Search

The decrease in agricultural productivity in successive cutting of sugarcane plants is associated with several extrinsic and intrinsic factors. However, no studies have focused on the physiological potential of sett roots in successive cuts in sugarcane culture. There have been no proteomic studies on sugarcane sett roots at different stages of cutting. In this study, the UPLC-ESI-TOF-MS system and bioinformatics tools were used to identify proteins of sett roots in the first and fifth cuts of sugarcane cultivar RB966928 in the sprouting stage. Differences in the proteome of sett roots of RB966928 in the first and fifth cuts detected in this study supports the hypothesis that the proteome of sett roots may change after successive cuts in sugarcane culture. A reduction in the number of proteins was observed in the roots of the fifth cut, whereas 34% of proteins, identified exclusively in the first cut, were absent in the fifth cut. Proteome analysis of sett roots in the first and fifth cuts showed that the changes after successive cuts were quantitative (number of proteins) and mainly qualitative. In this study, the detailed list of proteins identified in the first cut but absent in the fifth cut is relevant. The findings of this study may aid further research that employ biotic or abiotic elicitors to induce gene expression of essential proteins absent in sett roots of the fifth cut, and thus increasing the agricultural productivity and longevity of cane fields

Since sugar cane production depends on the germination of axillary buds, the analysis of the products of gene expression in axillary buds from different sugarcane varieties (Saccharum spp.) in each growth cycle is important to reveal the proteins related to sprouting potential for crop renovation and consequent increase in sugarcane production. Current study has employed a simple method for protein extraction from axillary buds of RB867515, RB866928 and CTC04 sugarcane varieties to obtain protein fractions for two-dimensional electrophoresis and proteomic analysis. The TCA/acetone method for protein extraction with modifications in the centrifugation processes and in the incubation time of samples revealed a large number of well-defined bands in SDS-PAGE system with molecular weights ranging between 120 and 10 kDa. The evidence that the method TCA/acetone modified (1) by using 200 mg of tissue axillary buds; (2) by inclusion of an incubation step at room temperature for 20 min under stirring; (3) by aliquots division for a better recovery from the supernatant; (4) by the absence of phenol in one extraction phase; and (5) by the increase in centrifugal rotation from 12,000×g to 13,860×g and an increase from 15 to 30 min centrifugation time (in the precipitation and wash steps) was more efficient than the other methods used for sugarcane, is one more example showing that methods for extracting proteins in plants are specific to different tissues.

In this study, we measured the genetic diversity within and among a set of 9 commercial sugarcane varieties used for alcohol and sugar production using 17 microsatellite DNA markers. The UGSM148 and UGSM59 primers were monomorphic for all 74 sugarcane samples. The estimated proportion of simple sequence repeated (SSR) polymorphic loci was 88.23%; 17 alleles were detected. The mean gene diversity of all SSR loci was 0.7279. The highest observed heterozygosity (HO) value was found in the RB72454 variety, whereas the lowest HO value was recorded in the SP813250 variety. The SP813250, RB845210, and RB835054 sugarcane varieties were the most genetically uniform varieties. An extremely high level of population differentiation was detected in the varieties exhibiting similar agronomic characteristics. Analysis of the genetic structure of the 9 sugarcane varieties using SSR markers was especially important to identify SSR loci with high levels of heterozygosity and to identify varieties showing the highest levels of heterozygosity. The monomorphic primers may be used to evaluate the genetic stability of sugarcane during cycles of vegetative multiplication, i.e., propagation via rhizomes.

High and low polymorphisms in simple sequence repeats of expressed sequence tag (EST-SSR) for specific proteins and enzymes, such as β-amylase, cellulose synthase, xyloglucan endotransglucosylase, fructose 1,6-bisphosphate aldolase, and fructose 1,6-bisphosphatase, were used to illustrate the genetic divergence within and between varieties of sugarcane (Saccharum spp.) and to guide the technological paths to optimize ethanol production from lignocellulose biomass. The varieties RB72454, RB867515, RB92579, and SP813250 on the second stage of cutting, all grown in the state of Parana (PR), and the varieties RB92579 and SP813250 cultured in the PR state and in Northeastern Brazil, state of Pernambuco (PE), were analyzed using five EST-SSR primers for EstC66, EstC67, EstC68, EstC69, and EstC91 loci. Genetic divergence was evident in the EstC67 and EstC69 loci for β-amylase and cellulose synthase, respectively, among the four sugarcane varieties. An extremely high level of genetic differentiation was also detected in the EstC67 locus from the RB82579 and SP813250 varieties cultured in the PR and PE states. High polymorphism in SSR of the cellulose synthase locus may explain the high variability of substrates used in pretreatment and enzymatic hydrolysis processes, which has been an obstacle to effective industrial adaptations.