A methodology study on chemical and molecular structure imaging in modified forage leaf tissue with cutting-edge synchrotron-powered technology (SR-IMS) as a potential research tool.

To date there is no any study on imaging molecular chemistry and chemical structure of biotech-modified plant tissue on a molecular basis. The objective of this methodology study was to apply a non-invasive and non-destructive synchrotron powered technology - SR-IMS to image molecular chemistry of the modified forage leaf tissue. The infrared molecular vibrational microspectroscopy powered with synchrotron light at Advanced Light Source (ALS, Lawrence Berkeley National Lab, Berkeley, California, Dept. of Energy, USA) were applied. The synchrotron beamline time was arranged by National Synchrotron Light Source (Scientist Dr. Lisa Miller, Brookhaven National Lab, Dept. of Energy, USA). The various molecular functional groups in the forage tissue included CH symmetric and asymmetric regions, amides I and II regions, structure and non-structure CHO regions, carbonyl ester region with peak areas at ca. 3644-3000 cm, ca 3005-2979 cm, ca. 1722-1483 cm, ca. 1488-1412 cm, ca. 1296-1189 cm, and ca. 1194-951 cm. The spectral peak area ratio imaging of chemical functional groups were also studied which included the ratio of peak area under ca. 1722-1483 cm to peak area under ca. 3005-2979 cm and the ratio of peak area under ca. 1722-1483 cm to peak area under ca. 1194-951 cm. The results showed that the advanced synchrotron-based technology - SR-IMS was able to image the forage tissue at an ultra-highly resolution within intact tissue within cellular and subcellular dimension. It revealed the forage tissue in a molecular chemical sense and provided an insight on nutrient properties and their molecular structure as well as chemical features. In conclusion, the synchrotron-radiation SR-IMS is able to image molecular structure of the forage leaf tissue at an ultra-highly resolution. The advanced SR-IMS technique could provide leaf tissue four kinds of information simultaneously: tissue structure, tissue chemistry, tissue nutrients, and tissue environment of forage.