Proteomic analysis of the sea‐island cotton roots infected by wilt pathogenVerticillium dahliae

Abstract

Verticillium wilt of cotton is a vascular disease mainly caused by the soil-born filamentous fungus Verticillium dahliae. To study the mechanisms associated with defense responses in wilt-resistant sea-island cotton (Gossypium barbadense) upon V. dahliae infection, a comparative proteomic analysis between infected and mock-inoculated roots of G. barbadense var. Hai 7124 (a cultivar showing resistance against V. dahliae) was performed by 2-DE combined with local EST database-assisted PMF and MS/MS analysis. A total of 51 upregulated and 17 downregulated proteins were identified, and these proteins are mainly involved in defense and stress responses, primary and secondary metabolisms, lipid transport, and cytoskeleton organization. Three novel clues regarding wilt resistance of G. barbadense are gained from this study. First, ethylene signaling was significantly activated in the cotton roots attacked by V. dahliae as shown by the elevated expression of ethylene biosynthesis and signaling components. Second, the Bet v 1 family proteins may play an important role in the defense reaction against Verticillium wilt. Third, wilt resistance may implicate the redirection of carbohydrate flux from glycolysis to pentose phosphate pathway (PPP). To our knowledge, this study is the first root proteomic analysis on cotton wilt resistance and provides important insights for establishing strategies to control this disease.

Proteomic and Virus-induced Gene Silencing (VIGS) Analyses Reveal That Gossypol, Brassinosteroids, and Jasmonic acid Contribute to the Resistance of Cotton to Verticillium dahliae

“…Secondary metabolites become especially abundant in plant cells when plants are threatened by diverse pathogens in nature (19,24,25). Generally, the production of secondary metabolites, such as phytoalexins and lignin, can inhibit the growth of pathogens directly or provide a physical barrier against the invading plant pathogens.…”

“…Using RNA-Seq-dependent transcriptional analysis, a subset of genes participating in lignin metabolism was demonstrated to be very important in the resistance of cotton to V. dahliae (19). Additionally, defense-and stress-related proteins, such as pathogenesis-related proteins and proteins likely to be involved in the oxidative burst, sugars, ethylene signaling, and isoprenoid synthesis, have recently been suggested to be involved in cotton response to V. dahliae (25,26). Most of the candidate genes involving in disease resistance are isolated from transcriptomic analysis, whereas only few genes have been functionally characterized (27,28).…”

The Thioredoxin GbNRX1 Plays a Crucial Role in Homeostasis of Apoplastic Reactive Oxygen Species in Response to Verticillium dahliae Infection in Cotton

“…Thus, we identified V. dahliae-responsive apoplastic proteins in the root tissues of G. barbadense. We used the dipinoculation method to infect cotton roots with V. dahliae spores, as previously described (Wang et al, 2011). To understand the process by which the pathogen colonizes root cells, we generated a V991-GFP strain, which enabled us to monitor the infection process of V. dahliae directly.…”

“…The roots of cotton seedlings (10 d old) were dip-inoculated with V. dahliae conidia suspension (1 3 10 6 conidia/mL) as previously described (Wang et al, 2011). Control plants were mock-inoculated with sterile water.…”

“…In addition, the MS and MS/MS data were also searched against the V. dahliae VdLs.17 protein sequence database (http://www.broadinstitute.org/annotation/genome/ verticillium_dahliae/MultiDownloads.html) to identify Verticillium proteins in cotton root apoplast extracts. Details of the procedures for in-gel digestion and mass spectrometric analysis referred to a previous work (Wang et al, 2011). Functional categories of the identified proteins were assigned using the Gene Ontology tool (http://www.geneontology.org).…”