|Khalili, Sadia - SWEDISH UNIV OF AG SCI|
Submitted to: Molecular and Cellular Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 9, 1997
Publication Date: N/A
Interpretive Summary: The stem of the flax plant is the source of linen fiber that is of commercial importance in Europe and Asia. The growing and processing of flax for fiber is gaining interest in the United States. However, the United States has essentially no means of processing flax for fiber. In order to assess processing methods, better knowledge of how the chemistry and structure of this plant tissue is affected by various methods is needed. This study demonstrated the ability to use infrared generated signals to produce images that provide this knowledge. This was accomplished by exposing sections of flax plant stems to infrared light and recording the absorption of that light by the sample. From this response, images of the chemical components were produced. Specific images were produced for cellulose, hemicellulose, two types of pectins, aromatics and wax components. Thus, all of the major chemical components in flax stems could be imaged in this manner. The results obtained indicated that this type of imaging could be used to provide essential chemical information about the enzyme or enzyme/chelator retting process that was otherwise not obtainable. This information can now be used to develop new enzymatic techniques that will make this process an economic feasibility.
Technical Abstract: The effect of enzyme and/or chelator treatments on the retting process were assessed using Fourier transform infrared (FT-IR) microspectroscopy which allowed the imaging and mapping of the changes in the distribution of key chemical components during fiber release from flax stems. Cross-sections of Ariane flax were treated with a 0.05% Flaxzyme, (a commercial enzyme retting mixture), a 50mM oxalic acid solution, a mixture of both buffer (p 5) or in buffer alone for 6 hours at 40 deg C. Exposure to the buffer solution resulted in the removal of some of the pectate salts and acetylated (hemicellulosic) materials, though other components were unaffected. Treatment with the enzyme mixture was effective in attacking some parenchyma tissue between fiber bundles and in removing some pectins from in cambium region but not from the epidermal tissue. Treatment with oxalic acid caused the cuticular and epidermal tissue to be removed and the eloss of some of the associated pectins. Treatment with both enzyme and oxalic acid resulted in the additional removal of parenchyma tissue surrounding the fiber bundles, affording the greatest degree of retting, where some bundles were separated into ultimate fibers. However, most of the fibers appeared to be still primarily held together by pectate salts and to a lesser extent by pectic esters and/or acids and hemicellulosic polysaccharides. The infrared imaging allowed ascertaining which actual chemical species were present after each treatment in relation to the anatomical features present.