Vegetative Insecticidal Protein (Vip): A Potential Contender From Bacillus thuringiensis for Efficient Management of Various Detrimental Agricultural Pests

Abstract

Bacillus thuringiensis (Bt) bacterium is found in various ecological habitats, and has natural entomo-pesticidal properties, due to the production of crystalline and soluble proteins during different growth phases. In addition to Cry and Cyt proteins, this bacterium also produces Vegetative insecticidal protein (Vip) during its vegetative growth phase, which is considered an excellent toxic candidate because of the difference in sequence homology and receptor sites from Cry proteins. Vip proteins are referred as second-generation insecticidal proteins, which can be used either alone or in complementarity with Cry proteins for the management of various detrimental pests. Among these Vip proteins, Vip1 and Vip2 act as binary toxins and have toxicity toward pests belonging to Hemiptera and Coleoptera orders, whereas the most important Vip3 proteins have insecticidal activity against Lepidopteran pests. These Vip3 proteins are similar to Cry proteins in terms of toxicity potential against susceptible insects. They are reported to be toxic toward pests, which can’t be controlled with Cry proteins. The Vip3 proteins have been successfully pyramided along with Cry proteins in transgenic rice, corn, and cotton to combat resistant pest populations. This review provides detailed information about the history and importance of Vip proteins, their types, structure, newly identified specific receptors, and action mechanism of this specific class of proteins. Various studies conducted on Vip proteins all over the world and the current status have been discussed. This review will give insights into the significance of Vip proteins as alternative promising candidate toxic proteins from Bt for the management of pests in most sustainable manner.

Antifungal Mechanism of Vip3Aa, a Vegetative Insecticidal Protein, against Pathogenic Fungal Strains

“…Analysis of SEC purified fractions revealed that the native molecular weight of Vip3Aa was 669 kDa, which may have an oligomeric structure of at least an octamer or more or an irregular highly aggregated structure ( Figure 1 A). It is known that the C-terminus of Vip3A proteins are cleaved by midgut proteases to produce a 62–66 kDa protease-resistant toxic core [ 8 , 23 ]. Recently, an approximately 340 kDa homo-tetramer structure has been identified from Vip3A digested by trypsin or insect midgut proteases [ 19 , 21 , 22 , 24 ].…”

“…Vip proteins are released during vegetative growth and have no resemblance to Cry toxins. Until recently, the Vip protein family was divided into four categories: Vip1, Vip2, Vip3, and Vip4 [ 8 ]. Vip1 and Vip2 proteins are the two parts of a binary toxin, which is toxic to coleopterans.…”

“…Vip3 proteins have a diverse host range, which includes a number of major lepidopteran pests [ 3 , 4 , 5 , 6 , 7 , 8 , 9 ]. Vip3A proteins must be cleaved by proteases prior to the recognition of specific 80 kDa and 100 kDa membrane proteins, different from those perceived by Cry toxins at the surface of the mid-gut epithelium [ 11 ].…”

Biotechnological Approaches for Host Plant Resistance to Insect Pests

“…There are three subfamilies of Vip proteins. Vip1 and Vip2 heterodimer toxins, effective against pests belonging to Hemiptera and Coleoptera orders, whereas Vip3, the most extensively studied family of Vip toxins have toxicity toward Lepidopterans et al Vip proteins are also known as second-generation insecticidal proteins, that can be used either alone or in combination with cry proteins to control a number of insect-pests ( Gupta et al, 2021 ). In terms of toxicity potential against susceptible insects, these Vip3 proteins are comparable to cry proteins.…”

Stability is essential for insecticidal activity of Vip3Aa toxin against Spodoptera exigua

“…Vegetative insecticidal proteins 3A (Vip3A), secreted from Bacillus thuringiensis (Bt) during their vegetative growth stage, are important insecticidal proteins that show toxicity against a wide variety of lepidopteran pests (Chakrabarty et al, 2020;Gupta et al, 2021). It was worth mentioning that Vip3A proteins displayed synergistic effect when coupling with Cry toxins for the control of agricultural pests (Wang et al, 2020;Lemes et al, 2014).…”