biology

Potato virus M

Potato virus M 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 Potato virus M rather than just read about it. In short: Potato virus M (PVM) is a plant pathogenic virus in the family Betaflexiviridae. PVM can infect plants in the family Solanaceae, and it's an economically important pathogen of potato and pepino worldwide.

Key takeaways

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

Reference excerpt

Potato virus M (PVM) is a plant pathogenic virus in the family Betaflexiviridae. PVM can infect plants in the family Solanaceae, and it's an economically important pathogen of potato and pepino worldwide.

Hosts and symptoms PVM was first isolated from potatoes in 1923, in the United States. It was also identified from other New World plants, such as pepino, tomato and tobacco. PVM is naturally transmitted by aphids in a non-persistent manner, however poor cultural practices can cause up to 50% crop loss by mechanical means and infected seed tubers. PVM is detected in mixed infections of potatoes along with other viruses, but it can also cause damage in single infections. In single infections of potato, PVM causes mild leaf symptoms, such as mottling, mosaic, crinkling and rolling of leaves, and necrosis, shoot and plant stunting. In comparison to healthy tubers, PVM lowers the yield of starch by 0.96%, affects the size of starch granules, and increases amylose, ash and phosphate content in the affected tuber. PVM is less damaging in other hosts. In the common bean it causes necrotic spots and lesions. In tomato plants, it can cause the leaves to turn yellow. In the amaranth its symptoms are chlorotic rings and necrotic spots. In quinoa it can cause chlorotic lesions.

Properties PVM capsid is a rod-shaped or slightly curved filament with dimensions of 650 x 12 nm. PVM possesses a +ssRNA genome that is 8.5 kb in length. The RNA strand has a 5' cap and a 3' poly-A tail in order to resemble mature eukaryotic RNA. The RNA genome encodes six open reading frames (ORFs) that produce several viral proteins. ORF 1 encodes a replicase that has three domains: methyltransferase, helicase and RNA-dependent RNA polymerase. ORF 2, 3 and 4 overlap one another and are collectively referred to as the triple gene block. These proteins are involved in membrane binding, cell-to-cell movement of virions and RNA silencing. ORF 5 encodes the coat protein, and ORF 6 encodes a protein capable of binding with RNA and DNA and suppress RNA silencing.

Worked examples

Example 1 — a first encounter with Potato virus M

Start with the simplest possible case. Write down what Potato virus M 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 Potato virus M 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 Potato virus M 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 Potato virus M

In research: Potato virus M 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 Potato virus M 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: Potato virus M is common in secondary-school and first-year university syllabi. It links to neighbouring topics Carlaviruses, Viral plant pathogens and diseases, so understanding it makes those chapters shorter.
In everyday life: Look for Potato virus M 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 “Potato virus M” →

Affiliate

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

How to study Potato virus M in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Potato virus M 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 Potato virus M out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Potato virus M in simple terms?

Why does Potato virus M 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 Potato virus M?

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 Potato virus M.