Quantification and comparison of gliadin proteins in ancient wheats grown in rainfed and irrigated conditions

Abstract

Protein quantification is crucial for assessing the nutritional and functional qualities of wheat. This study quantified the gliadin content, a major component of wheat storage proteins, in 24 wheat genotypes, including ancient varieties such as einkorn (Triticum monococcum), emmer (Triticum dicoccum), and spelt (Triticum spelta). These varieties were cultivated under rainfed and irrigated conditions in the Konya/Ilgın region of Türkiye. Gliadin proteins were extracted using a 70% ethanol solution to isolate the soluble fractions, which were subsequently analyzed using the Bicinchoninic Acid (BCA) assay. The results revealed significant variation in gliadin content among the genotypes. In general, samples grown under irrigated conditions exhibited higher protein concentrations compared to those grown under rainfed conditions. Among the varieties, Karahan (16339.07 µg mL-1) and Soana (15826.99 µg mL-1) had the highest protein contents under irrigated and rainfed conditions, respectively. These findings demonstrate the impact of both environmental and genetic factors on protein composition, highlighting the importance of ancient wheat varieties in sustainable agriculture and their potential to enhance modern dietary nutrition.

Keywords

• Ancient wheat
• BCA assay
• Gliadin
• Protein determination
• Wheat extraction

References

1. Akar T, Cengiz M, Tekin M (2019) A comparative study of protein and free amino acid contents in some important ancient wheat lines. Quality Assurance and Safety of Crops & Foods 11: 191-200.
2. Blum A (2011) Genetic Resources for Drought Resistance. Plant Breeding for Water-Limited Environments. Springer New York, New York, NY, pp. 217-234.
3. Dinu M, Whittaker A, Pagliai G, Benedettelli S, Sofi F (2018) Ancient wheat species and human health: Biochemical and clinical implications. The Journal of Nutritional Biochemistry 52: 1-9.
4. Lumpkin TA (2015) How a Gene from Japan Revolutionized the World of Wheat: CIMMYT’s Quest for Combining Genes to Mitigate Threats to Global Food Security. In: Ogihara Y, Takumi S, Handa H (eds) Advances in Wheat Genetics: From Genome to Field. Springer Japan, Tokyo, pp. 13-20.
5. Malalgoda M, Ohm J-B, Meinhardt S, Simsek S (2018) Association between gluten protein composition and breadmaking quality characteristics in historical and modern spring wheat. Cereal Chemistry 95: 226-238.
6. Osborne TB (1924) The vegetable proteins. Longmans, Green and Company.
7. Schoel B, Welzel M, Kaufmann SH (1995) Quantification of protein in dilute and complex samples: modification of the bicinchoninic acid assay. Journal of Biochemical Biophysical Methods 30: 199-206.
8. Shewry PR (2009) Wheat. Journal of Experimental Botany 60: 1537-1553.

9. Shewry PR, Halford NG, Belton PS, Tatham AS (2002) The structure and properties of gluten: an elastic protein from wheat grain. Philosophical Transactions of the Royal Society of London. Series B Biological Science 357: 133-142.
10. Shewry PR, Hey SJ (2015) The contribution of wheat to human diet and health. Food and Energy Security 4: 178-202.
11. Smith PK, Krohn RI, Hermanson GT, Mallia AK, Gartner FH, Provenzano MD, Fujimoto EK, Goeke NM, Olson BJ, Klenk DC (1985) Measurement of protein using bicinchoninic acid. Analytical Biochemistry 150: 76-85.
12. Thanhaeuser SM, Wieser H, Koehler P (2015) Spectrophotometric and fluorimetric quantitation of quality-related protein fractions of wheat flour. Journal of Cereal Science 62: 58-65.
13. Walker JM (1994) The Bicinchoninic Acid (BCA) Assay for Protein Quantitation. In: Walker JM (ed) Basic Protein and Peptide Protocols. Humana Press, Totowa, NJ, pp. 5-8.
14. Wiechelman KJ, Braun RD, Fitzpatrick JD (1988) Investigation of the bicinchoninic acid protein assay: Identification of the groups responsible for color formation. Analytical Biochemistry 175: 231-237.
15. Zilić S, Barać M, Pešić M, Dodig D, Ignjatović-Micić D (2011) Characterization of proteins from grain of different bread and durum wheat genotypes. International Journal of Molecular Science 12: 5878-5894.