Newly Discovered Stem Cell Pathway Will Increase Yields of Maize and Staple Crops

Biologists at Cold Spring Harbor Laboratory (CSHL) have made an important discovery that helps explain how plants regulate the proliferation of their stem cells. The newly discovered pathway channels signals from a plant's extremities (primordia) to the stem cell niche (meristem) located at the plant's growing tip.

The group led by CSHL Professor David Jackson identified the "braking signals from the leaves" in cells in the lower part of the meristem. They named the receptor FEA3. They also discovered the ligand that interacts with the receptor, a protein fragment called FCP1. Jackson's team studied maize plants in which FEA3 was dysfunctional.

When FEA3 receptors in the meristem are not able to function at all, "it is as if they are blind to FCP1," says Jackson. The inhibitory signal FCP1 sends from the leaves to the meristem is not received, and stem cells proliferate wildly. The plant makes too many stem cells, giving rise to too many new seeds that the plant cannot support with available resources.

When the team grew plants with "weak alleles" of the FEA3 gene, the function of the FEA3 receptor was only mildly impaired. This moderate failure of the braking signal from outside of the meristem gave rise to a modest, manageable increase in stem cells, and to ears that were significantly larger than ears in wild-type plants. These ears had more rows of kernels and up to 50 percent higher yield than wild-type plants.

Photo source: Cold Spring Harbor Laboratory

For more information, read the news release at the CSHL website.