Enhancement of Jasmonate-Mediated Antiherbivore Defense Responses in Tomato by Acetic Acid, a Potent Inducer for Plant Protection.

Daoqian Chen,Shaozhi Sun,Ningning Qin,Hao Zhang,Yuanyuan Song,Tingting Liu,Rensen Zeng,Min Shao

doi:10.3389/fpls.2019.00764

Daoqian Chen, Shaozhi Sun + Show 6 more

Open Access

https://doi.org/10.3389/fpls.2019.00764

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Abstract

Acetic acid (AA) has been proved as a chemical that could prime the jasmonic acid (JA) signaling pathway for plant drought tolerance. In this study, the capability of AA for priming of tomato defense against a chewing caterpillar Spodoptera litura and its underlying molecular mechanism were evaluated. AA pretreatment significantly increased tomato resistance against S. litura larvae. Upon larval attack, tomato plants pretreated with AA exhibited increased transcript levels of defense-related genes and elevated activities of polyphenol oxidase (PPO) and peroxidase (POD), and accumulation of protease inhibitor. Moreover, AA pretreatment resulted in upregulated transcription of JA biosynthesis genes and elevated JA accumulation in tomato seedlings upon insect attack. Furthermore, an apparent loss of AA-induced resistance was observed in a JA pathway-impaired mutant suppressor of prosystemin-mediated responses8 (spr8). These results indicate that AA enhances jasmonate-mediated antiherbivore defense responses in tomato. This raises the possibility of use of AA, a basic and simple biochemical compound, as a promising inducer for management of agricultural pests.

Highlights

Insect pests are one of the most important factors limiting the productivity of agricultural crops worldwide, which cause an estimate of 10–20% reduction in crop yields by both direct damage and indirect transmission of plant diseases (Ferry et al, 2006; Douglas, 2018)
After 2 days of larval feeding, the leaves of plants treated with water were severely damaged, while the plants treated with Acetic acid (AA) showed significantly lower leaf damage (Figure 1B)
The weight gain of the larvae fed on plants AA-pretreated was significantly lower than that on plants treated with water in all three independent experiments

Summary

Introduction

Insect pests are one of the most important factors limiting the productivity of agricultural crops worldwide, which cause an estimate of 10–20% reduction in crop yields by both direct damage and indirect transmission of plant diseases (Ferry et al, 2006; Douglas, 2018). Plants initiate defense responses by activation of jasmonate, Acetic Acid Enhances Tomato Defense ethylene and salicylic acid (SA) signaling pathways, induction of defense-related genes, and production of defense compounds (Mithofer and Boland, 2012; Douglas, 2018). The primed plants are able to induce more effective defense responses upon subsequent attack with minimal associated metabolic costs (Conrath et al, 2015). Antiherbivore defense priming could be initiated by environmental cues, such as prior insect damage, insect oviposition, pathogen challenge, and volatile emissions from neighboring plants, that reliably indicates an increased probability of a forthcoming attack (Peng et al, 2011; Kim et al, 2012; Rasmann et al, 2012; Mauch-Mani et al, 2017). Exogenous Si application primed rice defense against caterpillar rice leaffolder (Cnaphalocrocis medinalis) and root-knot nematode (Ye et al, 2013; Zhan et al, 2018)

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