Rice defense responses are induced upon leaf rolling by an insect herbivore

Abstract

BackgroundPlant defense against herbivores begins with perception. The earlier plant detects the harm, the greater plant will benefit in its arm race with the herbivore. Before feeding, the larvae of the rice pest Cnaphalocrocis medinalis, initially spin silk and fold up a leaf. Rice can detect and protect itself against C. medinalis feeding. However, whether rice could perceive C. medinalis leaf rolling behavior is currently unknown. Here, we evaluated the role of leaf rolling by C. medinalis and artificial leaf rolling in rice plant defense and its indirect effect on two important C. medinalis parasitoids (Itoplectis naranyae and Apanteles sp.) through a combination of volatile profiling, gene-transcriptional and phytohormonal profiling.ResultsNatural leaf rolling by C. medinalis resulted in an increased attraction of I. naranyae when compared to the undamaged plant after 12 h. Volatile analysis revealed that six out of a total 22 components significantly increased in the headspace of C. medinalis rolled plant when compared to undamaged plant. Principal component analysis of these components revealed similarities in the headspace of undamaged plant and artificially rolled plant while the headspace volatiles of C. medinalis rolled plant deferred significantly. Leaf rolling and feeding by C. medinalis up-regulated the plant transcriptome and a series of jasmonic acid (JA) and salicylic acid (SA) related genes. While feeding significantly increased JA level after 12 to 36 h, rolling significantly increased SA level after 2 to 12 h. Compared to artificial rolling, natural rolling significantly increased JA level after 36 h and SA level after 2 and 12 h.ConclusionsOur findings suggest that natural leaf rolling by C. medinalis can be perceived by rice plant. The detection of this behavior may serve as an early warning signal in favor of the rice plant defenses against C. medinalis.

Transcriptomic and Metabolomic Responses of Rice Plants to Cnaphalocrocis medinalis Caterpillar Infestation

“…Previously, it has been demonstrated that application of methyl jasmonate (MeJA) and methyl salicylate (MeSA) as topical sprays onto rice plants significantly improve rice defense against C. medinalis [ 14 , 15 ]. Recently, it was found that rice leaf rolling by C. medinalis larvae, but not by artificial leaf rolling, attracts the parasitoid Itoplectis naranyae as an indirect defense [ 16 ]. It is well known that plant response to herbivore damage is a dynamic process and that this process is associated with large-scale change at the mRNA, protein, and metabolite levels [ 5 , 17 ].…”

Manipulation of Jasmonate Signaling by Plant Viruses and Their Insect Vectors

“…In most cases, JAs function as chemical triggers to induce the biosynthesis of various defensive chemicals and proteins to counter pathogens and herbivores. Plant pattern-recognition receptors (PRRs) perceive molecular patterns from pathogens and herbivores to recognize herbivore-associated molecular patterns (HAMPs), damage-associated molecular patterns (DAMPs), and microbe/pathogen-associated molecular patterns (MAMPs/PAMPs) and thereby initiate JA signaling-dependent resistance [29,30]. These plant elicitor molecules can be peptides such as systemin, extracellular ATP (eATP), sucrose, volicitin, fatty acid conjugates, caeliferins and others [31,32].…”

Plant responses to multiple antagonists are mediated by order of attack and phytohormone crosstalk

“…However, we show that assessing the order of attack is necessary to best understand the complexity and mechanisms of plant-insect-pathogen interactions. Moreover, our study suggests complete pathways must be characterized as differences are evident even when a few transcripts and metabolites are analyzed., often measured with associated gene transcripts (Bedini, Mercy, Schneider, Franken, & Lucic-Mercy, 2018; Ángeles-López el al., 2016; Shi et al, 2019), may fail to capture mechanisms by which plants interact with multiple stressors. Our results demonstrate both the order of arrival, and the diversity of interactions, determine plant responses to stress through the combined action of defense gene activation, phytohormone accumulation, and modification of plant nutrients.…”