Chitin is a crucial component of fungi. As many fungi live as plant parasites , plants have special receptors that recognize chitin and help mount an immune response against fungal pathogens.
When those receptors are activated, the plants either deploy reactive oxygen species or specialized chitinazes to destroy the invading pathogens.
However, fungi have also adapted to the plant reactions and can evade the immune system of plants. The mechanisms of such evasion are mostly unknown .
An international team that included Slovenian , Dutch , and British scientists have studied a parasitic fungus, Verticillium nonalfalfae, that infects hop plants.
The scientists have found a new protein , VnaChtBP , that is produced in the fungi when it infects the plant. The new protein was shown to bind chitin. When the hop plants are infected with the fungus that carries the gene for this protein, the protein activity suppresses the production of reactive oxygen species by the host plant in response to the presence of chitin. The protein also binds the chitin in the fungus, preventing the destruction of the hyphae by the plant chitinases. The study has also found other proteins with a structure similar to VnaChtBP that help the fungus evade the plant defenses. This study has helped the botanists and mycologists understand the mechanisms of fungal plant infections better.
Reference :
“Chitin-Binding Protein of Verticillium nonalfalfae Disguises Fungus from Plant Chitinases and Suppresses Chitin-Triggered Host Immunity” – APS Publications. Accessed May 09, 2020.
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Silverswords are rare plants that grow only in certain areas in Hawaii, including Haleakala National Park . A team of specialists has decided to study how the silversword plants survive in the conditions of increasing drought brought about by climate change.
The team led by Paul Kruschelnycky has been experimenting with silverswords grown in the greenhouses and outplanted at several locations:
The silversword plants in the greenhouses were divided into groups based on the amount of water they were given. The seeds from the plants were obtained and then planted at the plots at higher, middle and low elevations. The plants grown at the greenhouses with a higher amount of water were more likely to die in the plots compared to plants grown with less water. The plants grown from the seeds initially obtained from higher elevations were more likely to survive compared to those obtained from the lower-level plants. The scientists have drawn the conclusion that in the conditions of the increasing drought, only plants that were initially adapted to obtaining less water could survive.
The results of the experiments coincide with actual events observed in the wild – silversword plants at lower elevations are currently dying out more rapidly compared to higher-elevation plants.
Reference :
“Clinal variation in drought resistance shapes past population declines and future management of a threatened plant” – ESA. Accessed May 09, 2020.
Link .
The processes in the plants are attracting a lot of interest from scientists. In the changing environment, when the quality of the soil worsens and drought, as well as infections, are becoming significant threats for agriculture, it is crucial to understand the plant world better and develop a strategy to protect both our crops and the diversity of the wild plants of the world.
The papers published in 2019 do their best to answer pertinent questions – how plants protect themselves from toxic substances and parasites? How likely are they to survive in stressful environments? How do they achieve complex adaptations to unusual conditions?
One of the areas where significant progress was made, but we have no space to discuss in-depth, is plant genetics.
For instance, it was found that some plants, for example, sorghum , can partially control their own genome. Other species, such as red algae , were shown to contain significantly fewer genes than were thought to be viable.
The scientists also do their best to increase the genetic diversity of existing crops – and search for wild relatives of domesticated plants. All of these efforts are aimed at one goal – to help our plants survive. We simply would not be able to last long on our planet if they don’t.
Cite This Page Key References
“Expansion of phycobilisome linker gene families in mesophilic red algae | Nature Communications” . Accessed May 09, 2020. Link .“Scientists hunt wild relatives of food crops to bolster defences” – PHYS.ORG. Accessed May 09, 2020. Link .