What Mustard Can Tell Us About Climate Change

Dec 07, 2016

How well could native California plants withstand increasing temperatures in a warming climate? Using the state’s native wild mustard plant as a model organism, new research led by scientists at San Diego State University and Siena College aims to answer that question. The study contributes to the growing body of research aimed at better understanding the effects of global climate change and heat stress on our ability to grow plants for food.

Thermotolerance, the ability of an organism to withstand heat, is a particularly important trait in plants as they are fixed in place and cannot move to cooler locations. Tolerance to external stresses such as cold, salt, or heat can have significant impacts on plant productivity and plant biogeography. Global climate change and the resulting increase in temperatures will have a substantial impact on both crop productivity and the survival of wild plant species, but very few specifics are known about how wild plants respond to high-temperature stress.

In a study published today in the journal Botany, the researchers looked at members of the Boechera genus, which includes more than 100 species of plants in the mustard family. The Boechera genus is restricted to North America, mostly west of the Rocky Mountains. Growing these species under a variety of controlled conditions, researchers found that Boechera is more thermotolerant than A. thaliana, a small, flowering plant that is native to Eurasia and is typically used in botanical research. Researchers also found that within various Boechera species, there are considerable differences when it comes to how well they tolerate heat.

“Our study highlights that there is considerable natural variation for thermotolerance and heat shock gene expression in wild plants,” said SDSU botanist Elizabeth Waters. “As our climate warms, it becomes crucial that we further develop our understanding of plant responses to high temperatures and have a clear understanding of the strategies that contribute to thermotolerance. Our study shows that there is considerable natural variation in how plants respond to temperature stress.”

The study also concludes that Boechera makes for a good model organism to further study thermotolerance, which will provide valuable insights into how thermotolerance works in plants.

“Continued studies of this interesting native California species should provide important insights into how plants acquire thermotolerance and protect photosynthesis from heat stress,” Waters added.

This work is an important contribution to both identifying the plants that are at the highest risk in a warming climate and also those that have the capacity to withstand high temperatures, the researchers noted. With this knowledge, scientists can further their understanding of heat tolerance with the goal of improving crops that lack the ability to withstand high temperature stress.

Source: sdsu.edu

Video: Why Your Food Future Could be Trapped in a Seed Morgue

In a world of PowerPoint overload, Rex Bernardo stands out. No bullet points. No charts. No jargon. Just stories and photographs. At this year’s National Association for Plant Breeding conference on the Big Island of Hawaii, he stood before a room of peers — all experts in the science of seeds — and did something radical: he showed them images. He told them stories. And he asked them to remember not what they saw, but how they felt.

Bernardo, recipient of the 2025 Lifetime Achievement Award, has spent his career searching for the genetic treasures tucked inside what plant breeders call exotic germplasm — ancient, often wild genetic lines that hold secrets to resilience, taste, and traits we've forgotten to value.

But Bernardo didn’t always think this way.

“I worked in private industry for nearly a decade,” he recalls. “I remember one breeder saying, ‘We’re making new hybrids, but they’re basically the same genetics.’ That stuck with me. Where is the new diversity going to come from?”

For Bernardo, part of the answer lies in the world’s gene banks — vast vaults of seed samples collected from every corner of the globe. Yet, he says, many of these vaults have quietly become “seed morgues.” “Something goes in, but it never comes out,” he explains. “We need to start treating these collections like living investments, not museums of dead potential.”

That potential — and the barriers to unlocking it — are deeply personal for Bernardo. He’s wrestled with international policies that prevent access to valuable lines (like North Korean corn) and with the slow, painstaking science of transferring useful traits from wild relatives into elite lines that farmers can actually grow. Sometimes it works. Sometimes it doesn’t. But he’s convinced that success starts not in the lab, but in the way we communicate.

“The fact sheet model isn’t cutting it anymore,” he says. “We hand out a paper about a new variety and think that’s enough. But stories? Plants you can see and touch? That’s what stays with people.”

Bernardo practices what he preaches. At the University of Minnesota, he helped launch a student-led breeding program that’s working to adapt leafy African vegetables for the Twin Cities’ African diaspora. The goal? Culturally relevant crops that mature in Minnesota’s shorter growing season — and can be regrown year after year.

“That’s real impact,” he says. “Helping people grow food that’s meaningful to them, not just what's commercially viable.”

He’s also brewed plant breeding into something more relatable — literally. Coffee and beer have become unexpected tools in his mission to make science accessible. His undergraduate course on coffee, for instance, connects the dots between genetics, geography, and culture. “Everyone drinks coffee,” he says. “It’s a conversation starter. It’s a gateway into plant science.”