Bản tin ngày thứ hai 12-9-2022
Bản tin ngày thứ hai 12-9-2022
Bản tin số 1
Researchers Propose New Approach for Regulating Genetically Engineered Crops
Researchers, through a Policy Forum article published in Science, are calling for a new approach to regulating genetically engineered (GE) crops. The researchers argue that current approaches for triggering safety testing vary dramatically among countries and generally lack scientific merit, particularly as advances in crop breeding have blurred the lines between conventional breeding and genetic engineering.
The article asserts that a more effective framework would examine the specific new characteristics of the crop itself by using “-omics” approaches rather than focusing on the methods and processes behind the creation of a GE crop. Genomics can be used to scan new crop varieties for unexpected DNA changes, while additional “-omics” methods such as transcriptomicsproteomics, epigenomics, and metabolomics test for other changes to the molecular composition of plants. These methods can be used like a fingerprint to determine whether the product from a new variety is “substantially equivalent” to products already being produced by existing varieties.
Fred Gould, University Distinguished Professor at North Carolina State University and the corresponding author of the article said that the approaches used right now – which differ among governments – lack scientific rigor. “The size of the change made to a product and the origin of the DNA have little relationship with the results of that change; changing one base pair of DNA in a crop with 2.5 billion base pairs, like corn, can make a substantial difference,” he added. Gould also said that the “-omics” approaches, if used appropriately, would not increase the cost of regulation, as most new varieties would not trigger a need for regulation.
Bản tin số 2
Multigene Engineering for Sustainable Biotechnological Production of Saffron's Active Ingredient
Figure: The research team from King Abdullah University of Science and Technology has devised a method to produce saffron's active ingredient from the fruit of an ornamental plant popular in China, Gardenia jasminoides, shown here on the left. On the right is saffron, the world's most expensive spice. Photo Source: KAUST
Saffron, the most expensive spice in the world is obtained from the stigma of Crocus sativa flowers. To produce a kilogram of saffron, it takes 150,000–200,000 flowers. Researchers at the King Abdullah University of Science and Technology (KAUST) have found a way to use a common garden plant to produce crocins, saffron's active ingredient, a compound with important applications in the therapeutic and food industry.
The golden yellow to the reddish-brown color of saffron comes from crocins, water-soluble pigments derived from carotenoids by a process catalyzed by enzymes known as carotenoid cleavage dioxygenases (CCDs). Crocins have high therapeutic potential, protecting neural cells from degradation. They also have antidepressant, sedative, and antioxidant properties. Crocins are also important in the food industry as natural food colorants. Harvesting and processing hand-picked stigmas of saffron are very labor intensive. Moreover, saffron is only grown in limited areas of the Mediterranean and Asia, and new biotechnological approaches to produce these compounds in large amounts are in great demand.
Researchers at KAUST have identified a highly efficient CCD enzyme in the fruits of Gardenia jasminoides, an ornamental plant used in traditional Chinese medicine. G. jasminoides produces the crocin precursor crocetin dialdehyde. The researchers have now established a system for investigating CCD enzymatic activity in plants and developed a multigene engineering approach for sustainable biotechnological production of crocins in plant tissues. Xiongie Zheng, lead author of the study said their biotechnological approach can also be used on crops, such as rice, to develop crocin-rich functional food.
Team leader Salim Al-Babili says their study paves the way for efficient biotechnological production of crocins and other high-value compounds derived from carotenoids (apocarotenoids) as pharmaceuticals in green tissues as well as other starch-rich plant organs.
For more details, read the article in KAUST Discovery.
Bản tin khoa học
The brassinosteroid biosynthesis gene TaD11-2A controls grain size and its elite haplotype improves wheat grain yields
Theoretical and Applied Genetics August 2022; vol. 135: 2907–2923
Key message
TaD11-2A affects grain size and root length and its natural variations are associated with significant differences in yield-related traits in wheat.
Brassinosteroids (BRs) control many important agronomic traits and therefore the manipulation of BR components could improve crop productivity and performance. However, the potential effects of BR-related genes on yield-related traits and stress tolerance in wheat (Triticum aestivum L.) remain poorly understood. Here, we identified TaD11 genes in wheat (rice D11 orthologs) that encoded enzymes involved in BR biosynthesis. TaD11 genes were highly expressed in roots (Zadoks scale: Z11) and grains (Z75), while expression was significantly suppressed by exogenous BR (24-epiBL). Ectopic expression of TaD11-2A rescued the abnormal panicle structure and plant height (PH) of the clustered primary branch 1 (cpb1) mutant, and also increased endogenous BR levels, resulting in improved grain yields and grain quality in rice. The tad11-2a-1 mutant displayed dwarfism, smaller grains, sensitivity to 24-epiBL, and reduced endogenous BR contents. Natural variations in TaD11-2A were associated with significant differences in yield-related traits, including PH, grain width, 1000-grain weight, and grain yield per plant, and its favorable haplotype, TaD11-2A-HapI was subjected to positive selection during wheat breeding. Additionally, TaD11-2A influenced root length and salt tolerance in rice and wheat at seedling stages. These results indicated the important role of BR TaD11 biosynthetic genes in controlling grain size and root length, and also highlighted their potential in the molecular biological analysis of wheat.
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