Chapter 3: Principles of Plant Growth

1. Chapter 3: Principles of Plant Growth • Plant cell

2. Cell Wall

3. Cell Wall • A rigid outer layer of the cell composed primarily of cellulose and lignin. The cell wall is durable enough to give plants structure and support, yet porus enough to allow water and other materials to pass in and out of the cell

4. The fluid surrounded by plasma membrane Made up of a complex protein matrix or gel Cytoplasm

5. Endoplasmic Reticulum (ER)

6. Endoplasmic Reticulum (ER) • A complex structure consisting of folded sacs & tunnels. Proteins produced by the ribosomes are passed through the ER membrane into the ER lumen, where they are sealed in vesicles for transport to the cell membrane, golgi apparatus, or other cell organelles. ER covered with ribosomes if referred to as “rough ER”. Whereas ER with few or no attached ribosomes is termed “smooth ER”

7. The site of protein synthesis. When found floating freely in the cytoplasm, they produce protein that will be used in the cell. When attached to the ER, they produce proteins used outside the cell. Ribosomes

8. Chlorophyll

9. Chlorophyll • The site of photosynthesis. Chloroplasts synthesize the pigment chlorophyll, giving plants their green color. Chlorophyll, along with other pigments, allow plants to capture and store energy from sunlight, which can later be utilized for photosynthesis.

10. Mitochondria

11. Mitochondria • The site of respiration within the cell. Mitochondria utilize oxygen to produce adenosine triphosphate (ATP). In turn, ATP provides energy for almost all the cell’s chemical reactions. Mitochondria contain DNA and are capable of manufacturing their own proteins.

12. Nucleus

13. Nucleus • The control center of the cell. The nucleus contains chromosomal DNA that regulates the production and structure of proteins within the cell. The nucleus is surrounded by the nuclear membrane, a porous membrane that allows materials to pass in and out of the nucleus.

14. Golgi Complex

15. Golgi Complex • A series of flattened sacs and vesicles. Proteins, as well as other molecules such as hormones & carbohydrates, pass through the various sacs of the golgi complex where they are chemically modified. After modification, the molecules are placed in vesicles for transport within ad out of the cell

16. A fluid filled cavity that stores water, salts, enzymes, food, and other materials required by the cell. They can make up 90% of the cell. The help support the cell. Vacuoles

17. Plant Tissues • Groups of cells that function as a unit. 4 groups. • Meristematic- a region in which undifferentiated cells divide. • Fundamental- parenchyma tissue in monocots. (equivalent of cortex and pith in dicots). Storage units. • Protective- Epidermal “skin” protects. • Vascular- Xylem & Phloem is the transport system.

18. Plant Organs • Groups of tissues form organs. • Roots • Stems • Leaves

19. Root

20. Terminal bud Axillary bud Node Internode Lenticel Terminal bud scar Bundle scar Leaf scar Stem

21. Leaves

22. Photosynthesis 6 CO2 + 12 H20 Green Plant C6H12O6 + 6 H20 + 6 O2 Light Energy

23. Transpiration • Loss of water by the plant. • How does the plant protect itself from losing to much water?

24. Heredity • Plant breeding.

25. Growth –vs- Time • S – shape growing curve. • Why is important to know when the plant is going to start a flush of growth?

26. Temperature • minimum, maximum, optimal temperatures for a crop • wheat min=40 max=90 (when flowering) • crops generally don't grow in areas where average 24 hour temperature <50 or >130

27. Radiant Energy (Amount, quality & duration of sunlight) • amount of light energy received • measured in foot candles • summer day = 10,000 • living room = 20 • crops need 100-10,000 • if not enough light, grow tall (leggy, weak stems) • weed control reduces competition for light • planting rate & row spacing • some plants need shade (tobacco), burlap, lathes, screens

28. Radiant Energy (Amount, quality & duration of sunlight) • energy that travels in wavelengths • short wavelengths = high energy (blue) • long wavelengths = low energy (red) • ultraviolet = invisible

29. Radiant Energy (Amount, quality & duration of sunlight) • amount of light of different colors • plants absorb red & blue, reflect green • smoke filters blue, sun looks red • glass & plastic filter light

30. Water • Photsynthesis • Needed for metabolic functions • Transpiration • Evaporation • Evapotranspiration

31. Atmosphere • The Primary gases are oxygen and Carbon dioxide for respiration and photosynthesis. • Excess sulfur dioxide, ethylene, fluorides & others can harm plants

32. Nutrient Requirement • C HOPKNS CaFe Mg Na Cl Cu Mn Co Zn Mo B • C Hopkins Café; mighty good (but) Not always Clean. CuM’n CoZ’n MoBy? • Nickel

33. Photoperiodism • Some plants needs a certain number of hours of day length to flower • Short day plants (i.e. poinsettias, strawberries, mums) need long nights uninterrupted to flower • Long Day plants (i.e. spinach sugar beets) need short nights • Day neutral (i.e. tomatoes)