30.1 A

EPSP Synthase and Glyphosate or Roundup

Effects?

Inhibits the _____________ pathway.

Affects ___________ (plants / animals / microorganisms?)

Inhibits EPSP Synthase

an essential enzyme of the shikimate pathway for aromatic armino acid biosythesis in plants and microorganisms (but NOT animals)

Inhibits the _____________ pathway. shikimate

Affects ___________ (plants / animals / microorganisms?)

30.1 B

How much money does Glyphosate gross a year?

30.1 B4

Glyphosate herbicidal properties

solid

low water solubility

used as a salt

extensive use in no-till or min-till farming

- very broad spectrum and non-selective as postemergence

- absorbed thru foliage and other photosynthetically active portions of plants (poorly absorbed thru roots)

30.1 B4

Glyphosate toxicological problems

Glyphosate is __________. (persistent/not persistent).

Glyphosate presents _________ problems (what kind of toxicological issue?)

absorbed in soil so little leaching and poorly effective applied to soil

no significant photodecomposition or volatilization

Glyphosate is __________. (persistent/not persistent).

Glyphosate presents _________ problems (what kind of toxicological issue?) only mild skin irritant, no other problems

30.1 C

How is roundup ready crop safe?

Overproduction of _________ and _________ in Roundup Ready crops.

"Roundup Ready" (corn, soybean, cotton)

crop safety by overproduction of EPSP and GOX (glyphosate oxidase), insensitive to glyphosate

also engineered w/ BT gene for resistance to lepidopteran insects

30.2 A

Action of glutamine synthase (how is ammonia detoxified?

adds ammonia to glutamate to make glutamine

30.3 ABCD

Tribufos

What is it?

How does it act?

What is it? Defoliant

Acts by injuring leaf --> produce hormone levels --> induce early abscission layer

30.3 ABCD

Concern with using tribufos?

30.4 

What are other organophosphate herbicides?

bensulide or betasan

krenite

31.A Funal Diseases

Infectious plant diseases are ___ due to fungi. (percentage)

You can have _____ different types of fungi on one plant. (# range)

Infectious plant diseases are ___ due to fungi. (percentage) 75%

You can have _____ different types of fungi on one plant. (# range) 10-15

31.A

Examples of fungal diseases on plants

rots

wilts

blights

rusts

smuts

mildews

31.A

How are fungis classified?

What are the 3 classifications?

classified according to lifestyle

airborne

seedborne

soilborne

31.B

Fungi control

Selectivity is _____ to control. (difficult / easy)

Reproduction cycle is _____. (slow / fast)

Mycelium has ________ regeneration property. (limited / unlimited)

Resistance is _____ (low / high).

Most difficult to control are the ones ____ (above / below ground).

Selectivity is _____ to control. (difficult / easy)

Reproduction cycle is _____. (slow / fast)

Mycelium has ________ regeneration property. (limited / unlimited)

Resistance is _____ (low / high).

Most difficult to control are the ones ____ (above / below ground) or systemic within plant.

31.C

What was used to control fungi?

Fungicide percentage of market of herbicides? 

Worldwide fungicide %

US fungicide %

copper, sulfur, mercury

retards growth of sensitive plants

mercury now banned

Fungicide percentage of market of herbicides? less important in US than other parts of world

Worldwide fungicide %20

US fungicide %8

31.C

To kill or halt fungi development, fungicides usually ________ spore gemination or _______________.

31.D

Which fungi enter plants readily?

Penetration often involves ____ between aqueous and lipid phases.

Transport thru cell or syncytium by ___________.

negatively charged

non-cationic fungicides

spores have hard time penetrating

Penetration often involves ____ between aqueous and lipid phases. partitioning

Transport thru cell or syncytium by ___________. protoplasmic streaming.

31.E

different types of fungicides, how are each used

chemotherapeutants apply before symptoms appear

protectants apply before pathogens come

eradicants apply to pathogen, long before disease and symptoms

seed treatments particularly for grain crops

systemics absorbed and translocated to growing points so full protection

31.E

define apoplastic, symplastic, and acropetal

apoplastic is moving UP

symplastic is moving DOWN

acropetal is moving to tip or margin of the same leaf

31.E

Advantages and disadvantages to using systemics

GOOD: eradicant properties, stop progression of existing infections, therapeutic, reduce environmental contamination

BAD: resistance/cross resistance (single gene mutation gives resistance)

32.A Multivalent or Multiple Targets.

Most multivalent targets are ____.

Resistance is ____. (low / high)

Early fungicides are _____ (cheap / expensive), _____ (un / reliable)

Most multivalent targets are ____. thiol reactive inhibiting enzyme sulfhydryl (SH) groups

Resistance is ____. (low / high) because of difficult in selecting against multiple targets.

Early fungicides are _____ (cheap / expensive), _____ (un / reliable)

32.B 

Mode of action of dithiocarbamates?

What reverses effects?

32B.

First organic fungicides?

thiram

zineb

despite nonsystemic action they are still very major fungicides

32B

Examples of dithiocarbamates

isothiocyanate

ethylenebisdithiocarbamtes (EBDCs)

thiram

maneb

32B

What are control problems for use of dithiocarbamates?

32B

Restriction of use of dithiocarbamates?

32B

Diethylamine analog of thiram is used medicinally to treat ____.

32C

Mode of action of phthalimides

nonspecific at -SH and -SR groups, inhibits enzymes

interferes with mitosis

32C

How are phthalimides used?

as a protective fungicide

foliage dusts and srpays

32C

Health hazards of phthalimides?

mutagens, possible carcinogens

teratogenesis (related to thalidomides by structure but does not give the same type of teratogenesis)