AtMYB44 regulates resistance to the green peach aphid and diamondback moth by activating EIN2‐affected defences in Arabidopsis

Abstract

Recently we showed that the transcription activator AtMYB44 regulates expression of EIN2, a gene essential for ethylene signalling and insect resistance, in Arabidopsis thaliana (Arabidopsis). To link the transactivation with insect resistance, we investigated the wild-type and atmyb44 mutant plants, genetically Complemented atmyb44 (Catmyb44) and AtMYB44-Overexpression Transgenic Arabidopsis (MYB44OTA). We found that AtMYB44 played a critical role in Arabidopsis resistance to the phloem-feeding generalist green peach aphid (Myzus persicae Sulzer) and leaf-chewing specialist caterpillar diamondback moth (Plutella xylostella L.). AtMYB44 was required not only for the development of constitutive resistance but also for the induction of resistance by both herbivorous insects. Levels of constitutive and herbivore-induced resistance were consistent with corresponding amounts of the AtMYB44 protein constitutively produced in MYB44OTA and induced by herbivory in Catmyb44. In both cases, AtMYB44 promoted EIN2 expression to a greater extent in MYB44OTA than in Catmyb44. However, AtMYB44-promoted EIN2 expression was arrested with reduced resistance levels in the EIN2-deficient Arabidopsis mutant ein2-1 and the MYB44OTA ein2-1 hybrid. In the different plant genotypes, only MYB44OTA constitutively displayed phloem-based defences, which are specific to phloem-feeding insects, and robust expression of genes involved in the biosynthesis of glucosinolates, which are the secondary plant metabolites known as deterrents to generalist herbivores. Phloem-based defences and glucosinolate-related gene expression were not detected in ein2-1 and MYB44OTA ein2-1. These results establish a genetic connection between the regulatory role of AtMYB44 in EIN2 expression and the development of Arabidopsis resistance to insects.

CmMYB19 Over-Expression Improves Aphid Tolerance in Chrysanthemum by Promoting Lignin Synthesis

“…These include AtMYB44 , which regulates tolerance to the green peach aphid and diamondback moth by activating the EIN2-mediated defense pathway [13]. Both AtMYB15 and AtMYB38 interact with a harpin protein to modulate the plant’s tolerance to infestation by the green peach aphid [16].…”

“…R2R3-MYB genes participate in a wide range of biological processes [11], which includes a few examples of involvement in the response to insect feeding. For example, the Arabidopsis thaliana transcription factor MYB102 restricts the development of Pieris rapae caterpillars [12], while MYB44 activity has been associated with tolerance to both the green peach aphid and the diamondback Moth in Arabidopsis [13]. To date, no MYB transcription factors have been associated with the response of chrysanthemum to aphid feeding.…”

Transgenic expression of a functional fragment of harpin protein Hpa1 in wheat induces the phloem-based defence against English grain aphid

“…In this regard, one important facet of this study is to extend the defensive scope of plant engineering with a harpin protein, from disease resistance (Dong et al , 1999, 2004; Chen et al , 2008 a , b ) and drought tolerance (Dong et al , 2004; Zhang et al , 2007) to resistance against insect pests, and to extend the defensive roles from biological model plants such as Arabidopsis (Dong et al , 2005; Lü et al , 2013) to agriculturally significant crops such as wheat. In particular, coincident roles of Hpa1 10–42 in inducing the phloem-based defence and altering agronomic traits, especially enhancing vegetative growth and increasing grain output (Fig.…”

“…Zhang et al , 2011). This mechanism has been shown to impede aphid infestations effectively in different plant species including wheat and other crops (Kehr, 2006; Tjallingii, 2006; Will and van Bel, 2006, 2008; Lü et al , 2011, 2013; C. Zhang et al , 2011).…”

“…One of the multiple effects of harpins in plants is to induce resistance to insects, especially aphids (Dong et al , 2004; Liu et al , 2010; Lü et al , 2011, 2013; C. Zhang et al , 2011).…”