Zhu Yan, Wang Zhi, Jing Yanjun, Wang Lili, Liu Xia, Liu Yongxiu, Deng Xin
Research Center of Plant Molecular and Developmental Biology, Key Laboratory of Photosynthesis and Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, 100093 Beijing, People's Republic of China.
Plant Mol Biol. 2009 Nov;71(4-5):451-67. doi: 10.1007/s11103-009-9538-2. Epub 2009 Aug 23.
Plant heat shock transcription factors (Hsfs) are commonly found to be involved in various stress responses. Several Hsfs displayed dwarf phenotype while conferred stress tolerance when over-expressed. However, the underlying mechanisms were not fully understood. Here we report the cloning and characterization of an Hsf (BhHsf1) from the resurrection plant Boea hygrometrica. Drought, heat and wound can induce BhHsf1 expression. The over-expression of BhHsf1 conferred growth retardation and stress tolerance in both Arabidopsis and tobacco. Evidence was presented to show that the growth retardation of aerial organs in the transgenic plants was resulted from the reduction of cell proliferation. Gene expression profiling using microarray hybridization and pathway analysis showed that Hsps and stress-associated genes were induced whereas the genes related to DNA replication and mitotic cell cycle were down-regulated in BhHsf1 over-expression Arabidopsis, which was in consistence with the observation of the impaired nuclear endoreduplication. Taking together, our results suggest that BhHsf1 may play dual roles in mediating the processes in heat stress tolerance and growth retardation via regulation of target genes related to stress protection and mitotic cell cycle.
植物热激转录因子（Hsfs）通常参与各种应激反应。几个Hsfs过表达时表现出矮化表型，但同时赋予了胁迫耐受性。然而，其潜在机制尚未完全了解。在此，我们报道了从复苏植物卷柏中克隆和鉴定一个Hsfs（BhHsf1）。干旱、高温和伤口都能诱导BhHsf1的表达。BhHsf1的过表达在拟南芥和烟草中都导致生长迟缓并赋予胁迫耐受性。有证据表明转基因植物地上器官的生长迟缓是细胞增殖减少所致。利用微阵列杂交进行基因表达谱分析和通路分析表明，在BhHsf1过表达的拟南芥中，热激蛋白（Hsps）和胁迫相关基因被诱导，而与DNA复制和有丝分裂细胞周期相关的基因被下调，这与核内复制受损的观察结果一致。综上所述，我们的结果表明BhHsf1可能通过调控与胁迫保护和有丝分裂细胞周期相关的靶基因，在介导热胁迫耐受性和生长迟缓过程中发挥双重作用。
