Reported in Nov. 12th Nature, Findings Suggests Brain Signaling Systems Evolved From Mechanism That Existed Before Divergence of Plants and Animals
NYU plant molecular biologist Gloria Coruzzi and collaborators have discovered evidence that plants have a signaling mechanism that is similar to one in the human brain. This discovery suggests that signaling between cells by excitatory amino acids may have evolved from a mechanism that existed before the divergence of plants and animals. It also helps explain why plants make neuroactive compounds that act on receptors in the brains of humans and other animals.
Coruzzi's NYU team and collaborator Hon-Ming Lam of the Chinese University of Hong Kong report their findings in the November 12th issue of Nature in a scientific correspondence entitled "Glutamate receptor genes in plants." For a copy of the article, contact Lauren Funkhouser at Nature at (202) 737-2355.
Examining the DNA of Arabidopsis (a common lab plant), Coruzzi's lab found genes that encode for glutamate receptors (iGluRs), which are known to be involved in cell signaling in the human brain. In the brain, glutamate receptors are activated by the amino acid glutamate. This lock-and-key relationship is the linchpin of one of the brain's cell-to-cell communication and activation systems.
Based on their findings, the NYU researchers have concluded that glutamate also acts as a chemical messenger in plants. They found that it is involved in communicating the presence of light and regulating light-dependent processes such as stem growth and chlorophyll synthesis. Furthermore, they found that Arabidopsis cannot respond properly to light when glutamate receptors are inhibited*.