Intro to Fungi
What are the 4 Phyla of Fungi (and non-fungi) covered in this class?
Ascomycota
Basidiomycota
Mucoromycota
Oomycota
List 2 features that can help you distinguish between asco and basidiomycota
- Sexual spores- ascospores vs basidiospores
- Sexual and asexual fruiting bodies
- Dolipore septa (basidiomycota)
- Hyphal clamp connections (basidiomycota)
What are the 2 steps of the disease cycle achieved by oospores? (Assume soil is not being moved)
List 5 characteristics of bacteria that differentiate it from fungi
1. Prokaryotic vs Eukaryotic
2. peptidoglycan cell wall vs chitin cell wall
3. Do not have absorptive nutrition vs absorptive nutrition (fungi)
4. Lacks sexual reproduction, reproduces by fission (bacteria) vs reproduction sexually and asexually (fungi)
5. Most bacteria are motile, most true fungi are non-motile except for chytrids and oomycetes (not true fungi)
Most bacterial plant diseases are caused by what kind of bacterial plant pathogen?
Gram-Negative
What is absorptive nutrition
What is the difference between Brown and White Rots (Wood Decay Basidiomycetes)?
Brown rots- degrade cellulose
White rots- degrade lignin (and maybe cellulose as well)
Sexual- zygospore
Asexual- sporangiospores
Who are the mollicutes bacteria?
Wall-less bacteria (they lack a cell wall)
I am a Gram-negative bacterium known to cause fire blight of Apples and pears, and I cause the crooked-shaped symptoms of leaves called Shepherd's crook. What am I?
Erwinia amylovora
To which fungal Phyla do most plant pathogens belong?
Ascomycota
What is the difference between a true sclerotia and a pseudosclerotia
True- melanized outer rind, hyphae on the inside
Pseudo- melanized all the way through
Define:
Homothallic and Heterothallic
Paragynous and Amphigynous
Homothallic: antheridia and oogonia on same individual (self-fertile)
Heterothallic: Requires two opposite mating types
Paragynous: "on the side" antheridium attachment
Amphigynous: "on both sides" antheridium attachment
Two major differences between Gram-Negative and Gram-Positive bacteria
Thin peptidoglycan cell wall (Gram-) vs Thick peptidoglycan cell wall (Gram +)
Two cell membranes (Gram-) vs single cell membrane (Gram +)
I cause tissue breakdown of many host plants, the rotting of internal tissues, and often have secondary infection that causes a foul odor. What am I?
Pectobacterium or Dickeya
What is an anamorph vs a teleomorph
Anamorph- asexual stage of fungal spores
Teleomorph- sexual stage of fungal spores
Name the sexual (3) and asexual (2) fruiting bodies produced in the Ascomycota
Sexual- Cleistothecium, Perithecium, Apothecium
Asexual- Pycnidium, acervulus
How can you distinguish Downy Mildew from Powdery Mildew?
Downy- Oomycete, sporangiophore branching, mostly on underside of leaf
Powdery- Ascomycete, produce conidia and chasmothecia, mostly on upper side of leaf
What is the function of quorum sensing in bacteria?
cell to cell communication between bacterial cells that is density dependent and allows bacetria to co-ordinate themselves to perform a particular task.
I am a Gram-negative bacterium and I cause Pierce's Disease of grapes. I'm not easily cultured, and can be transmitted by sharpshooters insects, and I am Xylem-limited. What am I?
Xylella fastidiosa
Name 3 features of True Fungi
- eukaryotic
- single-celled or filamentous body
- cell walls with glucan and chitin
- heterotrophic (absorptive nutrition)
- reproduces by spores
List the spore phases of the Wheat Rust lifecycle AND which host plant the pathogen is on at each stage
Spermatia- barberry
Aeciospores- barberry (dispersed to wheat)
Urediniospores- wheat
Teliospores- wheat
Basidiospores- barberry
What are two ways by which you can distinguish Pythium from Phytophthora?
Antheridia- Pythium = paragynous, any location, one or many; Phytoph = amphigynous or paragynous, lower hemisphere only, single antheridia
Mating types- most Pythium = homothallic, most Phytoph = heterothallic
Sporangia- Pythium= many possible shapes, Phytoph = smaller range of shapes
Zoospore release- Pythium = vesicle release, Phytoph= direct release
Two major differences in the disease cycle of a bacterial plant pathogen vs. fungi plant pathogen
Bacteria cannot directly penetrate the host cell, but require natural openings or wounds, vs. direct penetration (appressorium formation) in fungi.
I am a wall-less bacterium, and I cause the lethal bronzing disease on palms. I am phloem-limited and transmitted by leafhoppers. What am I?
candidatus Phytoplasma