Where the soil is toxic food cannot grow. In acidic soils, where aluminum becomes locked up in clay minerals, and dissolves into the soils as a toxic element, food production is hampered.
Approximately one-half of the world’s arable, land which is mostly in the Africa, Asia and South America, is unusable, due to aluminum toxicity in the existing acidic soils.
from Cornell University have cloned an aluminum tolerant gene in the sorghum plant. Sorghum is a major food crop in many countries in Africa, Central America and South Asia. Sorghum is, also, the world's fifth most important cereal crop.
The research teams’ efforts will be published in the September issue of Nature Genetics.
The published account will provide insights into how specialized proteins in the root tips of some cultivars of sorghum and such related species as wheat and maize can boost aluminum tolerance in crops.
Leon Kochian, the paper's senior author, a Cornell adjunct professor of plant biology and director of the U.S. Department of Agriculture--Agriculture Research Service (USDA-ARS) Plant, Soil and Nutrition Laboratory at Cornell said, "My lab has been working to identify the physiological mechanisms of plant aluminum tolerance as well as its molecular basis. The reason this is significant is there are extensive areas of the earth's lands that are highly acidic, with pH of 5 or below [pH below 7 is considered acidic]. Most of these areas are in the tropics or subtropics, where many developing countries are located."
used genetic mapping to identify a single gene that encodes a novel membrane-transporter protein responsible for the citric acid release. This gene is only turned on in order to express the protein and transport citric acid when aluminum ions are present in the surrounding soil.
The researchers employed the sorghum gene in order to engineer transgenic aluminum-tolerant Arabidopsis thaliana (a small mustard plant used in plant research because of its small genome and short life cycle) and wheat plants. According to Kochian, sorghum is harder to genetically transform.
Kochian said” This research also has environmental implications for badly needed increases in food production on marginal soils in developing countries For example, if we can increase food production on existing lands, it could limit encroachment into other areas for agriculture."
This is an important step towards resolving the food insecurity problems that many third world countries are experiencing.