New Techniques of Plant Tissue Culture and Their Potential for Plant Improvement

the chloroplast whose genes are actually in the nucleus. One example of this is a protein (an enzyme) called "Rubisco" that is involved in carbon-fixation in the chloroplast. The Rubisco enzyme is made up of eight large protein subunits and eight small protein subunits. The genes for the large subunit are found in the chloroplast DNA, but the genes for the small subunit protein are found in the nuclear DNA. This means that the small subunit protein comes from cytoplasmic RNAs and is transported into the chloroplast. Plant molecular biologists have tried to discover what it is that tells this protein to go into the chloroplast. Because only certain proteins go into the chloroplast, there must be specific information allowing a protein to do so. Scientists have found, often through this recombinant DNA technology, that the protein transported into the chloroplast contains a small group of amino acids