L?? - Abiotic Stress and Food Production

How does land usage effect food production?

Limits increase to food production

What are the impacts and requirements of land extension for food production?

Require different crops

Require water

Have climate impacts

What are the limits to moving non-food crops to marginal land?

Cold

Hot

Dry

Saline

Nutrient poor

Polluted

What happens to good land over time?

Becomes marginal due to over-use, salinization, pollution and climate change

How does irrigation prevent further agriculture?

Irrigation water has salt and a large amount evaporates before reaching the ground leaving salt

Most of our plants don’t grow in soil NaCL > 50 mM

This is secondary salinization

What is the process of producing salt tolerant crops?

Overexpression of a tonoplast Na+/H+ antiporter NHX1

How does NHXI work with the vacuole of plant cells?

Transports toxic Na+ to vacuole in exchange for protons (H+)

What does NHXI overexpression do?

Improve plant growth in salt

What is one of the main crops that is being developed as a naturally tolerant plant?

Halophytes (Salocornia)

What is Salocornia suitable for?

Human Consumption

Oil seed

Biofuel

What is the Yield Gap equation?

Yg = Yp - Y

What is the focus of predicting gain and loss under climate change in plants?

Plant leaf stomata - the nexus of carbon and water cycles

What are the aims of predicting gain and loss under climate change in plants?

Increase Co2 assimilation and crop stress resistance

What stress hormone closes stomata?

ABA

What occurs during water deficit in plants?

ABA produced

Perceived by ABA receptors

Induction of protective response

Closing of stomata in leaves

Reduced water loss

What are the negatives of ABA production?

Reduced CO2 uptake

Overheating

What are the components of measuring gas exchange by infrared gas analysis

Console: Setup conditions and store and log data

Leaf Chamber: Measures gas exchange

How is ABA measured with FRET biosensors?

ABA receptor (PY1) binds to protein phophatase (ABI1)

→ Link to fluorescent proteins

—> ABACUS is a fluorescent ABA sensor

What are the differences between ‘play-it-safe’ protection in plants and ‘Happy-go-lucky’

Play it safe protection

• Growth Arrest, Developmental Delay, Survival

Happy-go-lucky

• Less protection, Continued Growth and Development, Death Risk

What is survival like for Happy-go-lucky plants in rainy fields?

Better yield under transient, moderate stress drought

Will not survive long term stress

Requires Management

What is survival like for Play-it-safe plants in rainy fields?

Less yield under mild drought stress

Will survive and produce seed and long-term stress

Does not need Management

What are the majority of agricultural lines like genetically?

Loss of heterogeneity, inbred lines dominate

Why have agricultural crop lines lost heterogeneity?

Selection by climate change and farmers as well as targeted selection and breeding

What does Qualitative genetics in plants allow?

Generation of defined genetic populations OR natural variation
→ Resistance trait linked to presence of molecular markers

What does determination of traits in plants need to be in terms of Phenomics?

Quantitiative

Precise

High throughput