Scientists at the University of California Riverside (UC Riverside) have successfully decoded previously unknown signals that plants send to themselves to initiate photosynthesis. Led by UCR botany professor Meng Chen, the research team found four proteins containing building blocks that trigger photosynthesis.
Chen's team has previously shown that certain proteins in plant nuclei are activated by light, kicking off photosynthesis. The four newly identified proteins are part of that reaction, sending a signal that transforms small organs into chloroplasts, which generate growth-fueling sugars. Chen has compared the whole process of photosynthesis to a symphony. He said that “the conductors of the symphony are proteins in the nucleus called photoreceptors that respond to light." His team showed in their paper in Nature Communications that both red and blue light-sensitive photoreceptors initiate the symphony and activate genes that encode the building blocks of photosynthesis.
According to Chen, the unique situation, in this case, is that the symphony is performed in two “rooms” in the cell, by both local (nucleus) and remote musicians. The conductors (photoreceptors), who are present only in the nucleus, must send the remotely located musicians some messages over a distance. This last step is then controlled by the four recently-discovered proteins that travel from the nucleus to the chloroplasts.