Abstract
Verticillium wilt causes massive annual losses of cotton yield, but the mechanism of cotton resistance to Verticillium dahliae is complex and poorly understood. In this study, a comparative proteomic analysis was performed in resistant cotton (Gossypium barbadense cv7124) on infection with V. dahliae. A total of 188 differentially expressed proteins were identified by mass spectrometry (MALDI-TOF/TOF) analysis and could be classified into 17 biological processes based on Gene Ontology annotation. Most of these proteins were implicated in stimulus response, cellular processes and metabolic processes. Based on the proteomic analysis, several genes involved in secondary metabolism, reactive oxygen burst and phytohormone signaling pathways were identified for further physiological and molecular analysis. The roles of the corresponding genes were further characterized by employing virus-induced gene silencing (VIGS). Based on the results, we suggest that the production of gossypol is sufficient to affect the cotton resistance to V. dahliae. Silencing of GbCAD1, a key enzyme involving in gossypol biosynthesis, compromised cotton resistance to V. dahliae. Reactive oxygen species and salicylic acid signaling may be also implicated as regulators in cotton responsive to V. dahliae according to the analysis of GbSSI2, an important regulator in the crosstalk between salicylic acid and jasmonic acid signal pathways. Moreover, brassinosteroids and jasmonic acid signaling may play essential roles in the cotton disease resistance to V. dahliae. The brassinosteroids signaling was activated in cotton on inoculation with V. dahliae and the disease resistance of cotton was enhanced after exogenous application of brassinolide. Meanwhile, jasmonic acid signaling was also activated in cotton after inoculation with V. dahliae and brassinolide application. These data provide highlights in the molecular basis of cotton resistance to V. dahliae.
Highlights
Cotton (Gossypium spp.) is one of the most important economic crops globally
Data was from three biological replicates; a threshold of p Յ 0.05 and fold change of Ն2 or Յ0.5 was used to identify significantly differentially expressed protein spots
The rate of diseased plants and the disease index were calculated, and the results show that silencing of Gb14-3-3c and Gb14-3-3d improves resistance to the pathogen based on the reduced wilting and etiolated leaves observed in TRV:Gb14-3-3c and TRV:Gb14-3-3d seedlings (Fig. 4D)
Summary
Cotton (Gossypium spp.) is one of the most important economic crops globally. the yield of cotton is restricted by many unfavorable environmental conditions including biotic and abiotic stresses. These proteins are involved in the accumulation, polar transport or homeostasis of auxin (40 – 42), and their expression levels changed dramatically in cotton after inoculation with V. dahliae (Fig. 2B). Gossypol is Involved in the Resistance of Cotton to V. dahliae—Among these identified proteins, the protein GbCAD1 (ssp2124), related to the biosynthesis of the terpenoid phytoalexin gossypol [18], was clearly up-regulated in the roots after inoculation with V. dahliae (Fig. 3A).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
