Scientists develop biofortified rice to fight nutritional deficiencies

The UNIGE team, in collaboration with ETH Zurich and Taiwan’s NCHU, developed a rice strain enriched with vitamin B1 content.

Vitamin B1 is an essential micronutrient for humans. Its deficiency is the cause of many diseases of the nervous and cardiovascular systems. Researchers at the University of Geneva (UNIGE), in collaboration with teams from ETH Zurich and Taiwan’s National Chung Hsing University (NCHU), have made major advances in the fight against vitamin B1 deficiency, often associated with rice-based diets. I accomplished it.

By specifically targeting the vegetative tissues of rice grains, scientists were able to significantly increase vitamin B1 content without compromising agronomic yield. These results are Plant Biotechnology Journalcould help solve major public health problems in areas where rice is a staple food.

Most vitamins cannot be produced by the human body and must be obtained from the diet. Changing your diet usually covers your vitamin needs. However, deficiencies are common in populations where grains such as rice are the main or only food source. This is especially true for vitamin B1 (thiamine), whose deficiency is the cause of many neurological and cardiovascular diseases, such as beriberi.

Vitamin B1 contained in rice is lost during processing

Rice is a staple crop for half of the world’s population, especially in tropical countries of Asia, South America, and Africa. Rice grains contain little vitamin B1, and processing processes such as rice milling (grinding the outer layer to remove the bran) further reduce vitamin B1, resulting in 90% of it being ingested along with vitamin B1. Therefore, this habit further exacerbates chronic deficiencies.

Teresa Fitzpatrick’s laboratory, a full professor in the Department of Plant Sciences at UNIGE’s Faculty of Science, specializes in vitamin biosynthesis and degradation pathways in plants. Her group is collaborating with teams at ETH Zurich and NCHU in Taiwan to improve the vitamin B1 content of rice endosperm, the nutritional tissue that makes up the bulk of the seed and therefore the bulk of what you eat. focused on.

“Previous biofortification efforts by other teams have succeeded in increasing the vitamin B1 content of leaves and bran (the outer layer of rice grains), but the vitamin B1 content of ready-to-eat rice grains has not increased. “In our study, specifically, it was an increase in vitamin B1 content in the endosperm,” explains Teresa Fitzpatrick, lead author of the study.

The researchers generated a rice line that expresses a gene that sequesters vitamin B1 in endosperm tissue in a controlled manner. When grown in greenhouses, harvested and milled, the rice grains from these lines were found to have increased vitamin B1 content.

Promising experimental crops

This line was then sown in an experimental field in Taiwan and cultivated for several years. From an agronomic point of view, the analyzed traits were the same for both modified and unmodified rice. Plant height, number of stems per plant, grain weight, and fertility were all comparable.

On the other hand, in improved lines, the amount of vitamin B1 in the rice grains after the milling stage is increased by 3 to 4 times. Therefore, this modification allows accumulation of vitamin B1 without affecting yield.

“Most studies of this kind are done using crops grown in glasshouses. The fact that it is stable over a long period of time without affecting its chemical properties is very promising,” said Wilhelm Gruissem, Professor Emeritus at ETH Zurich and Distinguished Professor and Jade Mountain Fellow at NCHU. .

300 grams of rice made from this crop provides about one-third of the recommended daily intake of vitamin B1 for adults. The next step towards the goal of biofortified plants containing vitamin B1 is to pursue this approach in commercial varieties. However, before these plants can be cultivated, regulatory measures regarding biofortification through genetic engineering must be taken.