Chinese researchers have discovered a gene that allows plants to thrive in saline soil and have used this finding to create modified sorghum and rice plants that increase yields by at least 20% and produce more nutrients. According to the researchers, these findings could help combat the global salinization trend driven by climate change, overuse of fertilizers and increasing freshwater shortages.
The study, led by Professor Xie Qi of the Institute of Genetics and Developmental Biology of the Chinese Academy of Sciences, Professor Yu Feifei of the Agricultural University of China, and Professor Ouyang Yidan of the Huazhong Agricultural University, was published in the journal Science on Friday.
Most of the studies have been done on saline soils, which can also be alkaline. Yu described the new work as "filling the gap" in that salty soil contains sodium chloride and sodium sulfate, and alkaline soils both have vastly different properties, as sodium carbonate and sodium bicarbonate dominate.
Despite salinity tolerance, alkalinity tolerance in plants has not been extensively studied.
The initial focus of the study was the sorghum plant, which is native to Central Africa and was developed to be more tolerant of sodium-rich soils.
Genome-wide association studies (GWAS), a laborious statistical technique that analyzes the entire genome of individual plants to look for links between millions of genetic variants and specific traits, were used to kickstart the team's work.
After looking at more than 352 representative sorghum accessions, the team discovered a gene locus called Alkaline tolerance 1 (AT1) that was linked to desirable traits.
High alkalinity causes plants to exhibit stress-related behaviors in which harmful compounds accumulate, oxidize and ultimately kill cells.
But the AT1 gene encodes a unique G protein that can stop plant cells from secreting harmful compounds.
“We are further investigating the molecular mechanism behind tolerance based on the GWAS data. According to Yu, the chemical reaction in the products must be different, as saline soil and sodic soil cause different patterns in the products.
“By disabling AT1 or replacing it with another non-functional component, we stimulated the plant's protective response to stress brought on by alkaline conditions. With this method, sorghum yield and survival rates were improved in sodic soils.
Based on this information, the team genetically modified AT1 relatives in other crops such as rice, maize and millet.
The method increased the grain yield of sorghum and millet by 20% in field tests on very alkaline soils in Pingluo, Ningxia region in northwest China. In a study on soils like this one in Daan, Jilin, annual rice yields increased by 20 to 30%.
According to Yu, crops grown in saline-alkaline soils have a longer growth cycle and receive more nutrients, which enhances their flavor.
The effort put into this research is enormous; Some of the studies on the stress tolerance of sorghum were initiated by Professor Xie's team as early as 2014. Most of our recent efforts have required data validation for sorghum, rice, millet and maize. In the future, we can apply this principle to other plants, such as beans and potatoes.
The Institute of Genetic and Developmental Biology reported on Friday that 618 million hectares worldwide have been damaged by salinization.
According to the report, if this technique is used in low-salt-alkaline soils, which make up 20%, by 2022 half of the US grain supply could be produced annually.
Source: scmp.com/news/china/science
📩 26/03/2023 11:48