Increasing temperatures brought about by climate change negatively affect crop productivity. To deal with the heat, plants use hormones to grow larger, developing a bigger surface area they can use to cool down. However, it has been unclear which hormones do plants use in this mechanism, and scientists at VIB-UGent Center for Plant Systems Biology are finding an answer to that question.
The plant hormone jasmonic acid plays an important 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's team, including Ph.D. 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."
By investigating the gene expression in Arabidopsis seedlings under different temperature conditions, the researchers find 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. The scientists analyzed the growth of wheat under warm temperatures and found the same mechanism at work.
(Source: Crop Biotech Update, International Service for Acquisition of Agri-Biotech Applications. www.isaaa.org)
