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Functional Plant Biology Functional Plant Biology Society
Plant function and evolutionary biology
RESEARCH ARTICLE

Gene expression and evidence of coregulation of the production of some metabolites of chilli pepper inoculated with Pectobacterium carotovorum ssp. carotovorum

Arnaud Thierry Djami-Tchatchou A , Lerato Bame Tsalaemang Matsaunyane B , Chimdi Mang Kalu A and Khayalethu Ntushelo A C
+ Author Affiliations
- Author Affiliations

A Department of Agriculture and Animal Health, Science Campus, University of South Africa, Corner Christiaan De Wet and Pioneer Avenue, Private Bag X6, Florida 1710, South Africa.

B Agricultural Research Council-Vegetable and Ornamental Plants Institute, Private Bag X293, Pretoria 0001, South Africa.

C Corresponding author. Email: ntushk@unisa.ac.za

Functional Plant Biology 46(12) 1114-1122 https://doi.org/10.1071/FP18244
Submitted: 11 December 2018  Accepted: 12 July 2019   Published: 4 November 2019

Abstract

Chilli pepper (Capsicum annuum L.) is susceptible to Pectobacterium carotovorum subsp. carotovorum (Pcc), the causal agent of soft rot disease in crops. Understanding the molecular principles of systemic acquired resistance, which is poorly understood in chilli pepper, represents an important step towards understanding inducible defence responses and can assist in designing appropriate intervention strategies for crop disease management. Accordingly, we investigated (via real-time PCR and metabolomics profiling) the molecular response of chilli pepper to Pcc by characterisation of the crucial metabolic regulators involved in the establishment of defence response. We profiled 13 key inducible defence response genes, which included MYB transcriptor factor, ethylene response element-binding protein, suppressor of the G2 allele of Skp1, cytochrome P450, small Sar1 (GTPase), hydroxycinnamoyl-CoA:quinate hydroxycinnamoyl transferase, pathogenesis-related protein 1a, endo-1,3-β-glucanase, chitinase, proteinase inhibitor, defensin, coiled-coil-nucleotide-binding site-leucine-rich repeat (CC–NBS–LRR) resistance and phenylalanine ammonia lyase. In addition, we determined metabolomic shifts induced by Pcc in pepper. The PCR results revealed a significant induction of the selected plant defence-related genes in response to Pcc inoculation; the metabolomic profiling showed that of 99 primary metabolites profiled the quantities of acetylcarnitine, adenosine, adenosine 3′,5′ cyclic monophosphate, guanosine 3′,5′ cyclic monophosphate and inosine decreased in pepper leaves inoculated with Pcc.

Additional keywords: Capsicum annuum, primary metabolites, real-time PCR, soft rot disease.


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