruit is not endoreduplication, but endomitosis or nuclear fusion. To identify genes expressed differentially between in ‘Giant Laf’ and in ‘La France’, microarray analysis was performed with RNA from receptacle (fruit flesh) at 1 week before full bloom stage. To isolate the receptacle, laser microdissection was applied. Genes encoding proteins localized in nucleus and cytoskeleton were up-regulated in ‘Giant Laf’. Among these genes, we found several genes which shared homology with previously described DNA reduplication related genes. These are candidates of responsible gene of ‘Giant Laf’ mutation. Overall design: The gene expression profiles between European pear (Pyrus communis) ‘La France’ and its bud mutant ‘Giant Laf’ were compared. RNA was extracted from receptacle which was isolated from flower bud at 1 week before full bloom stage by using laser microdissection. Three biological replications were analyzed. Less...