Resistance to Powdery Mildew in Qingke Involves the Accumulation of Aromatic Phenolamides Through Jasmonate-Mediated Activation of Defense-Related Genes

Abstract

Powdery mildew (PM) leads to severe yield reduction in qingke (Hordeum vulgare L. var. nudum). Although studies have focused on identifying PM-related resistance genes, mechanistic insights into the metabolic regulation networks of resistance against PM have rarely been explored in qingke. Here, we integrated transcriptomic, proteomic and metabolomic data using PM-susceptible (G72) and PM-resistant (K69) accessions to systemically explore the mechanisms of PM resistance. The integrated results show that a rapidly transduction of jasmonic acid (JA) and (+)-7-iso-jasmonoyl-L-isoleucine (JA-Ile), and importantly, a inducing accumulation of aromatic PAs conferred qingke-specific resistance for PM stress. Functional analysis revealed that the four BAHD N-acyltransferase genes were responsible for the synthesis of aliphatic and aromatic PAs. The expression of the four genes are induced by methyl jasmonate (MeJA) and PM treatment. Co-expression network analysis shows that a histone lysine demethylase, JMJ705 gene, also induced by MeJA and PM treatment, had highly correlation with PAs biosynthesis. Chromatin immunoprecipitation (ChIP)-seq assays revealed that the level of trimethylated histone H3 lysine 27 (H3K27me3) of the four genes in MeJA and PM-treated plants was significantly reduced. Overall, our results suggest that a novel strategy for jasmonic acid signal-mediated demethylation controlling the accumulation of aromatic PAs to enhance plant immune resistance through removal of H3K27me3 and activating defense-related gene expression.

BarleyExpDB: an integrative gene expression database for barley

“…In addition, qRT-PCR validation of the candidate genes was performed, and the results showed high correlation coefficients with transcriptomic expression levels, confirming the reliability of the transcriptome analysis [25,32,34,36]. Notably, several researchers have performed in-depth experiments, such as overexpression and virus-induced knockdown, to verify the biological functions of candidate genes [25,37]. Taken together, these findings indicated that the RNA-seq data were valid.…”

“…However, existing studies have confirmed the high degree of uniformity among biological replicates of the same stage/treatment as well as the distinctness between stages/treatments by PCA [32][33][34], hierarchical clustering [34], and multidimensional scaling (MDS) analysis [35]. In addition, qRT-PCR validation of the candidate genes was performed, and the results showed high correlation coefficients with transcriptomic expression levels, confirming the reliability of the transcriptome analysis [25,32,34,36]. Notably, several researchers have performed in-depth experiments, such as overexpression and virus-induced knockdown, to verify the biological functions of candidate genes [25,37].…”

“…The recently released barley genome and pan-genome expanded the range of natural or induced sequence variation to facilitate genetic analysis and breeding [15,19,23]. Benefiting from the release of the genome, copious amounts of RNA-seqbased transcriptome data have been produced and are available for comparative analysis [24][25][26]. To support sharing and utilizing, researchers have constructed various repositories for RNA-seq datasets of barley [27][28][29].…”

Integrative metabolomic and transcriptomic analyses reveal the mechanisms of Tibetan hulless barley grain coloration

“…RNA isolation and cDNA generation were carried out as previously described ( Xu et al., 2022 ). qRT–PCR was performed using the SYBR Green system (TaKaRa, Dalian, China) under the following program: 95°C for 5 min followed by 35 cycles of 94°C for 30 s, 56°C for 30 s, and 72°C for 90 s. A housekeeping gene, HvUBQ1 , was used as an internal standard for calculating relative gene expression.…”

“…Anthocyanins have essential health properties that reduce the incidence of cancer, cardiovascular disease, and other chronic diseases ( Hatier et al., 2008 ). In addition, anthocyanins can protect qingke against UV light and drought and defend it from invasion by pathogens ( Zeng et al., 2020 ; Xu et al., 2021 ; Xu et al., 2022 ).…”