Combining Fourier-transform infrared spectroscopy and multivariate analysis for chemotyping of cell wall composition in Mungbean (Vigna radiata (L.) Wizcek).

Abstract Background Dissection of complex plant cell wall structures demands a sensitive and quantitative method. FTIR is used regularly as a screening method to identify specific linkages in cell walls. However, quantification and assigning spectral bands to particular cell wall components is still a major challenge, specifically in crop species. In this study, we addressed these challenges using ATR-FTIR spectroscopy as it is a high throughput, cost-effective and non-destructive approach to understand plant cell wall composition. This method was validated by analysing different varieties of mungbean which is one of the most important legume crop grown widely in Asia. Results Using standards and extraction of a specific component of cell wall components, we assigned 1050-1060 cm-1 and 1390-1420 cm-1 wavenumbers that can be widely used to quantify cellulose and lignin, respectively, in Arabidopsis, Populus, rice and mungbean. Also, using KBr as a diluent, we established a method which can relatively quantify the cellulose and lignin composition among different tissue types of the above species. We further used this method to quantify cellulose and lignin in field-grown mungbean genotypes. The ATR-FTIR-based study revealed the cellulose content variation ranges from 27.9% to 52.37%, and the lignin content variation ranges from 13.77% to 31.6% in mungbean genotypes. Conclusion Cell wall composition in different mungbean genotypes was determined by the developed FT-IR-based method, which was cross-validated using canonical wet-chemistry methods. Overall, our data suggested that ATR-FTIR can be used for the relative quantification of lignin and cellulose in different plant species. This method can be used for rapid screening of cell wall composition in large number of germplasms of different crops including mungbean.