Inducible Maize Defense Mechanisms Against the Corn Borer Sesamia nonagrioides: A Transcriptome and Biochemical Approach

Abstract

Rodríguez, V.M._2_MPMI after being attacked. These results were confirmed through biochemical analyses showing that the concentration of some cell wall-related compounds significantly changed after plant infestation in a genotype-dependent way. In conclusion, maize plants respond to the attack of the corn borer S. nonagrioides through cell wall fortification, activating genes involved in cell wall organization which finally is reflected in a higher concentration of some cell wall components, especially in resistant genotypes. INTRODUCTIONAttack by mobile herbivores is the major biotic challenge plants have to cope with during their life cycle. Although not exclusively, the largest group of herbivores is phytophagous insects which covers a diverse taxonomic group with more than one million species (Futuyma and Agrawal, 2009). Primary plant defense against insects consists of physical barriers. Once these barriers are breached, inducible defense mechanisms are activated to reduce herbivore damaging (Agrawal, 1998).Phytophagous insects trigger two types of inducible responses in plants: direct defenses that retard insect growth and development and indirect defenses that involve the production of metabolites that attract parasitoids and predators (Govind et al., 2010). Therefore, plants respond to insect feeding through an extensive transcriptome reprogramming and activation of defense mechanisms to improve plant survival. In the last decades technical advances in the genomic transcript profiling methods have allowed considerable progress in elucidating plant defense inducible mechanisms Pre-print version of the article: "Inducible Maize Defense Mechanisms against the Corn Borer Sesamia nonagrioides: A Transcriptome and Biochemical Approach" published on Molecular Plant-Microbe Interaction 2012. 25: 61-68. DOI: http://dx.doi.org/10.1094/ Rodríguez, V.M._3_MPMI (Hermsmeier et al., 2001;Wan et al., 2002). A comprehensive analysis of the transcriptome response in Nicotiana attenuata, a wild relative of tobacco, identified several gene families as being activated in response to insect-inflicted damage, including several transcriptional regulators and protein kinases (Gilardoni et al., 2010; Hermsmeier et al., 2001). Similar results were observed in other plant species (Reymond et al., 2004;Wei et al., 2009). Plant responses to defoliators have been broadly characterized in a number of different plant species (e.g. Kaur et al., 2010;Philippe et al., 2009;Reymond et al., 2004) but in contrast little is known about the plant response to attack by other herbivores such as stalk borers.'Stalk borers' include a number of moth species that attack the stalk of poaceous plants.The larvae of these Lepidoptera penetrate into the stalk and feed in the plant's pith tissues resulting in crop losses, early leaf senescence and interference with translocation of metabolites (Kfir et al., 2002). Individual inducible mechanisms have been reported to be involved in plant defense against these insects. For instance, silencing of the 13-L...

European Corn Borer (Ostrinia nubilalis) Induced Responses Enhance Susceptibility in Maize

“…Surprisingly, larvae gained significantly more weight following consumption of LCT compared to control or wounded tissues. Microarray analyses confirmed that numerous defense-related genes were up-regulated in LCT compared to control tissue and shared significant overlap with those reported for the Mediterranean corn borer ( Sesamia nonagrioides ) [52]. Although the expression of many defense-related genes were induced in response to ECB, a correspondingly broad increase proteins was not observed by iTRAQ analysis.…”

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

“…All chitinases belong to family 18 and 19 glycosyl hydrolases, and plant chitinases have been classified into six classes (Hamid et al, 2013). Plant chitinases have been shown to accumulate in response to pathogen attack as well as by herbivory (Kasprzewska, 2003;Rodríguez et al, 2012). When we applied the maize chitinases Pr4 and Endochitinase A, which were both present in fraction B and were attached to the chitin-binding beads, to maize leaves, it induced the expression of the pathogen defense gene marker pr5 (Fig.…”

“…Studies reporting the induction of chitinases in response to fungal attack in plants also are widely known (Schlumbaum et al, 1986). Maize contains a large chitinase gene family, and some of these are induced by FAW herbivory (Rodríguez et al, 2012). Since Pr4 and Endochitinase A were two of the most abundant proteins with a chitin-binding domain detected in FAW frass (Table III), we measured the transcript abundance of pr4 and endochitinase A in response to caterpillar herbivory.…”

“…Our search identified maize chitinases as possible effector molecules that induce pathogen defenses while suppressing herbivore defenses on the host. These maize chitinases are induced in response to insect herbivory and pass through the insect gut to be deposited back onto the host tissue (Rodríguez et al, 2012).…”

Impact of Cell Wall Composition on Maize Resistance to Pests and Diseases

“…Furthermore, the study demonstrates the powerful role of polysaccharide-polysaccharide cross-linking trough ester-linked DFAs as a natural resistance mechanism of maize against corn borers (damage by stem tunneling was 29% lower in C3H than in C3L) [124]. On the other hand, Rodríguez and coauthors [31] reported that the maize plants respond to the attack of MCB activating genes involved in the cell-wall organization, and moreover, the inbred line PB130 increase twice its DFAs concentration after MCB attack. Current investigations would confirm these motivating findings.…”