Related Experiment Video
Updated: Feb 19, 2026
07:35
Laser Microdissection-Based Protocol for the LC-MS/MS Analysis of the Proteomic Profile of Neuromelanin Granules
Published on: December 16, 2021
2.8K
Melanization Affects the Content of Selected Elements in Parmelioid Lichens
Lorenzo Fortuna1, Elena Baracchini2, Gianpiero Adami2
1Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, I-34127, Trieste, Italy.
Journal of Chemical Ecology
|November 4, 2017
Summary
Lichen melanization, a common trait in Parmeliaceae, influences elemental content. The study found that melanized lower cortices are crucial for iron complexation, impacting nutrient levels in lichen thalli.
Area of Science:
- Lichenology
- Biogeochemistry
- Plant Science
Background:
- Parmeliaceae lichens exhibit conserved melanization of the lower cortex, a trait with uncertain adaptive value.
- Melanins are known for diverse protective functions, including defense against radiation, oxidation, and microbial stress, and metal complexation.
- The role of melanization in elemental accumulation within lichen thalli remains largely unexplored.
Purpose of the Study:
- To investigate the impact of melanization on the elemental composition of lichen thalli.
- To determine if melanized tissues influence the uptake and retention of macro- and micro-nutrients.
- To elucidate the specific role of the melanized lower cortex in metal complexation.
Main Methods:
- Non-destructive micro-X-ray fluorescence elemental analysis was performed on upper cortex, lower cortex, and exposed medulla of nine lichen species.
- Total elemental concentrations (macro: Ca, K, S; micro: Fe, Mn, Zn) were measured using inductively coupled plasma atomic emission spectroscopy after acidic digestion.
- Sequential elution experiments on two species (Melanelixia glabratula, Punctelia subrudecta) were conducted to assess the chemical binding of Fe and Zn to melanized tissues.
Main Results:
- Melanized lichen species showed higher concentrations of iron (Fe) and zinc (Zn) compared to non-melanized ones.
- Removal of the melanized lower cortex led to a significant decrease in Fe content, but not Zn.
- Zn distribution was found to be homogeneous throughout the thallus, while Fe complexation appears linked to the melanized lower cortex.
Conclusions:
- Lichen melanization significantly affects elemental content, particularly iron accumulation.
- The melanized lower cortex plays a vital role in complexing iron, contributing to its higher concentration in these lichens.
- While zinc levels are elevated in melanized species, its distribution is not solely dependent on the lower cortex's melanization.
Related Concept Videos
01:19Pigmentation
4.6K
The color of the skin is influenced by a number of pigments, including melanin, carotene, and hemoglobin. Recall that melanin is produced by cells called melanocytes, which are found scattered throughout the stratum basale of the epidermis. The melanin is transferred to the keratinocytes via melanosomes.
Melanin occurs in two primary forms: eumelanin that provides black and brown pigment and pheomelanin that provides red color. Dark-skinned individuals produce more melanin than those with pale...
Melanin occurs in two primary forms: eumelanin that provides black and brown pigment and pheomelanin that provides red color. Dark-skinned individuals produce more melanin than those with pale...
4.6K
01:14Changes in Skin Color: Clinical Perspectives
3.9K
The first thing a clinician sees is the skin, so the examination of the skin should be part of any thorough physical examination. Most skin disorders are relatively benign, but a few, including melanomas, can be fatal if untreated. A couple of the more noticeable disorders, albinism and vitiligo, affect the appearance of the skin and its accessory organs.
Albinism
Albinism is a genetic disorder that affects (completely or partially) the coloring of skin, hair, and eyes. The defect is primarily...
Albinism
Albinism is a genetic disorder that affects (completely or partially) the coloring of skin, hair, and eyes. The defect is primarily...
3.9K
01:46Types of Selection
45.4K
Natural selection influences the frequencies of particular alleles and phenotypes within populations in several different ways. Primarily, natural selection can be directional, stabilizing, or disruptive. Directional selection favors one extreme trait and shifts the population towards that phenotype while selecting against individuals displaying alternate traits. Stabilizing selection favors an intermediate trait with a narrow range of variation. Deviation from the optimal phenotype towards an...
45.4K
01:39Epistasis
50.5K
In addition to multiple alleles at the same locus influencing traits, numerous genes or alleles at different locations may interact and influence phenotypes in a phenomenon called epistasis. For example, rabbit fur can be black or brown depending on whether the animal is homozygous dominant or heterozygous at a TYRP1 locus. However, if the rabbit is also homozygous recessive at a locus on the tyrosinase gene (TYR), it will have an unshaded coat that appears white, regardless of its TYRP1...
50.5K
02:00Photoreceptors and Plant Responses to Light
28.6K
Light plays a significant role in regulating the growth and development of plants. In addition to providing energy for photosynthesis, light provides other important cues to regulate a range of developmental and physiological responses in plants.
28.6K
02:27Background and Environment Affect Phenotype
7.8K
Although the genetic makeup of an organism plays a major role in determining the phenotype, there are also several environmental factors, such as temperature, oxygen availability, presence of mutagens, that can alter an organism’s phenotype.
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
7.8K