ften in delicate symbiotic relationships in which plants engage in, biochemical
ID: 227626 • Letter: F
Question
ften in delicate symbiotic relationships in which plants engage in, biochemical signaling occurs between the plants and various hosts (and pathogenic fungi or bacteria). This, and other factors lead drug researchers toward such heterologous systems in search of novel compounds that might be useful for medical or other biological research.
From a biodiversity and conservation theory standpoint, defend the intrinsic and explicitvalues of these delicate plant interactions? If they’re so weak, what good are they?
Explanation / Answer
Answer:
a. The symbiotic association between plants and their rhizosphere microbes involves the chemical communications that exist, and the biological processes they sustain. Primarily it is the loss of carbon compounds from roots that drives the development of enhanced microbial populations in the rhizosphere when compared with the bulk soil, or that sustains specific mycorrhizal or legume associations.
Overall the general rhizosphere effect could help the plant by maintaining the recycling of nutrients, through the production of hormones, helping to provide resistance to microbial diseases and to aid tolerance to toxic compounds. When plants lack essential mineral elements such as P or N, symbiotic relationships can be beneficial and promote plant growth.
However, this benefit may be lost in well-fertilized (agricultural) soils where nutrients are readily available to plants and symbionts reduce growth. Since these rhizosphere associations are commonplace and offer key benefits to plants, these interactions would appear to be essential to their overall success.
Example:
Below-ground diversity of arbuscular mycorrhizal fungi (AMF) is a major factor contributing to the maintenance of plant biodiversity and to ecosystem functioning. At low AMF diversity, the plant species composition and overall structure of microcosms that simulate European calcareous grassland fluctuate greatly when the AMF taxa that are present are changed.
b. Trees and fungi have constructed a close relationship with the passing of the ages. Fungi like to grow between the roots of trees and the arrangement is beneficial to both partners.
Trees are the lungs of the earth. They draw CO2 from the atmosphere and convert it into sugars, which then become a source of energy.
In the process they breathe O2 back into the atmosphere. This "green" production of biomass - trees account for 90% of the planet's land-based biomass - is a major influence on the health of our planet.
Trees grow better and faster when certain specialized micro-organisms occur in their root systems. One such organism is the Laccaria bicolor fungus.
The symbiotic relationship of the fungus and the tree root systems is advantageous to both. The fungus facilitates the uptake of scarce nutrients such as phosphates and nitrogen and protects the roots against parasites in the soil.
In return they are able to draw on the sugars in the roots. 85% of all plants and trees are dependent on symbiotic processes of this kind for their growth.
A sequencing of the genome of the fungus (Laccaria bicolor) revealed that the delicate balance between fungus and tree may also yield important information that could be used to monitor climate change. Research is being conducted to find out exactly how tree and fungus cooperate and react to stress factors such as drought or extreme temperatures resulting from climate change.
The hope exists that the assembled information will result in concrete applications in which trees and fungi can be deployed to the benefit of both people and the environment.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.