[ Objective] This study aimed to screen target genes regulated by heat shock factor AtHsfAla in Arabidopsis thaliana. [ Method] Using AtHsfAla-in- serted mutant athsfala （SALK-068042） and wild-type A. thaliana seedlings as experimental materials, target genes regulated by heat shock factor AtHsfAla were screened by microarray assay. Differentially expressed genes were screened by multiple method. Specific functions of differentially expressed genes were analyzed by gene ontology （GO） analysis. Signal transduction pathways, in which differentia｜ly expressed genes were involved, were analyzed by pathway analysis. Gene-gene interaction network was constructed by Signal-Net. [ Result] A total of 3 672 differentially expressed genes were screened out. Up-regulated differentially expressed genes were involved in 198 functions and 7 signal transduction pathways; down-regulated differentially expressed genes were involved in 94 functions and 10 signal transduction pathways. In the signal transduction network, it was found that cwlNV4 and HXK3 had relatively high ability of mediation; AT1 G14240 and cwlNV4 ex- hibited the most interactions with other genes, which were located in key positions throughout the gene-gene interaction network. [ Conclusion] Heat shock factor AtHsfAla regulates a large number of target genes in A. thaliana.
[Objective] This study was conducted to investigate the regulation of heat shock factor AtHsfA1a on ascorbate peroxidase under heat stress in Arabidopsis thaliana. [Method] After heat stress treatment on transgenetic A. thaliana with silenced endogenetic AtHsfA1a gene and wild A. thaliana plants as materials, the change in activity of APX enzyme was analyzed by spectrophotometry, the expression level of APX gene was investigated by real-time fluorescent quantitative PCR, and the binding condition of AtHsfAla with the promoter region of APX gene was analyzed by chromatin immunoprecipitation assay. [Result] The activity and mRNA level of APX in plants with silenced endogenetic AtHsfAla gene were higher than those in wild plants. Fragments of the promoter region of APX gene were not screened from the plants with silenced endogenetic AtHsfA1a gene, but found in wild plants. [Conclusion] This study provides a theoretical basis for the understanding of the important role of AtHsfAla in resistance to stress in plant, and is of great significance to the revealing of mechanism of resistance to stress in plant.
[Objective] This study aimed to investigate the effects of heat shock factor AtHsfAla on programmed cell death in Arabidopsis thaliana under cold stress. [ Method] AtHsfAla-silenced transgenic （NT） and wild-type （WT） A. thaliana seedlings were used as experimental materials to induce the formation of callus; the callus were cultured to single cells by suspension culture, subjected to cold stress, stained with DAPI, prepared into cell smears and observed under a fluorescence microscope. [ Result] Under cold stress, cell nucleus of wild-type A. thaliana displayed morphological changes, but no apoptotic bodies were found; apoptotic bodies were observed in AtHsfAla-silenced transgenic A. thaliana cells, and the cytoplasm was remarkably concentrated. [ Conclusion] Under cold stress, heat shock factor AtHsfAla exerted inhibitory effects on programmed cell death in A. thaliana, which was of great significance for clarifying the mechanism of stress responses in plants.
[ Objective] This study ~med to investigate the influence of high temperature on the expression of heat shock transcription factor AtHsfAla in different genotypes of Arabidopsis. [ Method ] Arabidopsis plants overexpressing heat shock transcription factor AtHsfA1 a were used as experimental materials and treated un- der high temperature at 39℃ for 1 rain and 5 min; total RNA of AtI-IsfAla was extracted, and the reverse transcription and amplification were conducted using RT- PCR technology, the amplification products were detected by electrophoresis. [ Result ] The expression levels of AtHsfA1 a in Arabidopsis plants overexpressing heat shock transcription factor AtHsfAla at high temperature and room temperature were higher than wild-type Arabidopsis; the expression levels of AtHsfAla in both wild-type Arab/dops/s and transgenic Arabidopsls plants overexpressing heat shock transcription factor AtHsfAla at high temperature of 39 ~C were higher than that at room temperature of 25 ~C, but the expression levels of AtHsfAla in wild-type Arab/dops/s and transgenic Arab/dops/s plants overexpressing heat shock transcription factor AtHsfAla varied little after high temperature treatment at 39 ~C for 1 rain or 5 rain. [ Conclusion] The expression of AtHsfAla is induced rapidly by high tem- perature, thus regulating the expression of early adversity-resistant genes. This study will lay the foundation demonstrating the mechanism of Arabidopsis heat shock transcription factor AtHsfAla.
[ Objective] This study aimed to investigate the effects of heat shock factor AtHsfAla on Caspase-3 activity in Arabidopsis thaliana under high tempera-ture stress, thus revealing the relationship between heat shock factor AtHsfAl a and programmed cell death in A. thaliana. [ Method ] Different genotypes of A. thaliana （AtHsfAla-silenced transgenic and wild-type） seedlings were treated at 42 ℃. According to the fragmentation level of fluorogenic substrate Ac-DEVD- pNA, Caspase-3 activity was determined by spectrophotometry. [ Result] After high temperature treatment, Caspase-3 activity in A. thaliana was enhanced signifi-cantly. Caspase-3 activity in AtHsfAla-si／enced transgenic A. thaliana was higher than that in wild-type A. thaliana, which indicated that AtHsfAla could inhibit Caspase-3 activity in A. thaliana under high temperature stress. [ Conclusion] Under high temperature stress, heat shock factor AtHsfAla might exert inhibitory effects on programmed cell death by reducing Caspase-3 activity. This study provided the basis for clarifying the mechanism of stress resistance in plants.
[ Objective ] Heat shock factors （HSFs） are the major transcription factors of eukaryotic heat shock responses. This study aims to investigate the adversity stress tolerance functions of Arabidopsis heat shock factor AtHsfAla, which has important significance for in-depth understanding of adversity stress tolerance mechanisms of plants and further utilization of heat shock factor genes. [Method] Genomic DNA of Arabidopsis was extracted with CTAB method and purified to obtain Arabidopsis DNA samples for in vitro site-specific recombination cloning （ Gateway cloning） to construct plant expression vector of heat shock factor AtHs- fAla. Firstly, donor vector pDONR 201/AtHsfAla was constructed based on attB and attP site-specific recombination method （BP reaction）, to identify E. coli transformants harboring correct sequence of AtHsfAla by sequencing; secondly, plant expression vector pBTWG2/AttlsfAla overexpressing Arabidopsis heat shock factor AtHsfAla was constructed based on attL and attR site-specific recombination method （LR reaction）, to screen E. coli transformants harboring target plasmid. [ Result] Plant expression vector of Arabidopsis heat shock factor gene AtHsfAla was constructed successfully. [ Conclusion] This study not only provided experimental materials for acquiring transgenic plants overexpressing heat shock transcription factor AtHsfAla, but also laid the foundation for further investigation of the diversity of adversity stress tolerance functions reanlated by HSFs.
