Study on Somaclonal Variations in In Vitro Cultures of Globe Artichoke

Nowadays in vitro propagation of globe artichoke can be applied by growers for large scale plant production. Somaclonal variations are often observed under these conditions and visual morphogenic change frequently occurring is reduced plant size. The final morphology of plant organs is also achieved through tight regulation of cell division and cell expansion. Proteins in the cell wall are believed to play important roles in regulation of cell wall extensibility, which is a key parameter in determining cell expansion. Among the cell wall proteins, expansins are unique in their ability to induce immediate cell wall extension in vitro and cell wall expansion in vivo. In order to elucidate the correlation between different expression level of these proteins and reduced plant size of some somaclonal variants of in vitro cultured globe artichoke, we have isolated a putative ?-expansin gene from genomic DNA derived from axenic cultures of Mola variety. Preliminary observations on the differential expression of this gene in micropropagated plants exhibiting different sizes will be described.