Comparative Transcriptome Analysis between Broccoli (Brassica oleracea var. italica) and Wild Cabbage (Brassica macrocarpa Guss.) in Response to Plasmodiophora brassicae during Different Infection Stages

Abstract

Clubroot, one of the most devastating diseases to the Brassicaceae family, is caused by the obligate biotrophic pathogen Plasmodiophora brassicae. However, studies of the molecular basis of disease resistance are still poor especially in quantitative resistance. In the present paper, two previously identified genotypes, a clubroot-resistant genotype (wild cabbage, B2013) and a clubroot-susceptible genotype (broccoli, 90196) were inoculated by P. brassicae for 0 (T0), 7 (T7), and 14 (T14) day after inoculation (DAI). Gene expression pattern analysis suggested that response changes in transcript level of two genotypes under P. brassicae infection were mainly activated at the primary stage (T7). Based on the results of DEGs functional enrichments from two infection stages, genes associated with cell wall biosynthesis, glucosinolate biosynthesis, and plant hormone signal transduction showed down-regulated at T14 compared to T7, indicating that defense responses to P. brassicae were induced earlier, and related pathways were repressed at T14. In addition, the genes related to NBS-LRR proteins, SA signal transduction, cell wall and phytoalexins biosynthesis, chitinase, Ca2+ signals and RBOH proteins were mainly up-regulated in B2013 by comparing those of 90196, indicating the pathways of response defense to clubroot were activated in the resistant genotype. This is the first report about comparative transcriptome analysis for broccoli and its wild relative during the different stages of P. brassicae infection and the results should be useful for molecular assisted screening and breeding of clubroot-resistant genotypes.

Antimicrobial activity of broccoli (Brassica oleracea var. italica ) cultivar Avenger against pathogenic bacteria, phytopathogenic filamentous fungi and yeast

“…However, the chitinase activity is known to be induced in broccoli following fungal infection, for example, with Plasmodiophora brassicae (Zhang et al . ).…”

“…Bioassays also showed that chitinases are unlikely involved in antifungal activity. However, the chitinase activity is known to be induced in broccoli following fungal infection, for example, with Plasmodiophora brassicae (Zhang et al 2016).…”

Not in your usual Top 10: protists that infect plants and algae

“…brassicae (Agarwal et al, 2011;Lemari e et al, 2015;Lovelock et al, 2013). Accordingly, SA-responsive gene expression is increased in tolerant hosts (Chen et al, 2015;Song et al, 2016) and higher SA levels during early infection correlate with resistance (Chen et al, 2015;Zhang et al, 2016b).…”

“…Plasmodiophora brassicae infection results in a heavily altered host metabolism (Jubault et al, 2013): transcriptional and proteomic changes occur in pathways involved in lipid, flavonoid and plant hormone metabolism, defence responses, and carbohydrate and cell wall synthesis of the Brassica hosts (Agarwal et al, 2011;Chen et al, 2015, Ludwig-M€ uller et al, 2009P€ asold et al, 2010;Siemens et al, 2009;Zhang et al, 2016b). In Arabidopsis, gall formation results from increased host vascular cambium activity combined with significant reduction of xylem development (Malinowski et al, 2012).…”

“…brassicae. During infection, resistance (R) genes and pathogen-related (PR) genes are expressed more strongly in tolerant than in susceptible plants, whereas the pathogen-associated molecular pattern (PAMP)-triggered immune response appears to be similar in both host types (Chen et al, 2015;Zhang et al, 2016b).…”