Wheat Genome Sequenced by Olomouc Scientists
Prof. Jaroslav Doležel in the CHR greenhouse with wheat samples
Researchers from the Centre of the Haná Region for Biotechnological and Agricultural Research (CHR) at Palacký University have completed a step of cardinal importance in terms of decoding the genetic information of common, or bread wheat (Triticum aestivum). They have completed the DNA library for all 21 chromosomes of the crop after decade-long research, which resulted in an award by the International Wheat Genome Sequencing Consortium. Their research is vital for the cultivation of more resistant and higher-yielding varieties of wheat, a major world food staple crop.
Research into the complicated wheat genome involves the collaboration of scientists from all over the world. The aim of the International Consortium is to decode the genetic information of the crop no later than 2017, and it would not be possible without the method developed in Olomouc. “The completion of the library has been our first major success and a big step towards our ultimate goal. Another step will be the completion of physical maps and then the decoding itself, in other words sequencing. All this would have been very difficult to accomplish without our strategy,” said Prof. Jaroslav Doležel, the CHR Scientific Director.
Isolated information stored in the DNA libraries
The wheat genome is so huge that it cannot be analysed as a whole. While the human genome contains approximately three billion letters of genetic code, the wheat genome contains roughly six times that. Therefore Olomouc scientists split the genetic information into smaller segments – chromosomes, which were then analysed separately. They used a flow cytometer, which sorts the chromosomes, and then isolated the DNA (deoxyribonucleic acid) from each chromosome. DNA is further divided into smaller segments, and these are stored for later use in an archive called a DNA library. “We have developed a method of constructing chromosome DNA libraries, making the decoding much easier,” explained Doležel.
The completion of the set of DNA libraries was officially revealed by the scientific community in January at Plant & Animal Genome XXII, a prestigious conference in San Diego, where Prof. Doležel’s team received an award for its major contribution to the wheat genome sequencing. Symbolically, it was almost exactly ten years after his team began the investigation. “In 2004, the first library of this kind was published. Until then, no one believed such a thing could be possible,” said Doležel with a smile.
First chromosome decoded completely, others in brief
DNA libraries are a prerequisite for decoding the whole wheat genome. So far, the first of the 21 chromosomes has been fully decoded, due to the collaboration of the CHR scientists with their French colleagues. “We obtained detailed information on the molecular structure of the 3B chromosome. We now know which genes it carries and how they are structured. These findings have accelerated the isolation of important genes as well as the application of molecular methods in cultivation. This research also allows us to reveal how the genetic information developed throughout evolution. The most beautiful thing about our work is how we proceed from basic research all the way to practical applications,” added Doležel. An article summing up their research findings has been sent to the prestigious journal Science.
The journal should also inform that the International Consortium has managed to decode tentatively the DNA of all the remaining chromosomes. Prof. Doležel’s team played a key role in this achievement as well. “We have been decoding the most complex plant genome ever, and what is more, in the highest quality. We are the only ones who have been able to divide the wheat genome into small segments, which we have passed on to other teams associated in the Consortium, from the USA to Japan,” said Doležel.
Another Green Revolution?
Both articles should be published in Spring 2014, on the 100th anniversary of the birth of Dr. Norman Ernest Borlaug, an American agronomist who is called the “father of the Green Revolution”. In 1970, he was awarded the Nobel Peace Prize for innovations in the cultivation of new, highly resistant and productive crop varieties, especially wheat. A conference taking place on the date of this anniversary will point out the risk of a food crisis. According to some scientists, such a crisis can be expected within twenty or thirty years, because our agricultural production cannot satisfy the needs of the increasing population.
Olomouc scientists have therefore begun analysing the genetic information of related wild-growing wheat varieties in order to find important characteristics which have disappeared during the course of cultivation. These could be inserted into the wheat genome by traditional crossbreeding or by means of genetic engineering.
The Centre of the Haná Region for Biotechnological and Agricultural Research is a joint project of Palacký University, the Institute of Experimental Botany at the Academy of Sciences of the Czech Republic, and the Crop Research Institute.
