Nutrition and Transport

Plant Nutrition

ELEMENT TYPICAL AMOUNT IN WHEAT PLANTS
(mg/g dry matter)
USE IN PLANTS DEFICIENCY EFFECTS
Nitrogen 40 Amino acids and proteins Poor growth, yellow leaves
Sulphur 3 Proteins Yellow leaves
Phosphorus 3 Nucleic acids and ATP Poor growth, leaves dull green with curly brown edges
Potassium 35 Helps protein and chlorophyll formation, & resistance to disease Yellow edges to leaves, die early
Calcium 3 Cell formation Poor buds, stunted growth
Magnesium 2 Needed for chlorophyll formation Yellow leaves
Iron 0.1 Needed for chlorophyll formation Yellow leaves


Overview of Transport in Tracheophyte Plants

WHERE TRANSPORT OCCURS SUBSTANCES TRANSPORTED METHOD OF TRANSPORTATION DIRECTION OF MOVEMENT REASON FOR MOVEMENT
Soil to root hair Water and soluble nutrients Osmosis and active transport Into plant To provide water required for photo-synthesis, to provide turgidity necessary to open stomata for gas exchange and transpiration
Root hair to root cortex As above Osmosis through cell cytoplasm and vacuoles Into plant As above
Root cortex to xylem As above Diffusion through cell wall pores and inter-cellular air spaces Into vascular bundle (Xylem) As above
VASCULAR BUNDLES (a) xylem to leaf cells containing chlorophyll As above Osmosis, diffusion, transpiration pull, root pressure Upwards to leaves To provide water to cells in leaf (Mesophyll) that contain chlorophyll for photosynthesis
(b) phloem to cells containing mitochondria Soluble inorganic ions, organic material (sucrose and amino acids) Active transport Up and down To provide nutrients to cells for respiration
Cells to stomata Water and carbon dioxide Diffusion Out of plant Reduces carbon dioxide concentration in plant and remove water (by-product of respiration)


The Root

4 Root Regions are:

  1. Root Cap - a toughened thimble-shaped covering of cells on the tip of the root
  2. Meristem - the region of greatest cell division (mitosis) from which all root cells are produced
  3. Zone of Elongation - the region where cells elongate to lengthen the root by taking in water
  4. Zone of Maturation - the region containing root hairs, and where the cells differentiate into the permanent cells of the root

Cross-Section of the Zone of Maturation


Movement of Water and Mineral Ions into the Root


The Stem

Cell Wall and Cytoplasmic Pathways


Stem Structure


Transport of Water, Mineral Ions and Nutrients in the Stem


Other Features of Stems


The Leaf

Leaf Cross-Section


Action of Stomata


Transport of Water, Mineral Ions and Nutrients in the Leaf


Did You Know That...? The tips of the stinging hairs of stinging nettles are actually made of glass that the plants manufacture from silicon in the soil.