To gain insight into evolutionary origins of auxin transport mechanism, we established a morphologically simple multicellular alga Klebsormidium flaccidum as a useful model for early evolutionary studies in plant lineage. We used this model to isolate and characterize the most primitive PIN auxin transporter being functional (Skokan R et al., Nat Plants 2019). We also contributed to the genome sequencing of the morphologically more complex alga Chara braunii (Nishiyama et al., Cell 2018) and identified corresponding PIN sequences. We also provided insights into the complexity of the evolutionary path of PIN proteins by identifying the importance of the intramolecular domain-domain coevolution, which is crucial for their divergent patterns of localization (Zhang Y et al., New Phytologist 2020).
We provided initial and important insights into how plant roots learned to grow down in response to the gravity. We discovered that efficient root gravitropism of higher plants evolved only at the onset of seed plant evolution and was intimately connected to the innovation within PIN proteins that acquired the apical polar localization necessary to efficient gravitropism. This event was an important moment in evolution of plant abilities to colonize efficiently dry land habitats (Zhang Y et al., Nat Commun 2019).
We also discovered critical role of functional innovations within the PIN gene family during evolution as essential prerequisites for the origin of flowering plants and their main parts such as shoot/root, inflorescence, and floral organs (Zhang Y et al., Science Adv 2020).
We also provided key insights into structure of PIN proteins (Abas M et al., PNAS 2021; Yang Z et al., Nature 2022), PIN polarity and trafficking (Glanc M et al., Nat Plants 2018; Glanc et al., Curr Biol. 2021) and into mechanism of auxin canalization (Hajny J et al., Science 2020; Friml J et al., Nature 2022) and auxin signaling for regulation of growth (Fendrych M et al., Nat Plants 2018; Li L et al., Nature 2021; Qi L et al., Nature 2022) and auxin-drived regeneration (Marhava P et al., Cell 2019; Hoermayer L et al., PNAS 2020).
