Researchers at Martin Luther University Halle-Wittenberg (MLU) have identified two genes that are key to how plants know when to flower. The researchers were able to show that the ELF3 and GI genes control the internal clock of plants that monitors the length of daylight and determine when it is the right time to flower.
In this study, the MLU research team wanted to understand which genes control a plant's internal clock, thereby influencing the flowering process. They did this by investigating two genes that were already known to play a crucial role in the circadian clock: ELF3 and GI. The two genes have been studied separately, but the researchers wanted to understand how they work together and how they jointly influence the circadian clock, for example by regulating when a plant flowers.
The team investigated how the two genes functioned in Arabidopsis thaliana. The scientists bred plants with various genetic defects. In one group, the ELF3 gene was defective, in the second group it was the GI gene. In the third group, both genes were switched off. The researchers then observed how the plants reacted to different periods of light and found that when one of the two genes was defective, the plants' circadian clock still functioned on a rudimentary basis. When both genes were switched off, the plant does not react at all. "The plants could still perceive the light, but they could no longer tell how long the light lasted. This explains why the mutants with the double gene defect produced flowers at the same time under different lengths of light period," says Dr. Usman Anwer from the Institute for Agricultural and Nutritional Sciences at MLU.