Influence of Cellulose Alterations in Plants

Cellulose in the plant cell wall influences a number of traits, and although not much is known in terms of the effects on the plant upon increase of cellulose content in the cell wall, a number of studies have linked mutations in the genes encoding cellulose synthases and other proteins that may be required for cellulose synthesis to changes in other properties. For example, the Arabidopsis cellulose synthase (AtCesA3) mutant, cev1, is found to be resistant to fungal pathogens and is constitutively activated for defense pathways in a manner similar to that for the pathogen-induced pmr4 mutant (Cano-Delgado et al., 2003; Ellis et al., 2002; Nishimura et al., 2003). Moreover, there is an accumulation of transcripts that are induced by jasmonic acid ( JA) and ethylene in this mutant (Ellis and Turner, 2001; Ellis et al., 2002). Increased ethylene production and/or sensitivity was observed for CesA3^eli1, CesA6^prc1, kor1, elp1/pom1, and in wild-type plants treated with 2,6-dichlorobenzonitrile (DCB) or isoxaben (Cano-Delgado et al., 2003; Desnos et al., 1996; Ellis and Turner, 2001; Ellis et al., 2002; Zhong et al., 2002). Only a brief list of changes have been mentioned here, but as is clear from these results that changes in cellulose synthesis/content in the cell wall are sensed by cells directly or indirectly through as yet unknown mechanisms.