It included a num ber of glycosyl transferases and several glycosyl hydro lases representing families having cellulase, b 1,3 glucanase, xylanase, xyloglucan endotransglucosylase hydrolase, glucan endo 1,3 beta D glucosidase, invertase and b D Sutent galactosidase activity. These enzymes are var iously required for cell wall loosening and elongation, formation of the secondary cell walls of vascular tissues, hydrolysis of the xylan backbone, post translational modifications of proteins and mobili zation of energy in form of sucrose. Also detected were pectin methylesterases involved in the modifica tion of the physical, chemical, and biological properties of pectins. The concomitant expression of a PME inhibi tor probably represented a need to regulate PME in young amaranth stems in order to avoid the wall rigidi fication associated with PME activity.

In addition, a putative b expansin protein was detected, these proteins modulate the interaction between hemi celluloses and cellulose presumably via a disruption of their shared hydrogen bonds. Within the extracellular oxido reductases group were found two peroxidases, belonging to the peroxidase 25 and 64 families, respectively. Peroxidases have been found to be expressed at moderate to high levels in developing stems, where they are believed to reduce cell wall extensibility due to their role in the formation of covalent links between pectin residues, hydroxyproline rich proteins like extensins, and lignin precursors. One gene encoding a multicopper oxidase of the SKS family was identified.

The function of these proteins in stem development is not well known, although the expression of SKS5 was latterly found to be up regulated in metal hyper accumulating ecotypes of Thlaspi caeru lescens. Another oxido reductase identified in amaranth stems was an 2 OG Fe oxygenase protein of unknown function that was recently found to be asso ciated with defense mechanisms against fungal infection in Arabidopsis. Several genes encoding proteins with putative interac tion domains with polysaccharides and or other proteins were identified. Many of the genes classified within this category are kinases, peptide receptors and receptor like kinases that regulate developmental processes in plants such as the CLAVATA1 like receptor, CLA VATA3 ESR related receptor, Abnormal Leaf Shape 2 receptor like kinase, leucine rich repeat receptor like kinase RLK7 and LRR XI 23 kinase. A number of hydroxiproline rich proteins, most probably representing arabinogalactan proteins, structural proteins and a related prolyl 4 hydroxylase needed for the hydroxylation Cilengitide of proline residues, were also highly expressed in stems.