iTRAQ Protein Profiling of Adventitious Root Formation in Mulberry Hardwood Cuttings

The ability to form mature adventitious roots (AR) provides a competitive advantage for clonal multiplication of elite genotypic plant species, because high economic losses occur as a result of insufficient rooting. To better understand potential mechanisms involved in AR formation, we utilized an iTRAQ-based proteomic approach on mulberry hardwood cuttings. A total of 4427 proteins were identified from the base of cuttings, of which 595 and 231 proteins showed differential accumulations in the two periods of rooting, respectively. Three differentially expressed enzyme proteins were validated by an enzyme assay and qPCR. Functional annotation analysis showed that dysregulated proteins were involved in glucose metabolism, flavonoids biosynthesis, cell wall modification, and hormone regulation, indicating potential contributions to adventitious rooting. These results provide fundamental and important information for research on the molecular mechanism of AR development in mulberry cuttings and facilitate rooting efficiency in agricultural practice.