With the advancement of socioeconomic conditions, China’s nutrition system has become increasingly robust, with related industries thriving and the overall nutritional health of the population continuously improving. Nevertheless, issues such as dietary energy deficiency, hidden hunger, and obesity still pose challenges to national health. As a staple crop, rice is rich in starch, protein, and a small amount of fat, with the aleurone layer containing vitamins, dietary fiber, and minerals. Breeding nutritionally enhanced rice varieties can increase the added value of rice and extend the rice industry chain, thereby meeting the basic need for sufficient food and the growing demand for quality nutrition. This effort represents a concrete practice of prioritizing “the health and safety of the people”. The conventional rice breeding team (the “Team”) at the Institute of Food Crops of the Jiangsu Academy of Agricultural Sciences (“JAAS”) has made a series of breakthroughs in the development of nutritionally enhanced rice varieties.
(1) Increasing Oleic Acid Content to Support the Rice Bran Oil Industry
Rice bran, the by-product removed during rice processing, is rich in fatty acids, amino acids, anthocyanins, and polyphenols. Rice bran oil extracted from it contains highly bioavailable nutrients such as fatty acid components, vitamin E, sterols, and γ-oryzanol, with an absorption rate of up to 90%. It also provides health benefits such as reducing blood cholesterol and lipid levels. Therefore, enhancing the nutritional profile of rice bran oil is of great significance to industrial development. The Fatty Acid Desaturase 2 (“FAD2”), located downstream of the oleic acid biosynthesis pathway, converts oleic acid into linoleic acid. The mutation of FAD2 blocks this conversion, thereby increasing oleic acid levels. Using CRISPR/Cas9 technology, the Team successfully developed japonica rice lines with significantly elevated oleic acid content, while maintaining stable agronomic traits. This study has laid a foundation for improving the quality of rice bran oil and the high-value utilization of rice by-products. The results were published in the Journal of Integrative Agriculture (Q1, CAS journal ranking). Master’s students Wu Yingying and Chen Zhihui, jointly trained by Jiangsu University and JAAS, are co-lead authors, with their supervisor Researcher Yang Jie as the corresponding author.
Original article:
https://www.sciencedirect.com/science/article/pii/S2095311925001224
(2) Enhancing Aleurone Layer Thickness to Improve Nutritional Quality of Rice Grains
The rice endosperm consists of the aleurone layer and the starchy endosperm. The starchy endosperm is rich in starchy carbohydrates, while the aleurone layer contains proteins, fatty acids, vitamins, dietary fiber, and trace elements. Targeting the ROS1 gene, this study applied base-editing technology in the background of Zhennuo 19, producing stable rice lines with increased aleurone layer thickness. The results indicated that the number of aleurone layers increased from 1-3 in the wild type to 3-5 layers. Concurrently, the contents of protein, fat, Zn, Ca, B1, B6, VC, and VE were significantly improved. This study has provided new insights into the nutritional quality improvement of rice grains and generated new genetic germplasms. The findings were published in Rice Science. Associate Researcher Xu Yang is the lead author, with Researcher Yang Jie as the corresponding author.
Original article: http://www.ricesci.org/EN/10.1016/j.rsci.2023.06.002
(3) Reducing Glutelin Content to Address Dietary Needs of Kidney Disease Patients
Glutelin, the main component of rice protein, is digestible by humans. However, patients with kidney dysfunction require low-protein diets. As early as 2000, the Japanese Journal of Nephrology published a research paper titled “The usefulness of low-glutelin rice in the dietary management of chronic renal failure during the maintenance phase (in Japanese: 保存期慢性腎臓不全の食事療法における低蛋白米の有用性)” findings on the dietary benefits of low glutelin content-1 (“LGC-1”) for patients with chronic kidney disease, showing reduced serum creatinine levels and slower disease progression. The Japanese variety LGC-1 and its derivatives contain approximately 3% glutelin, while clinical dietary needs call for even lower levels. Therefore, reducing glutelin levels while maintaining yield is a key objective in low-glutelin rice breeding. In this study, three CRISPR target sites were designed based on conserved sequences shared by members of the A and B subfamilies of rice glutelin synthesis genes. As a result, two low-glutelin rice lines were developed, each containing approximately 2% glutelin. Agronomic traits such as heading date, plant height, tillering, and grains per panicle showed no significant differences from the wild type. This study has demonstrated that gene editing can rapidly produce new low-glutelin rice germplasms tailored for kidney disease patients, offering a new approach to rice quality improvement. The results were published in the internationally renowned journal Plant Science. Chen Zhihui is the lead author, with Researcher Yang Jie, Professor Niu Hongbin (Henan Agricultural University), and Researcher Zhu Qian-hao (Commonwealth Scientific and Industrial Research Organisation [“CSIRO”], Australia) as corresponding authors.
Original article: https://doi.org/10.1016/j.plantsci.2022.111449
(4) Lowering the Glycemic Index (“GI”) of Rice to Lead the Trend in Healthy, High-Quality Rice
In China, diabetes ranks as the fourth most prevalent chronic disease among the elderly, affecting 116 million people. Approximately 100 million patients experience significant postprandial blood glucose fluctuations due to habitual consumption of conventional starchy staples. Additionally, younger generations are adopting low-GI diets for weight management. However, the lack of standardized and scientific GI assessment methods has led to inconsistent product quality. To meet the demands of this large consumer group, the Team has long focused on developing and selecting low-GI rice varieties. The variety Jiankang No. 1 features excellent palatability, meets top national quality standards, and has received both domestic and international low-GI certifications. To investigate the effects of “Jiankang No. 1” on postprandial blood glucose in patients with type 2 diabetes, the Team collaborated with Jing’an District Centre Hospital Affiliated with Fudan University to conduct a clinical human trial. The results showed that patients consuming Jiankang No. 1 had significantly lower postprandial peak glucose levels, time-in-range (“TIR”), and area under the curve (“AUC”) compared to those consuming regular white rice. The results confirm that “Jiankang No. 1” rice can help improve postprandial blood glucose control in patients with type 2 diabetes. The study was jointly carried out by the National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing of Jiangnan University, the Endocrinology Department of Jing’an District Centre Hospital Affiliated with Fudan University, China National Research Institute of Food and Fermentation Industries Co., Ltd., and Jiangnan Midao Jiangsu Technology Co., Ltd. and was published in Shanghai Medical & Pharmaceutical Journal, with Researcher Yang Jie as co-corresponding author. To date, the Team has applied for one new plant variety right and published four papers related to the development of new low-GI materials, the establishment of in vitro digestion rate testing methods, and the review of the latest advancements in low-GI rice research.
Additionally, the Team initiated and co-developed the association standard Paddy with low glycemic index with Jiangnan University, Jiangnan Midao Jiangsu Technology Co., Ltd., and Nanjing Agricultural University. The standard has passed technical review by agricultural societies in Jiangsu, Anhui, and Fujian Provinces and is currently being revised based on expert feedback.
Original article:
https://kns.cnki.net/kcms2/article/abstract?v=5hcLxvuG7Q5VQp1rOopycmiOqkUf7aF4_J6AQZ8m_qRDY165jR7H4x5hm0l2MZEBGvZXrRnjX-8nHpiT8DTmCEqV83pKQFHqwZTo_46KzLl0gw5VgyiNTjNhKKrU8D_1PQ6q-Ufnrf2LAuEgPBFKEA-Uwd_YXkjzuUXrD_nOzEwO8YdIEgNBDg==&uniplatform=NZKPT&language=CHS
