Plant resistance to aphid feeding: behavioral, physiological, genetic and molecular cues regulate aphid host selection and feeding

Abstract

Aphids damage major world food and fiber crops through direct feeding and transmission of plant viruses. Fortunately, the development of many aphid-resistant crop plants has provided both ecological and economic benefits to food production. Plant characters governing aphid host selection often dictate eventual plant resistance or susceptibility to aphid herbivory, and these phenotypic characters have been successfully used to map aphid resistance genes. Aphid resistance is often inherited as a dominant trait, but is also polygenic and inherited as recessive or incompletely dominant traits. Most aphid-resistant cultivars exhibit constitutively expressed defenses, but some cultivars exhibit dramatic aphid-induced responses, resulting in the overexpression of large ensembles of putative aphid resistance genes. Two aphid resistance genes have been cloned. Mi-1.2, an NBS-LRR gene from wild tomato, confers resistance to potato aphid and three Meloidogyne root-knot nematode species, and Vat, an NBS-LRR gene from melon, controls resistance to the cotton/melon aphid and to some viruses. Virulence to aphid resistance genes of plants occurs in 17 aphid species--more than half of all arthropod biotypes demonstrating virulence. The continual appearance of aphid virulence underscores the need to identify new sources of resistance of diverse sequence and function in order to delay or prevent biotype development.

Laccase GhLac1 Modulates Broad-Spectrum Biotic Stress Tolerance via Manipulating Phenylpropanoid Pathway and Jasmonic Acid Synthesis

“…Feeding by stylet may avoid aphid ingestion of potentially toxic phenolic from the phloem. Although numerous studies show that the aphid infection can induce flavonoid synthesis and accumulation in plants, and some flavonoids possess inhibitory effects on aphid growth and reproduction rate, details about the location of toxic compounds have not previously been determined (Smith and Chuang, 2014;Morkunas et al, 2016;Woźniak et al, 2017). Flavonoids are likely synthesized in a cytoplasmic metabolic environment, and the flavonoid biosynthetic genes are regulated by light, but the long distance movement of flavonoids is largely unknown (Buer et al, 2007).…”

Pea aphid infestation induces changes in flavonoids, antioxidative defence, soluble sugars and sugar transporter expression in leaves of pea seedlings

“…Plant defense response to aphid feeding is the result of injury and effectors in saliva (Smith and Chuang 2014). Aphids using fine stylets penetrate tissues intercellularly, making punctures, and wait a few seconds to analyze the physicochemical properties of the microenvironment around the style tip (Tjallingi 2006).…”

Development of PR genes panel for screening aphid-tolerant cultivars in Brassica juncea

“…Hence, development of an insect-resistant cultivar having a heritable and transferable resistance is the most sustainable option (Stoner and Shelton 1988;Ahuja et al 2010). The development of resistant cultivar through breeding programs for insect resistance is conducted mainly by first surveying for possible sources of insect resistance (antixenosis, antibiosis, tolerance) in varieties and strains locally available and hybridization to combine genes for resistance with desirable agronomic characters followed by screening for resistance characters in hybrid progenies (Warwick 2011;Smith and Chuang 2014). The evaluation of resistance is mainly carried out using parameters such as seedling survival, aphid injury to plants, aphid infestation, aphid fecundity and yield evaluation (Kavitha and Reddy 2012).…”