The Physiological Basis of Drought Tolerance in Crop Plants: A Scenario-Dependent Probabilistic Approach

Flashcards about drought tolerance in crop plants

What spatial and temporal scales does drought tolerance involve?

Mechanisms operating at different spatial and temporal scales, from rapid stomatal closure to maintenance of crop yield.

What do short-term drought tolerance mechanisms control?

Stabilizing shoot water potential.

What do long-term drought tolerance processes relate to?

Acclimation strategies for specific drought scenarios.

What is the result of short- and long-term feedback processes?

Trade-offs between carbon accumulation and the risk of deleterious soil water depletion.

What is a probabilistic approach used for in drought tolerance?

Estimating the benefit and risk of each combination of alleles.

What is water deficit in plants?

Results from insufficient soil water availability to meet the demand of a particular plant or canopy at a particular time, resulting in a change in plant water status.

What two factors does plant transpiration rate combine?

Evaporative demand and shoot characteristics

What is evaporative demand?

Transpiration rate of a given plant or canopy at a given time if soil water status was optimum; depends on leaf area, vapor pressure deficit, and wind dynamic

What is hydraulic conductance?

A ratio of the water flux between two points to the difference in water potential between those points

What is hydraulic capacitance?

A ratio of the change in tissue water content to the change in water potential

What is vapor pressure deficit (VPD)?

Difference between partial pressure of water vapor in leaves and atmosphere; driven by temperature, light, and air humidity

What is Air VPD?

Difference between partial pressure of water vapor in the air and that in water-saturated air at the same temperature; used in many studies

What is abscisic acid (ABA)?

A plant hormone with higher rate of biosynthesis under water deficit, which promotes stomatal closure; it affects many other processes, particularly root and shoot hydraulic conductance and root architecture

What is an environmental scenario?

A clustered pattern of time courses of soil water status, evaporative demand, light, and temperature in different fields; a given field can belong to different scenarios in different years

What are aquaporins?

Intrinsic membrane proteins that form pores facilitating water transfer through membranes

What are isohydric plants?

Plants that keep leaf water potential in a narrow range under water deficit and high evaporative demand through stomatal control

What are anisohydric plants?

Plants whose leaf water potential is left to fluctuate in a large range under water deficit and high evaporative demand

What are Plasma membrane intrinsic proteins (PIPs)?

A group of aquaporins that facilitate water transfer through the plasma membrane

What is water use efficiency?

A ratio of carbon capture to water consumption by a plant; may be instantaneous or integrated over the crop cycle

What is grain abortion?

Termination of the development of ovaries (prefertilization) or young grains (postfertilization), with large consequences on the grain number per unit of soil area