NEW BRUNSWICK, N.J. Rutgers researchers have discovered the basis for what makes corn kernels hard, a quality that allows corn to be easily harvested, stored and transported. The findings could lead to better hybrids and increase the supply for people in developing countries who rely on it as a nutritional staple.
The discovery explains how a breed of corn known as "quality protein maize," or QPM, incorporates two qualities essential for an economical and nutritious food crop: a source of key protein ingredients as well as a hard-shelled kernel.
Until the arrival of QPM a decade ago, corn did not provide a balanced protein mix when used as a sole food source. A hybrid developed in 1960 increased protein levels with essential amino acids but was commercially unsuccessful, because its soft kernels subjected the harvest to spoilage.
In a paper posted this week to the online early edition of the Proceedings of the National Academy of Sciences (PNAS), Rutgers geneticists reported their findings about genetic coding responsible for making QPM kernels sturdy. The sturdiness results from threshold levels of a specific gene product encoded by two gene copies. Their investigation explains the role of this gene product in generating a protein matrix around starch particles that imparts seed strength.
"While QPM was developed in the late 1990s, scientists have not had a thorough knowledge of how kernel strength could be achieved in a rational way," said Joachim Messing, professor of molecular genetics at Rutgers. "Our work contributes knowledge that will help other scientists develop better hybrids going forward, either through traditional breeding techniques or genetic engineering."
At the same time, the Rutgers findings will help scientists understand more about the evolution of seeds and their components.
Corn is naturally low in lysine and tryptophan, amino acids that are essential to make corn an adequate
|Contact: Carl Blesch|