You just published the genome of a conifer in Nature. Why is it so relevant?
In the first place, because of the difficulty. For the first time, an international research group has managed to sequence the genome of a conifer, in particular the Picea abies (a tree of Eurasian distribution). It is a complicated task because of the great quantity of DNA present in the cell nucleus, much more than in other plants. During evolution it has incorporated sequences that are similar to mobile transposable elements, which form most of its genome.
What would you highlight?
The analysis shows that the number of genes present in Picea abies (28,354) is close to that of Arabidopsis thaliana, a model angiosperm (flowering plant) for plant research with a 100 times smaller genome. Obtained data indicate that conifers have a low gene density and the great size of the genome of conifers (and many gimnosperms in general) is not due to a recent duplication of the whole genome. It rather looks like the big genomes of gimnosperms have been generated by a slow and progressive accumulation of mobile elements (LTR-transposons), probably as a consequence of the lack of an efficient mechanism for the elimination from the genome.
What was your contribution?
We have analysed gene sequences from ribosomal DNA and determined the size of the genome in a substantial number of specimens. Currently, we keep on researching, defining different gene linkage groups that have been investigated by other groups in the chromosomes of the Picea (it has 24).
And this scientific finding has also an economic impact…
And a very important one, because this knowledge will benefit forestry utilization. Conifers are fast-growing, great-sized species, cultivated for the use of their timber. Knowledge about the genome will allow us to go deeper into the biochemical mechanisms linked to timber production and, in the future, to isolate those genes, observe their regulation and try to bring those genes into other species’ genome.
Your research also tries to detect food industry fraud. How can that be done from a plant study point of view?
Identification of plant life is quite easy for a botanist when every diagnosis element is at hand (leaves, flowers and fruit, fundamentally). The problem lies in identifying living creatures when there are only parts, or they are transformed. In this case we need to use DNA-based identification. That is what we do with food industry fraud: check if the allegedly present species in the food item correspond to the labelling indications. DNA gives us an answer. Contrary to general belief, substitution of a species for a cheaper one with less quality is a widely spread practice in the plants field.
You have cooperated with police investigations identifying plant remnants. What does forensic botany entail?
It is one of the most exciting disciplines of botany and it has a lot of practical repercussion. It consists on the identification of individuals or plant species through morphological or DNA features that allow us to link plant samples present in the crime scene or victims to suspects. It is a challenge for investigators and it requires a close cooperation with security forces.