Plant responses to butterfly oviposition partly explain preference–performance relationships on different brassicaceous species
Griese, Eddie ; Pineda, Ana ; Pashalidou, Foteini G. ; Iradi, Eleonora Pizarro ; Hilker, Monika ; Dicke, Marcel ; Fatouros, Nina E. - \ 2020
Oecologia 192 (2020)2. - ISSN 0029-8549 - p. 463 - 475.
Egg-killing - Hypersensitive response - Oviposition-induced - Pieridae - Priming
The preference–performance hypothesis (PPH) states that herbivorous female insects prefer to oviposit on those host plants that are best for their offspring. Yet, past attempts to show the adaptiveness of host selection decisions by herbivores often failed. Here, we tested the PPH by including often neglected oviposition-induced plant responses, and how they may affect both egg survival and larval weight. We used seven Brassicaceae species of which most are common hosts of two cabbage white butterfly species, the solitary Pieris rapae and gregarious P. brassicae. Brassicaceous species can respond to Pieris eggs with leaf necrosis, which can lower egg survival. Moreover, plant-mediated responses to eggs can affect larval performance. We show a positive correlation between P. brassicae preference and performance only when including the egg phase: 7-day-old caterpillars gained higher weight on those plant species which had received most eggs. Pieris eggs frequently induced necrosis in the tested plant species. Survival of clustered P. brassicae eggs was unaffected by the necrosis in most tested species and no relationship between P. brassicae egg survival and oviposition preference was found. Pieris rapae preferred to oviposit on plant species most frequently expressing necrosis although egg survival was lower on those plants. In contrast to the lower egg survival on plants expressing necrosis, larval biomass on these plants was higher than on plants without a necrosis. We conclude that egg survival is not a crucial factor for oviposition choices but rather egg-mediated responses affecting larval performance explained the preference–performance relationship of the two butterfly species.
Survey of the response of 82 domestic landraces of Zea mays to cucumber mosaic virus (CMV) reveals geographical region-related resistance to CMV in Japan
Takahashi, H. ; Tian, A. ; Miyashita, S. ; Kanayama, Y. ; Ando, S. ; Kormelink, R. - \ 2018
Plant Pathology 67 (2018)6. - ISSN 0032-0862 - p. 1401 - 1415.
Cucumber mosaic virus - Hypersensitive response - Monocot - Necrotic local lesions - Virus resistance - Zea mays
Zea mays has been historically imported to Japan via two independent geographical routes: into southern Japan by trading with Europe in the 16th century and into northern Japan by import from North America in the 19th century. Breeding to genetically improve on quality traits and high yields has led to the current domestic landraces in each region. In a survey of 82 domestic landraces, nine out of 38 landraces originating from southern Japan showed complete immunity to cucumber mosaic virus yellow strain (CMV(Y)) without the formation of necrotic local lesions (NLLs). In contrast, three out of 44 landraces originating from northern Japan developed NLLs, but revealed no systemic spread of the virus. Due to the absence of good documentation on NLL formation in Z. mays, the response of domestic landraces Aso-1 and Aso-3, originating from Ibaraki in northern Japan, to a challenge with CMV(Y) and CMV(Ma-1) was further analysed. Aso-3 only formed NLL in response to CMV(Y) but not to CMV(Ma-1). Moreover, in CMV(Y)-inoculated Aso-3, virus spread was restricted to the primary infection site and the expression of defence-related genes was up-regulated, whereas Aso-1 became systemically infected with either CMV(Y) or CMV(Ma-1). The response of Aso-3 to CMV(Y) was inherited as a single dominant trait. Together, these results pointed towards the induction of hypersensitive response (HR)-mediated resistance to CMV(Y) in Aso-3. Although HR-mediated resistance to viruses has been studied mainly in dicots, the pathosystem CMV-Z. mays may provide a model to investigate HR-mediated resistance to viruses in monocot plants.
The NSm proteins of phylogenetically related tospoviruses trigger Sw-5b–mediated resistance dissociated of their cell-to-cell movement function
Leastro, Mikhail Oliveira ; Oliveira, Athos Silva De; Pallás, Vicente ; Sánchez-Navarro, Jesús A. ; Kormelink, Richard ; Resende, Renato Oliveira - \ 2017
Virus Research 240 (2017). - ISSN 0168-1702 - p. 25 - 34.
Avr - Hypersensitive response - NS protein - Resistance - Sw-5b gene - Tospovirus
The cell-to-cell movement protein (NSM) in members of the tospovirus species Tomato spotted wilt virus (TSWV) has been recently identified as the effector of the single dominant Sw-5b resistance gene from tomato (Solanum lycopersicum L.). Although most TSWV isolates shows a resistance-inducing (RI) phenotype, regular reports have appeared on the emergence of resistance-breaking (RB) isolates in tomato fields, and suggested a strong association with two point mutations (C118Y and T120N) in the NSM protein. In this study the Sw-5b gene has been demonstrated to confer not only resistance against TSWV but to members of five additional, phylogenetically-related tospovirus species classified within the so-called “American” evolutionary clade, i.e. Alstroemeria necrotic streak virus (ANSV), Chrysanthemum stem necrosis virus (CSNV), Groundnut ringspot virus (GRSV), Impatiens necrotic spot virus (INSV) and Tomato chlorotic spot virus (TCSV). Remarkably, a member of the species Bean necrotic mosaic virus (BeNMV), a recently discovered tospovirus classified in a distinct American subclade and circulating on the American continent, did not trigger a Sw-5b-mediated hypersensitive (HR) response. Introduction of point mutations C118Y and T120N into the NSM protein of TSWV, TCSV and CSNV abrogated the ability to trigger Sw-5b-mediated HR in both transgenic-N. benthamiana and tomato isolines harboring the Sw-5b gene whereas it had no effect on BeNMV NSM. Truncated versions of TSWV NSM lacking motifs associated with tubule formation, cell-to-cell or systemic viral movement were made and tested for triggering of resistance. HR was still observed with truncated NSM proteins lacking 50 amino acids (out of 301) from either the amino- or carboxy-terminal end. These data altogether indicate the importance of amino acid residues C118 and T120 in Sw-5b-mediated HR only for the NSM proteins from one cluster of tospoviruses within the American clade, and that the ability to support viral cell-to-cell movement is not required for effector functionality.
Prospects of herbivore egg-killing plant defenses for sustainable crop protection
Fatouros, Nina E. ; Cusumano, Antonino ; Danchin, Etienne G.J. ; Colazza, Stefano - \ 2016
Ecology and Evolution 6 (2016)19. - ISSN 2045-7758 - p. 6906 - 6918.
Egg deposition - Egg parasitoids - Hypersensitive response - Oviposition-induced plant volatiles - Phylogeny
Due to a growing demand of food production worldwide, new strategies are suggested to allow for sustainable production of food with minimal effects on natural resources. A promising alternative to the application of chemical pesticides is the implementation of crops resistant to insect pests. Plants produce compounds that are harmful to a wide range of attackers, including insect pests; thus, exploitation of their natural defense system can be the key for the development of pest-resistant crops. Interestingly, some plants possess a unique first line of defense that eliminates the enemy before it becomes destructive: egg-killing. Insect eggs can trigger (1) direct defenses, mostly including plant cell tissue growth or cell death that lead to eggs desiccating, being crushed or falling off the plant or (2) indirect defenses, plant chemical cues recruiting natural enemies that kill the egg or hatching larvae (parasitoids). The consequences of plant responses to eggs are that insect larvae do not hatch or that they are impeded in development, and damage to the plant is reduced. Here, we provide an overview on the ubiquity and evolutionary history of egg-killing traits within the plant kingdom including crops. Up to now, little is known on the mechanisms and on the genetic basis of egg-killing traits. Making use of egg-killing defense traits in crops is a promising new way to sustainably reduce losses of crop yield. We provide suggestions for new breeding strategies to grow egg-killing crops and improve biological control.
Role of Large Cabbage White butterfly male-derived compounds in elicitation of direct and indirect egg-killing defenses in the black mustard
Fatouros, N.E. ; Voirol, L.R.P. ; Drizou, Fryni ; Doan, Quyen T. ; Pineda, Ana ; Frago, Enric ; Loon, J.J.A. van - \ 2015
Frontiers in Plant Science 6 (2015)SEPTEMBER. - ISSN 1664-462X - 9 p.
Accessory reproductive glands - Brassicaceae - Egg parasitoid - Hypersensitive response - Induced plant defenses - Oviposition-induced plant volatiles - Pieris - PR-1
To successfully exert defenses against herbivores and pathogens plants need to recognize reliable cues produced by their attackers. Up to now, few elicitors associated with herbivorous insects have been identified. We have previously shown that accessory reproductive gland secretions associated with eggs of Cabbage White butterflies (Pieris spp.) induce chemical changes in Brussels sprouts plants recruiting egg-killing parasitoids. Only secretions of mated female butterflies contain minute amounts of male-derived anti-aphrodisiac compounds that elicit this indirect plant defense. Here, we used the black mustard (Brassica nigra) to investigate how eggs of the Large Cabbage White butterfly (Pieris brassicae) induce, either an egg-killing direct [i.e., hypersensitive response (HR)-like necrosis] or indirect defense (i.e., oviposition-induced plant volatiles attracting Trichogramma egg parasitoids). Plants induced by P. brassicae egg-associated secretions expressed both traits and previous mating enhanced elicitation. Treatment with the anti-aphrodisiac compound of P. brassicae, benzyl cyanide (BC), induced stronger HR when compared to controls. Expression of the salicylic (SA) pathway- and HR-marker PATHOGENESIS-RELATED GENE1 was induced only in plants showing an HR-like necrosis. Trichogramma wasps were attracted to volatiles induced by secretion of mated P. brassicae females but application of BC did not elicit the parasitoid-attracting volatiles. We conclude that egg-associated secretions of Pieris butterflies contain specific elicitors of the different plant defense traits against eggs in Brassica plants. While in Brussels sprouts plants anti-aphrodisiac compounds in Pieris egg-associated secretions were clearly shown to elicit indirect defense, the wild relative B. nigra, recognizes different herbivore cues that mediate the defensive responses. These results add another level of specificity to the mechanisms by which plants recognize their attackers.