
%0 Journal Article
%A Smith, MM 
%A O'brien, TP 
%T Distribution of Autofluorescence and Esterase and Peroxidase Activities in the Epidermis of Wheat Roots
%J Functional Plant Biology
%D 1979/04/01
%V 6
%N 2
%P 201-219
%K 
%R https://doi.org/10.1071/PP9790201
%U https://www.publish.csiro.au/paper/PP9790201 
%X In the wheat root, peroxidases and esterases specific for a-naphthyl esters of acetate, propionate and butyrate are concentrated in cell walls, particularly the outer wall of epidermal cells undergoing extension. In contrast esterases specific for &#946;-naphthyl esters of propionate and butyrate were intra- cellular and concentrated in epidermal and outer root-cap cells of the wheat root. Both &#945;-naphthyl and &#946;-naphthyl esters of longer-chain fatty acids proved to be poor substrates. The esterases and peroxidases associated with the outer epidermal wall may well be involved in turnover of phenolic acids cross-linked to polysaccharides. In this regard, ferulic acid and diferulate were shown to be constituents of wheat-root cell walls. The distribution of these substances can also be inferred from autofluorescence. Treatment with a commercial pig-liver esterase was without effect on the auto- fluorescence of the root cell-walls. Culture filtrates from Gaeumannomyces graminis did remove significant amounts of autofluorescent wall material. These preparations contained &#945;-naphthyl acetate esterase as well as many polysaccharide hydrolase activities. 
