Grand Green Challenges Flashcards
Grand Green challenges
Using molecular plant sciences to increased world food production
A growing world pop
- 2000: 6 bill
- 2050: 9.7 bill
- 2080: 10.4 bill
The silent pandemic
- 1bn suffer from famine + malnutrition
- 9 million due to the big 3 combined
- 6.3 million COVID-19: ‘20-‘22
Fluctuating food prices
- health is an economic concern
- sociopolitical factors
- climate and weather
Ukraine global shares
- wheat: 10%
- corn: 15%
- barley: 13%
Other plant uses
- animal feed (corn, grass, soybean)
- biofuels (soybeans, sugarcane, rapeseed, palm oil)
- fibres (cotton, flax, paper, hemp)
- construction (wood, bamboo, straw)
- fertiliser (seaweed, legumes, compost)
- horticulture (cut flowers, out/in-door plants)
- medication/recreation (artemisinin, taxol, morphine, nicotine, caffeine)
- molecular pharming
- phytoremediation
Solutions to improve food production
- Farm more land; No
- Increase yields ; yes
- Lifestyle changes ; yes
Land use for food production
- 50% habitable land
- 77% for meat and dairy (including feed)
Crops
- 82% calories
- 63% proteins
Changing our food choice will drastically
< land use
Additional challenges
- climate change (less land and less predictable water)
- pollution (less fertiliser, less pesticides)
Less land
- urbanisation
- rewilding
- non-food crops
- climate change
Less predictable water
- less underground water
- salinification
Less fertiliser
- N and P runoff; eutrophication; algal blooms; < biodiversity
Less pesticides
- vapour drift
- environmental + human health
Main crops (>10M km^2)
- Wheat
- Maize
- Rice
- Barley
- Sugarcane
- Soybean
- Cassava
- Rapeseed
Land use per crop type
1) cereals (wheat, rice)
2) coarse grains (maize, barley, oat)
3) oilcrops (rapeseed, palm)
4) pulses (soy, bean, pea)
5) roots, tubers (potato, cassava)
6) fruits (citrus, banana)
7) vegetables (tomato, lettuce)
8) tree nuts (almonds, cashew)
Europe
1) wheat
2) barley
3) maize
4) rapeseed
Americas
1) soybean
2) maize
3) wheat
4) sugarcane
Africa
- Maize
- Cassava
- Rice
- Wheat
Asia:
- Rice
- Wheat
- Maize
- Soybean
How to grow a crop plant…
- synchronously
- in optimal soil
- w/ optimal nutrients
- @ optimal water levels
- w/o disease, pests or weeds
A craft!
Crop domestication
Selection over millennia
Domestication syndrome
1) no fruit abscission
2) more, bigger fruits
3) circadian interference
4) determinate growth
5) colour variation
6) no vernalisation
7) ^ seed no
8) < seed shattering
9) < height
10) < dormancy
Conventional breeding
- trait introgression
- limited by reproductive barriers
- use high production varieties
Marker-assisted breeding
- use background markers to select F1 progeny with most recurrent parent markets
- smallest % donor genome
- e.g. virescence mutants
Speed breeding
- accelerate life cycles (increase generation no/ year)
- photoperiod modifications (flowering; temperature, earlier reproduction; circadian clock)
How to ^ genetic variation
1) ^ germplasm (create seed stock centres)
2) mutagenesis (chemical [EMS]/radiation [UV/gamma])
3) trans/cis gene transformation (not in EU)
4) genome editing: Precision Breeding Act
CRISPR-Cas9
- ORF disruption (indel)
- gene deletion
- base edits
- replacement (inefficient HR in plants)
Precision breeding
Genetic changes which could have arisen through traditional breeding or natural processes
Advantages of CRISPR-Cas9
Can be:
- transgene-free
- DNA-free (VIGE)
Key challenges of the future
1) drought-resistance
2) flood resistance
3) disease resistance
4) low N; nodulation
5) low P; AM symbiosis
6) improved photosynthesis
7) flowering time
8) morphology
Germination
- problem: low viability, low vigour, dormant seeds
- solution: QC, seed coating, priming
- e.g. sprouting wheat ears w no dormancy
Cold/frost damage
- problem: growing ice crystals disrupt cell structures
- solutions: adjust germination/ flowering times; acclimation; antifreeze proteins; cryoprotectants (trehalose, proline)
Biofortification
- problem: low nutritional value (vitamins, minerals, AAs)
- solution: metabolic engineering (breeding / GM Crops)
- e.g. golden rice (vitA); wheat (selenium); beans (iron)
Morphology
- problem: can we domesticate faster (via crop engineering?)
- solutions: domestication genes
New crops!
- problem: susceptible, low-yielding, monoculture
- solutions: domesticate other wild plants
- e.g. quinoa (seeds), echium (oil), nettle (fibre)
Weed control
- problem: environmental impact; herbicide R
- solutions: safer herbicides; safeners; Roundup GMO; precision farming
