By Jeff Mulhollem
A plant’s success may depend on how well the three sets of genetic instructions it carries in its cells cooperate, according to a new study led by plant scientists at Penn State. In an analysis of the hybrids of two crossbred tree species, the researchers found that two sets of those genes inherited from different species may not work well together, disrupting the plant’s ability to harvest light for photosynthesis and take up key nutrients. However, when the combination of inherited genes better matches up, those plants may be better able to adapt to changing environments.
According to the researchers, who published their findings in Proceedings of the Royal Society B, the work could help inform plant breeding to help produce plants that are more resilient to the changing climate. They focused on two of the three sets of genetic instructions, or genomes: One resides in the cell’s nucleus, or control center, while the other genome is contained in the chloroplast, the structure essential for photosynthesis. The third genome is in the mitochondria, which is crucial for cellular respiration, but the team did not include it in their analysis because the study focused on photosynthetic activity.
“Different components of a plant’s genome its genetic material work together to keep it functioning well, and when two different species or populations interbreed, or hybridize, this coordination can break down,” said study first author Michelle Zavala-Paez, doctoral candidate in Penn State’s Intercollege Graduate Degree Program in Ecology. She explained that when the nuclear and chloroplast the specialized organelle in plant cells converting light energy into chemical energy, or sugars, using sunlight, water and carbon dioxide, releasing oxygen as a byproduct genomes have evolved separately in different species, their “teamwork” might not work smoothly in hybrids and result in what is called “cytonuclear mismatch.”