Proteomic and Physiological Signatures of Altitude Adaptation in a Myrsine coriacea Population under Common Garden Conditions

Plants exhibit phenotypic plasticity in response to environmental variations, which can lead to stable genetic and physiological adaptations if exposure to specific conditions is prolonged. Myrsine coriacea demonstrates this through its ability to thrive in diverse environments. The objective of the article is to investigate the adaptive responses of M. coriacea by cultivating plants from seeds collected at four different altitudes in a common garden experiment. Through integrated physiological and proteomic analyses, we identified 170 differentially accumulated proteins and observed significant physiological differences among the populations. The high-altitude population (POP1) exhibited a unique proteomic profile with significant down-regulation of proteins involved in carbon fixation and energy metabolism, suggesting a potential reduction in photosynthetic efficiency. Physiological analyses showed lower leaf nitrogen content, net CO2 assimilation rate, specific leaf area, and relative growth rate in stem height for POP1, alongside higher leaf carbon isotopic composition (δ 13C ) and leaf carbon ( C ) content. These findings provide insight into the complex interplay between proteomic and physiological adaptations in M. coriace a and underscore the importance of local adaptations. This study enhances our understanding of how altitude-specific selection pressures can shape plant molecular biology and physiology, offering valuable perspectives for predicting plant responses to global environmental changes. Highlight This study unveils proteomic and physiological adaptations in a high-altitude M. coriacea population with reduced carbon fixation and energy metabolism. ### Competing Interest Statement The authors have declared no competing interest. * A : Net assimilation rate of CO2 C : Leaf carbon Ci : Internal CO2 concentration CIT : Total chlorophyll DAPs : differentially accumulated proteins FASP : filter-aided sample preparation GO : Gene ontology gs : Stomatal conductance KEGG : Kyoto Encyclopedia of Genes and Genomes Kleaf : Leaf hydraulic conductivity N : Leaf nitrogen PCA : principal component analysis POP1 : Population originating from Dores do Rio Preto, at an altitude of 2019 meters POP2 : Population originating from Domingos Martins at an altitude of 1229 meters POP3 : Population originating from Mimoso do Sul at an altitude of 930 meters POP4 : Population originating from Muqui at an altitude of 657 meters PPIs : protein-protein interaction RGRH : Relative growth rate in height SLA : Specific leaf area TCA : trichloroacetic acid UPGMA : Unweighted Pair Group Method using Arithmetic averages VD : Vein density δ 13C : Leaf carbon isotopic composition