Current knowledge and future research perspectives on cassava (Manihot esculenta Crantz) chemical defenses: An agroecological view.
Cassava (Manihot esculenta Crantz) is one of the most important staple crops worldwide. It constitutes the major source of carbohydrates for millions of low-income people living in rural areas, as well as a cash crop for smallholders in tropical and sub-tropical regions. The Food and Agriculture Organization of the United Nations predicts that cassava plantations will increase and production systems will intensify in the future, highlighting the need for developing strategies that improve the sustainability of production. Plant chemical defenses hold the potential for developing pest management strategies, as these plant traits can influence the behavior and performance of both pests and beneficial arthropods. Cassava plants are well-defended and produce a number of compounds involved in direct defense, such as cyanogenic glycosides, flavonoid glycosides, and hydroxycoumarins. In addition, volatile organic compounds induced upon herbivory and the secretion of extrafloral nectar act as indirect defense against herbivores by recruiting natural enemies. Here, cassava chemical defenses against pest arthropods are reviewed, with the aim of identifying gaps in our knowledge and areas of research that deserve further investigation for developing sound pest control strategies to improve sustainable production of this crop, and how these defenses can be used to benefit other crops. Cyanogenic content in cassava is also highly toxic to humans, and can cause irreversible health problems even at sub-lethal doses when consumed over prolonged periods. Therefore, the promotion of chemical defense in this crop should not aggravate these problems, and must be accompanied with the education on processing methods that reduce human exposure to cyanide.
Laboratório de Ecologia Química, Departamento de Ecologia, Centro de Ciências Biológicas e da Saúde, Universidade Federal de Sergipe - UFS, Av. Marechal Rondon, s/n - Jardim Rosa Elze, CEP 49100-000, São Cristóvão, SE, Brazil. Electronic address: delia.pintozevallos@gmail.com.
Delia M
DM
Pinto-Zevallos
Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas - UNICAMP, Caixa Postal 6109, Rua Monteiro Lobato 255, CEP 13083-862, Campinas, SP, Brazil.
Martín
M
Pareja
Laboratório de Ecologia Química, Departamento de Ecologia, Centro de Ciências Biológicas e da Saúde, Universidade Federal de Sergipe - UFS, Av. Marechal Rondon, s/n - Jardim Rosa Elze, CEP 49100-000, São Cristóvão, SE, Brazil.
Bianca G
BG
Ambrogi
D018556:Crops, Agricultural / Q000737:chemistry*; D003486:Cyanides / Q000494:pharmacology; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology; D006027:Glycosides / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D002365:Manihot / Q000737:chemistry*; D015394:Molecular Structure; D018515:Plant Leaves / Q000737:chemistry
D003486:Cyanides; D005419:Flavonoids; D006027:Glycosides; C007173:cyanogenic glycosides
Cassava; Cyanogenic compounds; Direct defenses; Euphorbiaceae; Extrafloral nectar; Indirect defenses; Manihot esculenta Crantz; Manioc; Plant volatile organic compounds; Yuca