Chinese scientists increase corn protein as food by successfully cloning a mutant gene in wild corn

Human ancestors began domesticating maize 9,000 years ago and gradually transformed the weed-like wild maize teosinte into what we have today. Source: The Paper

A couple of scientists in Shanghai have cloned a mutant gene in wild corn after 10 years of effort, dramatically increasing the protein content of corn. This study is not only beneficial for the genetic improvement of the protein content of modern corn kernels, but also has an important guiding significance for the reduction of fertilizer application and the protection of the ecological environment at the coming.

Wu Yongrui’s research team from Center of Excellence in Plant Molecular Science of Chinese Academy of Sciences and Wang Wenqin’s research team from Shanghai Normal University jointly published a research paper titled ” THP9 improves seed protein content and nitrogen use efficiency in maize” on Nature Thursday, noting that Teosinte High Protein 9 (THP9), a key variant of the gene controlling the formation of high protein quality and efficient nitrogen use in maize, has been successfully cloned from wild maize.

Since the domestication of maize by humans already 9,000 years ago, maize has become one of the most productive crops in the world, with an annual global production of 1.2 billion tons, of which 270 million tonnes in China, according to media reports. .

More than 70 percent of maize is used for animal feed, which is also the most commonly used and most important type of feed. However, the grain protein content of most hybrids is less than 8% due to the low grain protein content of common maize, so soy protein supplementation is often required in animal feeds.

However, China is heavily dependent on imports of soybeans, which has become a “bottleneck” problem in the country’s livestock and poultry industry. A 1 percentage point increase in the protein content of regular corn indicates that China can import almost 8 million tons less soybeans.

In this regard, increasing the protein content of maize is not only a strategic requirement to ensure national food security, but also one of the important ways to ensure the healthy development of livestock industry and poultry and animal feed manufacturing industry.

The mechanism of high protein formation in wild maize has been a long unsolved problem, as key genes to control total protein content and efficient nitrogen use in maize have not been found.

The two research teams began in 2012 to search for high-protein maize donor materials, protein content determination, genetic analysis and population construction, and reached an important experimental conclusion according to which wild maize contains key genes controlling high protein content.

The teams continuously created more than 10 generations of genetic material, extracted more than 40,000 DNA samples for genotype identification and determined the protein content of more than 20,000 samples for phenotype analysis, and finally cloned the first major gene THP9 controlling high protein content in maize.

The photo of Wu Yongrui’s research team working in a cornfield in Sanya, south China’s Hainan Province. Source: The Paper

In addition, the research teams conducted a large-scale field experiment in Sanya, Hainan province (southern China), to introduce the wild maize high-protein gene ThP9-T hybrid into Zheng Dan 958 maize production cultivar, which has the largest planting area in China. the country. It can significantly increase the protein content of hybrid seed, indicating that the gene has significant application potential in the cultivation of high-protein maize.

At present, the research results are moving from the laboratory to a wider application field, through cooperation with a breeding company in Anhui Province (East China), which actually could be commercialized, according to insiders.

world times