Researchers led by Keiichi Mochida at the RIKEN Center for Sustainable Resource Science (CSRS) in Japan have discovered that extended periods of high stress lead to iron deficiency and stunted growth in wheat crops. Experiments show reducing iron deficiency with a synthetic organic molecule called PDMA results in better growth and healthier plants. These findings are good news for farmers and consumers alike and could lead to treatments in the field that improve wheat production during prolonged periods of heat. The study was published in the scientific journal Nature Communications.
One of the biggest fears of ongoing climate change is that extended periods of heat will disrupt food production. Even moderate warming can reduce the yield of cool-season cereal crops such as wheat, with one global study estimating that wheat production declines by 6% for every increase of one degree Celsius. Not only do these crops do less photosynthesis and produce smaller kernels of grain, but the grain is also less nutritious. While most research into how plants adapt to heat stress has focused on acute stress—very high temperatures over a few days—Mochida and his team reasoned that the bigger threat posed by climate change is extended periods of moderately high temperatures.
The researchers characterized what happens to bread wheat after two weeks of moderate heat stress. Compared to wheat grown at normal temperatures, the stressed out wheat plants weighed less and analysis indicated they were doing less photosynthesis. When checking for nutrient deficiencies, the researchers discovered that the leaves from the heat-stressed plants contained less than half the normal amount of iron. Could their stunted growth be the result of iron deficiency?