Differentially Expressed Proteins and Associated Histological and Disease Progression Changes in Cotyledon Tissue of a Resistant and Susceptible Genotype of Brassica napus Infected with Sclerotinia sclerotiorum

Abstract

Sclerotinia rot caused by Sclerotinia sclerotiorum is one of the most serious diseases of oilseed rape. To understand the resistance mechanisms in the Brassica napus to S. sclerotiorum, comparative disease progression, histological and proteomic studies were conducted of two B. napus genotypes (resistant cv. Charlton, susceptible cv. RQ001-02M2). At 72 and 96 h post inoculation (hpi), lesion size on cotyledons was significantly (P≤0.001) smaller in the resistant Charlton. Anatomical investigations revealed impeded fungal growth (at 24 hpi and onwards) and hyphal disintegration only on resistant Charlton. Temporal changes (12, 24, 48 and 72 hpi) in protein profile showed certain enzymes up-regulated only in resistant Charlton, such as those related to primary metabolic pathways, antioxidant defence, ethylene biosynthesis, pathogenesis related proteins, protein synthesis and protein folding, play a role in mediating defence responses against S. sclerotiorum. Similarly a eukaryotic translation initiation factor 5A enzyme with increased abundance in susceptible RQ001-02M2 and decreased levels in resistant Charlton has a role in increased susceptibility to this pathogen. This is the first time that the expression of these enzymes has been shown to be associated with mediating the defence response against S. sclerotinia in cotyledon tissue of a resistant cultivar of B. napus at a proteomics level. This study not only provides important new insights into the resistance mechanisms within B. napus against S. sclerotiorum, but opens the way for novel engineering of new B. napus varieties that over-express these key enzymes as a strategy to enhance resistance and better manage this devastating pathogen.

Detecting the Hormonal Pathways in Oilseed Rape behind Induced Systemic Resistance by Trichoderma harzianum TH12 to Sclerotinia sclerotiorum

“…napus is susceptible to S . sclerotiorum [2, 34–36], whereas various resistant genotypes of oilseed have been observed, including R . alboglabra to S .…”

“…sclerotiorum [2], B . napus ‘Charlton’ cultivar [34, 35] and Brassica oleracea [37] as well as the hexaploid B . napus (AACCCC), derived from crosses between ‘Zhongshuang 9’ and B .…”

Translating the Genome for Translational Research: Proteomics in Agriculture

“…Another comparative proteomic study in oilseed rape shed light on proteins involved in lateral root formation and maintenance of low phosphorus in the tolerant genotypes (Yao et al 2011 ). Proteomics also provided important new insights into the resistance mechanisms within B. napus against S. sclerotiorum and also opened the way for novel engineering of new B. napus varieties with enhanced resistance and better management against the most serious disease of the oilseed rape (Garg et al 2013 ). More recently, a combined approach of proteomics with genomics was used to gain insights into the genetic programmes that operate during embryo development in B. napus L .…”

Antagonistic Evaluation of Bioactive Metabolite from Endophytic Fungus, Aspergillus flavipes KF671231

“…There was reduced bioactivity with further incubation and no antagonism was obtained with 10 d old culture filtrate. The culture filtrate recovered after 6 d of incubation was acidified in the pH range (1)(2)(3)(4)(5)(6). The filtrate showed maximum activity at pH 2.0, that is, 19 mm inhibition zone; zone size was reduced to 9 mm at pH 4.0.…”

“…Although a significant number of natural bioactive compounds have been reported to antagonize this fungus [4], Stevia (Stevia rebaudiana Bertoni; Asteraceae), an exotic annual plant originating from Paraguay, contains glucosides of a diterpenoid nature, which are used as a lowcaloric sweetener in some South American and South East Asian countries [5]. The main active ingredient of Stevia is a stevioside, which is 100 to 300 times sweeter than sucrose.…”