Abstract text: Streptophytes – the monophyletic group formed by all land plants as well as charophyte algae – exhibit very different lifestyles and inhabit rapidly changing habitats. Their evolutionary success story led to plant terrestrialization around 500 million years ago with subsequent diversification into various land plant lineages. All investigated land plants possess arabinogalactan-proteins which play important roles in physiological plant processes like sexual reproduction, calcium signaling and many more. Our previous studies hinted towards the evolution of classical AGPs, consisting of an intrinsically disordered protein backbone linked to a carbohydrate part, within the group of streptophyte algae. Typically, the carbohydrate part is built by a galactan scaffold to which arabinoses are attached as outer surface. We investigated the presence and absence of AGPs in streptophytes through biochemical, bioinformatical and immunocytochemical analyses. By investigation of AGP fractions in ten streptophyte algae representing the five major families in Zygnematophyceae, we were able to detect diverse glycosylation patterns while the core galactan structures seem to be conserved. This was in line with previous results from Spirogyra pratensis. To conclude, our data hint towards stepwise and independent evolution of the AGP characteristics during plant evolution in close proximity to plant terrestrialization.