How plants grow more to deal with heat

(10-08-2021) To cope with heat, plants grow larger. This gives them more surface area they can use to cool off. Plant hormones are involved in this process. Researchers from the VIB-UGent Center for Plant Systems Biology), elucidate the role of jasmonic acid.

Plants grow larger in order to cope with heath. This gives them more surface area they can use to cool off. We already knew that plant hormones are involved in this process, but their precise contributions remain mysterious. Now, researchers from the team of Ive De Smet (VIB-UGent Center for Plant Systems Biology), with colleagues from the University of Göttingen (Göttingen, Germany), the China Agricultural University (Beijing, China), and the Pushchino Scientific Center for Biological Research (Pushchino, Russia) elucidate the role of jasmonic acid. Their work appears in Nature Communications.

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Climate change results in increases in average temperatures. This negatively affects the productivity of crops. To handle the heat, plants use plant hormones to grow larger. In doing so, they develop a larger surface area that they can use to cool down. But it is not yet clear which of these plant hormones contribute and how they do so.

One specific plant hormone, jasmonic acid, plays a vital role in various stress responses, including wound response, cold, and heat stress. Does it also play a role in the heat-induced growth of plants?

Prof. Ive De Smet (VIB-UGent Center for Plant Systems Biology) and his team set themselves to the task of finding an answer to that question.

PhD student Tingting Zhu, first author of the study, says: "Our starting point was previously published data on the proteins affected in wheat seedlings exposed to high temperatures. To explore if jasmonate signaling indeed plays a role in the growth in response to warmer temperatures, we used both Arabidopsis and wheat as model plants."

Gene expression

By investigating the gene expression in Arabidopsis seedlings under different temperature conditions, the researchers show that this leads to an increased expression of the genes JOXs and ST2a. These genes control the breakdown of jasmonic acid, which normally stops growth. As the temperature rises, so does the activity of these two genes. In turn, this lowers the level of jasmonic acid, and lower jasmonic acid means more growth.

Finally, the scientists analyzed the growth under warm temperatures in wheat, a staple crop. They found the same mechanism at work.

Ive De Smet frames their finding: "A broader understanding of the conserved role of jasmonate signalling when plants are exposed to low or high temperatures contributes to ensuring food security under a changing climate."

Contact

Prof Ive DE SMET
VIB-Ghent University Center for Plant Systems Biology
ive.desmet@ugent.be
@IveDeSmet1978

Publication

Warm temperature triggers JOX and ST2A-mediated jasmonate catabolism to promote plant growth. Zhu et al. Nature Communications 2021

Funding

T.Z. is supported by a grant from the Chinese Scholarship Council, I.F. acknowledges funding through the German Research Foundation (DFG, INST 186/822-1) and A.G acknowledges funding from the Research Foundation – Flanders (FWO G008417N).