Plant Tissues and Propagation Techniques

Plant Systems Overview

• Plants are composed of tissues. Three main types are dermal, ground, and vascular
• Meristematic tissues are actively dividing cells responsible for plant growth. They are located in the meristems in various regions of the plant
• Different types of meristems exist according to location: Apical Meristem, Lateral Meristem, and Intercalary Meristems
• Non-Meristematic or Permanent Tissues are cells that are no longer actively dividing, and have differentiated into Dermal, Ground, and Vascular Tissues
• Dermal tissues protect the plant, covering it with a single layer of cells called the epidermis. Small pores (stomata) within the epidermis are responsible for gas exchange (CO2, O2), water vapor release
• Ground tissues make up most of the plant's interior, responsible for food and water storage, and metabolic processes
  • Parenchyma tissue: spherical/elongated, thin primary cell walls, main component of young plant organs, photosynthesis and storage.
  • Collenchyma tissue: elongated cells, unevenly thickened primary cell walls, provide mechanical support to stems and leaves.
  • Sclerenchyma tissue: dead cells, thick secondary cell walls, support older plant organs and add strength.
• Vascular tissue carries substances throughout the plant
  • Xylem transports water and dissolved minerals from roots to other parts of the plant.
  • Phloem transports sugars and amino acids from site of production (like leaves) to other areas
• Plant systems include shoot system (stem, branches, leaves) and root system (anchors plant, absorbs water and nutrients)

Plant Organ Systems

• Shoot system: Includes stems, branches, leaves, flowers, and buds
• Root system: Anchors the plant, absorbs water and minerals from soil. It's largely underground

Monocot vs. Dicot

• Monocots: One cotyledon in seeds, parallel leaf veins, scattered vascular bundles (in stem), lack a typical cambium, adventitious root system
• Dicots: Two cotyledons in seeds, net-like leaf veins, vascular bundles arranged in a ring, typical cambium present, usually a taproot system

Plant Parts

• Leaf: Veins (parallel or netlike), blade/lamina
• Leaf Apex, Leaf Base, Petiole, Margin, Midrib, Venules

Plant Circulation

• Vascular tissues (xylem and phloem) transport water, nutrients, and products of photosynthesis throughout the plant
• Xylem moves water and dissolved minerals upwards
• Phloem transports sugars, amino acids, and some ions

Plant Nutrition

• Plants absorb inorganic nutrients and water from the soil, via roots
• The stem transports materials between the roots and other parts of the plant
• Leaves contain chlorophyll to capture light energy for photosynthesis, a process that produces food for the plant

Plant Respiration

• Stomata, small openings in lower epidermis of leaves, allow for exchange of gases (water vapor, oxygen, and carbon dioxide).
• Guard cells regulate opening and closing of stomata

Plant Response to Stimuli

• Tropisms are directional movements in response to stimuli
• Phototropism: Growth response to light
• Geotropism: Growth response to gravity
• Hydrotropism: Growth response to water
• Thigmotropism: Growth response to touch/contact

Plant Reproduction

• Asexual reproduction: Requires one parent, offspring genetically identical to parent
• Sexual reproduction: Two parents, offspring genetically variable, involves fertilization

Plant Flower Anatomy

• Parts of a flower: Sepal, petal, stamen (filament, anther), pistil (stigma, style, ovary), ovule

Plant Pollination

• Pollination: Transfer of pollen (containing male germ cells) from anther of a flower to stigma
• Self-pollination: Pollen transfers between anther to stigma in same flower or different flowers in same plant
• Cross-pollination: Pollen transfers between anthers and stigma in different flowers of the same species
• Pollinators (insects, birds) transfer pollen

Vegetative Propagation

• Methods of asexual reproduction using vegetative parts (stems, roots, leaves)
• Types: Cuttings, Layering, Grafting

Types of Plants

• Angiosperms: Flowering plants with seeds enclosed in ovaries (fruits)
• Gymnosperms: Non-flowering plants with seeds not enclosed in ovaries
• Ferns: Non-flowering plants with spores