scholarly journals Turnabout Is Fair Play: Herbivory-Induced Plant Chitinases Excreted in Fall Armyworm Frass Suppress Herbivore Defenses in Maize

2016 ◽  
Vol 171 (1) ◽  
pp. 694-706 ◽  
Author(s):  
Swayamjit Ray ◽  
Patrick C.M.S. Alves ◽  
Imtiaz Ahmad ◽  
Iffa Gaffoor ◽  
Flor E. Acevedo ◽  
...  
2021 ◽  
Author(s):  
Yang Han ◽  
ERIN B TAYLOR ◽  
DAWN LUTHE

Abstract A large percentage of crop loss is due to insect damage yearly, especially caterpillar damage. Plant chitinases are considered excellent candidates to combat these insects since they can catalyze chitin degradation in peritrophic matrix (PM), an important protective structure in caterpillar midgut. Compared to chemical insecticides, chitinases could improve host plant resistance and be both economically and environmentally advantageous. The focus of this research was to find chitinase candidates that could improve plant resistance by effectively limiting caterpillar damage. Five classes of endochitinase (I-V) genes were characterized in the maize genome, and we further isolated and cloned four chitinase genes (chitinase A, chitinase B, chitinase I, and PRm3) present in two maize (Zea mays L.) inbred lines Mp708 and Tx601, with different levels of resistance to caterpillar pests. Further, we investigated the role of these maize chitinases in response to fall armyworm (Spodoptera frugiperda, FAW) attacks. Results from gene expression and enzyme assays from maize leaves indicated that both chitinase transcript abundance and enzymatic activity increased in response to FAW feeding and mechanical wounding. Furthermore, chitinase retained activity inside the caterpillar’s midgut since specific activity was detected in both the food bolus and frass. When examined under scanning electron microscopy, PMs from Tx601-fed caterpillars showed structural damage when compared to diet controls. Analysis of chitinase transcript abundance after caterpillar feeding and proteomic analysis of maize leaf trichomes in the two inbreds suggested that the chitinase PRm3 in Tx601 has potential insecticidal properties.


2014 ◽  
Vol 27 (5) ◽  
pp. 461-470 ◽  
Author(s):  
Wen-Po Chuang ◽  
Swayamjit Ray ◽  
Flor Edith Acevedo ◽  
Michelle Peiffer ◽  
Gary W. Felton ◽  
...  

In addition to feeding damage, herbivores release cues that are recognized by plants to elicit defenses. Caterpillar oral secretions have been shown to trigger herbivore defense responses in several different plant species. In this study, the effects of two fall armyworm (Spodoptera frugiperda) oral secretions (saliva and regurgitant) on caterpillar defense responses in maize (Zea mays) were examined. Only minute amounts of regurgitant were deposited on the maize leaf during larval feeding bouts and its application to leaves failed to induce the expression of several herbivore defense genes. On the other hand, caterpillars consistently deposited saliva on leaves during feeding and the expression of several maize defense genes significantly increased in response to saliva application and larval feeding. However, feeding by ablated caterpillars with impaired salivation did not induce these defenses. Furthermore, bioassays indicated that feeding by unablated caterpillars significantly enhanced defenses when compared with that of ablated caterpillars. Another critical finding was that the maize genotype and stage of development affected the expression of defense genes in response to wounding and regurgitant treatments. These results demonstrate that fall armyworm saliva contains elicitors that trigger herbivore defenses in maize.


2008 ◽  
pp. 85-105 ◽  
Author(s):  
R. Kapeliushnikov

The paper examines the problem of legitimation of the privatization’s outcomes in Russia and provides a critical appraisal of various political proposals for its resolution. The analysis proceeds from a distinction between two different types of ownership illegitimacy: "definite" and "vague" ones. The paper argues that the "vague" illegitimacy that has evolved in Russia is not an absolute obstacle for economic growth but rather an institutional birth trauma which is common for all post-socialist countries and which could be cured only by piecemeal approaching of relationships between "strong" and "weak" economic actors to principles of fair play.


2019 ◽  
pp. 91-106 ◽  
Author(s):  
Rostislav I. Kapeliushnikov

Using published estimates of inequality for two countries (Russia and USA) the paper demonstrates that inequality measuring still remains in the state of “statistical cacophony”. Under this condition, it seems at least untimely to pass categorical normative judgments and offer radical political advice for governments. Moreover, the mere practice to draw normative conclusions from quantitative data is ethically invalid since ordinary people (non-intellectuals) tend to evaluate wealth and incomes as admissible or inadmissible not on the basis of their size but basing on whether they were obtained under observance or violations of the rules of “fair play”. The paper concludes that a current large-scale ideological campaign of “struggle against inequality” has been unleashed by left-wing intellectuals in order to strengthen even more their discursive power over the public.


2018 ◽  
Vol 29 (5) ◽  
pp. 213-214 ◽  
Author(s):  
Graham Matthews

The author introduces the next three articles on the invasion of Fall Army Worm into Sub-Saharan Africa and Asia describing how the pest spreads, the damage it causes and approaches to its control.


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