Scientists from Embrapa Agroenergia in Brazil have developed a non-transgenic CRISPR edited sugarcane.The edited sugarcane varieties are called Cana Flex I and Cana Flex II. The respective distinctive features are easier cell wall digestibility and higher sucrose concentration in plant tissues.
The edited plants are considered non-transgenic, or DNA-Free, according to Normative Resolution No. 16 (RN No. 16) of the National Biosafety Technical Commission (CTNBio), issued on 12/9/2021. Both developments used the CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats), a “Nobel prized” and revolutionary gene manipulation technique discovered in 2012.
They respond to one of the biggest scientific challenges in the sugar cane sector: easy enzyme’s access into sugars trapped in cells, which facilitates ethanol production (first and second generation), and better extraction of other bioproducts.
In the case of Cana Flex I, the CRISPR technique silenced the gene responsible for the rigidity of the plant cell wall, in order to increase its “digestibility”. This means the enzymatic hydrolysis process – a chemical process that extracts compounds from plant biomass – is more efficient.
Cana Flex II: more sucrose
The second variety, Cana Flex II, was created by silencing a gene in the sugarcane tissue. As a result, the researchers achieved a considerable increase in sucrose production in the plant stems.
“Once we had found that characteristic of sugar accumulation, we transferred this knowledge to the sugarcane crop, which is the target of our research”, explains Embrapa researcher Hugo Molinari. According to him, they observed 15% more sucrose in the sugarcane stalk and a increase of 200% in the leaves. The study also identified a higher concentration of other sugars, such as glucose and fructose, both in juice and plant tissue.
“We also carried out tests to see if the gene had an effect on improving saccharification, which is the conversion of cellulose into industrial sugar. Once again, we observed an increase of around 12%”, Molinari said.
According to Molinari the main advantages of Cana Flex II are higher efficiency in bioethanol production, better varieties for industrial purposes, greater digestibility for animal feed and more value added for the sector as a whole.
“In 2020/2021, the world´s total production of sugar was 188 million tonnes, with Brazil being responsible for 39 million tons, equivalent to 21% of the global sugar production”, says Molinari.
He also said sugarcane cultivation can contribute to a cleaner energy matrix. “Today we know more than 45% of the Brazilian energy matrix is renewable and sugarcane contributes 30% to these renewable sources”, Molinari said.