Plant Physiology

Plant Physiology (Biology 327) - Dr. Stephen G. Saupe; College of St. Benedict/ St. John's University; Biology Department; Collegeville, MN 56321; (320) 363 - 2782; (320) 363 - 3202, fax; ssaupe@csbsju.edu

Pre-Lab Preparation: Stomata Lab

I. Questions

1. Define abaxial and adaxial.

2. Sketch and label a dicot-type stomatal apparatus.

3. Sketch and label a monocot-type stomatal apparatus.

4. The following diagram represents guard cells/stomata in a field of view in the microscope. Assume that the width of the field is 300 mm. Calculate (a) area of the field; and (b) stomata mm².

***diagram not inserted***

5. What can you conclude from the following data extracted from Woodward, FI (1988) Plants Today, July-August.

Date	CO₂ Partial Pressure
1700	27.7
1800	28.0
1850	28.6
1900	29.3
1950	31.2
1989	33.0

CO₂Partial Pressure (Pa)	Stomatal Density (% value at 34 or 35 Pa)
28	135
29	130
30	125
31	120
32	110
33	105

II. Safety

Biological Materials. All are non-hazardous.
Chemicals - Avoid contact with buffers and abscisic acid solutions.
Safety Eyewear - not required, though you are encouraged to wear goggles when handling chemicals.
Other.
Disposal. Materials can be disposed in garbage or down drain

III. Lab Materials

Plants

Broad beans (.3 wk, 1 per person)
Greenhouse plants (i.e., Wandering Jew, maize or other grass)

Chemicals

50 mM potassium phosphate buffer pH 6.0 (880 mL 50 mM KH₂PO₄ and 120 mL of 50 mM Na₂HPO₄)
50 mM KCl
10 uM Abscisic acid (FW 264.3; dissolve .0026 g in acetone make up to 100 mL)
1 M salt or sucrose in dropper bottle
immersion oil

Supplies

jeweler forceps
lens paper
60 x 15 mm petri dishes (4 per pair)
kimwipes
microscopes fitted with ocular micrometers
coverslips
stage micrometer
slides
aluminum foil � small squares to cover petri dishes
tool kits (with tape, ruler, marking pen, razor blades)