PLANT MINERAL NUTRITION 2 Flashcards
Potassium deficient conditions
growth reduction, yellowing, brown necrotic lesions
HAK
high affinity K+ transporter
Low concentration
Requires more energy
Potassium symporter and ATPase
AKT
low affinity K+ transporter
High concentration
Homeostasis
Ability of an organism to maintain an internal stability in response to environmental changes
Calcium
Forms a constituent of middle lamella of cell wall
Required at external surface of plasma membrane and tonoplast for membrane integrity
Acts as a second messenger in signal transduction
Calcium and membrane integrity
Glycerophospholipid
Magnesium
enzyme activities
energy transduction
chlorophyll structure
Magnesium transporters
MGTS
Micronutrients
have a narrow optimal concentration range
Iron
largely insoluble
Interveinal chlorosis
symptom of iron deficiency
poor mobile elements
Chelation
formation of bonds between two or more separate binding sites within a ligand and a single central atom
DTPA chelates Fe
Citrate
Binds to iron
chelates iron –> makes it soluble
Iron strategy 1 *
Dicot
Pea, tomato, arabidopis
Proton pumping ATP in rhizhophere –> Fe3+ and citrate (chelates–> makes soluble)
Reductase –> Fe3+-Chelate is reduced to Fe2+
Fe2+ is uptake using transporter
Iron strategy 2*
monocot
maize, barley, rice
Phytosiderophore (PS) secretes into soil using transporter –> chelates to Fe3-PS –> uses transporter
Fe3+
