14 March 2022 ESRFnews

Climate change is accelerating the flowering of many plants. Structural biology could help stop it.

SPRING 2021 sent a chill among French wine- makers. An intense frost descended on almost all vineyards in the country, including those in Bordeaux, Champagne and Languedoc-Roussillon, destroying an estimated 2bn of the year s harvest. The damage would not have been so bad, scientists noted, had the buds on the vines not broken so early in the season. If budbreak is getting earlier, a warming climate is to

blame, says Chloé Zubieta, a structural biologist at the Cell- ular and Plant Physiology Laboratory at CEA Grenoble. Climate change can really accelerate the growth of plants. They think it s later in the season, they flower earlier when they have less biomass, and produce less fruit. This is a worrying trend. It is particularly evident in a

horse chestnut in Geneva, Switzerland, that has been com- ing into leaf earlier and earlier in the season since official records began, over 200 years ago (see Evidence of early spring , p17). Scientists need to understand why plants are reacting to climate change in this way, especially if those plants are crops that humans depend on. But figuring out how, at a molecular level, plants respond to small changes in temperature has not been easy. It has long been known that, like humans, plants have circadian clocks that control their daily rhythms of photosynthesis and growth. Such rhythms can persist even when plants are isolated from daytime to night-time light changes, implying that they result from the intrinsic oscillations of clock genes encoded in certain proteins and protein complexes. It was only in 2011 that

scientists managed to identify a protein complex import- ant for integrating temperature signals into the plant circadian clock. Known as the evening complex, it helps to regulate growth in line with temperature in a model, small- flowering plant species, Arabidopsis thaliana. Exactly how it does this, however, was a mystery.

The structure STRUCTURAL BIOLOGY

In a warming world, we will need all the tools at our disposal to counteract the effects of climate change on crop plants