Researchers Discover How Protein Connecting Calcium and Hormone Regulates Plant Growth

A new study conducted by scientists from Tel Aviv University (TAU) finds that a unique mechanism involving calcium, the plant hormone auxin, and a calcium-binding protein is responsible for regulating plant growth. The researchers involved in the study say that a protein that binds to calcium regulates both auxin responses and calcium levels, creating an interface that determines how plants grow.

For several decades, it was believed that calcium and auxin interfaced during plant development, but the mechanism behind such process were unclear. Now, the research group led by Prof. Shaul Yalovsky of TAU's George S. Wise Faculty of Life Sciences has discovered that auxin communicates with calcium through a binding protein called CMI1.

Auxin levels determine where leaves develop on a plant, how many branches a plant has, and how roots develop. Calcium levels change in plants in response to environmental signals like high or low temperatures, touch and soil salinity, as well as in response to auxin levels. Plant responses to auxin are either slow or rapid. Slow responses take place over the course of hours and days and depend on gene expression pathways, whereas rapid responses take place within minutes. CMI1 enables rapid responses to auxin levels, which depend on the presence of calcium.

For more details, read the article in Tel Aviv University Newsroom.