Climate Change - Effects on Agriculture

Question 1

What does FAO say on cultivated areas affected?

Answer 1

Climate changes with only 3.5% safe from envrionmental limitations.

Question 2

Examples of crop yield change depending on geographic location?

Answer 2

Northern Europe with cooler temperatures has lower crop development.
Southern Europe means extream temperatures and low rainfall are limiting.

Question 3

Example of crops being affected differently?

Answer 3

Wheat has 6% reduction in crop yield per degree decrease in temperature.

Question 4

What causes dorught and temperature susceptibility?

Answer 4

RUBISCO enzyme disruption at temperatures above 35C.

Question 5

How does combined effect of drought and temperature affect plants?

Answer 5

Decrease in function of Photosystem II

Question 6

Inflorescence

Answer 6

This is the shape of the flower and their organization into branching systems.

Question 7

Example of crop reproductive phases being altered?

Answer 7

In cereals, flower intiation and infloresence is affected by water stress.

Question 8

When does sterility occur in cereals?

Answer 8

30C temperatures.

Question 9

How do water deficits in wheat affect wheat/rice in meisois?

Answer 9

35-75% decrease in grain set.

Question 10

What is plant response variable in among species?

Answer 10

Gene expression, metabolism, physiology and among cells/tissues.

Question 11

What does drought conditions with elevated CO2 caue?

Answer 11

ROS formation and crop stress due to CO2 clogging in stomata with excess oxygen.

Question 12

How does ROS negativel affect plants?

Answer 12

Plant development photosynthesis and respiration and inhibition of macromolecules.

Question 13

WOsmo-protectants

Answer 13

These are small organic molecules with neutral charge and low toxicity at high concentrations acting as osmolytes

Question 14

Importance of ROS in plants?

Answer 14

Cruical secondary signals in metaoblism, but promopt apoptosis at high levels.

Question 15

Metabolomic

Answer 15

This is the systematic study of all chemical processes concerning metabolites.

Question 16

Turgor Pressure

Answer 16

This is the force within cells pushing the plasma membrane against the cell wall.

Question 17

How does drought stress affect plants?

Answer 17

Turgor pressure
RUBISCO deactivation
Rubisco activase breakdown

Question 18

Whay does RUBISCO deactivation result in?

Answer 18

Xylulose-1,5 biphosphate formation which is inhibitory.

Question 19

Example of hormone variation under abiotic stresses?

Answer 19

Abscisic Acid, Ethylene

Question 20

What does Abscisic acid do for plants?

Answer 20

Regulates stress response by interactiong with various other hormones and stomatal regulation, seed germination and dormancy.

Question 21

Why is ABA important?

Answer 21

Regulation against climatic stresses

Question 22

Phytohormones

Answer 22

These are plant produced chemicals regulating growth, development, reproduction, longevity and death.

Question 23

Function of ethylene?

Answer 23

Gaseous being important in cell-cell interactions.

Question 24

How are CO2 effects tested?

Answer 24

Free Air CO2 Enrichment Experiments

Question 25

How does CO2 depend on photosynthesis?

Answer 25

Elevated CO2 in C3 has increase of 20% aboveground biomass.

Question 26

What is increasing biomass limited by?

Answer 26

Nitrogen and water availability.

Question 27

How do crops respond to CO2?

Answer 27

Many crops(wheat, soybean, rice, beans and peanut) increase in seed yield due to increased shoot biomass.

Question 28

What does CO2 increase in soya?

Answer 28

Seed yield, root length, root nodules and leaf size.

Question 29

Stomatal Index

Answer 29

This is the ratio of stomata to epidermal cells.

Question 30

What is an example of shoot architecture changing?

Answer 30

A CO2 responsive regulator of starch accumulation(CRCT) increases leaf sheath starch content and tilelring angle.

Question 31

Why is tillering angle important?

Answer 31

Gives branches a wider lateral spread.

Question 32

Why has wide tillering angle been selected against?

Answer 32

To favour crop density in plantations.

Question 33

What carbon metabolic processes are altered by CO2?

Answer 33

Sugar metabolism, glycolysis and ETC due to PS assmilation and respiration rate stimulation.

Question 34

How might transcriptional changes arise from CO2 effects?

Answer 34

Effects on master regulators.

Question 35

Why does root to shoot ratio increase with CO2?

Answer 35

Preferential mineral/water acquistion

Question 36

How does temeprature increase differ from CO2 increase?

Answer 36

CO2 increase linear across the globe whilst temperatures is more dependent on geographical location.

Question 37

Rubisco Activase

Answer 37

This is an enzyme removing inhibitory molecules from RUBISCOs catalytic site.

Question 38

How does temperature affect carbon assmiliation by RUBISCO?

Answer 38

Reduced function of Rubisco activase, as RUBISCO is stable up until 50C

Question 39

How is drought stress variable among region?

Answer 39

Already dry regions more severe.

Question 40

Functional Equilbriium Theory

Answer 40

Plants shift allocation among tissues of resources to optimise acquistion of most limiting resources.

Question 41

Why might root tissue investment over shoot be favoured?

Answer 41

Optimises water acquistion whilst reducing surface area for water loss by transpiration.