Molecular Plant Breeding 2024, Vol.15, No.2, 42-51 http://genbreedpublisher.com/index.php/mpb 47 associated with disease resistance while down-regulating the expression of PDF1.2 and LOX3 (Guo et al., 2018). Sequential expression of CaWRKY40 in chickpea increased plant resistance to Fusarium oxysporumf. sp. ciceri Race1 (Foc1) (Chakraborty et al., 2019). Upon being infected with pathogenic bacteria, plants and organisms respond by using signaling molecules such as SA, JA, ET, and ABA as well as modifying the signal transduction process. TaWRKY70 may play a role in the resistance of high-temperature wheat nursery plants (HTSP) to striped stalk rust (Puccinia striiformis f. sp. tritici, Pst) infestation-induced stripe rust (Wang et al., 2017a). TaWRKY70 showed a significant increase during the initial symptomatic stage of Pst infection and was induced by high temperature, ET, SA, and low-temperature stress (4 °C) treatments. However, its expression was down-regulated in plants treated with methyl jasmonate (MeJA) and heat stress (40 °C) (Wang et al., 2017a). OsWRKY13 is involved in resistance to infection by rice blast fungus (Magnaporthe grisea) by activating the SA signaling pathway and repressing the JA signaling pathway, directly or indirectly regulating the expression of genes upstream and downstream of SA and JA (Schluttenhofer and Yuan, 2014). All these WRKY genes are involved in controlling the control of defense responses in plants through JA or SA-mediated signaling pathways. 3.2 WRKY transcription factors and phytophagous insects There are few reports available on the association of WRKY transcription factors with phytophagous insects in plants. Certain WRKY transcription factors have been shown to influence the feeding behavior of phytophagous insects (Ganbaatar et al., 2016). For instance, when H2O2 and ET levels were increased in OsWRKY45 antisense repressor lines, the feeding and egg-laying preferences of Nilaparvata lugens (Stal) were diminished, leading to an anthelmintic effect. This indicates that WRKY transcription factors play a role in the plant's defense response to feeding by phytophagous insects (Huangfu, 2015). Additionally, GhWRKY18 and GhWRKY70 not only reduce cotton resistance to phytophagous insects, but also affect the fundamental growth and development of cotton (Chang, 2018). Finally, some of the WRKY transcription factors related to phytophagous insects were summarized in this study (Table 1) (Wu et al., 2020). Table 1WRKYs involved in herbivoreinduced defense responses (Adopted from Wu et al., 2020) Gene Species Research methods Stress type AtWRKY8 Arabidopsis Mutation Improve resistance to aphids AtWRKY40 Arabidopsis Expression analysis Improve resistance toBrevicoryne brassicae OsWRKY45 Rice Expression analysis Improve resistance toNilaparvata lugens OsWRKY53, OsWRKY70 Rice Expression analysis Induced by SSB larva 4 Conclusions WRKY is a class of plant-specific transcription factors that play a crucial role in the life activities of plants. With the advancements in genomics, bioinformatics, and genetic engineering, research on WRKY has become increasingly extensive and thorough. It's now known that WRKY transcription factors not only impact plant growth and development but also have a sophisticated and effective regulatory mechanism for external stresses. The WRKY gene can regulate a variety of stresses through synergistic or antagonistic mechanisms. Moreover, the co-expression of WRKY produces a complex regulatory network to counteract stress via multiple expressions. The use of WRKY transcription factors to screen stress-resistant plant varieties and enhance plant stress tolerance holds enormous potential in terms of economic and scientific value.
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