Heat Tolerant Pollen Could Improve Yields

Climate change poses many challenges for our civilization; one of them is its effect on food production. Many regions around the world are experiencing record high droughts and heat waves. These effects are already having an impact on certain crops, and the issue will only worsen in the future. Part of the solution to this particular issue will be crop varieties that are more tolerant of such harsh conditions.

Texas-based scientists from the USDA, I've taken a first step toward creating such plants. (via PLoS ONE) Current average yields for many crops in the US are actually only 22% of record yields from the past. This means that despite advances in agricultural technology, many of these plants are functioning at only partial capacity. The scientists believe this is due to the effects of increasing heat and other environmental factors. This discrepancy in yields was particularly prominent in crops in which the reproductive structure of the plant was of value.

This led the scientists to investigate the heat tolerance of pollen specifically. Improving this could have effects on a wide range of crops; including corn, oats, barley, rye, peanuts, and more. Previous work has already shown that pollen, the male reproductive cell of plants, is particularly sensitive to temperature. It actually does not normally contain what are known as heat shock proteins. These are proteins in cells that react to temperature and trigger various metabolic changes. Even if a plant has the ability to survive certain temperatures, the pollen can easily be damaged.

To test methods of counteracting this issue, they created genetically engineered strains of cotton and tobacco. They were engineered to overexpress a heat shock protein gene from the Arabidopsis plants. Arabidopsis is a small but well studied plants often used in biological research. By greatly overexpressing this gene in the entire plant, they were able to have some of the protein be produced in the pollen. This modified pollen germinated much better than control plants, after being exposed to increased temperatures or brief moments of extreme heat. The cotton also produced more seeds then unmodified strains, in both greenhouse and field experiments that involved elevated night and day temperatures.

These results make the scientists hopeful that such modifications can be made to other plants. Being able to give pollen more heat tolerance could greatly improve overall yields in this wide range of crops. Such attributes will be even more important as global temperatures continue to rise.