Abstract:
MLO proteins are a family of transmembrane proteins in land plants that play an important
role in plant immunity and host–pathogen interactions, as well as a wide range of development
processes. Understanding the evolutionary history of MLO proteins is important for understanding
plant physiology and health. In the present work, we conducted a phylogenetic analysis on a large
set of MLO protein sequences from publicly available databases, specifically emphasising MLOs from
the tomato plant and related species. As a result, 4886 protein sequences were identified and used to
construct a phylogenetic tree. In comparison to previous findings, we identified nine phylogenetic
clades, revealed the internal structure of clades I and II as additional clades and showed the presence
of monocotyledon species in all MLO clades. We identified a set of 19 protein motifs that allowed
for the identification of particular clades. Sixteen SlMLO proteins from tomato were located in the
phylogenetic tree and identified in relation to homologous sequences from other Solanaceae species.
The obtained results could be useful for further work on the use of MLO proteins in the study of
mildew resistance in Solanaceae and other plant families