Comparative Proteomic Analysis of Potato (Solanum tuberosum L.) Tuberization In Vitro Regulated by IAA

Auxin (IAA) is one of the important factors regulating potato tuberization among the multiple environmental signals and hormonal factors. To understand the molecular mechanism of potato tuberization regulated by IAA, a comparative proteomic approach was applied to analyze proteome change of tubers in vitro subjected to exogenous IAA treatments (0, 2 and 4 mg L-1) using two-dimensional gel electrophoresis (2-DE). Quantitative image analysis showed a total of 76 protein spots with abundance significantly altered (P < 0.05) more than 1.2-fold. Mass spectrometry analysis allowed the identification of 49 differential abundance proteins, mainly involved in metabolism and bioenergy, storage, redox homeostasis, transcription and translation, defense and rescue, chaperone and unknown. The promotion effects of low IAA concentration treatment (2 mg L-1) on tuberization were found in various cellular processes, which mainly included changes in the metabolism of carbohydrates and amino acids, the accumulation of storage proteins, the activation of more antioxidation and defense systems as well as the higher efficiency of transcription and translation for protein synthesis. The corresponding inhibition effects were shown at higher concentration (4 mg L-1). This study provides some new insights into the underlying molecular mechanism of potato tuberization regulated by IAA.