LAUSR

Abstract. Productivity of sugarcane (Saccharum spp.) crops varies at each cutting stage, reaching critical rates close to the fifth cut (fourth ratoon). Knowledge of proteins involved in the regrowth of sugarcane within the cutting process is important for the development of cultivars with greater longevity. The present study presents new information that the proteome of axillary buds is changed in successive cuts in sugarcane culture. Proteins were identified by UPLC-ESI-Q-TOF (ultra-high-performance liquid chromatography coupled with electrospray ionisation–quadrupole–time-of-flight) mass spectrometry and the Mascot tool. A reduction in the number of proteins was evident in the axillary buds of the fifth cut, as well as a reduction in the number of proteins exclusively detected in the axillary buds with the first cut, an indicator of reduction in the expression of genes that may be essential for the stability of culture development. The reduction in agricultural productivity, sprouting and tillering at advanced stages of the sugarcane crop is accompanied by alterations in axillary-bud gene expression, where <50% of the proteins (47.65%) were detected in both the first (plant cane) and in the fifth (fourth ratoon) cutting stage, whereas >50% (52.35%) were expressed in either the axillary buds of the plant cane or the axillary buds of the fourth ratoon. All MS data are available via jPOST and ProteomeXchange with identifiers JPST000331 and PXD007957, respectively.