Presentation on theme: "Chapter 6 Roots Plant organ systems. What are the primary functions of roots?"— Presentation transcript:
Chapter 6 Roots Plant organ systems
What are the primary functions of roots?
Fibrous and taproot systems
Root cap Parenchyma Mucigel Perception of gravity
Dicot root, l.s. Region of cell division Region of elongation
Region of maturation
Mature root structure
Monocot root, c.s.
Dicot root, c.s.
Phloem Xylem Endodermis
Endodermis regulates mineral absorption
Lateral (branch) roots
Specialized roots Storage roots
Cypress pneumatophores, Black River, NC
A barrel cactus 2 feet tall and 1 foot in diameter has roots more than 10 feet long. However, all of the roots are found in the soil no deeper than 6 inches. Why would a plant in such a dry climate have such shallow roots?
Aerial roots (poison ivy)
Aerial roots Velamen (orchids)
Aerial roots – velamen (orchids)
Prop roots – Mangrove swamp
Mycorrhizae A mutualistic fungal association with roots
Nitrogen fixation research Ammonia diffusion hypothesis of nitrogen transport into plants
Group activity If N is supplied as alanine, what does this imply the plant is able to do? As a scientist, what would you look for in a plant that would support the hypothesis that N is supplied as alanine?
Parasitic roots Witchweed
Parasitic roots Oscula of witchweed (Striga sp.)
Human uses of roots
yams sweet potatoes cassava
Rosemary's Root Beer Tonic Ingredients (4 servings) 3 oz Sassafras Bark, dried 2 oz Sarsaparilla root, dried 1 oz Dandelion Root, dried 1 oz Burdock Root, dried 1/2 oz Ground Ginger root 1/2 oz Ground Cinnamon 1/4 oz Orange Peel, dried Mix together all ingredients and store in a tightly closed container. In a large pot combine 1 quart of water and 4 tablespoons of dry mixture. Bring to a boil, cover and simmer for 15 to 20 minutes. Strain and sweeten with honey or stevia (also called "sweet herb") if desired. Source: Vegetarian Times, April 1993 link
Herbal medications Ginger
Valerian extract, derived from the dried rhizomes and roots of the plant, has been used for thousands of years as a folk remedy, tranquilizer and calmative for several disorders such as restlessness, nervousness, insomnia, hysteria, menstrual problems, and as a sedative for "nervous" stomach. Valerian extracts are currently used in scores of compounds and teas in Europe. Valeriana officinalis
Rotenone comes from Derris root and Lonchocarpus species leaf (Family: Leguminosae) It is an insecticide and also used as a fish poison. Rotenone disrupts cellular respiration and death is relatively slow compared to most nerve toxins. Rotenone is extremely toxic to fish and is used as a fish poison by South American Indians and in water management programs.
Root research CO 2 concentration and root growth CO 2 concentration and root growth Phytoremediation and molecular farming Phytoremediation and molecular farming –Mercury detoxificationMercury detoxification –TNT detoxificationTNT detoxification Root cap function Root cap function
-disrupts the uptake of nutrients and water -interferes with plant growth -vector for viruses Root nematodes
Root nematode damage
Root nematodes reduce crop productivity
Root nematode research Plant nematology at Cornell Plant nematology at Cornell Baum lab – Iowa State Baum lab – Iowa State Eric Davis - NCSU Eric Davis - NCSU