Dry adapted planted

Question 1

Xerophiles Ways to adapt to water stress

Answer 1

escapees, avoiders and tolerance

more water loss more water needs to be absorbed from roots

Question 2

How can transpiration rates be controlled

Answer 2

stromata control

airspaces

Question 3

How are plants osmoregulated to maintain turgor for rigidity

Answer 3

accumalation of osmotically activesubstrates
non structural sugars
stress metabolites
proline

Aquaporins regulation- water channels- NPA residues(water interactions, diffferent types in different membranes of the cell(complexity of subunit assembly in ER and modification in golgi)

Question 4

What strategies have plants evolved (xerophytes)

Answer 4

Rapid loss of water to surve in intense desiccation.
Shed leaves
Roots- long roots or loose roots in dry season
thick epidermis
Plant cuticle

Question 5

Biochemical adaptations

Answer 5

CAM photosynthesis
In the dark(cooler) Co2 taken into airspaces, fixed into malic and citric acid by PEP carboxylase
Light(hot)
Stomata stay closed, organic acids released and decarboxylated to CO2 for photosythesis

Two functional forms of PEPC- one at night
differs via specific mutation whihc would affect affinity for the substrate.
Split metabolims of photopsynthesisi in cells
Improtant for synthetic engineering cause food security

Question 6

Plant cuticle

Answer 6

Cutical biosynthesis