The Asian corn borer Ostrinia furnacalis feeding increases the direct and indirect defence of mid-whorl stage commercial maize in the field.

Jingfei Guo,Shuxiong Bai,Tiantao Zhang,Kanglai He,Zhenying Wang,Jinfeng Qi,Jianqiang Wu,Jiuran Zhao

doi:10.1111/pbi.12949

Abstract

SummaryThe Asian corn borer (Ostrinia furnacalis Guenée) is a destructive pest of maize (Zea mays L.). Despite large‐scale commercial maize production, little is known about the defensive responses of field‐grown commercial maize to O. furnacalis herbivory, and how these responses result in direct and indirect defence against this pest. To elucidate the maize transcriptome response to O. furnacalis feeding, leaves of maize hybrid Jingke968 were infested with O. furnacalis for 0, 2, 4, 12 and 24 h. Ostrinia furnacalis feeding elicited stronger and more rapid changes in the defence‐related gene expression (i.e. after 2 h), and more differentially expressed genes (DEGs) were up‐regulated than down‐regulated at all times post‐induction (i.e. 2, 4, 12 and 24 h) in the O. furnacalis pre‐infested maize plants. KEGG pathway analysis indicated that the DEGs in the O. furnacalis pre‐infested maize are involved in benzoxazinoids, phytohormones, volatiles, and other metabolic pathways related to maize resistance to herbivores. In addition, the maize leaves previously infested by O. furnacalis for 24 h showed an obvious inhibition of the subsequent O. furnacalis performance, and maize volatiles induced by O. furnacalis feeding for 24 and 48 h attracted the parasitic wasp, Macrocentrus cingulum Brischke. The increased direct and indirect defences induced by O. furnacalis feeding were correlated with O. furnacalis‐induced phytohormones, benzoxazinoids, and volatiles. Together, our findings provide new insights into how commercial maize orchestrates its transcriptome and metabolome to directly and indirectly defend against O. furnacalis at the mid‐whorl stage in the field.

Highlights

Plants have evolved many defence systems to combat insect attack (Chuang et al, 2014; Wu and Baldwin, 2010)
Plant defences are mediated by phytohormones, including jasmonic acid (JA), abscisic acid (ABA) and salicylic acid (SA) (Ankala et al, 2009; Howe and Jander, 2008; Kessler and Baldwin, 2002; Rehrig et al, 2014; Schweiger et al, 2014; Thaler et al, 2012; Tzin et al, 2015; Yan et al, 2012), and the accumulation of JA and SA plays an important role in regulating plant-induced resistance to insects (Kawazu et al, 2012; Kerchev et al, 2012; Nahar et al, 2011; Wang and Wu, 2013)
To identify the global transcriptomic changes that occurred in response to O. furnacalis attack, transcriptome data from maize leaves pre-infested by O. furnacalis for 0, 2, 4, 12 and 24 h postinfestation were collected

Summary

Introduction

Plants have evolved many defence systems to combat insect attack (Chuang et al, 2014; Wu and Baldwin, 2010). Plant defences are mediated by phytohormones, including jasmonic acid (JA), abscisic acid (ABA) and salicylic acid (SA) (Ankala et al, 2009; Howe and Jander, 2008; Kessler and Baldwin, 2002; Rehrig et al, 2014; Schweiger et al, 2014; Thaler et al, 2012; Tzin et al, 2015; Yan et al, 2012), and the accumulation of JA and SA plays an important role in regulating plant-induced resistance to insects (Kawazu et al, 2012; Kerchev et al, 2012; Nahar et al, 2011; Wang and Wu, 2013). Insect attack generally causes release of several interacting phytohormones (Caarls et al, 2015; Erb et al, 2012; Pieterse et al, 2012; Vos et al, 2013), allowing plants to make fast and specific responses to the complex biotic and abiotic environment (Stam et al, 2014)

Results

Discussion

Conclusion