PennState University researchers used rice seedlings to show that the stress of hotter temperatures may trigger a response in a plant's ribonucleic acid (RNA), which is a part of a cells' genetic messaging system, to manage this change in its environment.

The researchers studied over 14,000 different RNAs to look for changes in the RNA. Thus, they searched for changes in RNA's intricately folded structures that could signal acute heat stress. Since RNA is single-stranded, unlike the double-stranded DNA, it is able to fold back on itself and form more complex folds than DNA. They exposed two-week old rice seedlings to above normal temperatures for just ten minutes and compared with the control plants.

Results showed that the folds in the RNA of plants suffering from heat stress were looser than those in the control plants. The unfolding of the mRNA, a particular type of RNA, which transfers DNA instructions to the ribosome in a cell during the protein-making process, was also found to be correlated with a loss in the abundance of mRNA, suggesting that mRNA unfolding promotes its degradation, a method that cells use to regulate which genes express and when.

According to one of the researchers, Philip Bevilacqua, the results give hints on next steps for future research into more heat and drought resistant crops.

"So, if loss of structure results in loss of abundance and if that loss of abundance is not optimal, then you could imagine that we could change the sequences of the ends of the RNA, making them more stable, and, therefore, stabilize the production of those proteins," he said.

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Figure: A new study used rice seedlings to demonstrate that the stress of hotter temperatures may trigger a response in a plant’s RNA to manage the change in its environment. Image: Peter Nguyen