future of forests 3

Question 1

tree metabolism

Answer 1

everything a tree needs to survive
photosynthesis/respiration
respiration: breaking down carbs for energy
water and nutrient transport
reproduction and growth: hormone resource balance to make roots and flowers
defence: acclimatisation and adaptation to stress

Question 2

primary tree metabolism

Answer 2

carbs
lipids
proteins
nucleic acid

Question 3

secondary tree metabolism

Answer 3

hormones/vitamins
phenylpropanoids
alkaloids
terpenoids

Question 4

role of biochem in plant phenotype

Answer 4

genetic information in plant DNA
genes express to protein
protein function modified
metabolic pathway
biochem reactions are fundamental for visualisable properties of proteins

Question 5

drought as stress

Answer 5

drought is a period of water shortage
factors of stress include intensity, frequency, soil retention capacity and previous water status

Question 6

2 contrasting plant drought stress strategies

Answer 6

dying from thirst (desiccation): hydraulic failure
dying from famine (starvation): carbon starvation bc stomata close to save water
long term strategies for coping with drought e.g. large root system

Question 7

effects of drought on the plants

Answer 7

reduced photosynthesis to save water
reproduction and growth stop to save energy
respiration trying to maintain basal levels for defence
water/ nutrients trying to work

Question 8

aspects of plant defence

Answer 8

hormones (ABA): stomata closure
calcium signalling: secondary messenger for immune response
osmoregulation: coping with environmental stress, maintains plant function
antioxidants (redox activity): delays cell death
waxes

Question 9

3 molecules involved in water perception and pathway signalling

Answer 9

ABA (abscisic acid): stomatal closeure when water is low
reactive oxygen species (ROS): signal water levels and assist hormones
calcium ions Ca2+: aquaporin, cell wall and stomata

Question 10

plant physiological responses to drought

Answer 10

osmotic adjustment
root growth
leaf adaptation

Question 11

biochemical plant responses to cope with drought

Answer 11

ABA mediated stomatal closure
osmolyte accumulation
cuticular wax and suberin deposition
lignin deposition
aquaporins regulation

Question 12

consequences of drought

Answer 12

water shortage in cells compromises biochemical pathway bc almost 60% of all enzymes require water to function
increase in electrons causes redox activity and over production of ROS
ROS are toxic to cell
damage DNA and proteins
hard to remove ROS when they accumulate

Question 13

molecular adaptations of a plant

Answer 13

drought stress triggers activation in gene expression: can occur naturally or be modified
active drought-tolerant genes
protect cellular structures from desiccation
epigenetic modification (adding methyl group to repress expression)

Question 14

long term effect and ecological modification

Answer 14

lower tree vitality: more risk of pest/pathogen
forest dieback directly (plant die by drought) or indirectly (pathogen risk)
increased vulnerability to wildfires due to waxes and resins to protect the tunt
reduced biodiversity

Question 15

future directions on biomolecular studies

Answer 15

genetic modification for drought tolerance
forest management strategies
climate change adaptation: long term effects on tree epigenetics and stress memory
biotech application: bioengineering solutions e.g. drought resistant root stock

Question 16

molecular impacts of drought on Holm Oak

Answer 16

proteome
metabolome
transcriptome
maternal
(Mediterranean forest)
also seen in English Oak: temperate forest

Question 17

young seedling drought tolerance

Answer 17

seedling stages at germination point are most susceptible to stress
using proteome and transcript profiling and testing redox activity: shows LEA, HSP and catalase levels are highly impacted
heat shock proteins produced

Question 18

maternal inheritance and transgenerational tolerance

Answer 18

intra and inter specific study
compared well irrigated vs drought conditions to test offspring drought tolerance
physiological and proteomic analyses conducted on seedlings during drought
metabolic analysis and NIRS on acorns
evidence of inheritence

Question 19

location of DNA mehylation

Answer 19

can occur in 3 different positions on the DNA

Question 20

Maternal inheritance links to epigenetics

Answer 20

• have the seedlings proceeding from trees under dry locations (more frequent drought) any advantages to future drought?
• are there paternal trees teaching their genetic information to respond better?

Question 21

Plant vaccines and induced resistance

Answer 21

Induced resistance, small stress induced resistance to stress (in this case drought)
similar mechanism to vaccine
plant hormone (ABA) and non-proteic animo acid can increase drought resistance, reducing mortality rates

Question 22

Summary of drought effects

Answer 22

• Effects of drought stress pathway:
  Increase ROS
  Lower CO2 intake (closed stomata to save water)
• Response of drought stress pathway:
  stomatal closure, cuticle thickens
  enhancing phytohormones
  increase root length and density
  increase compounds that can protect against ROS activity including sugars (antioxidants)