Effect of Peroxyacetyl Nitrate on Growth & Cell Wall Metabolism of Avena Coleoptile Sections

It was reported earlier that growth of Avena coleoptile sections was inhibited by pretreatment of tissue with photochemically derived oxidants, including peroxyacetyl nitrate (PAN), a naturally occurring air pollutant. Other workers showed that cell expansion is dependent on plasticization of the cell wall. Various studies indicate that metabolism of cell wall constituents is affected by conditions which affect growth. It has been especially noted that even in the absence of growth substances, certain growth inhibitors such as galactose affect the basal metabolism of cellulose. Although the cell wall reaction directly governed by IAA has escaped detection, pectin metabolism appears to be particularly affected by IAA. Because of this close relationship between cell expansion and cell wall metabolism, the effect of PAN pretreatment, at sublethal levels, on subsequent glucose-C/sup 14/ absorption and incorporation into the cell wall was studied. It is shown in the present paper that PAN has a marked effect on cell wall metabolism in general and on cellulose metabolism in particular. 15 references, 1 figures, 3 tables.