hort301 phytohormones. phytohormones are naturally produced in plants chemicals regulating plant...
Post on 21-Dec-2015
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Phytohormones are• Naturally produced in plants• Chemicals regulating plant growth,
development and differentiation• Active at low levels • Present in several major classes:
a. Auxinsb. Gibberellinsc. Ethylened. Cytokininse. Abcisic acidf. Brassinosteroids
Gibberellic acid (GA)
• About 136 GAs with structural similarity
• Only a few are “active”: e.g. GA1, GA3, GA4, GA5 and GA7
GA biosynthesis pathway
Sumagic (Uniconazole-P)
Mutation in dwarf pea
Ultradwarf:No GAs
Dwarf:Contains :GA20
Traces of GA1
Tall:Contains:GA1
Experiment A+B: Effect of GA/GA inhibitor on pea growth
GA or Control solution GA inhibitor or Control solution
•Label pots (group and lab number, treatment)•Measure internode length of 2x 5 dwarf and 2x 5 tall pea plants
•Measure internode length of 2x 5 dwarf and 2x 5 tall pea plants again after 2 weeks in class (MONDAY Oct. 5th)
Treat dwarf plants with GA or Control solution
Treat tall plants with GA inhibitor or Control solution
Experiment C: Effect of auxin/pH on segment growth
•Cut maize seedlings in exactly 1 cm long segments using a razor blade (15x)
NOTE: Do not let the cut segments dry out!
•Label each dish
•Place five sections in a Petri dish containing either A) IAA (Auxin) solutions of 10-4MB) low pH water, pH 4.5C) neutral pH water, pH 7.0 (control)
•Incubate overnight in the dark.
•The next day (Sept. 22nd) measure the total length of all segments after incubation
•Calculate mean value and standard deviation. Compare the segment length of each treatment
Experiment D: Effects of ethylene on soybean seedlings
1
2
3
“Banana”
•Measure the height of the plants
•Place one pot each in a bag a) With a banana b) With a banana in a GreenBag c) Without a fruit
•Wait four days and come back to measure plant height again (FRIDAY Sept. 25th)
Todays experimental planGA treatment of dwarf mutant in pea
Measure length of 2x 5 pea plantsApply GA or Control solutionMeasure length of plants again after 2 weeks (MONDAY 5th)
GA inhibitor treatment of pea plantsMeasure length of 2x 5 pea plantsApply GA biosynthesis inhibitor or Control solutionMeasure length of plants again after 2 weeks (MONDAY 5th)
Auxin treatment of maize seedling segmentsCut maize seedlings in 1cm segments (15x)Place segments in IAA, low pH or Control solution Measure length of segments the next day (TUESDAY 22nd)
Ethylene treatment of soybean seedlingsMeasure length of 3x 5 soybean plantsPlace pot with 5 plants in bag with banana, wrapped banana or no bananaMeasure length of plants again after 4 days (FRIDAY 25th)
Pipettes
P1000
P200
P20
1000uL = 1ml
Use for: 200-1000uL
200uL = 0.2ml
Use for: 20-200uL
20uL = 0.02ml
Use for: 2-20uL