Non-host disease resistance response in pea (Pisum sativum) pods: Biochemical function of DRR206 and phytoalexin pathway localization

Abstract

Continually exposed to potential pathogens, vascular plants have evolved intricate defense mechanisms to recognize encroaching threats and defend themselves. They do so by inducing a set of defense responses that can help defeat and/or limit effects of invading pathogens, of which the non-host disease resistance response is the most common. In this regard, pea (Pisum sativum) pod tissue, when exposed to Fusarium solani f. sp. phaseoli spores, undergoes an inducible transcriptional activation of pathogenesis-related genes, and also produces (+)-pisatin, its major phytoalexin. One of the inducible pathogenesis-related genes is Disease Resistance Response-206 (DRR206), whose role in vivo was unknown. DRR206 is, however, related to the dirigent protein (DP) family. In this study, its biochemical function was investigated in planta, with the metabolite associated with its gene induction being pinoresinol monoglucoside. Interestingly, both pinoresinol monoglucoside and (+)-pisatin were co-localized in pea pod endocarp epidermal cells, as demonstrated using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging. In addition, endocarp epidermal cells are also the site for both chalcone synthase and DRR206 gene expression. Taken together, these data indicate that both (+)-pisatin and pinoresinol monoglucoside function in the overall phytoalexin responses.

A Novel Soybean Dirigent Gene GmDIR22 Contributes to Promotion of Lignan Biosynthesis and Enhances Resistance to Phytophthora sojae

“…The same specificity has been reported for DIRs from Thuja plicata (TpDIR5, 8) (Kim et al, 2002), Schisandra chinensis (ScDIR) (Kim K.W. et al, 2012), Pisum sativum (PsDRR206) (Seneviratne et al, 2015), and Linum usitatissimum (LuDIR1) (Dalisay et al, 2015). Coniferyl alcohol is the direct precursor for formation of lignan dimers.…”

Matrix assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) for direct visualization of plant metabolites in situ

“…This approach has its foundation in earlier studies like those described by Jun thaliana flowers and siliques [34], secondary metabolites in trichomes [35], defense induced synthesis of pinoresinol monogulcoside in pea pod endocarp [36], and the antibiome of roots with a developing biofilm of Bacillus amyloliquefaciens [37]. Due to the relative ease sample preparation, and the applicability of MSI to surface analysis by a variety of methods, imaging surfaces of plants should be a prolific area of research in years to come.…”

Anatomy of a nonhost disease resistance response of pea to Fusarium solani: PR gene elicitation via DNase, chitosan and chromatin alterations

“…DRR206 codes for an enzyme associated with a secondary pathway toward (lignan) production (Seneviratne et al, 2014). This pea gene when transferred to canola has conferred resistance against a fungal pathogen of canola (Wang et al, 1999);…”

“…PAL and CHS are also intermediates in the production of lignan (Seneviratne et al, 2014), lignin, flavonoids and isoflavonoids, e.g., the phytoalexin, pisatin (Cruickshank and Perrin, 1962; DiCenzo and VanEtten, 2006). …”