Functions of mucilage include adhesion, protection, nutrient acquisition, seed hydration and infection prevention. Plant exudates improve compression characteristics of soils, easing penetration and enhancing recovery of root induced soil compaction. So you should expect improvement in germination percentage.
Article Effects of mucilage on seed germination of the desert epheme...
"Analysis of the imbibition solution of seeds with a mechanically incised seed coat, revealed that plant defensins accounted for 30% of released proteins, although Rs-AFPs are minor proteins in the seed (0.5% of total seed proteins). The amount of plant defensins released from a single seed was estimated to be at least 1 μg, which is the amount of peptide required to mimic the inhibition halo formed around a germinating seed."
da Silva Conceição A, Broekaert WF. 12 Plant Defensins. Pathogenesis-related proteins in plants. 1999:248.