Lignin monomeric composition in soybean seed coats and resistance to mechanical damage

Abstract: Soybean seeds are crucial for global food production. Various factors affect the quality of soybean seeds, including mechanical damage, which can lead to reduced germination potential and decreased seedling vigor. The presence of lignin in the seed coat contributes to resistance to mechanical damage. However, the relationship between the monomeric composition of lignin and mechanical damage is unknown. To fill this gap, we evaluated the contents of monomers hydroxyphenyl (H), guaiacyl (G), and syringyl (S) in seed coats of three cultivars of soybean, namely, Doko, IAS-5, and Savana. The results revealed that the monomeric composition of lignin varied between resistant and susceptible cultivars. The levels of G and S monomers were inverse in the cultivars Doko and Savana, suggesting that the composition of lignin monomers may play a crucial role in the resistance of soybean seeds to mechanical damage. In addition, negative linear regressions between lignin and S monomer contents and S/G ratios could be helpful as an alternative to identify resistance in soybean seeds.