Molecular insights into the compatible and incompatible interactions between sugar beet and the beet cyst nematode

Abstract

Background Sugar beet (Beta vulgaris subsp. vulgaris) is an economically important crop that provides nearly one third of the global sugar production. The beet cyst nematode (BCN), Heterodera schachtii, causes major yield losses in sugar beet and other crops worldwide. The most effective and economic approach to control this nematode is growing tolerant or resistant cultivars. To identify candidate genes involved in susceptibility and resistance, the transcriptome of sugar beet and BCN in compatible and incompatible interactions at two time points was studied using mRNA-seq. Results In the susceptible cultivar, most defense-related genes were induced at 4 dai while suppressed at 10 dai but in the resistant cultivar Nemakill, induction of genes involved in the plant defense response was observed at both time points. In the compatible interaction, alterations in phytohormone-related genes were detected. The effect of exogenous application of Methyl Jasmonate and ET-generator ethephon on susceptible plants was therefore investigated and the results revealed significant reduction in plant susceptibility. Genes putatively involved in the resistance of Nemakill were identified, such as genes involved in phenylpropanoid pathway and genes encoding CYSTM domain-containing proteins, F-box proteins, chitinase, galactono-1,4-lactone dehydrogenase and CASP-like protein. Also, the transcriptome of the BCN was analyzed in infected root samples and several novel potential nematode effector genes were found. Conclusions Our data provides detailed insights into the plant and nematode transcriptional changes occurring during compatible and incompatible interactions between sugar beet and BCN. Many important genes playing potential roles in susceptibility or resistance of sugar beet against BCN, as well as some BCN effectors with a potential role as avr proteins were identified. In addition, our findings indicate the effective role of jasmonate and ethylene in enhancing sugar beet defense response against BCN. This research provides new molecular insights into the plant-nematode interactions that can be used to design novel management strategies against BCN.

The phenylpropanoid pathway inhibitor piperonylic acid induces broad‐spectrum pest and disease resistance in plants

“…Three biological replicates, each consisting of four pooled plants, were used per treatment. Library preparation, sequencing and data analysis were as in (Ghaemi et al, 2020). Briefly, libraries were prepared using the QuantSeq 3' mRNA-Seq library prep kit (Lexogen), library quality was verified using an Agilent Bioanalyzer 2100 and libraries were sequenced on an Illumina NextSeq 500 platform.…”

Transcriptomic Analysis of Resistant and Susceptible Responses in a New Model Root-Knot Nematode Infection System Using Solanum torvum and Meloidogyne arenaria

“…1,029 genes were upregulated, and 180 genes were down-regulated at at least onetime point in both A2-J and A2-O infected plants (Figure 2B). Previous studies showed that the expression of genes associated with the salicylic acid (SA), jasmonic acid (JA), and ethylene (ET) signaling pathways are induced in resistant plants infected with PPNs (Ye et al, 2017;Zhang H. et al, 2017;Bali et al, 2019;Du et al, 2020;Ghaemi et al, 2020), so we investigated the expression of marker genes for hormone biosynthesis, hormone signaling (Figure 2C), and defense responses (Figure 2D). Infection with A2-O significantly induced the expression of SA-regulated genes that encode basic pathogenesis-related protein 1 (PR1) and β-1,3glucanase (PR2), as well as a JA biosynthesis gene (lipoxygenase D (LoxD)), the JA-regulated gene protease inhibitor II (PI-II), and two ET biosynthesis genes (1-aminocyclopropane-1-carboxylate synthase (ACS) and 1-aminocyclopropane-1-carboxylate oxidase (ACO)) (Farmer et al, 1992;Yan et al, 2013;Booker and DeLong, 2015;Zhang et al, 2018;Marhavý et al, 2019;Figure 2C).…”

Rice diterpenoid phytoalexins are involved in defence against parasitic nematodes and shape rhizosphere nematode communities

“…Three biological replicates, each consisting of four pooled plants, were used per treatment and time point. Library preparation, sequencing and data analysis were performed as described in Ghaemi et al (2020). For each time point, Gene Ontology (GO) enrichment analysis was performed using G:PROFILER (Raudvere et al, 2019) on significantly differentially expressed genes (FDR-adjusted P < 0.05 and |log 2 -FC| > 0.7).…”