The second is related to the intracellular functions of microbe-delivered effectors and it is called effector-triggered immunity (ETI reviewed in Cui et al., 2015). One depends on the perception of microbe-derived molecular patterns (called also pathogen-associated molecular patterns, PAMPs) and it is called PAMP-triggered immunity (PTI reviewed in Peng et al., 2018). Pathogens trigger innate immune mechanisms in plants by virtue of two different pathways. In conclusion, our study points to the specific role of HvMPK3 in molecular and root hair phenotypic responses of barley to flg22.
In addition, differential proteomes correlated with root hair phenotypes and suggested tolerance of HvMPK3 KO lines to flg22. These results were supported and validated by chitinase activity analyses and immunoblotting for HSP70. Further analyses showed that the same protein families were less prone to flg22 elicitation in HvMPK3 KO plants compared to wild types. Using differential proteomic analysis we show that TALEN-induced MPK3 knock-out lines of barley ( HvMPK3 KO) exhibit constitutive downregulation of defense related proteins such as PR proteins belonging to thaumatin family and chitinases. In the present study, we investigated the involvement of barley ( Hordeum vulgare) MPK3 in response to flagellin peptide flg22, a well-known bacterial elicitor. Much of the existing knowledge on the role of plant MAPKs in defense mechanisms against microbes stems from extensive research in the model plant Arabidopsis thaliana.
Mitogen activated protein kinases (MAPKs) integrate elicitor perception with both early and late responses associated with plant defense and innate immunity. 4Laboratory of Transgenic Models of Diseases, Institute of Molecular Genetics of the CAS, Vestec, Czechia.3Institute for Genomics, Biocomputing and Biotechnology, Mississippi Agricultural and Forestry Experiment Station, Mississippi State University, Starkville, MS, United States.2Laboratory of Growth Regulators, Palacký University and Institute of Experimental Botany, Czech Academy of Sciences, Olomouc, Czechia.1Department of Cell Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University Olomouc, Olomouc, Czechia.Tomáš Takáč 1†, Pavel Křenek 1†, George Komis 1, Pavol Vadovič 1, Miroslav Ovečka 1, Ludmila Ohnoutková 2, Tibor Pechan 3, Petr Kašpárek 4, Tereza Tichá 1, Jasim Basheer 1, Mark Arick II 3 and Jozef Šamaj 1*