Wednesday, December 17, 2008

さきみだれる = blue light + cryptochrome 2

We scientists have a special way to ruin a poetic or romantic moment. For example, we might be sitting in front of the most powerful sunset, and all that we can think of is Rayleigh scattering and how what we see is just the effect of the fourth power on the frequency factor.

And now another natural phenomenon might be ruined: 咲き乱れる (さきみだれる), for which we do not even have a proper translation — it took a Japanese haiku master to come up with such a concept.

Here is how the editors of Science summarize the paper by Liu et al. from the department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles:

Plants respond to light with a variety of developmental and physiological changes. The receptor for the blue-light wavelengths is cryptochrome. How blue light causes cryptochrome to alter cellular function has been a puzzle. Now, using a yeast two-hybrid screen, Liu et al. have identified a protein from Arabidopsis, CIB1, which, in the presence of blue light, interacts with the cryptochrome. CIB1 and cryptochrome colocalize in the plant cell nucleus, where CIB1 functions as a transcription factor. Together, these proteins bring the input of blue light into the signaling pathways that regulate flowering.

By the way, this cryptochrome mechanism is one of these tricks Nature is using over and over, in us humans too. CIB1, which is short for cryptochrome-interacting basic-helix-loop-helix, appears to affect primarily the amplitude, but not the period, of the circadian rhythm of the FT mRNA expression. Therefore, next time you complain about jet-lag, think the same mechanism also controls floral initiation and more poetically, 咲き乱れる.

Now, if we could only remember how to let a thousand flowers bloom in research labs!

Click this link to access the paper: Photoexcited CRY2 Interacts with CIB1 to Regulate Transcription and Floral Initiation in Arabidopsis.