Course I (Mandatory)

Name of the Course: Tools Plant Science and Human Welfare

30 Hours                                                                                    Credits: 02

Module-1: Plant Science              (15 Lectures)

1. Biodiversity and Significance of Plants (5 Lectures)

1.1.1. General classification of plants.

1.1.2. Various plants types: Herb, Shrub, Tree, Climbers, Creepers.

1.1.3. Botanical marvels: Pitcher plant (Nepenthes), Sun dew (Drosera), Touch-me-not (Mimosa), Rafflesia, Cuscuta

2. Interesting Facts about plants: (5 Lectures)

1.2.1. Do plants talk? (Communication in plants)

1.2.2. Plant movements (example- flower, tendrils etc.)

1.2.3. Plant Defense and mimicry.

3. Aesthetic and Traditional Aspects of Plants (5 Lectures)

1.3.1. Aesthetic Botany: Concept, Significance

1.3.2. Gardens and landscapes (Indoor gardening, Terrace and gallery gardening)

1.3.3. Traditional practices involving plants (Example- Banana leaves, coconut, Rice etc.)

Module-2: Plants in Human Welfare (15 Lectures)

1. Plants as Food (5 Lectures)

2.1.1. Plants as Food (Root, stem, leaves, tuber, corm, flower, rhizome, fruit, seed used as food with one example)

2.1.2. Microgreens (Fenugreek, Wheatgrass etc.)

2.1.3. Plant derived beverages (Tea, Coffee and Squash)

2. Plants in Daily Life (5 Lectures)

2.2.1. Plants used for cosmetics, perfumes, ecofriendly colours, fabrics, soap, shampoo, toothpaste.

2.2.2. Plants used in sports and musical instruments, building infrastructure, furniture, writing- drawing.

2.2.3. Importance of Medicinal Plants - Amla, Brahmi, Chakramuni (Multivitamin plant) and Stevia (Madhuparni).

3. Next Generation Plant Cultivation (5 Lectures)

2.3.1. Hydroponics and Aeroponics

2.3.2. Vertical gardening

2.3.3. Spirulina farming

Internal Continuous Assessment: 40% (20 marks): Field report, Assignments, Presentation and Quiz

Semester End Examination: 60% :( 30 marks)  Any 2 questions out of 4 (15 marks each)

Module-1: Plant Science              (15 Lectures)

1. Biodiversity and Significance of Plants (5 Lectures)

1.1.1. General classification of plants.

1.1.2. Various plants types: Herb, Shrub, Tree, Climbers, Creepers.

1.1.3. Botanical marvels: Pitcher plant (Nepenthes), Sun dew (Drosera), Touch-me-not (Mimosa), Rafflesia, Cuscuta

2. Interesting Facts about plants: (5 Lectures)

1.2.1. Do plants talk? (Communication in plants)

1.2.2. Plant movements (example- flower, tendrils etc.)

1.2.3. Plant Defense and mimicry

1.2.1: Do Plants Talk?

Introduction

Do Plants Talk?

While plants may not talk in the way humans do, with spoken words and conversations, they possess sophisticated means of communicating with each other and their environment. This form of communication is essential for their survival, growth, and interaction with other organisms. Plants use a variety of signals to convey information about their internal states and external conditions. These signals can be chemical, electrical, or mechanical, and they enable plants to respond to environmental changes, defend against predators, attract pollinators, and establish symbiotic relationships with other organisms.

Plants’ communication methods, though different from human speech, are incredibly complex and effective. For example, when a plant is under attack by herbivores, it can release specific chemicals that warn neighboring plants of the danger, prompting them to activate their defense mechanisms. This form of communication ensures that plants can collectively respond to threats, enhancing their chances of survival.

Definition of Plant Communication

Plant communication refers to the exchange of information (signals) between plants and other organisms, facilitating survival, growth, and interaction. These signals can be sent and received within the same plant (intraorganismic communication), between plants (interorganismic communication), or even between plants and other species such as fungi, bacteria, and insects (metaorganismic or transspecific communication).

Types of Plant Communication

1. Interorganismic Communication

Interorganismic communication refers to the interactions between different organisms, such as plants and fungi, insects, or other plants. These interactions are crucial for the survival and growth of plants, as they help in nutrient acquisition, defense against herbivores, and reproduction.

Examples:

• Plant-Fungi Symbiosis: Mycorrhizal fungi form symbiotic relationships with plant roots, extending their network to increase nutrient absorption. In return, the plant provides the fungi with carbohydrates. For instance, the fungi can help the plant absorb phosphorus more efficiently from the soil.

• Plant-Insect Interactions: Plants can release volatile organic compounds (VOCs) when attacked by herbivores. These VOCs can attract predatory insects that prey on the herbivores, thereby protecting the plant. For example, when corn plants are attacked by caterpillars, they release chemicals that attract parasitic wasps, which then lay their eggs in the caterpillars.

• Plant-Plant Communication: Plants can warn neighboring plants of impending threats. For example, when a sagebrush plant is damaged by herbivores, it releases VOCs that neighboring sagebrush plants detect, prompting them to produce defensive chemicals to deter the herbivores.

2. Intraorganismic Communication

Intraorganismic communication involves the signals within the same plant, coordinating activities between different parts, such as roots, stems, and leaves. This type of communication ensures that the plant functions as a cohesive unit, responding to environmental stimuli effectively.

Examples:

• Hormonal Signaling: Plant hormones like auxins, cytokinins, and gibberellins are transported from one part of the plant to another to regulate growth and development. For instance, auxins produced in the shoot tips travel down to the roots, influencing their growth and branching.

• Electrical Signaling: Plants use electrical signals to coordinate responses to injury or environmental changes. For example, when a leaf is damaged, an electrical signal can travel to other parts of the plant, triggering the production of defensive chemicals.

• Mechanical Signaling: Plants can detect mechanical changes such as touch or wind, leading to adjustments in growth. The classic example is the "sensitive plant" (Mimosa pudica), whose leaves fold up when touched, a response coordinated through mechanical and electrical signaling.

3. Metaorganismic (Transspecific) Communication

Metaorganismic communication, also known as transspecific communication, involves interactions between plants and non-plant organisms, including fungi, bacteria, and even animals. These interactions often play a significant role in the plant's ability to thrive in its environment.

Examples:

• Nitrogen-Fixing Bacteria: Leguminous plants form symbiotic relationships with nitrogen-fixing bacteria such as Rhizobium. The bacteria colonize the plant roots and convert atmospheric nitrogen into a form that the plant can use for growth, while the plant supplies the bacteria with carbohydrates.

• Plants and Pollinators: Plants communicate with pollinators through visual signals (brightly colored flowers) and chemical signals (nectar scent). This ensures the transfer of pollen and successful reproduction. For example, the bright colors and sweet scent of a sunflower attract bees, which facilitate pollination.

• Plant-Pathogen Interactions: Plants can recognize the presence of pathogenic microbes and initiate defense responses. This involves the release of specific chemicals that inhibit pathogen growth or attract beneficial microbes to outcompete the pathogens.

Mechanisms of Plant Communication

1. Chemical Signals

Volatile Organic Compounds (VOCs): These are organic chemicals that easily become vapors or gases, playing crucial roles in plant communication.

• Released to warn neighboring plants of herbivore attacks.

  • Unique Mixtures: Each plant species has a distinct blend of volatile compounds, akin to a unique chemical language.

  • Functions:

    • Attract Pollinators: Flowers emit specific volatiles when ready to be pollinated, ensuring successful reproduction.

    • Fruit Signals: VOCs from fruits attract animals that eat and disperse seeds, aiding in seed distribution.

    • Defense: Leaves emit volatiles to repel predators, acting as a chemical defense mechanism.

    • Threat Communication: Plants emit volatiles in response to threats, alerting neighboring plants to prepare defenses.

  • Example: When corn plants are damaged by caterpillars, they release chemicals that attract parasitic wasps, which lay their eggs in the caterpillars. When grass is cut, it releases VOCs that attract predators of herbivores like caterpillars.

Root Exudates: Substances secreted by plant roots into the soil, influencing the surrounding environment.

• Chemicals secreted by roots influence the growth of neighboring plants and soil microbes.

  • Allelopathic Chemicals: These are chemicals that inhibit the growth of nearby competing plants, reducing competition.

  • Example: Black walnut (Juglans nigra) releases juglone, inhibiting the growth of many other plant species nearby.

2. Mechanical Signals

Thigmomorphogenesis: The process by which plants alter their growth in response to mechanical stimulation or physical touch.

• Plants respond to physical touch and mechanical stimuli by adjusting their growth and development.

Vibration Sensing: The ability of plants to detect and respond to vibrations caused by external factors.

• Plants detect vibrations caused by insect movements or environmental factors, triggering defense mechanisms.

  • Example: Mimosa pudica, known as the sensitive plant, folds its leaves in response to touch as a defense mechanism to deter herbivores.

3. Nutrient Sharing and Signaling via Mycorrhizal Networks

Mycorrhizal Fungi: Fungi that form symbiotic relationships with plant roots, creating extensive underground networks.

• Symbiotic relationships between plant roots and fungi form networks known as the "Wood Wide Web."

• • Function: These networks allow for the exchange of nutrients and signaling molecules.

  • Notable Researchers: Cathie Aime at Purdue University investigates how fungi and plants exchange small RNA, affecting each other's gene expression.

Resource Redistribution: The movement and sharing of resources like carbon, nitrogen, and water between plants.

• Plants share resources through these networks.

  • Example: Older "nurse" trees in a forest provide young saplings with essential nutrients through these fungal networks.

Defense Signaling: The transmission of chemical or electrical signals that activate defense mechanisms in neighboring plants.