When plants face biting cold, floods or parched soil, they can’t run away or seek shelter like animals. Instead, they have to develop ways to overcome and survive them until the weather improves.Some plants do this by putting a pause on productivity until the weather improves. In our recently published research, we discovered which genes control the “pause-and-play” mechanism of plant growth and are key for the survival of Canada’s crops.Our goal is to understand the genetic factors that control growth so they can eventually be used to improve the resilience of crops grown in Canada and around the world.A changing climate means extreme weather events are becoming more frequent. These findings could help create climate-resilient, genetically engineered crops that can recover faster and more efficiently after climate shocks.These plants might be more likely to complete their life cycle and produce food during the harvest season, even after experiencing snowstorms, heat waves or flooding.How plants respond to stressTo get an idea of how plants tolerate stress, we measured root growth under a series of environmental stresses that Canadian and globally relevant crops commonly face throughout their life cycles. These included cold temperatures, salt stress and drought-like conditions. For our first experiments, we used thale cress (Arabidopsis thaliana). A Brachypodium distachyon plant. (Neil Harris/University of Alberta), CC BY-SA Roots are particularly useful for this type of research because they grow continuously and respond quickly to environmental change. By measuring root length over time, we could see when growth slowed down and when it resumed. We tested the root length in model organism.We found that tested plants paused their root growth when exposed to cold or salt stress. When the stress was removed and the plants returned to normal growing conditions, root growth resumed as normal within about 24 hours.However, plants did not respond the same way to every type of stress. We found that plants can recover from osmotic or drought stress, but it takes a little longer for them to do so. We referred to that dynamic as “pause and push” because plants need time to push through and recover.To test whether the same stress response occurs in other plant species, we partnered with researchers from the United States Department of Agriculture. Together, we repeated the experiments using two wild grasses that are closely related to major cereal crops: brachypodium (Brachypodium distachyon) and annual ryegrass (Lolium multiflorum).The grasses showed similar patterns of stress response and recovery. That suggests the mechanism that pauses and restarts growth may be shared across many plant species.Pinpointing stress-recovery genesObserving these dynamics is one thing, but how can scientists figure out what’s going on at the genetic and molecular level?One common approach is to attach a fluorescent marker to genes of interest. Scientists often use a green fluorescent protein, originally discovered in jellyfish, that glows under specific light. When this protein is inserted into a plant genome, researchers can fuse it to a gene of interest to see when and where that gene becomes active as it lights up inside cells.We knew that the lack of growth during stress was due to a decrease in cell division, so we targeted genes related to cell division. Using fluorescent markers, we observed how the plant cells lit up differently in response to stress and stress recovery.After counting thousands of cells for months, we could see certain genes were present in fewer cells when plants were under cold, drought and salt stress. However, within about 24 hours of being put back into optimal growth conditions, their numbers returned to normal.One gene stood out in particular: Cyclin-dependent Kinase A;1 (CDKA;1). This gene helps regulate the cell cycle, the process that controls when cells divide and grow. A related gene named CDK1 exists in animals and humans, where it performs similar functions. After performing more experiments targeting CDKA;1 in plants, we found that inhibiting the gene prevented plants from recovering from cold and salt stress. This suggests CDKA;1 plays a vital role in helping plants resume growth once environmental conditions stabilize.Supporting food securityOur focus is on helping crops recover faster. We can’t stop heat waves or snowstorms. Pinpointing genes, however, can help plants recover from these events and still produce in time for harvest.Understanding these genes opens the door to new approaches in crop breeding. Researchers could look for natural variants of these genes that already exist in crop populations. Traditional breeding programs could then select for varieties that recover faster after stress.Another option is modern gene-editing tools such as CRISPR. This tool allows scientists to make precise changes to a plant’s DNA, including strengthening or adjusting genes involved in stress recovery.As our research progresses, we hope to adjust the genetics of these Canadian crop varieties and create our own CRISPR-edited lines that are better able to cope with a changing climate.Improving stress recovery could also expand where crops can be grown. Regions that currently experience unpredictable weather or short growing seasons may become more suitable for agriculture if crops can recover quickly after stress.For Canada, this could help stabilize production in areas where climate variability is increasing. For the global food system, it could make crops better equipped to handle the environmental uncertainty expected in the coming decades.By identifying the genes that allow plants to pause growth during stress and restart, we’re beginning to understand a critical survival strategy in plants. This knowledge can eventually help ensure crops continue to produce reliable harvests in a changing climate.The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.