In strong sunlight, plants give off excess energy as heat to prevent damage, but when the light dims they are slow to switch off this process, reducing photosynthesis. Now researchers have shown that increasing the pace at which plants resume full photosynthesis can boost their yields by about 15%.
Stephen Long of the University of Illinois in Urbana, Krishna Niyogi of the University of California, Berkeley, and their colleagues engineered tobacco plants (Nicotiana tabacum) by increasing the expression of three genes involved in protecting plants from bright light — PsbS, VDE and ZEP. They found that photosynthesis recovered more quickly under fluctuating light conditions than in unengineered plants. The dry weight of engineered plants grown in the field was 14–20% higher than that of normal plants.
This could be a way to increase the productivity of food crops, the authors say.