LS302 Defense Mechanisms in Plants and Animals

Any change in environmental conditions that negatively impacts a plant's growth and development.

A plant's ability to adapt or survive in adverse environmental conditions.

Permanent changes in plant structure and function to withstand long-term stress.

Soil saturation with water, leading to oxygen deprivation in roots.

Plants' mechanisms against damaging reactive oxygen species.

Various factors in the environment that negatively affect plant growth.

Environmental stress caused by insufficient water availability.

Methods plants use to avoid stressful conditions, without active metabolic response.

Low temperatures can harm plants by damaging cell membranes, denaturing proteins, and disrupting cellular processes.

Plants activate a signaling pathway involving the CBF protein to regulate cold-responsive genes and enhance freezing tolerance.

A DNA sequence in cold-responsive genes that the CBF protein binds to, activating transcription.

Plants adjust to cold conditions by increasing the concentration of sugars like sucrose, which helps stabilize membranes.

Low temperatures can cause cellular damage through membrane rupture, protein denaturation, and the formation of ice crystals.

Plants activate various defense mechanisms against pathogens and injuries.

Plants have built-in protective mechanisms, like physical barriers and chemical compounds, to resist pathogens.

Plants produce enzymes to break down and neutralize harmful pathogens.

A condition where plants are exposed to high levels of toxic heavy metals, impacting their growth, development, and overall health.

Heavy metals harm plants by disrupting cellular processes, including competitive uptake of essential nutrients, interfering with protein function, displacing essential cations, and generating harmful reactive oxygen species (ROS).

Heavy metals persist in the environment and accumulate in soil, water, and plants, potentially entering the food chain and posing risks to human health.

Radiation exposure can harm plants, causing growth abnormalities, reduced yield, and even cell damage, but some plants have evolved adaptations to survive in radioactive environments.

Plants exposed to radiation can develop protective mechanisms, such as altered growth patterns, increased antioxidant production, and potential DNA repair mechanisms.

UV-A radiation can promote plant growth but also cause damage to photosynthesis by affecting the light-harvesting processes.

UV-B radiation can impair photosynthesis by inhibiting the function of a key protein complex (Photosystem II) and altering gene expression related to its production.

Plants have developed mechanisms to tolerate UV radiation, including synthesizing protective pigments and altering their growth patterns to minimize exposure.

UV-C radiation, while effective at killing microorganisms, can damage plant DNA, impair photosynthesis, and cause morphological changes.

UV radiation harms the photosystem II (PSII) complex, reducing Rubisco activity and hindering photosynthesis.

UV radiation can alter the production of plant growth hormones, affecting development and morphology.

Plants face challenges when oxygen is limited, like during waterlogging.

During anaerobiosis, plants switch to ethanol fermentation, producing less toxic compounds to avoid self-poisoning.

Anaerobic conditions cause temporary acidity in plant cells, triggering key enzymes like pyruvate decarboxylase.

Without oxygen, plants switch from efficient oxidative phosphorylation to less efficient fermentation, producing less ATP.

Even during anaerobiosis, plants need a constant sugar supply for energy production.

The process of a plant expressing specific genes to adapt to oxygen-deficient conditions, resulting in the production of enzymes for glycolysis and sugar-phosphate metabolism.

Specific enzymes such as alcohol dehydrogenase, pyruvate decarboxylase, and lactate dehydrogenase are produced by plants in anaerobic environments to help them survive.

A plant's ability to survive stressful conditions by using stored energy reserves without actively modifying its metabolism.

Rhizomes (underground stems) of wetland plants store energy reserves, allowing apical buds to survive anaerobic winter conditions with low metabolic activity.

Water-submerged plant shoots elongate rapidly to reach air and sunlight, driven by even gentle stress.

Highly reactive molecules like superoxide radicals and hydrogen peroxide produced in plants, potentially damaging cells.

ROS play a role in plant signaling pathways, influencing processes like root hair growth and stomatal movement.

The process of forming a protective layer of suberin on plant tissues, like roots, to prevent water loss and resist pathogens.

Specialized tissue in plants, particularly in roots, that contains large air spaces to allow oxygen transport to submerged roots during floods.

Enlarged lenticels on plant stems, which are pores that allow gas exchange. They become bigger in response to flooding stress.

Roots that grow from unusual locations on the plant, such as stems, to help access water and nutrients in flooded conditions.

The absence of oxygen, a condition that occurs in waterlogged soils, making it difficult for roots to function.

This occurs when a plant cannot take in enough water to meet its needs, due to low water availability in the soil.

Plants experience stress due to extreme temperatures, either too hot or too cold, disrupting their growth and survival.