biology

Phytoplasma pruni

Phytoplasma pruni is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Phytoplasma pruni rather than just read about it. In short: Candidatus Phytoplasma pruni is a species of phytoplasma in the class Mollicutes, a class of bacteria distinguished by the absence of a cell wall. The specific epithet pruni means "living on Prunus", emphasizing the fact that the phytoplasma is a parasite of various Prunus species, otherwise known as stone fruits.

Key takeaways

Phytoplasma pruni belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Phytoplasma pruni to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Phytoplasma pruni from memory before moving on to harder problems.

Reference excerpt

Candidatus Phytoplasma pruni is a species of phytoplasma in the class Mollicutes, a class of bacteria distinguished by the absence of a cell wall. The specific epithet pruni means "living on Prunus", emphasizing the fact that the phytoplasma is a parasite of various Prunus species, otherwise known as stone fruits. The phytoplasma is commonly called the X-disease phytoplasma. Like all phytoplasmas, Candidatus Phytoplasma pruni infects both plants and insects. Potential plant hosts include peach, cherry, plum, and others. Known insect hosts include various species of leafhoppers. Since the pathogen can not live outside of host cells, it must be transmitted to a new plant host by an infected leafhopper.

Taxonomy The name 'Candidatus Phytoplasma pruni' was informally suggested by the International Research Program for Comparative Mycoplasmology in 2004, but the taxon was not formally described until 2013. It belongs to the X-disease group (16Sr group III), subgroup A (16SrIII-A), the most studied subgroup of 16SrIII. This subgroup of phytoplasma is associated with a number of diseases:

PX11CT1R is the reference strain for 'Candidatus Phytoplasma pruni'.

Related strains Certain strains of phytoplasmas related to 'Candidatus Phytoplasma pruni' are associated with diseases of various plant species, including blueberry, clover, goldenrod, milkweed, spirea, pecan, poinsettia, potato, and walnut. These strains are classified in other subgroups of group III as follows:

A 'Candidatus Phytoplasma pruni'-related strain in subgroup 16SrIII-F has also been implicated as the cause of a greening disorder of Trillium grandiflorum and other Trillium species.

X-disease

X-disease was first discovered in California in 1931, where it was described as cherry buckskin. In 1933, the disease was found on peach in Connecticut, where it was called "X disease of peach" due to its unknown cause and mysterious nature. For many years, X-disease of peach was believed to be caused by a virus that was carried by insect vectors from nearby forests to peach orchards. In 1971, X-disease was found to be associated with mycoplasma-like organisms (now called phytoplasmas). X-disease is an infectious disease of stone fruits (Prunus spp.). The disease is caused by Candidatus Phytoplasma pruni, a strain of phytoplasma belonging to 16Sr group III, the X-disease group of phytoplasmas.

Hosts Historically, X-disease has been a major limiting factor in peach production in the United States. In addition to peach (Prunus persica), other species of the genus Prunus are susceptible to infection by the X-disease pathogen, including Prunus americana (wild American plum), Prunus armeniaca (apricot), Prunus avium (cherry), Prunus besseyi (Bessey cherry), Prunus cerasus (cherry), Prunus domestica (European plum), Prunus dulcis (almond), Prunus japonica (Chinese bush-cherry), Prunus munsoniana (wildgoose plum), Prunus persica var. nectarina (nectarine), Prunus salicina (Japanese plum), and Prunus virginiana (wild chokecherry).

Vectors X-disease is transmitted by various species of leafhoppers in family Cicadellidae, including Colladonas clitellarius, C. montanus, C. geminatus, Euscelidius variegatus, Fieberiella florii, Graphocephala confluens, Gyponana lamina, Keonella confluens, Norvellina seminuda, Osbornellus borealis, Paraphlepsius irroratus, and Scaphytopius delongi.

Distribution X-disease is present in North America (Canada, Costa Rica, United States) and South America (Argentina). It is localized in Canada (British Columbia, New Brunswick, Ontario) and widespread in the United States (California, Colorado, Connecticut, Massachusetts, Michigan, Missouri, Nebraska, New York, North Dakota, Oregon, Pennsylvania, Utah, Virginia, Washington). The disease may also be present in Asia (India, Japan), Europe (Poland), and additional U.S. states.

See also Cherry X-disease Milkweed yellows phytoplasma

References

Worked examples

Example 1 — a first encounter with Phytoplasma pruni

Start with the simplest possible case. Write down what Phytoplasma pruni claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Phytoplasma pruni before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Phytoplasma pruni ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Phytoplasma pruni

In research: Phytoplasma pruni appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Phytoplasma pruni in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Phytoplasma pruni is common in secondary-school and first-year university syllabi. It links to neighbouring topics Bacterial plant pathogens and diseases, Bacterial tree pathogens and diseases, Candidatus taxa, so understanding it makes those chapters shorter.
In everyday life: Look for Phytoplasma pruni outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Phytoplasma pruni” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Phytoplasma pruni in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Phytoplasma pruni means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Phytoplasma pruni out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Phytoplasma pruni in simple terms?

Why does Phytoplasma pruni matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Phytoplasma pruni?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Phytoplasma pruni.