Plant Hormones: Ethylene
Explain ethylene synthesis, perception, transport, and interactions with growth, senescence, abscission, stress, and cannabis reproductive expression.
Educational reference · evidence, sources, and limits shown below
Explain ethylene synthesis, perception, transport, and interactions with growth, senescence, abscission, stress, and cannabis reproductive expression.
Terms to know
- Ethylene
- Gaseous plant hormone produced from methionine through ACC and involved in development and stress responses.
- ACC
- 1-aminocyclopropane-1-carboxylic acid, immediate precursor of ethylene.
- Abscission
- Programmed separation of an organ through a specialized cell layer.
- Senescence
- Regulated decline and nutrient remobilization preceding organ death.
Core science
Ethylene is synthesized by living tissues and diffuses through air spaces. It participates in seedling responses, cell expansion, root architecture, wound signaling, flooding responses, senescence, abscission, and interactions with pathogens. Production and sensitivity vary by organ, stage, oxygen, injury, and other hormones.
Because ethylene is a gas, measured room concentration reflects tissue production, air mixing, ventilation, leakage, and other removal processes. However, internal synthesis and perception continue even in a ventilated room. Mechanical damage, pathogens, root hypoxia, and senescing tissues can raise local signaling before a room sensor detects anything.
Cannabis sex expression has been manipulated experimentally with compounds that affect ethylene synthesis or signaling, and ethylene-related genes are part of the reproductive network. These tools do not reduce sex determination to one hormone. Genotype, photoperiod, developmental stage, stress, and interacting pathways remain important.
Why this matters in cultivation
- Remove diseased and decomposing plant waste promptly and investigate the cause of premature abscission. Ventilation is useful, but it is not a substitute for root and disease control.
- Treat any chemical manipulation of ethylene signaling as a regulated experimental operation requiring label, exposure, residue, and reproductive-containment review.
Measure and record
Tissue/event
Organ, stage, wound, wilt, root hypoxia, disease, senescence, or abscission event.
Environment
Temperature, airflow, ventilation, plant density, root-zone oxygen risk, and waste load.
Ethylene measure
Sensor or assay method, location, calibration, sampling time, and detection limit.
Treatment
Compound identity, active ingredient, concentration, legal status, timing, and controls.
Response
Leaf angle, abscission, senescence, root response, flower sex expression, and recovery.
Common misconceptions
Correction: It regulates many vegetative, stress, and reproductive processes.
Correction: Plants synthesize and perceive ethylene internally and locally.
Correction: Sex expression is genetic and developmental, with hormonal and environmental modulation.
Evidence limits
Room ethylene measurements can miss local tissue concentrations. Cannabis chemical-manipulation results are treatment- and genotype-specific and may not be lawful for consumable crops.
Related encyclopedia topics
- THC-ENC-015–018, THC-ENC-073–080, THC-ENC-195, and THC-ENC-241–260.
Source notes
- Taiz L, Moller IM, Murphy A, and Zeiger E. Plant Physiology and Development. 7th ed. Oxford University Press, 2022. Publisher record
- Garcia-de Heer L, Kretzschmar T, and Mieog J. Harnessing Sex Reversion via Chemical Intervention in Cannabis sativa L. Plants. 2026;15:1291. Open source
- THC – Teaching Healthy Cultivation. Cannabis Plant Science Source Packet v1. May 2026. Project source packet.
- Canadian Food Inspection Agency. The Biology of Cannabis sativa L. (Cannabis, Hemp, Marijuana). 2021. Open source
This lesson summarizes the source material and its evidence limits for education. Use direct measurement, controlled comparison, and the cited sources when conditions differ or a decision carries meaningful risk.