Host Transcriptional Profiling at Early and Later Stages of the Compatible Interaction Between Phaseolus vulgaris and Meloidogyne incognita

Abstract

The root-knot nematode (Meloidogyne incognita) is one of most devastating pathogens that attack the common bean crop. Although there is evidence that some cultivars have race-specific resistance against M. incognita, these resistance sources have not proved effective, and nematodes are able to circumvent the host's defense system. We constructed RNA-seq based libraries and used a high-throughput sequencing platform to analyze the plant responses to M. incognita. Assessments were performed at 4 and 10 days after inoculation corresponding to the stages of nematode penetration and giant cell development, respectively. Large-scale transcript mapping to the common bean reference genome (G19833) resulted in the identification of 27,195 unigenes. Of these, 797 host genes were found to be differentially expressed. The functional annotation results confirm the complex interplay between abiotic and biotic stress signaling pathways. High expression levels of the wounding-responsive genes were observed over the interaction. At early response, an overexpression of the N gene, a TIR-NBS-LRR resistance gene, was understood as a host attempt to overcome the pathogen attack. However, the repression of heat shock proteins resulted in a lack of reactive oxygen species accumulation and absence of a hypersensitive response. Furthermore, the host basal response was broken by the repression of the ethylene/jasmonate pathway later in the response, resulting in a continuous compatible process with consequent plant susceptibility.

Genome-wide analysis of expansin superfamily in wild Arachis discloses a stress-responsive expansin-like B gene

“…The upregulation of AraEXLB8 orthologs in response to nematode infection was also reported in the Arachis RKN-resistant genotypes (Guimaraes et al 2015; Tirumalaraju et al 2011) as well as the downregulation of a P. vulgaris EXLB gene at the later stages of its compatible interaction with M. incognita (Santini et al 2016). The shift in the spatial distribution of the AraEXLB8 transcripts in RKN-inoculated Arachis roots, comparing to those detected in drought stressed, indicates the precise and stress-dependent regulation of this gene.…”

Transcriptome analysis of root‐knot nematode (Meloidogyne incognita)‐infected tomato (Solanum lycopersicum) roots reveals complex gene expression profiles and metabolic networks of both host and nematode during susceptible and resistance responses

“…Microarray-based transcriptomic studies have been conducted in Arabidopsis (Barcala et al, 2010;Fuller et al, 2007;Hammes et al, 2005;Jammes et al, 2005), tomato (Bar-Or et al, 2005;Portillo et al, 2013;Schaff et al, 2007), a resistant soybean line (Ibrahim et al, 2011) and RKN-tolerant aubergine Solanum torvum (Bagnaresi et al, 2013). To date, only a few studies have utilized NGS to investigate differential host gene expression patterns during RKN-host interactions, including rice galls and giant cells (GCs) (Ji et al, 2013;Kyndt et al, 2012), resistant soybean roots (Beneventi et al, 2013), resistant and susceptible alfalfa cultivars (Postnikova et al, 2015) and common bean roots (Santini et al, 2016). However, previous studies were either on hosts or dissected nematodes with a limited number of disease developmental stages.…”

Transcriptional profiling of wheat (Triticum aestivum L.) during a compatible interaction with the cereal cyst nematode Heterodera avenae

“…Auxin metabolism and cell wall modification genes were also induced 15 . Host transcriptional profiling of Phaseolus vulgaris in response to RKN during compatible interactions showed that 797 host genes were differentially expressed; the resistance was repressed, and reactive oxygen species were reduced 16 . The transcriptome response of rice to sedentary endoparasitic RKN and migratory root rot nematode (RRN, Hirschmanniella oryzae ) showed that RKN suppress the salicylic acid and ethylene pathways, stimulate host metabolism, and strongly induce the expression of plant development-associated hormones, while the migratory nematode (RRN) induces program cell death and oxidative stress 17 .…”