Given that multicellularity evolved independently in the lineage preceding Ulva evolution ( Coates et al., 2014), it is interesting to decipher which molecular mechanism regulates morphogenesis and, in particular, the contribution of bacteria to this regulation process. Remarkably, the growth, cell differentiation, and morphogenesis of Ulva species depend on their interaction with specifically associated bacteria and the chemical mediators these bacteria produce ( Goecke et al., 2010 Egan et al., 2013 Wichard, 2015). Ulva species are characterized by either a tubular (‘enteromorpha’) or a flattened form (‘sea lettuces’) ( Blomster et al., 2002 Hayden et al., 2003), but both morphotypes can also appear concomitantly in some species, such as Ulva compressa and Ulva mutabilis ( Tan et al., 1999 Steinhagen et al., 2019 a, b). green tides ( Fletcher, 1996 Smetacek and Zingone, 2013 Zhang et al., 2019). Eutrophication of coastal waters results in rapid growth of some macroalgal species, significantly increasing their biomass and thus forming, e.g.
The genus Ulva (Ulvales, Chlorophyta) comprises a group of green macroalgae which grows predominantly in intertidal zones. Understanding macroalgae–bacteria interactions permits further elucidation of the evolution of multicellularity and cellular differentiation, and development of new applications in microbiome-mediated aquaculture systems.Īlgal growth, cell wall, cross-kingdom interaction, morphogenesis, morphogenesis-promoting factor, phytohormone, rhizoid, seaweed, siderophore Introduction We demonstrated that gametes acquired the iron complex of thallusin, thereby linking morphogenetic processes with intracellular iron homeostasis. Thallusin, released by Maribacter sp., induced rhizoid and cell wall formation at a concentration of 11 pmol l −1. We uncovered novel ecophysiological functions of thallusin, a sesquiterpenoid morphogen, identified for the first time in algal aquaculture. We performed bioassay-guided solid-phase extraction in water samples collected from U. Hence, our study sought to identify algal growth- and morphogenesis-promoting factors (AGMPFs) capable of phenocopying the activity of Maribacter spp. This ecological reconstruction forms a tripartite community which can be further studied for its role in cross-kingdom interactions. (MS6), which produce various stimulatory chemical mediators, completely recovers morphogenesis. However, co-culturing with Roseovarius sp. Under axenic conditions, the macroalga Ulva mutabilis develops a callus-like phenotype with cell wall protrusions. (Chlorophyta) depend on bacteria releasing morphogenetic compounds. In particular, the growth and development of the sea lettuce Ulva spp.
Macroalgal microbiomes have core functions related to biofilm formation, growth, and morphogenesis of seaweeds.