This has exciting potential in biotechnology, horticulture, forestry, and plant pathology. For example, the stately American chestnut was once a widespread tree in our Eastern forests. Today it has virtually disappeared because of a disease-producing fungus that causes chestnut blight. The American chestnut recently has been grown in plant tissue culture. These trees could then be planted in our forests and the American chestnut would once again be one of our most important hardwood species.
Plants are chemical factories .
Many of the chemicals that they produce are useful to humans. Besides food, plants provide raw materials for paper, building materials, solvents and adhesives, fabrics, medicines, and many other products. Botanists study the chemicals produced by different plants to find new uses for them. For example, we use some plant chemicals to treat certain types of cancer. The earth's biological diversity , or the kinds of organisms that populate the earth, is decreasing.