AtMYB12-Expressing Transgenic Tobacco Increases Resistance to Several Phytopathogens and Aphids

Abstract

Phytopathogens and pests are two major factors that limit the growth of plants. The expression of a flavonoid regulator gene, AtMYB12(AT2G47460), has been reported to increase the endogenous flavonoid content of tobacco and tomato. Previous research has only focused on the regulation mechanism of v-myb avian myeloblastosis viral oncogene homolog (MYB) transcription factors under single stress conditions. Here, research showed that AtMYB12 was involved in regulating the resistance of tobacco to multiple biological stresses such as phytopathogens and aphid. We reported that transgenic tobacco carrying AtMYB12 was more resistant to Ralstonia solanacearum when the up-regulated expression of several defense-related markers, such as NbPR1a, NbNOA1, and NbrbohB, was activated, suggesting that the priming defense of a plant may contribute to bacterial disease resistance. The improvement of the resistance of AtMYB12-expressing transgenic tobacco is achieved by promoting the production of ROS, H2O2, and NO. AtMYB12-expressing transgenic tobacco also has resistance to fungal pathogens, such as Colletotrichum nicotianae Averna and Alternaria alternate. The enrichment of flavonols components, such as rutin, which directly inhibit the growth of C. nicotianae and A. alternate, may also contribute to the defense mediated by AtMYB12 over-expression. At the same time, the results also confirm that AtMYB12-expressing transgenic tobacco enhanced plant resistance to aphid-infested (Aphidoidea) pests. These results suggest that the AtMYB12 gene is a good candidate for pest and disease control, with limited resistance costs and enrichment in flavonols, and that AtMYB12 has a potential in the breeding of disease-resistant tobacco crops.

Different Fruit-Specific Promoters Drive AtMYB12 Expression to Improve Phenylpropanoid Accumulation in Tomato

“…Phenylpropanoid is a class of secondary metabolites synthesized from phenylalanine in plants, which mainly includes caffeoylquinic substances and flavonoids, such as caffeoylquinic acids (CQAs), quercetin, quercetin rutinoside (rutin), and kaempferol rutinoside [ 1 , 2 , 3 ]. Flavonoids play an important role in improving the resilience of plants against various biological and abiotic stresses [ 4 , 5 ]. Rutin, for instance, enhances plant resistance against a variety of bacterial diseases by activating the salicylic acid (SA) synthesis pathway and regulating the expression of disease resistance genes, such as NPR1 [ 6 ].…”

Functional characterization and structural basis of a reversible glycosyltransferase involves in plant chemical defence

“…The other hand, tectorigenin may not trigger the rice immune response or trigger the responses independent of the resistance to R. solani . Previous studies had revealed that flavonoid regulator genes of AtMYB12 and OsF3H could negatively resist to some pathogens or pest, but positively resist to others (Ding et al ., 2021; Wu et al ., 2022). Ideally, more pathogen types can be tested here.…”

Metabolic engineering to enhance the accumulation of bioactive flavonoids licochalcone A and echinatin in Glycyrrhiza inflata (Licorice) hairy roots

“…AtMYB12 overexpression improves pathogen resistance in transgenic tobacco plants ( Ding et al, 2021 ). In transgenic tobacco, AtMYB12 induces the production of flavonoid compounds, such as rutin, as well as reactive oxygen species, H 2 O 2 , and NO ( Pandey et al, 2015 ; Ding et al, 2021 ).…”

“…AtMYB12 overexpression improves pathogen resistance in transgenic tobacco plants ( Ding et al, 2021 ). In transgenic tobacco, AtMYB12 induces the production of flavonoid compounds, such as rutin, as well as reactive oxygen species, H 2 O 2 , and NO ( Pandey et al, 2015 ; Ding et al, 2021 ). Similar to tobacco, our results revealed that the genes involved in pathogen resistance pathways ( Figure 4 ), defense-associated plant hormone signaling ( Figure 4 ), and WRKY TFs ( Figure 5 ) were significantly enriched in AtMYB12 -OX hairy roots.…”