Plants have their own defenses, which their enemies and plant pathogens. His inability to move is largely defensive adjustments that help plants to survive and reproduce successfully. One of the most important defense mechanisms is the production of secondary metabolites. These metabolites are chemicals that are not involved in photosynthesis in normal plants. Allelochemicals act as poisons for herbivores and in some cases, also reduce the digestibility of plant cell wall.

Some of the external structural features in the stem and leaves (spines, thorns, spines, etc) to deter herbivores greatly. These mechanisms of defense mechanisms to prevent, injure or kill the Grazer. Some defensive substances such as waxes, resins, lignin, etc are released into the epidermis of plants and herbivores avoid feeding on them.

Herbivores are the first link in the food chain as energy source for organisms that are of highest rank in the food chain. Plants are the only source of food for herbivores and the co-evolution of adaptations that allow them to help buy food, regardless of the defense mechanisms in plants. Some of these adaptations are:

* Synthesis of enzymes that can reduce the effect of secondary metabolites
* The existence of internal symbiotic bacteria, fungi or protozoa, which break down plant cellulose so it can be digested by herbivores helps
* The mechanical fittings, such as cutting teeth in moths, which helps them to eat the soft leaves. According to recent studies by Renato Almeida Sarmento and his team, led invading Tetranychus evansi manipulates its host (tomato), by interfering with signaling pathways involved in defense mechanism [1].

Primary hosts of T. evansi are solanaceous crops such as tomatoes, potatoes, snuff, etc. mites puncture the leaves during feeding, causing yellowing or bleaching of leaves. Then the leaves are falling and in the case of severe attack the plant dies. The research study showed that Sarmento T. evansi manipulate host defenses by suppressing the induction of salicylic acid and jasmonic acid signaling pathways involved in defense mechanisms of plants in tomato plants. Salicylic acid and jasmonic acid play a crucial role in immunity of plants. Mites reduce the amount of inducible defense compounds and volatile substances (eg, protease inhibitors), which play a crucial role in plant defense. Control of pathogens affecting these crops is an important area of ​​research. The result of research by Sarmento allows a better understanding of plant-herbivore interactions. Opens the door to new research in two directions:

* Biological control of Tetranychus evansi at an affordable price to the farmer.
* Development of varieties in a position to fight against the manipulations of herbivores.

Reference:

[1] Sarmento R, Lemos F et al. A herbivore, the plant defense manipulated. Ecol Lett. 14 March 2011 (3): 229-236.

Anna Purna is a freelancer, writing articles about your favorite interest of health and nutrition.