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SYDNEY: Some species of crop-destroying fungi, in the genus Fusarium, can transfer two of their four chromosomes into other harmless fungi, transforming them into destructive pathogens.
The Fusarium genus of fungi contains over 20 species and is responsible for billions of dollars in damage to crops such as wheat, corn, bananas and tomatoes in Australia and around the world.
"By discovering more about the aggressive nature of these pathogens we can develop ways to protect our agricultural products," said plant pathologist Kemal Kazan, from the CSIRO Institute in Brisbane, one of the authors on the study published in Nature.
"Holy Grail" of plant pathology research
One species of Fusarium graminearum, which is harmful to wheat and barley, and effects both the malting and brewing industries. Other crops such as bananas, tomatoes and cotton are under risk from Fusarium oxysporum.
Some species of Fusarium are harmless or non-pathogenic and cannot overtake agricultural crops, explained Kazan, but these fungi are at risk of becoming counterparts if they come into contact with one another.
"Understanding how fungi are able to adapt and define themselves to be plant pathogens is considered the Holy Grail of this research," said Brett Summerell, director of conservation and horticultural research at Botanic Gardens Trust in Sydney, who did not take part in the study.
Evolving nature of the pathogenic fungi
"It is possible, that in the absence of certain types of food they undergo types of evolutionary changes to expand their host range," said Kazan.
The international consortium that Kazan was a part of wanted to know why the different pathogens are specialised in different plant species. "We thought one way of answering questions is to sequence genomes of different Fusarium species," he said.
The researchers compared the genomic sequences and were able to deduce that horizontal gene transfer took place, which has only been seen on rare occasions in some eukaryotes.
What is the motivation?
A very interesting type of behaviour.
I cannot help wondering about the type of evolutionary or survival logic behind this mechanism. Maybe we are looking at a simply way of multiplication?!