Plant Organs: Roots PDF

Plant Organs: Roots www.usask.ca Plant Organs § Just like various cells work together to form tissues, several tissues can work together to form organs. § The plant organs we will look at include: § ______________________ roots § ______________________...

Plant Organs: Roots www.usask.ca Plant Organs § Just like various cells work together to form tissues, several tissues can work together to form organs. § The plant organs we will look at include: § ______________________ roots § ______________________ stems § ______________________ leaves § ______________________ inflorescences Roots § Roots will end up making up one-third to half of the total plant dry weight. What are the function of roots? § Roots perform four vital plant functions: § ______________________ absorption § ______________________ 9 nchorage § ______________________ Storage § ______________________ nitrogen fixation Absorption § Roots must have _________________contact extensive with soil particles. Absorb _________________________ water +dissolved nutrients Why do the roots need oxygen? > RESPIRATION - § Plants require large amount of water. According to Alberta Agriculture and Forestry, spring wheat grown under optimal conditions requires 420-480 mm of water per growing season in southern Alberta. Spring wheat will germinate, grow rapidly, and reach a peak water use of nearly 7 mm per day during the flowering and seed formation. Absorption § Roots absorb nutrients such as: simple minerals like _________________ N , P K , S , also absorb vitamins, hormones, and other organic substances that have leached out of decaying material. Anchorage § Roots provide _______________ Support for plants. § Anchor shoots so the plant can remain in a position that allows it to carry out photosynthesis effectively. § Support is needs for environmental conditions such as ___________________ wind+rain § Plants that develop roots poorly are more susceptible to _____________________ lodging Anchorage § __________________ Adventitious Roots roots that are formed from the stem tissue instead of root tissue. § Corn develops a unique anchorage system called ___________________ Prop roots. arise from the stem (above the soil surface) and radiate out from the stem to provide additional support for the plant. Storage § For ___________________________________ b iennial perennial winter-annual , , plants, root storage is very important. § Root storage provides a means for surviving the winter and resuming growth the following spring. At the end of the growing season the plant stores food in the __________________ root. In the spring this food is used for energy to grow a new _________________ shoots. Storage § For some crops such as alfalfa it is very important to allow the plant to store food in the roots for next year. § Cutting to late in the year will prevent this from occurring and increase the likelihood of ________________ winter kill § Other plants also store their food in the roots: Carrot, beet, turnip, radish (not potato) JBIENNIALS [ underground Stem Root Crops § Some of the biennial root crops we harvest include: beets, carrots, radishes We harvest in the ________________________ first yepr of growth and don’t allow these plants to use this stored food to produce seeds the next year. * Sugar Beet § Is an important root crop that is grown for its sugar. § Grown in Southeastern Alberta. § Harvested in fall in the year which they are planted. § Tops are feed to animal, the swollen root is washed, shredded and crushed. Getting the Sugar from Sugar Beet § The juice is collected and refined. § The pulp remaining after the extraction of the juice is a rich food for domestic animals. § The sugar that is produced from the sugar beet is identical to the sugar that is derived from the sugarcane. https://www.youtube.com/watch?v =KuZNSGdg2ms Sesame street https://www.youtube.com/watch?v =VRZX1bAnbes&t=1s Nitrogen Fixation PEAS SOXBEANS LENTIL § Nitrogen fixation occurs in the CHICK PEA ALFALfA __________________ legumes (plants that have their seeds in true pods). § The legumes form unique relationships with bacteria called ___________________________ rhizobium § Note: Frankia is a genus of nitrogen fixing bacteria that live with actinorhizal plants which includes several trees and shrubs that grow in Canada. Nitrogen Fixation § Rhizobium live in the roots of legume plants: form colonies called ______________________ nodules (bumps in the legume roots). § Rhizobium take nitrogen from the soil air and fix it for the plant to use. How much nitrogen is in the air? LOTS Use special enzymes to fix nitrogen. Nodules 00 g PINKISH COLOURN Nitrogen Fixation § It is a _________________________ symbiotic relationship meaning both the bacteria and legume plant benefit by living together. § The plant provides food, water and a safe place for the bacteria to live in return for nitrogen. § Each plant species has its own special strain of Rhizobium that it forms a relationship with. Inoculation § When growing peas, lentil, alfalfa, we _______________ inoculate the seeds with the Rhizobium. § The Rhizobium is purchased in bags usually mixed with peat and spread on the seeds. § Special care must be taken when working with Rhizobium so it stays alive. - EXPIRES expiration date THE DIFFERENCE BETWEEN MONOCOT AND DICOT ROOTS How do roots develop? § The original root, called the ________________, radicle emerges first from the seed to provide the germinating seedling water and nutrients. § At the same time, smaller seminal roots also emerge (side roots).  Tap Roots/Dicot Plants § Dicots: The radicle TAP ROOT forms the tap - root (major -SECONDARY central root). Secondary roots grow from the tap root. Examples of tap roots include: ALfALf A · Tap Roots/Dicot Plants & TAPROOT Fibrous Roots/ Monocot Plants § The primary root system (the radicle) functions for a very short time in monocots. § In monocots, the radicle is replaced by the secondary root system early in the growth of the plant. § This secondary root system develops from the _____________ crown (just below soil surface). § It grows rapidly to form the ________________ fibrous (branching) root system. Fibrous Roots/ Monocot Plants Crown Crown HOW DOES THE ROOT GROW AND FUNCTION? Generalized Root § Tip of the root is protected by a ____________ root cap § The root cap covers the _________________ apical meristem (the growth point). § Root cap can also penetrate hard soils (concrete). § The root cap sloughs off cells which are replace by new cells from the meristem. Cell Enlargement § Behind the apical meristem in the area of _______________________________ cell enlargement § The cells grow and expand pushing the root through the soil. Cell Maturation § Behind the cell enlargement area is the area of cell maturation. § The cells will ______________________ specialize into specific tissues/organs. § Different tissues will perform different functions.  CURATION Generalized Root X - CELL GROWTH ⑳ Roste Root Hairs § Crucially important for absorption. § There are not very long individually, but combined length is huge. § The root hairs increase the __________________ Surface area of the root allowing more cells to be in contact with the soil. § Transplanting: DON'T BREAK ROOT HAIRS Root Hairs ROOT HAIRS - MERISTEM d How roots take up water § Root hairs take up water by _______________ Osmosis § Water (and nutrients) absorb through the outer layers of the root to the center of the root where the xylem is located. § The root’s _____________ Xylem then brings the water to the shoot and the rest of the plant.  Copyright Sourcing Slide 1: Permission: Saskatoon, SK: University of Saskatchewan. Slide 8: Source: https://commons.wikimedia.org/wiki/File:Prop_roots_of_maize_J2.jpg Permission: CC BY-SA 3.0 Courtesy of Jamain. Slide 10: Source: https://pixabay.com/en/carrots-vegetables-plants-170477/ Permission: CC0 1.0 Public Domain. Courtesy of GoGinland. Slide 11: Source: https://commons.wikimedia.org/wiki/File:Carrot_flowers.jpg Permission: CC BY-SA 3.0 Courtesy of Fir0002. Slide 12: Source: https://pixabay.com/en/sugar-beet-harvest-agriculture-crop-837810/ Permission: CC0 1.0 Public Domain. Courtesy of WikimediaImages. Slide 16: Source: https://commons.wikimedia.org/wiki/File:Medicago_italica_root_nodules_2.JPG Permission: CC BY-SA 3.0 Courtesy of Ninjatacoshell. Slide 21: Source: https://commons.wikimedia.org/wiki/File:Dicotyledoneae_Asteraceae_herb_- _root_system,_primary_root_becomes_tap_root_and_lateral_roots.JPG Permission: CC0 1.0 Public Domain. Courtesy of RoRo. Slide 22: Source: https://pixabay.com/en/radishes-root-vegetables-pink-red-201555/ Permission: CC0 1.0 Public Domain. Courtesy of RLeighTardi. Slide 24: Source: https://pixabay.com/en/organic-onions-vegetable-plot-14525/ Permission: CC0 1.0 Public Domain. Courtesy of PublicDomainPictures. Slide 25: Source: https://commons.wikimedia.org/wiki/File:Grass-plant-structure.png Permission: CC BY-SA 3.0 Courtesy of Wackymacs. Slide 26: Source: https://commons.wikimedia.org/wiki/File:2011-03-22_Poa-annua-roots.JPG Permission: CC BY-SA 3.0 Courtesy of Sten Porse. Slide 27: Source: https://commons.wikimedia.org/wiki/File:Tap_Root_%26_Fibrous_Root.png Permission: CC BY-SA 4.0 Courtesy of CRCHF. Slide 32: Source: https://commons.wikimedia.org/wiki/File:Root-tip-tag.png Permission: CC BY-SA 2.5 Courtesy of SuperManu. Slide 34: Source: https://commons.wikimedia.org/wiki/File:Mycorhizae_fungus_(10333483254).jpg Permission: CC BY 2.0 Courtesy of Oregon Caves from Cave Ju8nction, USA.