Recently, scientists from the University of Bayreuth in Germany and the Max Planck Institute for Developmental Biology in Tubingen have developed a new type of sensor that can display the spatial distribution of auxin in plant cells in real time, and can quickly detect the effects of environmental changes on plants. The impact of growth. This sensor opens up a new perspective for researchers to observe the inner workings of plants. Related research results were published in the recent "Nature" magazine.

Whether it is the embryonic development of seeds, the growth of roots, or the response of plants to the direction of sunlight, auxin has the function of coordinating the response of plants to external stimuli. In order to trigger a response to external stimuli, it must be present in the desired tissues. So far, people have not been able to directly determine the spatial and temporal distribution of auxin at cell resolution.

This time, researchers have developed a new genetically encoded biosensor that can quantitatively visualize the distribution of auxin in plants. Its special feature is that it is a kind of artificial protein that plants can produce by themselves after modification, without having to be introduced externally. They used this sensor to observe in real time the dynamic process of the temporal and spatial distribution of auxin in tissues.

When developing this biosensor, the researchers discovered that there is a protein in E. coli that can couple with two fluorescent proteins, and fluorescence resonance energy transfer (FRET) occurs when these paired proteins are very close. This protein can bind to the amino acid tryptophan, but it binds auxin much worse. They hope that through genetic modification, it can better bind to auxin and make its FRET effect only occur when the protein binds to auxin.

Researchers have genetically modified plants to produce proteins that meet these requirements in cell tissues under certain stimuli. Thus, a new type of biosensor was born: a strong fluorescent signal indicates the location of auxin in the cell tissue, providing an accurate "snapshot" of the distribution of auxin in the cell, and will not permanently affect the auxin control process.

"The development of sensors is a long process. In this process, we have gained basic insights into how proteins can be selectively changed to bind specific small molecules." Biert Hart, Professor of Protein Design at Bayreuth University Ke said, "It is expected that in the next few years, new biosensors will discover more new insights into the inner workings of plants and their response to external stimuli."