Control of DNA Packaging May Lead to More Nutritious Rice

A study conducted by researchers from the Mississippi State University and Ohio State University revealed that the chromatin, the packaged form of the DNA, plays an essential role in controlling rice endosperm sizes and grain quality. The findings may allow scientists to improve the nutritional value of rice. The endosperm portion of the grain is an important component in determining the nutrient content for most cereal crops as it provides growing plant nutrition, such as starch, oils and protein.

Inside the plant cell, the two meter long DNA is packaged as chromatin to fit the 20 micrometer (one millionth of a meter) nucleus. A piece of DNA wraps around a group of basic proteins called histones to form a structure similar to the coil of a telephone cord. Several proteins can adjust the tightness of the DNA-histone interaction. Genes positioned in loosely packaged chromatin regions are usually active since they are more accessible to transcription factors.

The scientists pinpointed the chromatin modification genes that control endosperm sizes and grain quality. They also identified 344 unique proteins associated with chromatin and found a large number of histone variants in the crop. The findings suggest that manipulating the chromatin-controlling genes may be an effective approach to improve rice yield and quality.

For more information, read http://www.csrees.usda.gov/newsroom/impact/2008/nri/07281_rice_nutrition.html