Sieve element occlusion (SEO) proteins, or forisomes, are phloem proteins which accumulate during sieve element differentiation [1]. This domain represents the N-terminus of SEO proteins.

1: Molecular and phylogenetic characterization of the sieve element occlusion gene family in Fabaceae and non-Fabaceae plants. Ruping B, Ernst AM, Jekat SB, Nordzieke S, Reineke AR, Muller B, Bornberg-Bauer E, Prufer D, Noll GA; BMC Plant Biol. 2010;10:219. PMID:20932300