intro to plant infecting bacteria and fungi

Question 1

what are outside plant bacteria called?

Answer 1

epiphytes

Question 2

what are inside plant bacteria called?

Answer 2

endophytes

Question 3

how can a bacterial colony differ in form? name 3 examples

Answer 3

• punctiform (small dots)
• circular (spots)
• irregular
• rhizoid (like roots)

Question 4

how can bacterial colonies differ in elevation?

Answer 4

• flat
• raised
• convex
• pulvinate (tall)
• umbonate (taller middle, like a nipple)

Question 5

what are symptoms of plants being infected with bacteria?

Answer 5

• necrotic spots
• rotting
• wilting
• galls
• bacterial exudate

Question 6

what are bacterial exudates caused by?

Answer 6

extremely high concentration in vascular tissue, can burst out of tissue, will flow into water

Question 7

what are weather patterns that can cause damage to the plant, allowing entry for bacteria?

Answer 7

• frost
• hail
• wind, sand/soil blown from wind, splashes caused by wind

Question 8

what are vectors that enable entry into a plant for bacteria?

Answer 8

• humans -> irrigation
• insects/mites/pollinators
• birds
• splashes caused by movement

Question 9

what are phytoplasmas?

Answer 9

• bacteria, limited to phloem
• lack cell wall -> polymorphic
• obligate pathogens

Question 10

what is an obligate pathogen?

Answer 10

a pathogen that can only replicate inside the cells of the plant

Question 11

what are symptoms caused by phytoplasmas?

Answer 11

• witches’ broom (proliferation of stems and leaves)
• flower proliferation
• lethal yellowing

Question 12

how large are plant infecting bacteria?

Answer 12

1-2 micrometres

Question 13

what % of plant diseases are caused by fungi?

Answer 13

70%

Question 14

what is a mycelium? what are hyphae?

Answer 14

the vegetative part of a fungus consisting of branching tubular cells called hyphae. these grow through and across tissues absorbing nutrients

Question 15

what are septate hyphae?

Answer 15

hyphae divided by septa, no septa = aseptate

Question 16

what is yeast growth?

Answer 16

reproduction by budding or cell division, performed by single celled fungi

Question 17

how do biotrophic fungi access a plant using haustoria?

Answer 17

• the haustoria is inserted into cell - - grows inside host tissue, allows fungi to extract host range
• often specialised w a narrow host range

Question 18

how do necrotrophic fungi access a cell?

Answer 18

• kill plant tissue using toxin and/or enzymes
• can be specialised or generalist

Question 19

how do fungi reproduce?

Answer 19

• sexually: teleomorph stage
• asexually: anamorph stage
• different spores can be produced depending on life cycle

Question 20

what are symptoms of plants infected with fungi?

Answer 20

• root rots
• vascular wilting