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.