Silver Leaf Disease From Plant Fungus Infects Human; Pathogen Leaps Between 2 Kingdoms in Tree of Life

Some animal diseases can be transmitted to humans; in those cases, they are called zoonotic diseases or zoonoses. However, it is unheard of for a human to be inflicted by a disease from plants. But for the first time, such a case had been reported.

Indian Man Got Silver Leaf Disease

A number of botanical species, including pears, roses, and rhododendrons, are cursed by the silver leaf disease. If not promptly treated, the fungus Chondrostereum purpureum can kill a plant by infecting its leaves and branches. The fungal illness was never considered a problem for people until this year.

An unusual instance of a pathogen seemingly spanning entire kingdoms in the tree of life was reported after a 61-year-old Indian mycologist appeared to have developed a very bad case of silver leaf sickness in his throat. According to the case study, a male patient visited a medical facility in eastern India. He had a cough, hoarse voice, weariness, and difficulty swallowing. His neck CT X-ray scan revealed a pus-filled abscess next to his trachea.

Humans frequently contract fungal illnesses. Ringworm, athlete's foot, and thrush frequently settle in the moist parts of our skin. But the fungal disease from a plant was different.

Any disease needs the proper equipment to settle within a host and multiply. They not only require a way to get the necessary nutrients but also need a few coping mechanisms to deal with a hostile environment and destroy them with various killer agents and chemical weapons.

A fungus that has evolved to thread its hyphae through leaves and stems to succeed inside our flesh is rare. It is even more puzzling given that the patient in this case study appeared to have a completely functional immune system and showed no signs of being on immunosuppressant medication, having HIV, diabetes, or any other type of chronic illness.

The researchers noted that cross-kingdom human pathogens and their potential plant reservoirs have significant implications for the emergence of infectious diseases. While superbug bacterial species and novel viruses that emerge from animal populations frequently catch our attention, we rarely give plant diseases in our neighborhood much thought. Even if it's exceedingly unlikely, the fact that it's a possibility makes it a topic that needs consideration.

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What Is Silver Leaf Disease?

A fungus produces a silver leaf that spreads through fresh wounds to infect wood and the xylem, which conducts water. The infection releases a poison that is transported to the leaves by the xylem, turning them silvery gray.

Over a few years, the illness worsens, causing leaves to curl upward at the margins and turn brown. It will later affect the limbs and scaffold, and the tree's demise is inevitable.

A defining sign of the illness is the heartwood of dead or dying limbs discoloring a dark brown. On the surface of the fungus-killed trunks and branches, spore-forming basidiocarps grow. These tiny, leathery, shelf-like structures commonly develop on afflicted trees' north side. Their lower surface is smooth and purple, while their upper surface is grayish-white and unevenly zoned. Although they can develop at any time of the year, fall is when they often form. During wet or rainy conditions, spores are released from the basidiocarps' bottom surface and are then carried by the wind. For two years, a basidiocarp can produce spores. Wounds exposed to sapwood that have not yet fully healed are prone to infection. The virus is contained as soon as spores infect the exposed xylem until the infested branch perishes.