Podcast
Questions and Answers
Which plant hormone was the first known plant hormone?
Which plant hormone was the first known plant hormone?
What experiment by Charles Darwin and his son Francis led to the concept of plant hormones?
What experiment by Charles Darwin and his son Francis led to the concept of plant hormones?
Which of the following is not a plant hormone?
Which of the following is not a plant hormone?
Which group of plant hormones bear little resemblance to their animal counterparts?
Which group of plant hormones bear little resemblance to their animal counterparts?
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What promotes differential cell elongation in the lower parts of the seedling resulting in it bending toward the light source?
What promotes differential cell elongation in the lower parts of the seedling resulting in it bending toward the light source?
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What are the relatively simple, small molecules such as ethylene gas and indole-3-acetic acid (IAA) collectively called?
What are the relatively simple, small molecules such as ethylene gas and indole-3-acetic acid (IAA) collectively called?
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What is the notable exception among the steroidal hormones in the plant hormones group?
What is the notable exception among the steroidal hormones in the plant hormones group?
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What is the role of the SHAGGY/GSK3-type kinase BIN2 in the BR signaling pathway?
What is the role of the SHAGGY/GSK3-type kinase BIN2 in the BR signaling pathway?
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What did Nemhauser and colleagues demonstrate about the regulation of Arabidopsis hypocotyl elongation by auxin and BR?
What did Nemhauser and colleagues demonstrate about the regulation of Arabidopsis hypocotyl elongation by auxin and BR?
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What remains to be identified for the majority of phytohormones, according to the text?
What remains to be identified for the majority of phytohormones, according to the text?
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What is the role of BRI1 in the BR signaling pathway?
What is the role of BRI1 in the BR signaling pathway?
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What happens to BES1 and BZR1 upon a BR stimulus?
What happens to BES1 and BZR1 upon a BR stimulus?
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What effect does elevating endogenous auxin levels have on plants in hypocotyl elongation assays?
What effect does elevating endogenous auxin levels have on plants in hypocotyl elongation assays?
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What is BIN2's role in the absence of a BR signal?
What is BIN2's role in the absence of a BR signal?
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What do genetic studies suggest about the convergence of auxin and BR pathways?
What do genetic studies suggest about the convergence of auxin and BR pathways?
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What do bioinformatic analysis identify specifically in the promoters of auxin-induced, BR-induced, and auxin/BR-induced genes?
What do bioinformatic analysis identify specifically in the promoters of auxin-induced, BR-induced, and auxin/BR-induced genes?
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Which type of receptor proteins are typically found in bacterial two-component systems?
Which type of receptor proteins are typically found in bacterial two-component systems?
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Which receptors function as negative regulators of the ethylene pathway?
Which receptors function as negative regulators of the ethylene pathway?
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Which protein is a positive regulator of ethylene signaling?
Which protein is a positive regulator of ethylene signaling?
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What stabilizes EIN3 and EIL1, preventing their degradation in the absence of ethylene?
What stabilizes EIN3 and EIL1, preventing their degradation in the absence of ethylene?
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At which point do the ethylene and JA signaling pathways converge?
At which point do the ethylene and JA signaling pathways converge?
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Which signaling pathways appear to converge and mutually regulate some developmental processes?
Which signaling pathways appear to converge and mutually regulate some developmental processes?
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Where are histidine kinase (HK) domains typically found?
Where are histidine kinase (HK) domains typically found?
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What is the function of Ethylene in plants?
What is the function of Ethylene in plants?
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Which hormone promotes seed dormancy and is involved in stress signaling pathways in plants?
Which hormone promotes seed dormancy and is involved in stress signaling pathways in plants?
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What do Cytokinins regulate in plants?
What do Cytokinins regulate in plants?
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What is the function of Gibberellins (GAs) in plants?
What is the function of Gibberellins (GAs) in plants?
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What is a common theme in plant hormone signaling?
What is a common theme in plant hormone signaling?
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What mechanism does Auxin use to regulate SCF–substrate interactions?
What mechanism does Auxin use to regulate SCF–substrate interactions?
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What does the axr2-1 mutant do in relation to auxin response?
What does the axr2-1 mutant do in relation to auxin response?
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Study Notes
- Plants hormones include Ethylene, IAA (Auxin), Cytokinins, JA, BRs, and ABA. Each hormone has distinct functions.
- Ethylene promotes fruit ripening, senescence, and responses to pathogens and abiotic stresses.
- IAA (Auxin) regulates cell division and expansion, vascular differentiation, lateral root development, and apical dominance.
- Cytokinins were first identified by their ability to promote cytokinesis.
- JA is a volatile signal that modulates pollen development and responses to pathogen infection.
- BRs regulate cell expansion and photomorphogenesis (light-regulated development).
- GAs are diterpenoid compounds that promote germination, stem elongation, and the induction of flowering.
- ABA promotes seed dormancy and is involved in several stress signaling pathways.
- Hormonal control plays a role in virtually every aspect of plant growth and development.
- A single hormone can regulate multiple processes, while multiple hormones can influence a single process.
- The effects of each hormone have historically been defined by applying exogenous hormones.
- The discovery of hormone biosynthetic and response mutants has provided new insights into phytohormone roles.
- The molecular mechanisms behind phytohormone action are being elucidated through genetics and molecular analysis.
- Ubiquitin-mediated degradation of key regulatory proteins is a common theme in plant hormone signaling.
- Auxin uses a novel mechanism to regulate SCF–substrate interactions.
- The axr2-1 mutant is a dominant gain-of-function mutation in an Aux/IAA gene, which confers reduced auxin response due to the inability to be targeted for proteolysis by the SCFTIR1 ubiquitin ligase.
- The Ubiquitin-Mediated Proteolysis of Aux/IAA Proteins Regulates Auxin Response.
- The SCFTIR1 ubiquitin ligase ubiquitinates the Aux/IAA proteins, marking them for degradation.
- The hormone promotes Aux/IAA–TIR1 interaction, but the molecular mechanisms behind this regulation are unclear.
- Auxin-induced modification of Aux/IAA proteins has not been discovered.
- The axr2-1 protein constitutively represses auxin response due to the inability to be targeted for proteolysis.
- The effect of the mutation on AXR2 stability has been demonstrated through a pulse-chase experiment.
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Description
Test your knowledge of plant signaling pathways with this quiz. Explore topics like ARF targets, Aux/IAA genes, ethylene, cytokinin, and modular signaling systems.
