Tomato histone H2B monoubiquitination enzymes SlHUB1 and SlHUB2 contribute to disease resistance against Botrytis cinerea through modulating the balance between SA- and JA/ET-mediated signaling pathways. Issue 1 (December 2015)

• Record Type: Journal Article
• Authors: Zhang, Yafen; Li, Dayong; Zhang, Huijuan; Hong, Yongbo; Huang, Lei; Liu, Shixia; Li, Xiaohui; Ouyang, Zhigang; Song, Fengming
• Is Part Of: BMC plant biology. Volume 15:Issue 1(2015)
• Page Start: 1
• Page End: 20
• Publication Date: 2015-12
• Subjects: Botrytis cinerea -- Defense response -- Histone H2B ubiquitination -- RING E3 ligase -- Signaling pathway -- Tomato (Solanum lycopersicum); Plant molecular biology -- Periodicals; Botany -- Periodicals; 580.5
• DOI: 10.1186/s12870-015-0614-2
• Languages: English
• ISSNs: 1471-2229

Abstract

Abstract Background Histone H2B monoubiquitination pathway has been shown to play critical roles in regulating growth/development and stress response in Arabidopsis. In the present study, we explored the involvement of the tomato histone H2B monoubiquitination pathway in defense response againstBotrytis cinerea by functional analysis of SlHUB1 and SlHUB2, orthologues of the Arabidopsis AtHUB1/AtHUB2. Methods We used the TRV-based gene silencing system to knockdown the expression levels ofSlHUB1 orSlHUB2 in tomato plants and compared the phenotype between the silenced and the control plants after infection withB. cinerea andPseudomonas syringae pv.tomato (Pst) DC3000. Biochemical and interaction properties of proteins were examined usingin vitro histone monoubiquitination and yeast two-hybrid assays, respectively. The transcript levels of genes were analyzed by quantitative real time PCR (qRT-PCR). Results The tomato SlHUB1 and SlHUB2 had H2B monoubiquitination E3 ligases activityin vitro and expression ofSlHUB1 andSlHUB2 was induced by infection ofB. cinerea andPst DC3000 and by treatment with salicylic acid (SA) and 1-amino cyclopropane-1-carboxylic acid (ACC). Silencing of eitherSlHUB1 orSlHUB2 in tomato plants showed increased susceptibility toB. cinerea, whereas silencing ofSlHUB1 resulted in increased resistance againstPst DC3000. SlMED21, a Mediator complex subunit, interacted with SlHUB1 but silencing ofSlMED21 did not affect the disease resistance toB. cinerea andPst DC3000. TheSlHUB1 - andSlHUB2 -silenced plants had thinner cell wall but increased accumulation of reactive oxygen species (ROS), increased callose deposition and exhibited altered expression of the genes involved in phenylpropanoid pathway and in ROS generation and scavenging system. Expression of genes in the SA-mediated signaling pathway was significantly upregulated, whereas expression of genes in the jasmonic acid (JA)/ethylene (ET)-mediated signaling pathway were markedly decreased inSlHUB1 - andSlHUB2 -silenced plants after infection ofB. cinerea . Conclusion VIGS-based functional analyses demonstrate that both SlHUB1 and SlHUB2 contribute to resistance againstB. cinerea most likely through modulating the balance between the SA- and JA/ET-mediated signaling pathways.