Genetic clues to plant growth reported in articles in New Scientist news and PLoS Biology 16 Sep 2008. Growing plants are known to have a period of maximum growth at dawn. This is under control of numerous hormones, including auxin, ethylene, gibberellins, abscisic acid, brassinosteroids, and cytokinins. To get the growth spurt happening at the right time the hormone release must be coordinated to the plant’s circadian rhythm, which is reset each day with the change in light at dawn and dusk. A group of biologists have studied the genes that activate the growth hormones in mustard plants grown in varying light and temperature conditions. They found 71 hormone genes were turned on in the early morning and 55 of them had the same promoter sequence of DNA. A promoter sequence is a part of a gene that activates the gene when a protein called a transcription factor binds to it. The researchers suggest that the circadian clock triggers the production of a protein that turns on the hormone genes at the right time in the light/dark sequence to ensure the hormones are active at the right time.
Editorial Comment: Note how many hormone genes are involved in this process, yet they are regulated by only a few control genes. These findings remind us that it is not enough for the evolutionists to explain how individual genes came into being, but they also have to explain how they are co-ordinated according to the needs of a plant. It is the coordination between genes that makes an organism function properly, and to get that right requires an understanding of how the whole organism is meant to function. This is no problem as the plant was made by an intelligent Creator who is outside the plant. It requires many leaps of blind faith to believe that co-ordinating 71 genes came about by a mindless process that knows nothing of the whole plant or how it works with its environment. (Ref. Botany, design, biorhythms)
Evidence News 12 December 2008