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1.11: Plant Hormones

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    Plant growth regulators (phytohormones) are small organic molecules that occur naturally in plants. Phytohormones can regulate plant physiological growth processes such as flowering, germination, stem elongation, seed dormancy, fruit ripening, and gene expression.

    There are several phytohormones such as gibberellic acid (\(\mathrm{GA}_{3}\)) can increase stem growth parameters. Moreover, ethylene can affect fruit ripening in bananas.

    \(\PageIndex{1}\). Student Learning Outcomes (SLOs)

    • SLO 11.01: Apply the best practices for learning phytohormones
    • SLO 11.02: Describe the characteristics of Auxins and Cytokinins
    • SLO 11.03: Describe the characteristics of Gibberellins and ABA
    • SLO 11.04: Describe the characteristics of Ethylene and Salicylic acid
    • SLO 11.05: Identify given plant species with their scientific names based on their key features
    • SLO 11.06: Explain the differences between natural and synthetic phytohormones
    • SLO 11.07: Explain the reason why ABA is named as a stress hormone

    \(\PageIndex{2}\). Big Picture


    \(\PageIndex{3}\). Vocabulary and Key Concepts


    \(\PageIndex{4}\). Test Your Knowledge

    • Assessment 11.3.1: TRUE or FALSE: Phytohormones affect plant development process [growth + differentiation]
    • Assessment 11.3.2: TRUE or FALSE: Brassinosteroids act locally.
    • Assessment 11.3.3: Define seed dormancy and provide a specific function for plants.
    • Assessment 11.3.4: TRUE or FALSE: GAs promote bolting (flowering and flower stalk)

    \(\PageIndex{5}\). Can You Spot These Plants?


    \(\PageIndex{6}\). Check Your Answers

    1. TRUE
    2. TRUE
    3. Seed dormancy causes not germination of viable seeds even under favorable conditions. Seed dormancy is survival mechanism of controlling germination.
    4. TRUE

    This page titled 1.11: Plant Hormones is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by Gokhan Hacisalihoglu (Florida State Open Publishing) via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.