Recently, Molecular Plant published an article titled "De novo Domestication: An Alternative Route toward New Crops for the Future" by Prof. Yan Jianbing at HZAU and Prof. Alisdair R. Fernie from Max Planck Institute of Molecular Plant Physiology. The article first reviewed the history of crop domestication, then presented severe challenges in current agricultural field and put forward the concepts of "Re-domestication" and "De novo domestication". In the end, it provided a perspective on how the combination of our current understanding of crop plant domestication and improvement could be harnessed in attempt to develop new crops, realize crop genetic improvement and address the conflict between agricultural production and human food demand.
Based on the idea of plant breeding, the two authors further extended their view to divide the history of domestication and improvement of crops into four generations, and pointed out that the progress of biotechnology and genome breeding technology combined with the mining of big data, genome editing and precision breeding opens the door to design breeding, which is expected to trigger the "third green revolution" in agriculture. The authors believed that in addition to the urgency of agricultural development caused by population growth, the main challenges for future agriculture include the sustainability of agricultural development, the tolerance of crops to environmental change or extreme environments, and the increasing need to bio-fortify the micronutrient content of our crops.
To address the above problems, the two authors proposed a solution of "re-domestication" of semi-domesticated crops and "De novo domestication" of new crops. The advantage of "re-domestication" is that semi-domesticated species which
have adapted to the planting environment can be used directly. And "De novo domestication" can be achieved through traditional techniques such as human selection and genome editing. Artificial selection needs in excess of 20 generations to change the phenotypes of wild or crop wild hybrids. In terms of some specific traits with less complicated gene basis, such process can be short. But there is a negative fact that harmful mutations in species will be conserved through the "carrying effect" via artificial selection during the process of "De novo domestication". In recent years, the booming gene editing technology has effectively solved "carrying effect" and contributed to the efficiency and precision of "De novo domestication". At present, there have been 3 cases of rapid improvement of wild species which evolved into culturable crops via gene editing technology.
The achievements in agriculture in the 20th century, especially the first green revolution, are of great significance to feed the world’s population. But at present, China's agricultural model of high input and high output has been facing more challenges. The process of crop domestication involves only a limited number of genes (for example, only about 1200 protein-coding genes are under selection in maize.) Therefore this opens up the possibility of knowledge-driven crop re-domestication or even de novo domestication.
This paper has also pointed out key steps to de novo domestication of new crops: determine candidate species, identify target genetic basis, transform wild plants to domesticate crops rapidly via gene editing, determine gene regulation and control of the target beneficial traits, apply genome editing and other techniques to achieve precise regulation of the target beneficial traits, and tailor crops with different beneficial traits to various demands.
Translator: Jiang Jingjing
Supervised by: Guo Haiyan
Source: http://news.hzau.edu.cn/2019/0505/54145.shtml
