Bioe 20B Plant Nutrition (Nov 7) PDF

REMINDERS ANNOUNCEMENTS 1. Discussion sections this week are on your own: Scavenger Hunt Thursday, 11/7/24 2. Due Sunday: HW 6, Quiz 6, Mid-Course Check In 3. Midterm 2 is on November 21st (Development to Photosynthesis) Week 6, Day 2 4. Extra credit for being caugh...

REMINDERS ANNOUNCEMENTS 1. Discussion sections this week are on your own: Scavenger Hunt Thursday, 11/7/24 2. Due Sunday: HW 6, Quiz 6, Mid-Course Check In 3. Midterm 2 is on November 21st (Development to Photosynthesis) Week 6, Day 2 4. Extra credit for being caught up with videos by Nov. 19th Plant Nutrition TODAY’S AGENDA (8-9:35AM) Macronutrients & Micronutrients Soils – not just for mud fights Mutualisms – Fungi & Bacteria help fix nitrogen & get nutrients 5 min-break Creative Nutrition: Carnivores & Parasites Kahoot! NUTRITION EXTREMES IN NATURE Plant DEBATE of the Day Brambles (blackberry bushes) are carnivorous…or are they*? Sheep farmers believe they are…do you? *Plant can utilize nutrients from animals that get caught in its branches but does it NEED them to survive? Plant Nutrition  Learning Goals for Today 1 Macronutrients & Micronutrients 2 Soils – not just for mud fights 3 Mutualisms – Fungi & Bacteria help fix nitrogen & get nutrients 4 Creative Nutrition: Carnivores & Parasites Macro & Micronutrients Macronutrient: Nitrogen Phosphorus Potassium Purpose: Green foliage Strong roots Plant growth and blooms “up” “down” “all around”  Macro & Micronutrients What is most plant biomass built from? Carbon from fixing carbon in photosynthesis What is the difference between macronutrients and micronutrients? For nucleic For acid/protein coenzymes synthesis Macronutrients (more than 1g/kg dry mass): Nitrogen, phosphorous, Potassium, Sulfur, Calcium, Magnesium Micronutrients (less than 1g/kg dry mass): Zinc, iron, manganese and more Macro & Micronutrients What are essential nutrients in plants? Nutrients needed for plant to complete normal lifecycle How can we determine what is an essential nutrient? Control = plant will all nutrients given Hydroponics experiment Experiment = plant will all nutrients minus X nutrient *key difference b/w animal and plant à plants = generational  Learning Goals for Today 1 Macronutrients & Micronutrients 2 Soils – not just for mud fights 3 Mutualisms – Fungi & Bacteria help fix nitrogen & get nutrients 4 Creative Nutrition: Carnivores & Parasites Soils What is soil composed of? Living Non-living Living and non-living components Bacteria Gravel, sand, silt, clay Fungi Water Viruses Air Worms Minerals Insects Dead organic matter Soils What is loam? Soil that is made with a balance of all 3 soil types: 40% sand, 40% silt, 20% clay Soils Why is it important to have a mixture? Clay helps hold onto nutrients that would otherwise leach out of topsoil Sand helps with drainage Air spaces can hold O2 and H2O Soils The negative ions (anions) tend to dissolve in water = prone to leaching Soil is composed of inorganic and Lost from system organic matter including ions. (inaccessible to plant roots) Remember Negative ions Nitrogen NO3- or NH4+ Phosphorus H2PO4- Potassium K+ Sulfur SO42- Calcium Ca2+ Magnesium Mg2+ Clay has an important role to play in soil and plant health: Cation Exchange Soils Clay has a negative charge How does clay help with leaching? K+, Ca2+ Mg2+ all positive (Cations) tend to stick to clay Plants take advantage of this to get the nutrients they need…how? Cation Exchange!  Soils Describe the process of cation exchange How do plants detach the ions they need and get them into their roots? 1) Transporters in root hairs are pumping H+ into soil 2) Cellular respiration in root releases releases more H+ 3) H+ binds clay more strongly than the other ions = Kicks ions off clay and makes available for plant root = CATION EXCHANGE  Learning Goals for Today 1 Macronutrients & Micronutrients 2 Soils – not just for mud fights 3 Mutualisms – Fungi & Bacteria help fix nitrogen & get nutrients 4 Creative Nutrition: Carnivores & Parasites Mutualisms Myco = Mechanism “mushroom”, for finding “fungus” Mutualism Partner Benefits to Plant Other Notes each other Fungi Strigolactones Ectomycorrhizal: (Mycorrhizal Associations) released from Penetrate through ↑ nutrient/H2O plant attract apoplast only Ectomycorrhizal absorption due to fungi. Ex: woody plants (pines, oaks) Arbuscular/ ↑ SA in roots endomycorrhizal: Arbuscular/endomycorrhizal Penetrate into plant Ex: most herbaceous plants root cells Bacteria Bacteria break Low O2 environment Flavonoids down triple- helped by production of Rhizobia Bacteria and other leghemoglobin makes bonded N2 plant the breaking of the triple Ex: legumes Free living soil bacteria produced bond by nitrogenase (peanuts, do this all the time chemical more favorable. Form soybeans, peas, compounds nodules! beans) Mutualisms How does plant give the bacteria the anaerobic environment it needs to fix nitrogen? Bacteria get sequestered in vesicles with a lignified wall Leghemoglobin – binds O2 Mutualisms If you were to graph the leghemoglobin/oxygen dissociation curve, would you expect it to be left-shifted or right-shifted? Left-shifted to hold onto oxygen more tightly for conditions to be anaerobic Review Plants can form two kinds of mutualisms. Mycorrhizal _______________ Associations are mutualisms formed with a fungus which provides the plant with increased ____________ nutrients largely by increasing the ____________ Surface area of the plant roots. bacteria A second kind of mutualism is formed with ___________ nitrogen which provides the plant with ______________. Mutualisms How do plants form mutualism with fungi? Strigolactones! Mutualisms What is the tradeoff of the plant sending out a strigolactone signal to the surrounding environment to attract fungi? Parasitic plants can hijack the signal originally meant Parasitism for mutualism with fungi. Parasite Symbiosis Fungi Mutualisms Witchweed (Striga) is a parasitic plant that can intercept a strigolactone signal.  Learning Goals for Today 1 Macronutrients & Micronutrients 2 Soils – not just for mud fights 3 Mutualisms – Fungi & Bacteria help fix nitrogen & get nutrients 4 Creative Nutrition: Carnivores & Parasites  5-min Break! Attendance Time Scan the QR code or go to https://tinyurl.com/W6D2plantnutrition to answer the following question: Q: Provide 3 examples of essential nutrients that plants need to survive. (This will be used for taking attendance today.) Creative Nutrition Why might carnivory have evolved in plants? Carnivory in plants is an adaptation that allows plants to thrive in low nutrient and especially low nitrogen soils. Creative Nutrition  Creative Nutrition How is the snapping mechanism of the Venus flytrap similar to an action potential? Depolarization from contact with a root hair must pass threshold similar to sodium entering a neuron  These are the notes that go with the plant nutrition lecture that is online. Key Points to Know: What are the main macro and micro nutrients for plants? What is an essential nutrient in a plant? What are the key components of soil and why do you need a mix of gravel, sand, and clay? What is cation exchange and how do plants take advantage of negatively charged clay particles in the soil? What are the two sources of protons for cation exchange? Plants form mutualisms with a fungus (Mycorrhizal Associations) and with bacteria (rhizobia bacteria) among others. Compare and contrast these associations. What does the plant get out of each and what does the fungus and bacteria get out of each? What organisms fixes nitrogen – plant or bacteria? Rhizobia bacteria need a low oxygen environment to fix nitrogen – how does the plant provide this?  On your own… Compare and contrast mycorrhizal/plant symbiosis and rhizobia bacteria/plant symbiosis. What are each of the players? What does each player get out of it? How do they find each other? Why are these symbiotic associations beneficial? Kahoot Review: Plant Nutrition