Overview

About 43.8% of the world's population live on rice, mainly in East Asia, Southeast Asia and South Asia. However, the protein content of rice as a major grain crop is lower than that of soybean, and the content of lysine, threonine and tryptophan is lower. As the first essential amino acid, lysine is not only the basis of protein synthesis, but also the precursor of ketogenic amino acids and carnitine. When lacking energy, lysine synthesizes ketone bodies and participates in β - oxidation of fatty acids, and can also promote the human body to fully absorb other amino acids and nutrients. Who recommends that the lysine content of grain should reach 5.5%. Lysine deficiency will affect the growth and development of human body, especially children, and cause protein energy malnutrition (PEM).

Our Project

Our project aims to improve the protein content of rice and create high protein rice. Therefore, the polyploidization of rice should be carried out first to transform diploid rice into tetraploid, so as to achieve the overall improvement of protein content. The next step is to improve the high-quality protein in rice. Therefore, the targeted editing of gluten gene by gene editing can improve the lysine content and improve the nutritional value of rice. Because many studies have shown that globulin in rice has high allergenicity, considering the food safety problem, we should reduce the proportion of globulin to ensure food safety on the basis of increasing the protein content.

Products and Applications

We first constructed a pYLCRISPR /Cas9 multi-target vector for site directed mutagenesis of OsGluB1 and OsGlb, thereby gene editing our experimental rice. The empty vector and construction method of this vector were obtained from a paper published by the liuyaoguang research group of the College of life sciences, South China Agricultural University.
Our rice knocked out gluten and globulin through CRISPR/Cas9 gene editing technology, and screened double gene mutant plants that meet our requirements and have good quality. Since then, rice with higher protein content and lysine content than ordinary rice has been produced, and its allergenicity will be reduced.
People in developed countries and regions usually take measures to take these essential amino acids from diverse foods to meet the needs of human growth, while in some less developed countries and regions, there are no more diversified foods for them to choose from, and they will be relatively more dependent on the nutritional components in grains. Further increasing the lysine content and total protein content of rice will be more conducive to improving the nutrition of daily staple foods and alleviating some malnutrition problems for people in these less developed countries and regions.

Our Challenge

1. Public acceptance is not high. The public's attitude towards increasing lysine in rice is relatively negative. They doubt the necessity of doing so, so we need to invest more to let the public understand the importance of staple food nutrition.
2. As a breeding project, we should not only focus on a few traits related to protein nutritional quality changed in rice after gene editing. We should pay more attention to more indicators to optimize our project, which will take more time.
3. In China, gene editing has relevant control laws and regulations. Before commercial application, safety data and materials need to be submitted to relevant departments for review according to the requirements of regulations.

Legal Analysis

This project involves polyploidization and gene editing of plants. In terms of regulations and policies, according to the guidelines for safety evaluation of genetically edited plants for agriculture (Trial) formulated and published by the Ministry of agriculture and rural areas of the People'sRepublic ofChina, Article 2 of which has very clear requirements for molecular characteristics and genetic stability related to gene editing. First, we need relevant information about target genes. We need to master the structure, function and metabolic pathway of target genes in detail and comprehensively evaluate the impact of target gene modification on safety from all aspects. Secondly, relevant information about gene editing methods is needed. After that, we need to provide the situation after target gene editing, and also need to analyze the situation of vector sequence residue and gene editing off target. In terms of genetic stability, first of all, we should detect the stability of target gene editing and provide experimental data of no less than three generations. Secondly, we should provide not less than three generations of experimental data to investigate the stability of the target traits we need, as well as analysis data or traits that do not increase environmental and food safety risks. In addition, according to Article 13 of the regulations on the safety management of agricultural genetically modified organisms issued by the People'sRepublic ofChina, agricultural genetically modified organisms test should generally go through three stages: intermediate test, environmental release and productive test. It shows that before our project is transformed into industrialization, we should carry out small-scale test under controlled conditions, medium-scale test under natural conditions and large-scale test. We should choose different sites for field test to ensure that our project is pollution-free and safe to the environment