11-05-2006, 09:32 AM
Why does the blue rose remain so elusive?
![[Image: images.jpg]](http://i108.photobucket.com/albums/n37/outdoor_01/images.jpg)
This is the result of one basic situation. Plants have various colour pathways that determine the way in which colour is specifically expressed in petals. While scientists can extract a gene from one plant where the colour expression in the petals is blue, when inserted into roses, this colour expression changes to pink. The reason for this is the pH of the cells. For example if you insert a blue gene from petunias which have a cell pH which is more acidic than roses into the rose DNA, it forms a pink pigment. If we try to change the genes that determine cell pH, then we risk changing a whole range of other cell functions as well. Changing the pH so that the gene is expressed as blue petals may change other characteristics, and these may alter the plant significantly in a range of ways. It may be blue, but it may not be a rose as we know it.
This is the result of one basic situation. Plants have various colour pathways that determine the way in which colour is specifically expressed in petals. While scientists can extract a gene from one plant where the colour expression in the petals is blue, when inserted into roses, this colour expression changes to pink. The reason for this is the pH of the cells. For example if you insert a blue gene from petunias which have a cell pH which is more acidic than roses into the rose DNA, it forms a pink pigment. If we try to change the genes that determine cell pH, then we risk changing a whole range of other cell functions as well. Changing the pH so that the gene is expressed as blue petals may change other characteristics, and these may alter the plant significantly in a range of ways. It may be blue, but it may not be a rose as we know it.
