![Microbotryum violaceum - Silene pusilla (Julia Kruse) 2](https://upload.wikimedia.org/wikipedia/commons/5/54/Microbotryum_violaceum_-_Silene_pusilla_%28Julia_Kruse%29_2.jpg)
''
Microbotryum violaceum
''Microbotryum violaceum'', also known as the anther smut fungus, was formerly known as ''Ustilago violacea''. It is a Basidiomycete obligate parasite of many Caryophyllaceae. But it has now separated into many species due to its host specificity ...
'' is a host-specific anther
smut (fungus)
The smuts are multicellular fungi characterized by their large numbers of teliospores. The smuts get their name from a Germanic word for dirt because of their dark, thick-walled, and dust-like teliospores. They are mostly Ustilaginomycetes (phylum ...
disease that infects ''
Silene latifolia
''Silene latifolia'' subsp. ''alba'' (formerly ''Melandrium album''), the white campion is a dioecious flowering plant in the family Caryophyllaceae, native to most of Europe, Western Asia and Northern Africa. It is a herbaceous annual, occasio ...
'' and sterilizes the host plant. When infected with this disease, the flowers generate pathogenic
spore
In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...
s, which can then be transferred to other plants by pollinating insects. Therefore, this disease is sometimes classified as a
sexually transmitted infection
Sexually transmitted infections (STIs), also referred to as sexually transmitted diseases (STDs) and the older term venereal diseases, are infections that are Transmission (medicine), spread by Human sexual activity, sexual activity, especi ...
.
Smuts
They are fungal diseases that can infect different parts of the host plants (i.e. leaves, stems, flowers) and usually create black spores called
teliospore
Teliospore (sometimes called teleutospore) is the thick-walled resting spore of some fungi ( rusts and smuts), from which the basidium arises.
Development
They develop in '' telia'' (sing. ''telium'' or ''teliosorus'').
The telial host is the p ...
s in the infected area. Teliospores produce
sporidia
''Sporidia'' are result of homokaryotic smut fungi (which are not pathogenic), asexual reproduction through the process of budding.
Thus far, this has only been observed ''in vitro''.
References
*C.J. Alexopolous, Charles W. Mims, M. Blackwe ...
, white smut, and can survive under harsh environmental conditions. Therefore, the most effective way to prevent the spread of this fungal disease is to remove and destroy the infected area of the plant. Fungicides can be used to control the spread of smut; however, they must be applied before symptoms appear to be effective.
Transmission
In male ''S. latifolia'', ''M. violaceum'' eliminates pollen production in the anthers and replaces the pollen with fungal teliospores. These teliospores can then be transferred by pollinators to other plants, resulting in the spread of the infection. In females, the infection can subdue the development of the reproductive organs,
styles and
ovaries
The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. T ...
, resulting in complete sterilization.
Risk of infection
Male ''S. latifolia'' tend to have a lower rate of infection compared to female ''S. latifolia'' because males have the ability to drop contaminated flowers before the entire plant is infected by ''M. violaceum''; whereas, females do not have that male
phenotype
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological proper ...
. So females hold onto the flowers with the intention to develop fruits carrying seeds with the purpose of creating offspring. However, these "offspring" merely carry the fungal disease and cannot develop into mature plants.
Effect of sterilizing diseases
Sterilizing diseases do not attract a lot of attention in the research field compared to diseases that cause mortality in humans. However, there is an abundance of these diseases across
biological kingdoms (i.e.
plant
Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...
s,
animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...
s,
fungi
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...
). They can create detrimental effects on a species’ population size because, although the organism does not immediately die, it cannot reproduce for the next generation. This chain of reaction leads to a decreased population size, which in extreme situations could lead to
extinction
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...
. In addition, hosts with long life-spans can act as a “disease reservoir” in transmission by being a constant source for spreading the disease for years.
Related examples
''Gypsophila repens''
''
G. repens'' is a hermaphroditic plant species that is also plagued by ''M.'' ''violaceum'', but it is usually only partially diseased. The same branch can have healthy and diseased flowers, and some of the diseased flowers can still have functional stigmas and produce seeds; whereas, the stigmas in diseased flowers of most host species are usually greatly reduced in their function or aborted, leading to sterility. A study conducted by López-Villavicencio et al. (2005) drew the conclusion that ''M. violaceum'' had recently undergone a host shift to ''G. repens'' from another diseased ''
Caryophyllaceae
Caryophyllaceae, commonly called the pink family or carnation family, is a family of flowering plants. It is included in the dicotyledon order Caryophyllales in the APG III system, alongside 33 other families, including Amaranthaceae, Cactacea ...
'' species because of the disease's failure to completely infect and sterilize ''G. repens''.
''Spodoptera frugiperda''
''S. frugiperda'', the
fall armyworm
The fall armyworm (''Spodoptera frugiperda'') is a species in the order Lepidoptera and one of the species of the fall armyworm moths distinguished by their larval life stage. The term "armyworm" can refer to several species, often describing th ...
, is affected by the
ectoparasitic
Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has c ...
nematode
The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...
''Noctuidonema guyanense,'' which can usually be found on the “intersegmental membranes of the abdomen of both sexes of its adult hosts,” and is transmitted through mating, but not found on the host's larvae. ''N. guyanese'' can shorten the lifespan or reduce flight ability and fecundity in its adult host, thus acting as a sexually transmitted parasitic infection.
''Homo sapiens''
''
Chlamydia trachomatis
''Chlamydia trachomatis'' (), commonly known as chlamydia, is a bacterium that causes chlamydia, which can manifest in various ways, including: trachoma, lymphogranuloma venereum, nongonococcal urethritis, cervicitis, salpingitis, pelvic inflamma ...
'' is the ''M. violaceum'' of
human
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
s, except it is a bacterial sexually transmitted infection rather than fungal. It is primarily transmitted through
sexual intercourse
Sexual intercourse (or coitus or copulation) is a sexual activity typically involving the insertion and thrusting of the penis into the vagina for sexual pleasure or reproduction.Sexual intercourse most commonly means penile–vaginal penetrat ...
, but can also be vertically transmitted from mother to child during birth. The latter form of transmission leaves the child wit
chlamydial conjunctivitisand
pneumonia
Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severity ...
. Due to this complication, along with female infertility, the main focus of research and screening strategies for chlamydia is women. However, there is emerging research that shows that men also experience reduced fertility because of “decreased semen quality and impaired sperm fertilizing capacity and DNA integrity”.
See also
*
Sex determination in ''Silene''
References
{{Reflist
Fungal plant pathogens and diseases