The Role of Expansins A in Petunia Development

Expansins, a diverse set of proteins found in plants and some other organ- isms, appear to play a key regulatory role in cell expansion, thereby serving critical functions in plant morphogenesis, development, and adaptation to stress. We have isolated a number of expansin genes from Petunia. Their ongoing functional analysis provides evidence for their involvement in cell wall functions, including cellulose metabolism, disruption of noncovalent cellulose/glycan bonds, and separation of the cell wall matrix during cell expansion.