Short answers, pulled from the story.
The LUX gene is a gene located on the third chromosome of Arabidopsis thaliana that codes for the LUX ARRHYTHMO protein. This protein is a critical component of the Evening Complex and regulates the plant's circadian rhythms.
Scientists at the Plant Gene Expression Center at the University of California, Berkeley sequenced the LUX gene in the year 2000. This sequencing effort revealed the gene's role in how plants measure time.
The LUX gene regulates plant growth by repressing the expression of Phytochrome Interacting Factor 4 and Phytochrome Interacting Factor 5 during the evening. Without functional LUX, plants exhibit an elongated hypocotyl phenotype due to unchecked growth at night.
When the LUX gene fails to function, Arabidopsis thaliana loses its ability to maintain circadian rhythms and enters a state of arrhythmia. This failure leads to an elongated hypocotyl phenotype and disrupts the natural balance required for healthy development.
The NOX gene, or BROTHER OF LUX ARRHYTHMO, is a paralog that binds to DNA sequences similar to those of LUX and interacts with ELF4. While LUX is essential for circadian rhythms, NOX is not strictly required for circadian rhythms but helps recruit the Evening Complex to promoters of PIF4 and PIF5.
Orthologs of the LUX gene have been discovered in Pisum sativum, Hordeum vulgare, and Chlamydomonas reinhardtii. These orthologs control similar circadian and flowering mechanisms across different plant species.