Trichome - Plant hair | Unique Functions скачать в хорошем качестве

Trichome - Plant hair | Unique Functions

Trichomes are hair-like structures on the epidermis of plants. Many animals are covered with fur, which they use for insulation, warmth, and courtship displays. Surprisingly, many plants are also covered with hair, known as unique trichome structures evolved from their epidermal cells. While animals can move freely to avoid predators, plants can't. That's why these trichomes become their first line of defence against enemies! Unlike animal hair, though, trichomes are often living cells. Glandular trichomes, on the other hand, secrete chemical substances. Glandular trichomes appear to be the stars of the tomato show when it comes to pest resistance. Depending on the type, they secrete an array of biological and chemical weapons from built-in glands, including sesquiterpenes, methylketones, acylsugars, jasmonic acid, and monoterpenes. These do everything from producing unappealing smells and tasting bad to trapping insects Take Basil (Ocimum basilicum) for example. Its leaves are covered with glandular trichomes that secrete a pungent and intense fragrance of essential oil, causing most insects to steer clear of it. As for humans, they make the most of Basil's aromatic properties and extract its essential oils to create natural mosquito repellents. Additionally, many people adore the unique aroma of basil and often use it as a common herb in cooking. Multi-functional trichomes Trichomes are used for more than just defence in plants. The trapping mechanism of carnivorous plants like the Venus Flytrap (Dionaea muscipula) is actually made up of various unique trichomes. First, the glandular trichomes on the trap secrete nectar to attract prey. When an unsuspecting prey enters the trap, it triggers the sensors inside and causes the trap to close. Finally, the glandular trichomes secrete enzymes to break down and digest the prey, giving full play to the functions of the trichomes. They serve various functions, such as protection against herbivores, reducing water loss, and reflecting excess light. Understanding trichomes involves examining their structure, development, functions, and diversity among plant families. Types of Trichomes 1. Glandular Trichomes: *Secrete* substances like essential oils, resins, and mucilage. Common in families like Lamiaceae (mint family) and Asteraceae (daisy family). 2. Non-Glandular Trichomes: “Do not secrete" substances but provide physical protection. Found in many plant families, including Solanaceae (nightshade family) and Brassicaceae (mustard family). Functions of Trichomes 1. Protection: Act as a physical barrier against herbivores and pathogens. Some trichomes can trap insects, aiding in defense. 2. Environmental Adaptation: Reduce water loss by reflecting sunlight and reducing airflow across the leaf surface. Insulate against extreme temperatures. 3. Chemical Defense: Glandular trichomes can produce toxic or deterrent chemicals to ward off herbivores. 4. Interaction with Pollinators: Some trichomes produce scents or sticky substances that attract pollinators. Trichome Development 1. Cellular Basis: Trichomes originate from epidermal cells. Their development is regulated by genetic and environmental factors. Involves cell differentiation and specialized gene expression. 2. Genetic Regulation: Key genes like GLABRA1 (GL1) in Arabidopsis thaliana are crucial for trichome formation. Transcription factors and signaling pathways play significant roles in trichome development. Major Plant Families with Trichomes 1. Asteraceae (Daisy Family): Diverse types of glandular and non-glandular trichomes. Examples: Sunflowers, daisies. 2. Lamiaceae (Mint Family): Rich in glandular trichomes producing essential oils. Examples: Mint, basil, lavender. 3. Solanaceae (Nightshade Family): Non-glandular and glandular trichomes present. Examples: Tomato, potato, tobacco. 4. Brassicaceae (Mustard Family): Non-glandular trichomes common. Examples: Mustard, cabbage, Arabidopsis. 5. Fabaceae (Legume Family): Variety of trichome types. Examples: Peas, beans. Functions of Trichomes: 1. **Protection**: They protect plants from herbivores by making the plant less palatable or harder to eat. 2. **Environmental Stress**: Trichomes can reduce water loss by trapping moisture and creating a microenvironment around the leaf surface. 3. **UV Radiation**: They can protect plants from harmful UV radiation. 4. **Temperature Regulation**: Trichomes can reflect light and reduce leaf temperature. 5. *Defense**: Some trichomes are glandular and can produce substances that deter insects and other pests. #hairyplant #Trichome #planthair #plant_hair #role #function #explained