06/14/2018 11h11

Unicamp research makes way for sugarcane with higher sugar content

Valor Econômico

Stagnant for years, sugarcane productivity may take off after new scientific breakthrough. A team led by researcher Anete Pereira de Souza, from the Institute of Biology at Unicamp, after using an innovative technique discovered in which part of the genetic code of the plant is the gene fragment responsible for the production of sugar. The discovery will enable improvements and genetic modifications that increase sugarcane’s capacity to produce sucrose, but the technique can also be used, for example, to create pest-resistant varieties of sugarcane.

Reaching this group of genes would not have been an easy task if the research had used the genome sequencing technique. That is because sugarcane has a very complex genome, with a number of homologous chromosomes that can reach 14. Research institutions in the country have sought to decode the entire genome of sugarcane, yet without success.

The discovery was only possible because the researcher decided to use a plant that had a similar genotype to that of sugarcane, sorghum, as a “model” to locate the sugar gene. “We analyzed the sorghum in the region where there are genes that increase sugar production. There are genes [in sorghum] that contribute to the increase of sugar that have already been studied at least 10 years ago. With that, we looked for these regions in the sugarcane genome,” she explained.

The search for these fragments in the sugarcane genome, in turn, was only possible because the team of researchers had at hand a bank of fragments of the entire sugarcane genome, which had been built with the collaboration of research programs, such as the Interuniversity Network for the Development of the Sugarcane Industry (Ridesa). The research conducted by Unicamp’s team was funded by Fapesp, CNPq and Capes.

“We looked for in our bank the fragments of genes that had these pieces, such as the one of the sorghum. We recovered, sequenced, and saw a region with more than 1 million bases that has genes very similar to that of sorghum,” he said.

This path, called “genomic selection”, represents a “shortcut” for genetic research with sugarcane, since the sorghum genome has been extensively studied and can be used to discover genes responsible for other characteristics of sugarcane, such as resistance to pests, at high temperatures, or to the formation of fibers.

Anete says that using the genomic selection will make it possible to conduct a genetic improvement program for six or five years. “The classic in sugarcane research is 12 years,” she said. Reducing research time means allowing for genetic improvements faster, which may anticipate the increase in sugar and ethanol production, she added.

The genomic selection technique started being used in plants in research studies in other countries between 2014 and 2015. In Brazil, this is the first genetic research that uses the methodology, and it can also be used for other species, such as pastures and rubber trees, for example.

However, the researcher stressed that only this technique “will not revolutionize the yield of sugarcane alone”, since this also depends on the field research and the search for better genetic profiles.