LIFE IN A CHANGING WORLD - TCH GENE-REGULATION OF EXPRESSION AND RESPONSES TO ENVIRONMENTAL SIGNALS

The Arabidopsis TCH genes were discovered as a consequence of their ma rked upregulation of expression in response to seemingly innocuous sti muli, such as touch. Further analyses have indicated that these genes are upregulated by a variety of diverse stimuli. Understanding the mec hanism(s) and factors that control TCH gene regulation will shed light on the signalling pathways that enable plants to respond to changing environmental conditions. The TCH proteins include calmodulin, calmodu lin-related proteins and a xyloglucan endotransglycosylase. Expression analyses and localization of protein accumulation indicate that the p otential sites of TCH protein function include expanding cells and tis sues under mechanical strain. We hypothesize that the TCH proteins may collaborate in cell wall biogenesis.