Contents lists available at ScienceDirect Pesticide Biochemistry and Physiology journal homepage: www.elsevier.com/locate/pest The rescue of botanical insecticides: A bioinspiration for new niches and needs Jannaina Velasques a,1 , Marlon Henrique Cardoso a,b,c,1 , Guilherme Abrantes a , Breno Emanuel Frihling a , Octávio Luiz Franco a,b,c , Ludovico Migliolo a,⁎ a S-Inova Biotech, Programa de Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande, MS, Brazil b Programa de Pós Graduação em Patologia Molecular, Faculdade de Medicina, Universidade de Brasília, Brasília, DF, Brazil c Centro de Análises Proteômicas e Bioquímicas, Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília, DF, Brazil ARTICLE INFO Keywords: Plant metabolites Defensive proteins Insect control Agriculture Plant biotechnology ABSTRACT Crop protection is the basis of plant production and food security. Additionally, there are many efforts focused on increasing defensive mechanisms in order to avoid the damaging effects of insects, which still represent significant losses worldwide. Plants have naturally evolved different mechanisms to discourage herbivory, in- cluding chemical barriers such as the induction of defensive proteins and secondary metabolites, some of which have a historical link with bio-farming practices and others that are yet to be used. In the context of global concern regarding health and environmental impacts, which has been translated into political action and re- strictions on the use of synthetic pesticides, this review deals with a description of some historical commercial phytochemicals and promising proteinaceous compounds that plants may modulate to defeat insect attacks. We present a broader outlook on molecular structure and mechanisms of action while we discuss possible tools to achieve effective methods for the biological control of pests, either by the formulation of products or by the development of new plant varieties with enhanced chemical defenses. 1. Background Plants can synthesize a number of chemical compounds derived from primary metabolism, and although most of them are for essential functions such as growth, physiologic development and reproduction, there is still a small fraction that can be allocated as a substrate for secondary compound pathways [1]. Among a wide range of products, some classes deserve special attention due to their role in adaptation processes and defense mechanisms: the proteinaceous compounds and the secondary metabolites. Both classes can be produced for different purposes. As constitutive substances they can reduce the digestibility of plant tissues or cause direct toxicity, and as inducible substances they are synthesized in response to tissue damage. From an evolutionary perspective, those compounds have a close relationship to the protec- tive apparatus that allowed plants to resist insect attack successfully, and they have also influenced their nutritional ecology. Therefore, these compounds can be toxic to a range of species while offering a potentially benign method of pest control [2]. Itis not possible to describe the exact moment in when humans started using plants and their products to control insects and microorganisms, but it has been historically associated with the onset of agriculture. If initially the use of botanicals was restricted to intuitive and naturalist procedures, the knowledge has spread and survived through different civilizations until the 19th century, when the first scientific observations associated with empirical practices allowed the significant use of botanical extracts as pesticides [3]. In the same period the identification and characterization of some plant secondary com- pounds enabled their use and description as repellents and biocides, mostly alkaloids such as nicotine and its isomer anabasine. But two other important classes also came to change the way of synthesizing natural compounds, bringing bioinspiration to laboratories; these are- rotenones and pyrethrins, which have influenced several synthetic analogue formulas. Until World War II, botanical pesticides were widely used for insect control in agriculture. However, at the end of 1930s they were largely replaced by synthetic organic compounds, more persistent and less se- lective, such as HCH (C 6 H 6 Cl 6 ); DDT (C 14 H 9 Cl 5 ); aldrin (C 12 H 8 Cl 6 ), dieldrin (C 12 H 8 Cl 6 O) and chlordane (C 10 H 6 Cl 8 ) [4]. Organochlorines ruled the agricultural scene until the 1970s, when some questions concerning selectivity and environmental persistence were trigged by a http://dx.doi.org/10.1016/j.pestbp.2017.10.003 Received 18 June 2017; Received in revised form 12 September 2017; Accepted 4 October 2017 ⁎ Corresponding author at: PPG Biotecnologia/UCDB, Avenida Tamandaré 6000, Jardim Seminário, CEP 79117-900 Campo Grande, MS, Brazil. 1 These authors equally contributed to this article. E-mail address: ludovico@ucdb.br (L. Migliolo). Pesticide Biochemistry and Physiology xxx (xxxx) xxx–xxx 0048-3575/ © 2017 Elsevier Inc. All rights reserved. Please cite this article as: Velasques, J., Pesticide Biochemistry and Physiology (2017), http://dx.doi.org/10.1016/j.pestbp.2017.10.003