10. May 2024

Temperature is one of the important factors on which crop yields depend. Extreme temperature fluctuations, especially heat waves, affect the reproductive system of plants, leading to reduced yields. Biologists at CEITEC Masaryk University are trying to understand the molecular basis of this phenomenon and in their recent research have discovered how increased temperature affects the sensitivity of the plant reproductive apparatus and pollen development. This finding suggests how to target the breeding of new plant varieties that will be more resistant to climate change.

Global warming caused by climate change is leading to extreme weather fluctuations, for example, we are experiencing heat waves in spring that were previously uncommon. This has a significant impact on crop yields for a number of reasons. The reproductive system of plants is sensitive to elevated temperatures and pollen production is particularly vulnerable to high temperatures, which in extreme cases can lead to male sterility. Scientists at CEITEC Masaryk University have therefore focused on male meiosis, a process that produces haploid cells from which pollen develops. They found that heat stress during meiosis leads to chromosome division defects, which leads to errors in the distribution of genetic material to daughter cells and halts pollen development. This has a serious impact on plant reproduction and fruit and seed production. 

"Important for the correct distribution of genetic material to daughter cells are the so-called centromeres, the parts of the chromosomes to which microtubules attach, which are sort of cellular ropes by which chromosomes are attracted to the newly emerging cells. We found that increased temperature causes centromeres to shrink in meiotic cells, and this leads to more errors in the division of chromosomes into newly forming cells, which affects pollen development," says Lucie Crhák Khaitová from CEITEC Masaryk University. 

The study, published in the scientific journal eLife, provides new insights into how temperature affects fundamental cellular processes such as chromosome segregation. "This discovery was unexpected for us. All cells in the human body have centromeres, and they normally function at 37 °C. So, it is a surprise to us that plant meiotic centromeres are sensitive to temperatures as low as around 30 °C. This suggests that it should be possible to increase the resistance of these centromeres and create plant varieties that are better adapted to temperature fluctuations," adds Karel Říha, molecular biologist and head of the research group. 

In their research, the scientists used a unique methodology that allows them to visualise chromosome division directly in the reproductive tissues of plants. They were therefore able to observe "live" the progress of male meiosis in live anthers of plants cultured directly in front of a microscope lens in a chamber simulating a higher temperature environment.

Now scientists are trying to elucidate the mechanism behind the sensitivity of plant centromeres to elevated temperatures. These findings will contribute to understanding the effect of temperature changes on plant fertility and will be important for breeding crops that are more resilient to climate change - i.e. crops that produce higher yields even with larger temperature fluctuations.