Raman spectroscopy (RS) has gained popularity in recent years to characterize biological materials, and can be a valuable tool for plants. Current approach to plant health and disease diagnosis depends on chemical extraction and pathophysical screening. RS on the other hand can be used to identify key biological composition of plants, and investigate underlying ultrastructural changes without staining and complicated sample preparation.
This work presents investigation and quantification of plant health and growth status (specifically changes in cell-wall) using RS. We analyzed samples of sunflower plant at different time points of normal growth, and those with Phomopsis or dead arm stem canker disease. RS was performed on thin sections of the stem of growing plant using specialized test beds, and on dried thick lignified stem of diseased plant. The signatures were then analyzed to identify composition and underlying structural changes in cells-walls. Specifically, we focused on primary metabolites such as proteins, amino acids, polysaccharides, and monosaccharides, which are responsible for plant growth and development.
Overall, we show that RS can be a valuable tool to gain structural and chemical changes in plants under varying physiological conditions (specifically normal growth and disease) without detailed sample preparation approach.