Tag: Plants and light

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How did we work out that UVR8 is a solar-UV-B plus UV-A photoreceptor?

What were our findings?

We reported in two recent research papers and an update review, that functional UVR8 is required for the perception by plants of solar UV-radiation with wavelengths shorter than approximately 340 nm, which includes the whole UV-B band plus the shorter wavelengths in the UV-A band. In sunlight, cryptochromes are required for the perception by plants of blue light and the longer wavelengths within the UV-A band leading to changes in gene expression. In sunlight cryptochrome-mediated signalling is driven mostly by violet and blue light with wavelength longer than 400 nm. In comparison wavelengths between 350 nm and 400 nm of solar radiation seem to play only a minor role in the regulation of gene expression.

This is an important step forward in our understanding of the perception of different wavelengths of sunlight by plants as the former accepted view was that UVR8 is a UV-B photoreceptor that participated only in the perception of UV-B radiation while all wavelengths of UV-A radiation were perceived by cryptochromes and the other UV-A/Blue photoreceptors, phototropins and ZTL.

Continue reading “How did we work out that UVR8 is a solar-UV-B plus UV-A photoreceptor?”

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Brighter times for our growth chambers

The latest LEDs from Nichia and other suppliers are game changers. I designed a replacement light source for our Aralab Fitoclima 1200 growth chambers and Nikolai Belevich (Biotechnology Institute) assembled a prototype before the start of the pandemic. This post was written time ago, but I am publishing it now that the final design of the light sources is ready for use after extensive testing. Nikolai Belevich also assembled the six light boxes for three growth chambers based on the final design, to which he also contributed.

In this post I briefly describe the prototype and some of the steps that led to the final design. I also discuss how the latest LED components, icnluding some specifically designed for horticulture, have qualitatively changed lighting possibilities in growth chambers and rooms.

Continue reading “Brighter times for our growth chambers”

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Measuring campaign in the Alps

I joined a field measuring campaign organized by my collaborator T. Matthew Robson (see Matt’s CanSEE website for information on the research project) with the participation of José Ignacio García Plazaola and Beatriz Fernandez-Marin from the University of the Basque-Country.

Matthew described the aim of our work as:

By characterising the patterns of response to UV radiation in terms of the photoprotection and UV-screening of plants across a diversity of species, we hope to better understand how and why these response evolved and what environmental cues underpin their induction.

We spent the last weeks of May the at 2100 m a.s.l. in the Alps at the Jardin Botanique du Lautaret measuring solar radiation and the responses of plants to it. I did some measurements of solar radiation but spent most of the time photographing plants and lichens to record their optical properties in the ultraviolet-A, visible and near-infrared regions of the spectrum.

Villar-d’Arêne, French Alps, 2100 m a.s.l.

Several of the photographs I took of site, crew, plants and lichens available at my photography website in a post published earlier today (as I have the server set up for easy creation of galleries). These photographs are stored at Flickr.

Matthew has also written a post about the trip and project in his blog.

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Two book preprints

We have published two books through Leanpub. They are not yet 100% complete but they are available for download.

R for Photobiology: Theory and recipes for common calculations

https://leanpub.com/r4photobiology

Cover image.
Cover of the book “R for Photobiology”.

This handbook describes how to use R as a tool for doing calculations related to research in photobiology. Photobiology is the branch of science that studies the interactions of living organisms with visible and ultraviolet radiation. The most frequently used calculations are related to the characterization of radiation and of the responses of organisms to radiation. Many of these calculations are also used in Biophysics, Meteorology and Geophysics.

Learn R …as you learnt your mother tongue

https://leanpub.com/learnr

Book cover
Cover of the book

Learn the R language as a child would: Do not struggle, just play! If going gets difficult and frustrating, take a break! If you get a new insight, take abreak to enjoy the victory!