By running a computational analysis of the genomes of the papaya, poplar, Arabidopsis and grape species, scientists have uncovered hundreds of conserved non-coding sequences that are found in the DNA of all four species.
These non-coding sequences are not genes, but are located in the promoters upstream of genes and are around 100 DNA base pairs in length.
As the four species have evolved separately for around 100 million years, the fact that these regions have been conserved suggests they play an important role in the plants’ development and functioning.
The team at the Univ. of Warwick believe these regions are involved in controlling the expression of the genes they are upstream of – in other words determining whether the genes are turned “on” or “off” according to the environmental conditions or developmental stage of the plant.
For example, some genes will be required for defense against pathogens, or others will be required for germination.
Sascha Ott, of the Warwick Systems Biology Centre, says, “We know that certain genes are conserved between species – but we also see that sequences outside of genes are conserved. The regions outside genes that we have discovered have been kept for millions and millions of years across four species. There must be a reason for this – if something has been around for so long it is probably useful in some way. We believe it may be because these regions have a very important role to play in how the plant develops and functions.”
This research was supported through the BBSRC/EPSRC grant Plant Responses to Environmental Stress in Arabidopsis (PRESTA).