New gene sheds light on cell signaling.

Researchers have thought that plant cells miss out on a useful form of communication because their walls block the entrance of large signal molecules. Now, a study on maize plants casts doubt on that theory, scientists report.

Philip W. Becraft of Iowa State University in Ames and his colleagues have found a maize gene, called crinkly4 (cr4), that encodes a previously unidentified receptor, part of which acts as an enzyme. Other plants appear to have these receptors also, Becraft says.

Similar receptors in mammals hook up to large signal proteins, leading the researchers to suspect that the plant counterparts do too. The plant receptors appear to receive signals that alter the growth of seed and leaf epidermis.

Plants that have a mutation in cr4 are short, with rough, dull, crinkly leaves that tend to adhere to each other as they grow. Epidermal cells of those leaves are unusually large, and some don't lock together like those of normal plants, the team reports in the Sept. 6 Science.

About 10 percent of the mutant plants' seeds lack aleurone cells, which help break down starch and protein in the endosperm. The seed uses these nutrients as it matures. Malt manufacturers may have a particular interest in manipulating aleurone development because the aleurone in barley helps starch turn into fermentable sugar, Becraft notes.