Môn Sinh học - Chapter 37: Plant nutrition

Ch. 37 Warm-UpWhat conclusions should we draw from van Helmont’s experiment?Where would you expect a deficiency of a relatively immobile element to be seen first in a plant? (pg. 756)What are the possible consequences of selling off water rights to cities and developments?Chapter 37Plant NutritionWhat you need to know:Mutualistic relationships between plant roots and the bacteria and fungi that grow in the rhizosphere help plants acquire important nutrients.Nonmutualistic nutritional adaptations enable plant survival in adverse habitats.Nutritional RequirementsEssential element: required for plant to complete life cycle and produce another generationMacronutrients (large amounts): CHNOPS + K, Ca, MgNitrogen = most important!Micronutrients (small amounts): Fe, Mn, Zn, Cu, etc.Soil QualityTexture – topsoil w/ humus (decayed organic material) prevents packing of clay  porous (retain H2O) yet aeration of rootsChemical compositioncation exchange: roots add H+ to soil to replace cations (K+, Ca2+, Mg2+) absorbed by plantSoil particle surrounded byfilm of waterRoot hairWateravailableto plantRoot hairAir spaceCation exchange in soilSoil waterSoil particleAvailability of soil water and mineralsMutualistic Relationships:Rhizobium bacteria supply nitrogen at roots (fix atmospheric N2 to usable N)Plant supplies sugar & amino acidsMycorrhizae (plant + fungus)Role of soil bacteria in the nitrogen nutrition of plantsUnusual nutritional adaptations: epiphytes, parasitic plants, canivorous plantsEpiphyte: grow on another plant, absorb H2O from rain through leavesParasitic Plants: not photosynthetic; absorb sugar and minerals from living hostsCarnivorous Plants: photosynthetic, but obtain some nitrogen and minerals by digesting small animals