Identification of YAB11-NGAL1 controlling leaf serrations through enhanced genome-wide association studies of Populus

Leaf margins are complex plant morphological features and contribute to the diversity of leaf shapes which effect on plant structure, yield and adaptation. Although several regulators of leaf margins have been identified, the genetic basis of natural variation therein has not been fully elucidated. We first profiled two distinct types (serration and smooth) of leaf morphology using the persistent homology mathematical framework (PHMF) in poplar. Combined genome-wide association studies (GWAS) and expression quantitative trait nucleotide (eQTN) mapping to create a module of leaf morphology controlling using data from Populus tomentosa and P. simonii association population, respectively. Natural variation of leaf margins is associated with transcript abundances of YABBY11 ( YAB11 ) in poplar. In P. tomentosa , PtoYAB11 carries premature stop codon ( PtoYAB11PSC ) resulting in lost its positive regulation in PtoNGAL-1 , PtoRBCL , PtoATPA , PtoATPE , and PtoPSBB . Overexpression of PtoYAB11PSC serrated leaf margin, enlarged leaves, promoted photosynthesis and increased biomass. Overexpression of PsiYAB11 in P. tomentosa could rescue leaf margin serration and increase stomatal density and light damage repair ability. In poplar , YAB11 - NGAL1 is sensitive to environmental conditions and play positive regulator of leaf margin serration. It might be important regulator which bridge environment signaling to leaf morphological plasticity.