PLANTS DISEASES + DEFENCES

What do plants use nitrates for

make protein for healthy growth

How can you tell Nitrate Deficiency has occurred

yellow/pale green leaves, reduced crop yeild

How do farmers resolve nitrate deficiency

Chemicals + Manure

What do plants use magnesium ions for

make chlorophyll in leaves

How can you tell magnesium ion deficiency has occurred

Plant growth is stopped

What are the symptoms of tobacco mosaic virus

Discoloration

What are the symptoms of rose black spot

Spots on leaves

How are poisons used as a defence

Deter or kill insects

How are thorns and hairs act as a defence

Stop animals from damaging/touching the plant

How does magnesium deficiency cause stunted growth

lack of magnesium, lack of chlorophyll, low photosynthesis, not enough glucose to release energy from respiration

How do nodules benefit bacteria

obtain glucose which is used for respiration

How do nodules benefit plants

obtains nitrate ions needed to combine with glucose for amino acid

What can plants catch diseases from (4)

fungi, pests, viruses and bacteria

How do farmers diagnose diseases of the plant

Basic observations and matching symptons to a gardening manual
Send sample of diseased plant to plant pathologist
Trial and Error

What do plant pathologists do

Take tissue sample of plant and look under microscope to see issue in more detail
Look for unique antigens
Run DNA tests

How does trial and error work

If you think your plant has a specific disease then try and provide it with something that may help (if magnesium deficiency give magnesium)

What do physical defences do

physically prevent the entry of a pathogen

What are the examples of physical defences

Waxy cuticle on leaves and stem
Cellulose cell walls
Layers of dead cells around trunk

What chemical defence can kill pathogens

Antimicrobial substances

What do antimicrobial substances do

Kill bacteria or fungi

How do leaves that curl act as a mechanical defence

They curl when an insect drops on them

What are the types of chemical defences

Antimicrobial substances, Poisons

What are the types of mechanical defences

Thorns/hairs and leaves that curl

What are the main causes of diseases

Infection by microorganisms
Attack by larger organisms
Lack of essential materials

What are 5 physical changes that could indicate a plant has a disease

Stunted growth
Spots on leaves
Discolouration
Abnormal lumps
Patches of decay

What are chemical defences

chemicals that plants secrete to destroy pathogens

What are mechanical defences

structures that reduce the chance of being attacked