Cellular Plant Anatomy PDF

The Plant Cell BOT 110  The Plant Cell I. Endosymbiotic Theory II. Eukaryotic Cell III. The Plant Cell 8/30/2024 2 The Endosymbiotic Theory Dr. Ly...

The Plant Cell BOT 110  The Plant Cell I. Endosymbiotic Theory II. Eukaryotic Cell III. The Plant Cell 8/30/2024 2 The Endosymbiotic Theory Dr. Lynn Margulis 3 The Endosymbiotic Theory Eukaryotes arose from a symbiotic relationship between various prokaryotes Large host cell An aerobic prokaryote that evolved into the mitochondria A photosynthetic cyanobacteria that evolved in to the chloroplast 4  Evidences Same size as bacteria Their own DNA and ribosomes Double membrane on the outside Both mitochondria and chloroplast have: The ability to reproduce independently The Endosymbiotic Theory https://www.researchgate.net/profile/Tatiana_Shutova/pu https://media.sciencephoto.com/image/c0231020/800wm blication/265181454/figure/fig1/AS:669515117522946@ 5 1536636251192/A-Electron-microscopy-picture-of-a- higher-plant-chloroplast-B-Light-microscope-image.ppm The Eukaryotic Cell Plant Cell Taylor et al. 2018 Animal Cell Taylor et al. 2018 6  The Eukaryotic Cell Plant Animal Plasma membrane Cytoplasm Cell Wall Nucleus Centrioles & centrosomes Plastids Mitochondria Small vacuoles Large vacuoles Endoplasmic reticulum Cilia or flagella Golgi apparatus Ribosomes 7  Eukaryotic Cell Organelles Cell Nucleus and Endomembrane Mitochondria Cytoskeleton Membrane RIbosomes system 8  plants Three structures that are unique to http://rachithscellanalogy.weebly.com/uploads/9/1/8/9/9189496/3253047_orig.jpg Cell walls Functions: Protects the cell Provides structural support that keeps plants upright Raven and Johnson et al. 2020 Cell walls Synthesized to the exterior of the protoplast. The building blocks of the primary wall are synthesized in the cell Raven and taylor et al. 2020 cytoplasm but exported (via exocytosis) to the exterior where they are assembled into the structural components in the wall.  Middle lamella Primary wall Secondary wall Cell walls Polysaccharides and pectins Cellulose, hemicellulose Cellulose, hemicellulose and pectin and lignin glycoprotein Pectins aid in cell Provides strength Lignin strengthens adhesion and flexibility to cell walls and aids in the cell water conductivity Cell walls Hoefnagels et al. 2019 Lignins Cell walls Plasmodesmata Allows water and small molecules to move from cell to cell Membrane-lined passages Taylor et al. 2018 or channels that connect adjacent plant cells via holes in the primary cell wall Crang et al. 2018 Cell walls 2 forms of plasmodesmata Primary - formed from the sites where strands of endoplasmic reticulum were trapped in the developing cell plate during cytokinesis Secondary - formed by insertion into existing cell walls between https://www.78stepshealth.us/plasma- nondividing cells. membrane/images/3342_900_1399- primary-secondary-cell-wall.jpg Cell walls Plasmodesmata A tube of a plasma membrane containing a cytoplasmic sleeve and a desmotubule Passageway of water and other substances, proteins, mRNA, and viral genomes https://www.researchgate.net/profile/Chih-hang-Wu-2/publication/51075 748/figure/fig1/AS:11431281176239284@1690079142086/Schematic-representation-of-plant- plasmodesmata-Plasmodesmata-are-channels-that-connect.jpeg Cell walls Secondary Cell Walls rigid, thick, and lignified deposited after cell enlargement ceases push inward against the cytoplasm and reduce protoplasmic volume has multiple layers of different orientation https://www.researchgate.net/profile/Amy- and chemical Grunden/publication/272835310/figure/fig1/AS:314894667796480@1452088147987/Structure-of-the-wood-cell-wall-a-Structure- of-a-wood-cell-wall-made-up-of-the-middle.png composition Cell walls Secondary Cell Walls may cover the entire cell surface or be deposited in a helical or spiral fashion depending on cell function Cell walls Pits Holes in the secondary wall represent a secondary cell wall gap in adjacent cells that allows for the high rate of water movement from cell to cell Both simple and bordered pits exist in pit pairs—one pit for each of the two adjacent cells Plastids Anabolic organelles Developmentally related Proplastid – precursor of plastids; found in meristematic regions of the plants Etioplast – chloroplast that has not been exposed to light; contains crystalline bodies that carry the precursor of chlorophyll Gerontoplast – develops from a chloroplast during leaf senescence Plastids Chloroplast Site of photosynthesis Bound by double membrane Contains DNA and ribosomes Larger and more complex than mitochondria Stroma - internal fluid Thylakoids – Interconnected sacs forming a network suspended in the stroma; site of light reaction Granum – a stack of thylakoids Contains chlorophylls and carotenoids Taylor et al. 2018  1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&a Plastids Chromoplast https://images.unsplash.com/photo-1566196725116- uto=format&fit=crop&w=1000&q=80 Pigment synthesis and storage Contain a diversity of carotenoid 0527b2a8a25d?ixlib=rb- https://asset.library.wisc. edu/1711.dl/HHKHHFIQSS pigments (yellow, orange or red) QAV8J/M/h1380- 604cf.jpg Responsible for the color of flowers, fruits and some roots (e.g. carrots and sweet potato) and tubers Ecological functions ▪ To attract pollinators ▪ To aid seed dispersal https://image.shutterstock.com/image-photo/fruits-vegetables- containing-lycopene-healthy-260nw-1551886673.jpg  Plastids Leucoplast Non-pigmented plastids Found in organs that are associated with long term storage such as roots and seeds Three types ▪ Amylopast – starch synthesis and storage; found in roots and storage tissues; may be involved in gravity sensing in the roots ▪ Proteinoplast – protein synthesis and storage; found in many seeds ▪ Elaioplast – lipid synthesis and storage; found in cotyledons of oil seeds, citrus fruits and anthers of flowering plants Vacuoles Largest, fluid-filled organelle with single membrane [tonoplast] Meristematic cells contain numerous small pro-vacuoles which eventually fuse, forming a large acidic central vacuole Contains water, enzymes, salts, weak acids, sugars, ions and pigments Tonoplast 24 Vacuoles Helps the cell grow by regulating turgor (can make up 50-90% cell volume) Small vacuoles in seed storage cells hold protein reserves Contain malic acid in CAM plants https://qsstudy.com/wp-content/uploads/2017/03/turgidity.jpg https://www.researchgate.net/profile/Nathan- Oehrle/publication/321740050/figure/fig4/AS:7208 02018238465@1548864001289/Transmission- electron-microscopy-observation-of-DN47-and- BSH-3-seeds-PSV-protein.png 25 Vacuoles Helps the cell grow by regulating turgor (can make up 50-90% cell volume Small vacuoles in seed storage cells hold protein reserves Contain malic acid in CAM plants Contain anthocyanin pigments to attract pollinators Contain poisonous or bitter compounds https://www.researchgate.net/profile/Nobuhiro-Sasaki- 2/publication/257561529/figure/fig1/AS:614015696908289@1523404158974/Flower-phenotypes-a-microscopic- that protect the plants form herbivores photographs-of-transverse-cross-sections-of-petal.png and fungal attack https://static.wixstatic.com/media/da4d39_dcde60f0afe841e8b1cb08e7bf7f810a~mv2.png/v1/fill/w_800,h_758,al_c/da4d 39_dcde60f0afe841e8b1cb08e7bf7f810a~mv2.png 26  Vacuoles Calcium oxalate crystals Helps the cell grow by regulating turgor (can make up 50-90% cell volume https://www.mdpi.com/crystals/crystals-10-00591/article_deploy/html/images/crystals-10-00591-g002.png Small vacuoles in seed storage cells hold protein reserves Contain malic acid in CAM plants Contain anthocyanin pigments to attract pollinators Contain poisonous or bitter compounds that protect the plants form herbivores and fungal attack Safely stores toxic waste products (secondary metabolites and crystals) Calcium cystolith carbonate crystals lithocyst Vacuoles Helps the cell grow by regulating turgor (can make up 50-90% cell volume) Small vacuoles in seed storage cells hold protein reserves Contain malic acid in CAM plants Contain anthocyanin pigments to attract pollinators Contain poisonous or bitter compounds https://plantae.org/wp-content/uploads/2018/03/Autophagy-1.jpg that protect the plants form herbivores and fungal attack Safely stores toxic waste products (secondary metabolites and crystals) Degrades (autophagy) and recycles old organelles Participate in programmed cell death via https://d3i71xaburhd42.cloudfront.net/bcce5ac25ac140bae41338b0c36cf7f077b92ca7/5-Figure3-1.png autolysis Thank You 29