Chapter 13 Plant secondary nutrients
Chapter 13 Plant secondary nutrients
Calcium
Calcium
Calcium in physiology Uptake and translocation Higher plants often contain appreciable amounts Ca and generally in the order of about 5-30 mg Ca/g dry matter The high Ca2+ concentrations related with the high Ca+ levels in media, not related with the Ca2+ uptake mechanism of the roots cells The uptake rate of Ca2+ is usually lower than that of k+ Why
Calcium in physiology ◼ Higher plants often contain appreciable amounts Ca and generally in the order of about 5-30 mg Ca/g dry matter ◼ The high Ca2+ concentrations related with the high Ca2+ levels in media, not related with the Ca2+ uptake mechanism of the roots cells. ◼ The uptake rate of Ca2+ is usually lower than that of K+. ◼ Why ? Uptake and translocation
RADIAL ROOT TRANSPORT Phloem Casparian Xylem with heat stri secondary walls Cellular pa (symplast and transmembrane) Cortex Root hair Epidermis Stel Apoplast pathway Endodermis Casparian stri 9 1998 Sinauer Associates, Inc
Uptake and translocation This low Ca2+ uptake potential occurs because Ca2+ can be absorbed only by young root tips in which the cell walls often are still unsuberized未木栓化 The amount of absorbed by the plant depends on the concentration in the root medium and is also genetically controlled The calcicole(钙生植物)> calcifuge(避钙植物 Dicotyledons>monocotyledons This is related with cation exchange capacities and oxalate content in the tissue
Uptake and translocation This low Ca2+ uptake potential occurs because Ca2+ can be absorbed only by young root tips in which the cell walls often are still unsuberized未木栓化. The amount of absorbed by the plant depends on the concentration in the root medium and is also genetically controlled. The calcicole(钙生植物)>calcifuge(避钙植物) Dicotyledons>monocotyledons This is related with cation exchange capacities and oxalate content in the tissue