It has become known that the rise in the temperature of the planet and the consequent rise in sea level is a threat to ecosystems around the world, but what scientists are currently warning about is the threat to the survival of humans themselves due to the food shortage coming to the world as a result of the exacerbation of crop infection with fungi as one of the consequences of temperature rise.
In an article published in the journal Nature on May 2, researchers Sarah Gore, a professor at the University of Exeter in England, and Eva Stockenbück, a professor at the University of Kiel in Germany, explained why the scientific community fears fungi are invading crops and how to contain the problem before it worsens.
Speaking to the University of Exeter website, Gore warned of a global health catastrophe due to the rapid spread of plant fungi in the world, as resistance to them is increasing and affecting important crops such as cereals, potatoes and bananas.
Stockenbück said fungi that infect plants in warm regions are starting to appear in Europe due to the high temperature, and if we know that the fungus is already destroying large amounts of crops now and continues to gain immunity to antifungals, we will realize the magnitude of the problem.
The fungus infects myrrh trees in Asia but became very virulent when it moved to Europe (Pixaby)
It's not new
Infection of crops with fungi is not new, but it is repeated throughout history, as the stem rust fungus has always damaged wheat crops, and the disease is described in the writings of "Theophristus", one of Aristotle's disciples (370-288 BC).
One of the most important fungi that has had a profound impact on agriculture and human life throughout history is ergot fungus, which infects wheat, barley and oats.
Humans are exposed to poisoning with this fungus through the use of flour that comes from grains infected with the fungus, and the symptoms are gangrene, convulsions and hallucinations, and ergot poisoning occurred several times between the 14th and 17th centuries and its victims were in the thousands, and the infection was repeated in the last quarter of the twentieth century.
Apart from cereal crops, coffee was exposed to another fungus that severely affects its production, the coffee rust fungus, which in 1885 wiped Sri Lanka off the list of coffee producers after destroying its plantations, and production fell to only 5% in 15 years, and the fungus is still spreading in South and Central America.
Coffee rust mushroom poses a major threat to production in some Asian, South and Central American countries (Pixaby)
Why do fungi represent a real threat?
Plants become infected by bacteria, fungi, viruses or worms, but fungi rank in the top six in the list of pests that affect the top 5 crops: rice, wheat, corn, soybeans and potatoes.
The danger of fungi is that they are by nature easily spread, they multiply with spores released by the fungus to move through the air, and in some species they can travel long distances, the stem rust fungus that infects wheat, for example, produces spores that travel across continents, and in other types of fungi the spores remain latent in the soil for decades and then activate to produce other generations of mushrooms.
Another reason why fungi are pathogenic is their ability to change their genes to adapt to the environment, as they can receive genes from other fungi, bacteria, or even plants.
What renewed fears?
Concern increased when fungi were able to exploit modern farming methods to their advantage, as now large areas are grown with one plant species and all plants carry the same genetic fingerprint, making them easy prey for a fast-mutating organism such as fungi. The situation is further critical that 77% of the antifungals currently in use target only one component of the fungus, which can easily change it due to its ability to mutate.
But how does global warming increase the spread of plant fungi? A high temperature may cause the plant to become infected earlier than usual (e.g. late blight fungus in potatoes and tomatoes), shorten the incubation period to produce more fungi in the same season (e.g. coffee rust), or increase the likelihood of plant exposure to fungi (e.g. Panama disease in bananas) due to hurricanes caused by global warming or severe fungus infections (e.g. downy mildew in vines).
High temperature also weakens plant immunity, making it easily contagious, and at the same time leading to generations of fungi that are more resistant to high temperatures and more virulent.
Tornadoes help spread the fungus that causes Panama disease in bananas (Pixels)
Consequences of the increased spread of fungi
Warming the planet leads to the emergence of fungi that usually thrive in high temperatures in areas where they were not found, the stem rust fungus that infects wheat already appeared in England and Ireland while it originally grows in the tropics.
Obviously, this phenomenon means the loss of a larger amount of plant, but the most dangerous is that the fungus may become more virulent if it moves to an area other than its habitat, such as the fungus that causes the disease of myrrh trees (Ash tree), as it has little effect on trees in Asia, where it is usually found, but by moving to Europe it became very virulent and destroyed European maran trees.
One of the most dangerous phenomena is the transformation of some fungi that used to coexist with plants into disease-causing fungi that may even change their host and become capable of infecting humans or animals.
Growing large areas of genetically identical plants that are easily infected with fungi (Pixaby)
Ways to confront fungi
The quality of antifungals should be reconsidered, as it is no longer appropriate to use compounds that target one component in the fungus, because it can simply change it so that the antifungal becomes ineffective, and as an alternative to antifungals, enemies of natural fungi such as Trichoderma fungus can be used, which hinders plant fungi by competing for food and place or parasitizing them.
Genes can also be used to control the spread of fungi, genetically modifying the plant by introducing genes that give it resistance to fungi is one of the solutions, especially if two or more genes are introduced, and then planting varieties with different resistance genes together, because the genetic diversity in the plant makes it difficult for the fungus to invade it. But the biggest challenge is that the idea of genetically modifying plants is not accepted by people.
Since prevention is better than cure, the development of means to detect the disease at the beginning will trap the infection and reduce the resources required to overcome it, for example artificial intelligence and remote sensing methods can be used for this purpose.
When technology is not available, society can be engaged in resistance and raise awareness of the problem, such as an initiative by researchers in South Africa to engage individuals interested in science in researching and recording a plant pathogen on farms.
In any case, it is not the responsibility of farmers to protect crops alone, but support from all groups, as botanists, governments, financiers and policymakers can do a lot to address another of the challenges we face due to global warming.
Fungi have become more capable of infecting crops after global warming has helped them invade new environments, and this portends a global health catastrophe unless current farming methods change and society is involved in confronting the problem.