Heat Shock Factors HsfB1 and HsfB2b Are Involved in the Regulation of Pdf1.2 Expression and Pathogen Resistance in Arabidopsis
Heat Shock Factors HsfB1 and HsfB2b Are Involved in the Regulation of Pdf1.2 Expression and Pathogen Resistance in Arabidopsis
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DOI：
10.1093/mp/ssn095
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发表时间：
2009-01-01
期刊：
影响因子：
27.5
通讯作者：
Schoeffl, Friedrich
中科院分区：
文献类型：
--
作者：
Kumar, Mukesh;Busch, Wolfgang;Schoeffl, Friedrich
为了评估热胁迫诱导的B类热激因子在拟南芥中的功能作用，我们研究了AtHsfB 1和AtHsfB 2b的T-DNA敲除突变体。对双敲除hsfB 1/hsfB 2 B b植株的微阵列分析显示，在突变体植株中防御素基因Pdf 1.2 a/B的基础mRNA水平同样强烈上调。Pdf表达进一步增强茉莉酸处理或感染坏死营养真菌芸苔链格孢。单突变体hsfB 2b和双突变体hsfB 1/B2b在接种A.芸苔属侵染没有迹象表明Hsf与Pdf1.2启动子直接相互作用，Pdf1.2缺乏完美的HSE共有Hsf结合序列。然而，在hsfB 1/B2b植物中检测到晚期HsfA 2依赖性HSE结合形成的变化。这表明HsfB 1/B2b可能与A-Hsf类相互作用，调节热休克反应的关闭。鉴定Pdf基因作为HSF依赖性负调控的靶基因是HSF在生物和非生物反应调控中相互关联的第一个证据。
In order to assess the functional roles of heat stress-induced class B-heat shock factors in Arabidopsis, we investigated T-DNA knockout mutants of AtHsfB1 and AtHsfB2b. Micorarray analysis of double knockout hsfB1/hsfB2b plants revealed as strong an up-regulation of the basal mRNA-levels of the defensin genes Pdf1.2a/b in mutant plants. The Pdf expression was further enhanced by jasmonic acid treatment or infection with the necrotrophic fungus Alternaria brassicicola. The single mutant hsfB2b and the double mutant hsfB1/B2b were significantly improved in disease resistance after A. brassicicola infection. There was no indication for a direct interaction of Hsf with the promoter of Pdf1.2, which is devoid of perfect HSE consensus Hsf-binding sequences. However, changes in the formation of late HsfA2-dependent HSE binding were detected in hsfB1/B2b plants. This suggests that HsfB1/B2b may interact with class A-Hsf in regulating the shut-off of the heat shock response. The identification of Pdf genes as targets of Hsf-dependent negative regulation is the first evidence for an interconnection of Hsf in the regulation of biotic and abiotic responses.