Comparative transcriptome analysis of R3a and Avr3a-mediated defense responses in transgenic tomato

Abstract

Late blight caused by Phytophthora infestans is one of the most devastating diseases in potatoes and tomatoes. At present, several late blight resistance genes have been mapped and cloned. To better understand the transcriptome changes during the incompatible interaction process between R3a and Avr3a, in this study, after spraying DEX, the leaves of MM-R3a-Avr3a and MM-Avr3a transgenic plants at different time points were used for comparative transcriptome analysis. A total of 7,324 repeated DEGs were detected in MM-R3a-Avr3a plants at 2-h and 6-h, and 729 genes were differentially expressed at 6-h compared with 2-h. Only 1,319 repeated DEGs were found in MM-Avr3a at 2-h and 6-h, of which 330 genes have the same expression pattern. Based on GO, KEGG and WCGNA analysis of DEGs, the phenylpropanoid biosynthesis, plant-pathogen interaction, and plant hormone signal transduction pathways were significantly up-regulated. Parts of the down-regulated DEGs were enriched in carbon metabolism and the photosynthesis process. Among these DEGs, most of the transcription factors, such as WRKY, MYB, and NAC, related to disease resistance or endogenous hormones SA and ET pathways, as well as PR, CML, SGT1 gene were also significantly induced. Our results provide transcriptome-wide insights into R3a and Avr3a-mediated incompatibility interaction.

Comparative transcriptome profiling of potato cultivars infected by late blight pathogen Phytophthora infestans: Diversity of quantitative and qualitative responses

“…In this case, the plant places a higher priority on building a robust defense response in preference to growth [ 120 ]. This noticeable shift in priority from photosynthesis to defense response has been reported [ 27 , 34 , 52 , 94 , 121 , 137 , 139 , 149 ].…”

“…The recognition and resistance response of plants to late blight is an intricate dynamic process involving two multifaceted stages: PTI and ETI [ 139 , 143 , 149 ]. PTI results from the recognition of pathogen-associated molecular patterns (PAMPs) at the initial stage of infection which is triggered by plant pattern recognition receptors (PRRs) [ 10 , 143 , 149 ].…”

“…The signal is delivered to the cell by endocytosis, which activates several protein kinases, such as the mitogen-activated protein kinase cascade, which is an important downstream part of PTI [ 10 ]. At a later stage of infection, when the pathogen gains entrance into the host, there is a recognition of pathogen virulence proteins (effectors) by resistance genes that result in ETI [ 36 , 139 , 143 , 149 ]. ETI and PTI exhibit similar defense responses that include calcium-mediated signaling, activation of mitogen-activated protein kinases (MAPKs), production of reactive oxygen species (ROS), transcriptional reprogramming, and biosynthesis of antimicrobial compounds, even though they have different recognition mechanisms [ 31 ].…”

“…ETI and PTI exhibit similar defense responses that include calcium-mediated signaling, activation of mitogen-activated protein kinases (MAPKs), production of reactive oxygen species (ROS), transcriptional reprogramming, and biosynthesis of antimicrobial compounds, even though they have different recognition mechanisms [ 31 ]. There is an overlap between these two pathways during defense response resulting in local as well as systemic acquired resistance [ 39 , 139 ], and ETI have been regarded as an amplified PTI [ 31 ], with a longer duration and higher magnitude [ 120 ]. However, as the basal defense system becomes suppressed during a pathogen attack via the secretion of effectors by the pathogen that successfully attacks signaling components that regulate the basal defense system, the host becomes susceptible [ 60 ].…”

Screening of wild species and transcriptome profiling to identify differentially regulated genes in response to late blight resistance in potato

“…Russet Burbank ( Hegde et al., 2021 ). Recently, a comparative transcriptome analysis of the R3a and Avr3a genes-mediated defense response in transgenic tomato revealed that phenylpropanoid biosynthesis pathway, plant–pathogen interaction, and plant hormone signal transduction pathways are significantly upregulated, whereas carbon metabolism and photosynthesis pathways genes were downregulated upon pathogen infection ( Xue et al., 2021 ). This also includes TFs such as WRKY, MYB, and NAC associated with disease resistance and endogenous phytohormones such as salicylic acid and ethylene pathways, and pathogenesis-related genes were significantly induced.…”