As climate change accelerates, we’re going to be under pressure to learn things in the lab and move them into the field faster. I can’t see how we’re going to do this without more acceptance of genetically modified plants.– Marc Nishimura, plant immunity researcher, Colorado State University Scientists have long been trying to understand why plants become more vulnerable to disease when temperatures rise. While relevant research is ongoing, a group of researchers from universities around the world sought ways to restore the plants’ ability to defend against pathogens in hot weather. “Plants get a lot more infections at warm temperatures because their level of basal immunity is down,” said Sheng-Yang He, a plant biologist at Duke University who led the research team. “So we wanted to know, how do plants feel the heat? And can we actually fix it to make plants heat-resilient?” The study, published in Nature, focused on Arabidopsis thaliana, an unassuming weed widely known as the mouse-ear cress, considered the ‘lab rat of plants’ by plant biologists. Arabidopsis thaliana thrives on roadsides, open paths and vacant lots and is used in experiments worldwide due to its short life cycle and short and easy-to-modify genome. The scientists said the main defense hormone of Arabidopsis thaliana is salicylic acid, which is used by many plants, including major crops, to resist disease. However, the production of salicylic acid can be disrupted when temperatures rise a few degrees. “Extreme weather conditions associated with climate change affect many aspects of plant and animal life, including the response to infectious diseases,” the researchers wrote. “Production of salicylic acid, a central plant defense hormone, is particularly vulnerable to suppression by short periods of hot weather above the normal plant growth temperature range via an unknown mechanism.” After years of lab work, the researchers isolated the CBP60g gene, which can withhold the production of the salicylic acid hormone in plants when temperatures rise, neutralizing their defense mechanism. The solution genetically bypassed the gene to restore the plant’s defense at hotter temperatures. “This was a multi-year and multi-institutional effort,” Christian Danve Castroverde, a biologist at the Wilfrid Laurier University in Canada and co-author of the study, told Olive Oil Times. “In 2013, [we] discovered that short periods of high temperature dramatically impact the hormone defenses of Arabidopsis plants against infection by a bacterium called Pseudomonas syringae,” he added. “After several more years, we were eventually successful in identifying the molecular basis of how Arabidopsis immunity is suppressed by warm temperature conditions.” The researchers bypassed the gene in the lab by adding a ‘promoter.’ The short DNA sequence forces the gene to transcribe (copy the DNA sequence into an RNA molecule), restoring Arabidopsis thaliana’s ability to produce the salicylic acid hormone. “Including the salicylic acid receptor and biosynthetic genes, optimized CBP60g expression was sufficient to broadly restore salicylic acid production, basal immunity and effector-triggered immunity at the elevated growth temperature without significant growth trade-offs,” the researchers wrote. The team has started testing gene modification on food crops such as rapeseed. They also plan to experiment with more crops, including wheat and potatoes. However, Castroverde said a significant amount of field research is required before applying the fix at a large scale. “Many plants have CBP60g-like genes, and a lot of them have the capacity to make salicylic acid,” he said. “It looks like plants already have a weapon in their arsenal. Our challenge now is just harnessing this power. In terms of agricultural applications, I believe we have to wait until we have successful results in field trials.” Nevertheless, the specific solution proposed by the research team to restore the plant immune system ...