L39: How Plant Cells Respond to Stimuli

Calcium Ion (Ca2+)

Key factor in cellular signalling and movement.

Polymerisation

Process of joining monomers to form polymers.

[Ca2+] Gradient

Concentration difference of calcium ions across a membrane.

Signal Cascade

Process transmitting a signal through a series of steps.

Second Messenger

Molecules amplifying and transferring signals within cells.

Stimulus-Response Coupling

Linking external stimuli to cellular responses.

Guard Cells

Cells regulating stomatal openings for gas exchange.

Stomata

Pores in leaves allowing gas exchange for photosynthesis.

Abscisic Acid (ABA)

Hormone triggering stomatal closure during drought.

Ion Channels

Proteins regulating ion flow across cell membranes.

Potassium Channels

Ion channels specifically allowing K+ movement.

Chloride Channels

Ion channels specifically allowing Cl- movement.

Voltage Clamping

Technique measuring ion channel activity under controlled voltage.

Patch Clamp Technique

Method for studying single ion channel proteins.

Jaffe's Laws

Principles governing stimulus-response relationships in signalling.

Hydraulic Valves

Structures controlling fluid flow in plants.

Transpiration Stream

Movement of water through plants driven by evaporation.

Solute Movement

Transport of ions and molecules across membranes.

Turgor Pressure

Pressure from fluid in cells maintaining structure.

Light Signals

Stimuli affecting plant growth and stomatal movement.

Auxin

Plant hormone influencing growth and development.

Cytokinins

Hormones promoting cell division and growth.

Drought Stress

Condition causing water deficiency in plants.

Gating Mechanism

Process controlling ion channel opening and closing.

Calcium Oscillations

Fluctuations in calcium ion concentration affecting signalling.

Photosynthetic Demand

Need for CO2 during photosynthesis influencing stomata.

CO2 Concentration

Level of carbon dioxide affecting stomatal behavior.

Water Scarcity

Limited availability of water for agricultural use.

Virtual Water Trade

Water embedded in traded agricultural products.

Crop Transpiration

Water loss from plants affecting agriculture.

Stomatal Conductance

Rate of gas exchange through stomata.

Guard Cell Memory

Ability of guard cells to 'remember' Ca2+ changes.

Signal Amplification

Increasing the strength of a biological signal.

Biologically Meaningful Form

Transformed signal that elicits a cellular response.

Environmental Stress

External conditions negatively impacting plant health.

Pathogen Response

Plant reaction to infections or diseases.

Elicitors

Molecules triggering plant immune responses.

Photosynthesis

Process converting light energy into chemical energy.

Agricultural Water Use

Water consumption for farming activities.

Water Table Drawdown

Decline in groundwater levels due to extraction.

Stomatal Opening Signals

Factors promoting the opening of stomata.

Stomatal Closing Signals

Factors inducing the closure of stomata.

Ion Transport Regulation

Control of ion movement across cell membranes.

Calcium Buffering

Process of maintaining stable calcium ion levels.

K+ Efflux

Outward movement of potassium ions from cells.

Cl- Efflux

Outward movement of chloride ions from cells.

ABA-Induced Ca2+ Rise

Increase in cytosolic calcium due to ABA.

Signal Transduction Pathways

Series of molecular events translating signals into responses.

Photosynthetic Efficiency

Effectiveness of photosynthesis in converting light to energy.

Crop Yield

Amount of crop produced per unit area.

Water Importer

Country reliant on imported water resources.

Water Exporter

Country with surplus water resources available for export.