Working group session:
Functional Genomics
Presentation type:
poster
Authors:
Gao, Wei; Long, Lu; Zhu, Longfu; Xu, Li; Gao, Wenhui; Sun, Longqing; Liu, Linlin; Zhang, Xianlong
Presenter:
Zhu, Longfu
Correspondent:
Zhu, Longfu; Zhang, Xianlong
Abstract:
Verticillium wilt causes massive yield losses of cotton, but the mechanism of cotton resistance to Verticillium dahliae is complex and poorly understood. Proteomic and transcriptome are efficient measures to explore disease resistance response genes in cotton infected with V. dahliae. Combined with virus induced gene silencing (VIGS), it is possible to uncover the molecular mechanism of cotton to V. dahliae quickly.
Comparative proteomic analysis was performed in Gossypium barbadense cv. '7124' upon 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. 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, through VIGS compromised cotton resistance to V. dahliae. Reactive oxygen species and salicylic acid (SA) 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 SA and jasmonic acid (JA) signal pathways. Moreover, brassinosteroids (BRs) and JA signaling may play essential roles in the cotton disease resistance to V. dahliae. The BR signaling was activated in cotton upon inoculation with V. dahliae and the disease resistance of cotton was enhanced after exogenous application of brassinolide (BL). Meanwhile, JA signaling was also activated in cotton after inoculation with V. dahliae and BL application. HDTF1 encoded putatively a nuclear homeodomain transcription factor and was suppressed in cotton upon inoculation with V. dahliae and Botrytis cinerea. Silencing of HDTF1 significantly enhanced cotton resistance to V. dahliae and B. cinerea. Meanwhile, accumulation of the phytohormone jasmonic acid (JA) and activation of JA-related signal pathway were found in HDTF1-knockdown plants. While, no difference was found in content of salicylic acid (SA) and the expression of SA-related genes between the control and HDTF1-silenced cotton. Based on the studies, HDTF1 seems to be an important factor in regulating JA signaling and disease resistance to V. dahliae and B. cinerea in cotton.
All these results provide highlights in the molecular basis of cotton resistance to V. dahliae.