How do Plants Protect Themselves: Defense Mechanisms, Biological Counterattacks and Signaling

Plants protect themselves from different threats including insects, harsh weather, pests and diseases. Over millions of years they have evolved to survive the changes and challenges around them. In this article, we will cover in detail about how plants protect themselves along with reasons they need to protect. 

Table of Contents

• Why do Plants need Protection
• Types of Defence Mechanism
• Internal and External Defense Signalling
• Interesting Facts about Plants Defence

Why do Plants need Protection

Based on their surroundings, growing conditions, and the types of predators, plants have developed special defense mechanisms to protect themselves. These mechanisms are crucial for preventing damage and ensuring that the plant survives and reproduces. A major threat that plants need to protect themselves from is the animals that eat them. To protect themselves from being eaten by animals many plants have grown thorns, prickles and spines. Although thorns and prickles can save them from getting eaten by bigger animals, smaller insects and bugs. As a result, the plants start to evolve and adopt more defense mechanisms against such threats such as altered leaf structures or thickening of stems that may reduce the chances of harm and improve their chances of survival.

Types of Defense Mechanisms Plants Adopt

There are majorly two types of defense that animals adopt to protect themselves from various threats around them. 

• Constitutive Defenses 
• Induced Defenses 

Constitutive defenses: These types of defense mechanisms are present in a plant, whether it is being attacked or not. They are the defense mechanisms that are integrated into the chemistry and structure of the plant offering them an in-built resistance against predators.

For instance, prickles, spines, and thorns deter animals from eating the plant. Bitter or toxic chemicals that make it difficult and dangerous for herbivores to eat them. For many plant species, these defenses serve as the initial line of defense because they are always present.

Induced Defenses: The defense generated as the response of a threat is called an induced defense. This defense is generated only when necessary. This kind of defense mechanism helps the plants in conserving their energy. Some examples of induced defense are the appearance or behaviour change that reduces additional damage. For example, certain plants may become less visible to predators by blending in with their surroundings. Some of them release protective chemicals that are poisonous for herbivores.

Internal and External Defense Signaling 

Signaling is an effective way plants detect danger and send information to its part or to another plant for activating its defense mechanism.

Internal Signaling: A plant after getting attacked sends a chemical signal that spreads to other parts of the plant, resulting in defensive reactions like the synthesis of toxins or the strengthening of the cell walls.

External Signaling: Plants on being attacked by a threat releases volatile compounds called VOC that spreads into the air and signals other plants about the danger. It is a way for plants to alert nearby plants for recognising these signals and start their own defenses against the threat.

Interesting Facts about Plants Defense

• Protective chemical treatments are frequently used by gardeners to prevent insect damage to plants.
• Many plants produce defensive chemicals to help protect themselves from predators and disease.
• Touching or consuming the toxic substances from some plants may occasionally cause severe sickness. 
• Caffeine and nicotine are some common examples of plant’s defensive chemicals. 
• Toxic substances found in some plants can be dangerous to both people and animals.