Abstract
Plant-insect interaction is an important field for studying plant immunity. The beet armyworm, Spodoptera exigua, is one of the best-known agricultural pest insects and is usually used to study plant interactions with chewing insects. Here, we describe a protocol for insect feeding assays with Spodoptera exigua lavae using model host plant Arabidopsis thaliana, which is simple and easy to conduct, and can be used to evaluate the effect of host genes on insect growth and thus to study plant resistance to chewing insects.
Keywords: Plant-insect interaction, chewing insects, Spodoptera exigua, Arabidopsis thaliana, Insect feeding assay
Background
Plants face a variety of biotic stresses throughout their lives, such as herbivore attack and pathogen infection. The beet armyworm, Spodoptera exigua, is a worldwide phytophagous pest with a broad host range, damaging various vegetable crops and causing considerable economic agricultural losses (Howe and Jander, 2008; Hu et al., 2013). Spodoptera exigua larvae usually feed on both foliage and fruit, and are extremely destructive. Arabidopsis thaliana is a host plant of Spodoptera exigua, and is also a classic model plant to study plant resistance to herbivores. Here, we describe a method adapted from our previous work (You et al., 2019) to conduct the feeding assays with Spodoptera exigua larvae on Arabidopsis thaliana rosette leaves. By counting the weight of the larvae after feeding leaves from different genotypes, we were able to evaluate plant resistance to herbivore attacks in the laboratory settings.
Materials and Reagents
Equipment
Software
Procedure
Data analysis
Count the weight of each larva in each dish, and calculate the average. Statistical analysis should be done by calculating the average of three independent experiments and standard deviation using Microsoft Excel or any other statistical analysis software. Significance of the difference between two samples can be obtained by performing the Student’s t-test (Figure 4D). Usually, the larvae grow well after eating the leaves. In some cases, one or two larvae will die, and avoid using the dead larvae for analysis. Otherwise, collect all larvae for data analysis.
Recipes
Acknowledgments
This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant XDB11030200), the Ministry of Science and Technology of China (Grant 2015CB942900), and the National Natural Science Foundation of China (Grants 31730010 and 31770303). This protocol was adapted from the methods described in You et al. (2019).
Competing interests
The authors declare that they have no competing interests.
References
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