Proteome of germinating and dormant axillary buds of sugarcane and analysis of sprouting-related proteins

Abstract

The germination potential of the axillary buds is crucial for the installation of new sugarcane crop and is highly relevant for the maintenance of the crop during the regrowth cycles. In this way, 1-DE-UPLC-ESI-Q-TOF system of mass spectrometry in a shotgun approach evaluated total and differential proteome of germinating and dormant axillary buds of cultivar RB867515 in second ratoon. The current paper investigates whether differently expressed proteins can be detected in germinating axillary buds or not. The proteome of germinative and dormant axillary buds were obtained using TCA/acetone in triplicates with subsequent proteins and polypeptides pre-separation by SDS-PAGE and UPLC. Mass spectra were obtained via MS/MS and were confronted with Viridiplante mass spectra from NCBIprot, SwissProt and UniProtKB databases, using Mascot tool from Matrix Science. A total of 159 proteins were identified. In total, 46 proteins were exclusively detected in the germinating buds, while 41 proteins were exclusively reported in the dormant buds and 72 proteins were common in germinating and dormant buds. Different proteins, involved with biotic and abiotic stress, were detected at equivalent proportions in germinating (29.5%) and dormant (31.7%) buds, while contrasting proportions of proteins involved with energy metabolism were detected in germinating (22.7%) and dormant (12%) buds. Budding potential in the third cut seems to be determined by specific proteins related to energy metabolism and steps of the biosynthesis of primary and secondary metabolites for shoot growth and development. Seven enzymes (Aconitase, Succinate dehydrogenase, Pyruvate dehydrogenase, Fructose-6-phosphate 1-phosphotransgerase, Chacone synthase, Chalcone isomerase, and Monodehydroascorbate), one protein subunits (RuBisCo large subunit-binding protein) and one protein of Argonaute protein family (Tudor-Sn) supposedly involved with germinating potential of axillary buds and two enzymes (Hexokinase and Aldehyde dehydrogenase) supposedly involved with non-budding were highlighted.