Research Team Presents Circadian Clock Insights that Could be Key to Increased Wheat Yield

Research conducted by scientists at Earlham Institute and John Innes Centre reveals the multiple ways in which the wheat circadian clock maintains balance. Published in PLOS Biology, this work is the first to gauge the role of circadian rhythms across the entire genome of polyploid wheat.

The circadian clock is a finely balanced time-keeping mechanism that guides organisms through day and night, as well as changes in seasons. The accuracy of this clock affects a plant's health and productivity. In model plants, the circadian clock controls genes that influence pest resistance, water use, cold and heat tolerance, nitrogen efficiency, and photosynthetic yields. The researchers wanted to see whether the same was true in wheat.

Dr. Hannah Rees, the lead author of the study, said that understanding how the circadian clock works in wheat is tricky because the wheat grown today is the result of three wheat species merging into one. The researchers generated a high-resolution dataset to investigate the circadian balance between sets of three homoeologous genes - known as triads - from the hexaploid bread wheat. Gene expression was mapped out at regular intervals and under different light conditions to mimic the rising and setting sun.

They found that around 30 percent of the genes in wheat were regulated in some way by circadian rhythms, including genes responsible for regulating photosynthesis, starch metabolism, heat and cold resistance, and even marshaling biological defenses to attacks from plant pests. The researchers also found widespread activity between competing genes and said that circadian balance is not always necessarily a good thing. While maintaining similar expression seems to be important for some sets of genes, other sets appear to be given the freedom to experiment and potentially do new things.

For more details, read the article on the Earlham Institute website.