Lecture 18 exam 3 Flashcards
signs of SCN are
seeing the nematode itself or cysts w/ the scn
SE
sieve element
sugars will be transported from the blank to the blank
sieve element to the apopolast of the adjoining giant cell
General nematode life cycle
egg
j1
m1
j2
hatch
j2
m2
j3
m3
j4
m4
adult w gender
how to the nematodes move within the root
by mechanical or by enzyme aided means
soybean cyst nematode
heterodera glycines
the blank and blank are also modified to do what
xylem and phloem are modified to provide nutrition
what happens at the 48 hr mark of root knot
induction of feeding cells and the worm becomes sedentary
symptoms of pratylenchus worms
-root lesions
-enxtensive root necrosis
-root rots due to 2ndary infections
-plants are unhealthy and stunted
-decreased yeilds
-plants pulled easily from soil due to damaged roots
life cycle of sting nematodes
-juveniles devlop within eggs in soil
-j2 hatch and are attracted to compounds excreted by roots
-j2 feed as ectoparasites on root hairs
-molt to j3
-j3 and then on feed on root meristem tissue
-amphimixis
because there is karyokinesis but not cytokineses giant cells are
multinucleated
damaged turf is not able to withstand
severe heat or even mild drought stress
a plant will not develop the blank when it senses an infection so you get blank
the meristem, so you get a plant with few roots if theres lots of infections causing decreased yeild
with root knot nematodes what are formed on the root
galls
endoparasites enter
the root to feed
what is a sieve element
a type of cell in the phloem
pratylenchus worms reporduce by
amphimixis means
pratylenchus worms will not
modify the plant tissue itself
belanolaimus females lay
eggs in pairs in the soil
as the nematode grows the
number of giant cells formed increase enclosed within the galls
belanolaimus worms actually require
80% sand content in soil to survive
giant cells also have blank within them
more dense cytoplasm
nematode signals trigger
feeding site formation
from the apoplast the dugars and aminos are being brought into
giant cells using plant transporters
migratory ectoparasites feed
from exterior of root by inserting the stylet into the tissue
structure arounf giant cells is modified and is called the
gall
symptoms of belanolaimus
irregular patches or yellowing foliage
adaptations for plant parasitism
hollow stylet
morphological and physiological changes to the esophagus
j3 and onward pratylenchus worms feed
on the root apical meristem
with SCN the egg mass is blank, the cyst is blank, and the female is blank
egg mass is inside the cyst
the cyst is inside the root
the female is outside the root
lesion worm of coffee
pratylenchus coffeae
when the female cyst dies what happens
the color changes from a white to brown color
nematodes will select
specific cells for feeding
root rot with pratylenchus is usually caused by
a complex of soil microorganisms due to secondary infections
once damage is noticed from lesion nematodes theres
normally too many worms to do anything about it
umami transporters move what
amino acids
pratylenchus worms overwinter where
in infected plant material
cytokinesis
when cells are dividing and forming septa (cell walls)
lesion worm of tobacco
pratylenchus penetrans
the lesion nematode is called
pratylenchus
cyst nematodes
heterodera
if a nematode is migratory then
all life stages will be veriform
what type of cells are modified into giant cells mostly
vascular parenchymal cells
migratory ectoparasites will remain
veriform throughout the life cycle
plants with pratylenchus damage are prone to
lodging and wind damage
bc they go in and out of the root, belanolaimus worms find what type of environment easiest
sandy soil bc the sand gives them more friction to move with
j2 pratylenchus worms feed on
root hairs
lesion worm of potato
pratylenchsu brachyurus
belanolaimus worms are what type of parasite
migratrory ectoparasite
pratlyenchsu worms are what type of parasite
migratory parasites
belanolaimus worms feed on
root hairs and root apical meristem using a very long stylet
root knot nematodes cause
more damage worldwide than any
other genus
when giant cells form you get
karyokinses but not cytokinesis
sweet transporters transport what
sugars (sucrose)
the sting nematode is called
belanolaimus
what happens in the 24 hr range of root knot
invasion, the migration to the intercellular target site
with pratylenchus worms all life stages are
infective, (j2 to adult)
poor response to irrigation, or fertilizers can be a sign of
a nematode problem
cyst nematodes are where
within the root
as the cells die in the root
the nematode will find new roots to infect
the egg mass is located where for root knot
outside the root
the pratylenchus worm blank is pretty destructive
intracellular migration
CAT 6 transporters bring
aminos from apoplast into the giant cell
where are the eggs in root knot nematodes? Where are the females?
the eggs are outside the root, the females are within the root
GC
giant cell
invaginations in the giant cell do what
increase the surface area for transporter placement
once the nutrients are brought into the giant cell thw
nutrients are then absorbed by the nematode through the stylet
pratylenchus worms live how long
have a 45 to 65 day life cycle
general root knot nematode life cycle (start at j2)
-j2 infects
-root is parasitized
-feeding on structure because of formation of gulls
-once feeding you get multiple molts
-leaves tissues to find mate @ m4
-nematode mates and dies
gall inducing root knot nematodes
meloigodyne
the root apical meristem is
the tip of the root
the margin between healthy and nematode damaged turf is
gradual, not sharp
pratylenchus worms will lay eggs where
singly or in small groups inside plant tissue or in the soil
root knot nematodes are what type of parasite
Sedentary endoparasite
nematode damaged tissue will start to
degenerate and can cause secondary infection because of other pathogens getting in from their damage
things the pratylenchus worms infect
field crops
vegetablesit trees
ornamentals
where are pratylenchus worms located
temperate and tropical areas
what happens at the 3 to 4 day mark of root knot
nutrient acquisition: vascularisation of feeding site, and nematode turns to an adult
root knot nematodes form
complex feeding sites in roots called giant cells
root knot nematodes have a wide
hsot range and can parasitize more than 2000 plant species
once a plants root has been invaded the plant will try to
limit damage by undergoing apoptosis
belanolaimus life cycle lasts
18 to 24 days
most important belanolaimus worm is
belanolaimus longicaudatus
The belanolaimus worms mostly affect
turf grass
if you have a plant with less of a root system then
symptoms are exacerbated when there is a drought or less water available (theres not enough root surface area to collect the water)
the infective stage of root knot nematode is
the j2 stage
how do root knot nematodes reproduce
parthogenisis
nematodes will modify blank in the cells to make more blank
transcription in the cell to make more transporters
there are blank on the cell walls of giant cells
invaginations
most common root knot nematode
southern root knot nematode
how are giant cells formed
you get nuclei division (karyokinesis) without cytokinesis
SUC transporters would do what
bring sucrose from apoplast into the giant cell
apoptosis
programmed cell death
ectoparasites feed externally by
inserting stylet
feeding site formation equals the formation of
syncytia or giant cells
karyokinesis
division of nuclei
in rkn the knot is blank, the eggs are blank, and the female is blank
the knot is inside the root, the eggs are outside the root, and the female is inside the root
cell walls bw giant cells are blank but around the galls are blank
thinner
thicker
