TheYABBYGenes of Leaf and Leaf-Like Organ Polarity in Leafless PlantMonotropa hypopitys

Abstract

Monotropa hypopitysis a mycoheterotrophic, nonphotosynthetic plant acquiring nutrients from the roots of autotrophic trees through mycorrhizal symbiosis, and, similar to other extant plants, forming asymmetrical lateral organs during development. The members of the YABBY family of transcription factors are important players in the establishment of leaf and leaf-like organ polarity in plants. This is the first report on the identification ofYABBYgenes in a mycoheterotrophic plant devoid of aboveground vegetative organs. SevenM. hypopitys YABBYmembers were identified and classified into four clades. By structural analysis of putative encoded proteins, we confirmed the presence of YABBY-defining conserved domains and identified novel clade-specific motifs. Transcriptomic and qRT-PCR analyses of different tissues revealedMhyYABBYtranscriptional patterns, which were similar to those of orthologousYABBYgenes from other angiosperms. These data should contribute to the understanding of the role of theYABBYgenes in the regulation of developmental and physiological processes in achlorophyllous leafless plants.