Vessels have independently evolved in six different plant groups.

1. Vessels have independently evolved in six different plant groups. Flowering plants have them Conifers Don’t The examples of xylem we will see in the lab all have vessels

2. Phloem is a complex tissue that includes sieve elements Sieve Cells (Conifers) Sieve-Tube Elements (Angiosperms)

3. Sieve Elements Serve as a Conduit for the Movement of Photosynthate This movement is based on a pressure gradient generated osmotically. To generate this gradient sugar must be loaded at the source and unloaded at the sink. Living membranes are necessary for this mechanism to work. Read about phloem transport in the text pp. 722 -726.

4. Sieve elements are greatly reduced.They lose their vacuole, nucleus, and most of the rest of their cellular structure as they mature. Adjacent sieve elements are interconnected by clusters of pores through which materials flow from one element to another.

5. Sieve-tube members are one type of sieve element. They are found only in the flowering plants.

6. Sieve-Tube Members Have Sieve Plates

7. Sieve-Tube Members are Associated with Companion Cells

8. Gymnosperms have a different type of sieve element called a sieve cell

9. Associated with albuminous cells

10. Vascular Tissue System Xylem Always includes tracheary elements Tracheids and/or vessel elements May have Parenchyma Fibers Other types we will not consider

11. Vascular Tissue System Phloem Always has sieve elements If sieve-tube members then also companion cells If sieve cells then also albuminous cells Some plants have sieve elements that are neither. In these cases, the cells are simply called sieve elements May also have Parenchyma cells Fibers

12. Not surprisingly, the differences in the tissue organization between the root, stem, and leaf are related to their function.

14. The environmental pressures to which the root is subject is reflected in its anatomy. These are Anchorage

16. Vascular tissue forms a cylinder inside of the root

17. Basic root functions: Anchorage Absorption

18. The root epidermis must allow for the movement of water and minerals, hence, does not have a cuticle, hence, does not have stomata with guard cells.

19. Root hairs are extensions of individual epidermal cells that increases the surface area for absorbing water and nutrients. Root hairs are simply extensions of basal epidermal cells.

20. In the shoot, axillary buds form new branches.

21. In roots, branching occurs from within in a tissue layer called the pericycle.

22. Shoot System The shoot system is composed of the stem and the leaf. These are subject to different environmental imperatives, and this is reflected in their anatomy.

23. The epidermis of the shoot is associated with a cuticle ………….

24. Shoot System Epidermis is associated with a cuticle, and the epidermis is perforated by stomata.

25. stoma

26. The Epidermis of the shoot is also associated with cellular structures attached to the basal epidermal cells called trichomes

27. These trichomes of Coleus are multicellular and help defend the plant…..

28. In dicot (= Eudicot) stems the vascular tissue is arranged in a ring of vascular bundles embedded in the ground tissue. Unlike in roots, the vascular tissue of the shoot is not restricted to one mass in the center.

30. How does the internal organization of the vascular tissue between the root and stem reflect the different environmental stresses to which each is subject?

31. The basic function of the leaf is Photosynthesis

32. A thin flat structure optimizes the materials used to construct the leaf as this provides the maximum surface area to intercept light. No cell in the leaf is far from the outside this facilitates diffusion of gasses in and out of the leaf

33. Cross section of lilac leaf

34. Cross section of lilac leaf Ground Tissue

35. Dermal Tissue

36. Vascular Tissue

38. The Movement of Water and Solutes in Plants

39. Important Concepts • Plasmodesmata.

40. Important Concepts • Plasmodesmata. • Active Transport

41. Important Concepts • Active Transport: Potassium ions are more than 70x more concentrated in the root cells than in the soil.

42. Important Concepts • Plasmodesmata. • Active Transport • Osmosis

43. Important Concepts • Plasmodesmata. • Active Transport • Osmosis • Hydrogen Bonds • (Cohesion of Water Molecules)

44. Important Concepts • Plasmodesmata. • Active Transport • Osmosis • Hydrogen Bonds • (Cohesion of Water Molecules)

45. Important Concepts • Plasmodesmata. • Active Transport • Osmosis • Hydrogen Bonds • (Cohesion of Water Molecules) • Imbibition • (Adhesion of Water Molecules)

46. Types of Transport in the Plant Body Symplastic – Via Plasmodesmata

47. Types of Transport in the Plant Body Symplastic – Via Plasmodesmata Apoplastic – Via Cell Walls and Intercellular Spaces

48. Types of Transport in the Plant Body Symplastic – Via Plasmodesmata Apoplastic – Via Cell Walls and Intercellular Spaces Transcellular – Across membranes from cell to cell

49. Movement proceeds symplastically, apoplastically and transcellularly through the epidermis and cortex but apoplastic movement into the vascular cylinder is blocked by a layer of cells called an endodermis. • Movement of Water and Minerals in the Root

50. In the roots mineral nutrients are concentrated by active transport and then moved symplastically from parenchyma cell to parenchyma cell to one adjacent adjacent to a tracheary element. These nutrients are then actively transported out of the cell into the apoplast bounded by the endodermis. • This can result in a localized pressure increase called root pressure due to the osmotic (transcellular) movement of water across the endodermis