Receptors of Garlic (Allium sativum) Lectins and Their Role in Insecticidal Action

Abstract

Garlic (Allium sativum) lectins are promising candidate molecules for the protection against chewing (lepidopteran) as well as sap sucking (homopteran) insect pests. Molecular mechanism of toxicity and interaction of lectins with midgut receptor proteins has been described in many reports. Lectins show its effect right from sensory receptors of mouth parts by disrupting the membrane integrity and food detection ability. Subsequently, enter into the gut lumen and interact with midgut glycosylated proteins like alkaline phosphatase (ALP), aminopeptidase-N (APN), cadherin-like proteins, polycalins, sucrase, symbionin and others. These proteins play critical role in life cycle of insect directly or indirectly. Lectins interfere with the activity of these proteins and causes physiological disorders leading to the death of insects. Lectins further transported across the insect gut, accumulated in various body parts (like haemolymph and ovary) and interact with intracellular proteins like symbionin and cytochrome p450. Binding with cytochrome p450 (which involve in ecdysone synthesis) might interfere in the development of insects, which results in growth retardation and pre-mature death.

Molecular Mechanism Underlying the Entomotoxic Effect of Colocasia esculenta Tuber Agglutinin against Dysdercus cingulatus

“…During the last two decades, the search for potential biological pesticides has focused on plant lectins [ 32 , 33 , 34 , 35 , 36 ]. Interestingly, monocot mannose binding plant lectins have been recognized as a broader potential biological insecticide that affects both the hemipteran and lepidopteran pests [ 32 , 37 , 38 , 39 ]. CEA belongs to MMBL superfamily with significant insecticidal activity against RCB [ 2 ].…”

“…Moreover, localization of CEA in the midgut, haemolymph and ovary of CEA supplemented diet fed RCB indicated the internalization of the lectin through midgut epithelial cells as evident in the case of other lectins like GNA, ASAL, and Hippeastrum hybrid agglutinin (HHA) [ 8 , 38 , 39 ]. This finding indicates the possibility of having intracellular targets of CEA, which may contribute significantly to entomotoxicity.…”

Development of Transgenic Cotton Lines Expressing Allium sativum Agglutinin (ASAL) for Enhanced Resistance against Major Sap-Sucking Pests

“…Plant lectins are known to inhibit the nutrient absorption and cause severe disruption of the epithelial cells in the midgut of insects by stimulating endocytosis resulting in disorganization and elongation of the striated brush border microvilli, leading to the swelling of epithelial cells and complete closure of the gut lumen [25]. Earlier, it was reported that over-expression of mannose-specific lectins (ASAL and GNA) in transgenic rice lines proved more effective in reducing survival, fecundity and feeding ability of major sap-sucking insects, viz., BPH, GLH and WBPH [8], [14], [17], [18], [21].…”

Biochemical characterisation of lectin from Indian hyacinth plant bulbs with potential inhibitory action against human cancer cells

“…In plants, they are expressed in all parts and are extracted from seeds, bulbs, leaves, fruits, roots, and flowers [8][9][10][11]. Due to their diverse role in plants such as storage of proteins [12], protection from insects [13], cell wall propagation [14], a carrier for sugar moieties [15] and mitogenic stimulation [16], lectins have been explored more in detail over the last couple of years. Besides their biological activities plant lectins are also used for diagnostics purpose of various diseases, and widely used in drug delivery systems [17].…”