iTRAQ-based proteomic analysis of heteromorphic leaves reveals eco-adaptability of Populus euphratica Oliv.

Heterophylly is regard as adaptation to different environments in plant, and Populus euphratica is an important heterophyllous woody plant. However, information on its molecular mechanism in eco-adaptability remains obscure. In this research, proteins were identified by isobaric tags for relative and absolute quantitation (iTRAQ) technology in lanceolate, ovate, and dentate broad-ovate leaves from adult P. euphratica trees, respectively. Besides, chlorophyll content, net photosynthetic rate, stomatal conductance, transpiration rate and peroxidase activity in these heteromorphic leaves were investigated. A total number of 2,689 proteins were detected in the heteromorphic leaves, of which 56, 73, and 222 differential abundance proteins (DAPs) were determined in ovate/lanceolate, dentate broad-ovate/lanceolate, and dentate broad-ovate/ovate comparison groups. Bioinformatics analysis suggested these altered proteins related to photosynthesis, stress tolerance, respiration and primary metabolism accumulated in dentate broad-ovate and ovate leaves, which were consistent with the results of physiological parameters and Real-time Quantitative PCR experiments. This research demonstrated the mechanism of the differential abundance proteins in providing an optimal strategy of resource utilization and survival for P. euphratica, that could offer clues for further investigations into eco-adaptability of heterophyllous woody plants.