Plant Biology: Photoreceptors and Circadian Rhythms

Flashcards covering key concepts related to plant photoreceptors and circadian rhythms.

Plants can detect __ to adjust their circadian rhythms.

Infrared light.

The characteristic period of circadian rhythms in plants is __ to temperature.

Insensitive.

Circadian rhythms may continue for days without __ cues.

Environmental.

Entrainment occurs in plants adapting to __ as the seasons progress.

Day length.

LHY, CCA1, and PRR9 are examples of __ genes in plants.

Circadian rhythm.

Photoreceptors in plants can perceive various __ of light.

Wavelengths.

Phytochrome is a photoreceptor that exists in two inter-convertible __.

Forms.

The inactive form of phytochrome is known as __.

Pr.

The active form of phytochrome that regulates gene transcription is known as __.

Pfr.

Phototropins mediate the __ response towards blue light.

Phototropic.

Positive phototropism is growth __ a light source.

Towards.

Negative phototropism (skototropism) is growth __ from light.

Away.

Phytochromes absorb red light primarily at __ nm.

668.

The action spectrum for phototropism is similar to the __ spectrum for phototropins.

Absorption.

Phototropins participate in light-induced opening of __.

Stomata.

Crytochromes affect __ development in seedlings.

Flowering.

Auxin concentration causes growth towards the __ bud.

Apical.

The light level that influences flowering in plants is linked to __.

Circadian rhythms.

Timing of __ is crucial for plant responses to environmental changes.

Dawn.

Cold stress impacts the overall __ of plant rhythms.

Amplitude.

Cell elongation in response to light is stimulated by __.

Auxin.

The wavelength around __ nm is known for its effects on plant phototropism.

436.

Phototropins can also stimulate __ movement in chloroplasts.

Chloroplast.

Light wavelengths below 300 nm are categorized as __.

Ultraviolet (UV) light.

The phytochromes involved in signaling for photomorphogenesis primarily absorb __ light.

Red.

The photoconversion of phytochrome happens in the __ when red light is absorbed.

Cytoplasm.

The term __ describes the cycle that lasts close to 24 hours in plants.

Circadian.

Plants can detect varying __ levels throughout their environment.

Brightness.

The Pfr form of phytochrome activates __ of genes.

Transcription.

The action of __ receptors includes leaf flattening and biomass accumulation.

Photoreceptors.

Phototropism effects are primarily mediated by __ receptors.

Blue-light.

A chromophore change within phytochrome occurs upon absorbing __ light.

Red.

The light stimulus affects which part of plants ultimately leading to __.

Growth.

Phototropins activate a protein __ cascade in response to blue light.

Kinase.

The timing of __ is observed to influence dusk in plants.

Flowering.

Plant receptor proteins that detect light wavelengths are termed __.

Photoreceptors.

Mechanism of action for cryptochromes is __.

Unknown.

The interaction of light with plants affects their __ behavior.

Growth.

Colonization of light through stomata is regulated by __ receptors.

Phototropin.

The wavelength range of visible light for photoreceptors is approximately __ nm to 750 nm.

400.

Pr form converts to Pfr form upon absorbing __ light.

Red.

The two components of phytochrome function include light absorption and __ to gene transcription.

Signal transduction.

Circadian rhythm sensitivity to __ is a key property for plants.

Temperature.

The major role of phytochrome is regulating __ in response to light cues.

Growth.

Plants adjust to __ by changing their physiological processes.

Photoperiod.

Photomorphogenic responses depend heavily on detailed __ encoding in plants.

Signal pathways.

Photoprotective measures in plants are enhanced by __ responses to UV.

Defense.

Entrainment by light-dark cycles helps plants adapt their __.

Circadian rhythms.

The timing of flowering may involve interactions with __ lengths.

Day.

A key response mediated by blue-light receptors includes __ adjustments to light.

Leaf.

Auxin distribution leads to differential __ in plant growth.

Growth rates.

Shade avoidance is promoted by sensing __ levels in light.

Red.

Phototropism is essential for maximizing __ efficiency in plants.

Light.

The second form of phytochrome may respond to __ light.

Far-red.

Light absorption and chlorophyll synthesis are affected by __ signals in plants.

Phytochrome.

The shape of phototropin changes upon __ blue light exposure.

Absorbing.

Physiological processes such as __ are guided by photoreceptors.

Growth.

Cryptochromes contribute to photoperiodic responses in __ development.

Seedling.