A new gene discovered that improves the yield and fertilizer use efficiency of cereal crops

Date posted: 07 September 2018

During the last 60 years fertilizers have become indispensable for increasing crop yield and supplying enough food for an ever increasing global population. However, the increased use of agro-chemicals has been shown to cause serious environmental, health and economic damage. A major new study ‘Modulating plant growth–metabolism coordination for sustainable agriculture’ published in Nature on August 30th 2018 reveals the discovery of a gene that improves the yield and fertilizer use efficiency of cereal crops such as wheat and rice.

Led by Professor Xiangdong Fu from the Chinese Academy of Sciences’ Institute of Genetics and Developmental Biology, and Professor Nicholas Harberd from the Department of Plant Sciences at the University of Oxford, part-funded by the BBSRC-Newton Rice Initiative, the study identified a novel natural gene variant that increases the rate at which plants incorporate nitrogen from the soil. The discovered gene variant increases the amount in plant cells of a protein called GRF4. GRF4 is a ‘gene transcription factor’ that stimulates the activity of other genes – genes that themselves promote nitrogen uptake and assimilation.

Professor Harberd said: ‘We discovered that GRF4 coordinates plant incorporation of nitrogen from the soil with the incorporation of carbon from the atmosphere. While such overall coordinators of plant metabolism have long been known to exist, their molecular identity had previously remained unknown, and our discovery is therefore a major advance in our understanding of how plants grow.’

This is a major breakthrough towards global sustainable agriculture goals, especially as much of today’s high yielding cereals are Green Revolution Varieties (GRVs) that require large amounts of fertiliser. Within these varieties the promotive metabolic coordinating activity of GRF4 is inhibited by a growth-repressing protein called DELLA. This inhibition reduces the ability of GRVs to incorporate nitrogen from the soil, and is the reason why farmers need to use high fertilizer levels to obtain high GRV yields. Research into GRF4 should therefore become a major priority in enhancing crop yield and fertilizer use efficiency for a sustainable food future.