Cloning and expression profiles of 15 genes encoding WRKY transcription factor in wheat （Triticum aestivem L.）

WRKY proteins are involved in various physiological processes, including biotic and abiotic stress responses, hormone responses and development. However, no systematic identification, expression and function analysis of WRKY genes in wheat were reported. In this study, we isolated 15 wheat cDNAs with complete open reading frame （ORF） encoding putative WRKY proteins using in silico cloning. Phylogenetic analysis indicated that the 15 wheat WRKY genes belonged to three major WRKY groups. Expression analysis revealed that most genes expressed drastically in leaf, except Ta WRKYIO which expressed in crown intensively. Four genes were strongly up-regulated with the senescence of leaves. Eight genes were responsive to low temperature, high temperature, NaCl or PEG treatment. Moreover, differential expression patterns were also observed between wheat hybrid and its parents, and some genes were more responsive to PEG treatment in the hybrid. These results demonstrated that wheat WRKY genes are involved in leaf senescing and abiotic stresses. And the changed expression of these WRKY genes in hybrid might contribute to the heterosis by improving the stress tolerance in hybrids.     

Expression profile analysis of 9 heat shock protein genes throughout the life cycle and under abiotic stress in rice

Plant heat shock proteins (Hsps) facilitate protein folding or assembly under diverse developmental and adverse environmental conditions. Nine OsHsps were identified in our previous study from a proteomic analysis of rice cv. IRAT 109 leaf samples at the seedling stage under drought stress. To obtain additional information on the 9 OsHsp genes, this study focused on an expression profile analysis at different development stages throughout the life cycle of rice, and under different abiotic stresses and phyto-hormone treatments. The 9 genes exhibited distinctive expression patterns in different organs or development stages. Five of the genes (OsHsp72.90, OsHsp72.57, OsHsp71.18, OsHsp24.15 and OsHsp18.03) showed high expression in the endosperm, indicating that OsHsp genes may play important roles in rice seed development. All 9 OsHsps were up-regulated under heat, polyethylene glycol, and abscisic acid treatment, whereas salt stress caused up-regulation of 6 genes (OsHsp93.04, OsHsp71.10, OsHsp71.18, OsHsp72.57, OsHsp24.15 and OsHsp18.03) and cold stress resulted in down-regulation of OsHsp93.04 and OsHsp72.57. These diverse expression profiles imply potential functional diversity of the Hsp gene family in rice.     

Enhancing rice resistance to fungal pathogens by transformation with cell wall degrading enzyme genes from Trichoderma atroviride

Three genes encoding for fungal cell wall degrading enzymes (CWDEs), ech42, nag70 and gluc78 from the biocontrol fungus Trichoderma atroviride were inserted into the binary vector pCAMBIA1305.2 singly and in all possible combinations and transformed to rice plants. More than 1800 independently regenerated plantlets in seven different populations (for each of the three genes and each of the four gene combinations) were obtained. The ech42 gene encoding for an endochitinase increased resistance to sheath blight caused by Rhizoctonia solani, while the exochitinase-encoding gene, nag70, had lesser effect. The expression level of endochitinase but exochitinase was correlated with disease resistance. Nevertheless, exochitinase enhanced the effect of endochitinase on disease resistance when the two genes co-expressed in transgenics. Resistance to Magnaporthe grisea was found in all kinds of regenerated plants including that with single gluc78. A few lines expressing either ech42 or nag70 gene were immune to the disease. Transgenic plants are being tested to further evaluate disease resistance at field level. This is the first report of multiple of expression of genes encoding CWDEs from Trichoderma atroviride that result in resistance to blast and sheath blight in rice.     

Cloning and expression of putative ethylene receptor genes in soybean plant

Ethylene plays important roles in plant growth, development, and stress responses, and ethylene receptors have been identified and studied extensively in various plant species. Here we report the cloning of four ethylene receptor genes from soybean, i.e. GmETR1, GmERS1, GmETR2 and GmEIN4. Construction of the phylogenic tree showed that GmETR1 and GmERS1 belong to subfamily I whereas GmETR2 and GmEIN4 belong to subfamily II. The four ethylene receptor genes showed different tissue-specific expression patterns in roots, stems, leaves, cotyledons, flowers, pods and seeds of soybean. These genes were differentially regulated by various abiotic stresses and plant hormones. The possible roles of the four genes in soybean plant were also discussed.     

Proteomic analysis of blast-resistant near-isogenic lines derived from japonica rice,var. Yunyin,infected with Magnaporthe oryzae

Rice blast is one of the most devastating dis- eases in the world and outbreaks occur frequently. The differences in protein expression between blast resistant and susceptible near-isogenic lines （NILs） of japonica rice var. Yunyin infected with Magnaporthe oryzae were ana- lyzed using proteomics, indicated that 67 different proteins were identified from 75 obtained proteins using the matrix- assisted laser desorption/ionization time-of-flight mass spectrometry technique. Seven specific expression proteins, 43 up-regulated proteins and 17 down-regulated proteins were identified among the 67 proteins. The bioinformatical analysis demonstrated that these 67 different proteins were involved in many biological physiological processes including five proteins related to photosynthesis, 25 pro- teins related to metabolism, six proteins related to anti- oxidants, 10 proteins related to protein synthesis and modification, five proteins related to signal transduction,four proteins related to adversity stress and 12 non-func- tional proteins. These identified proteins were directly or indirectly related to stress. Five proteins related to different physiological processes were selected. Their cDNA sequences were predicted and their expression patterns were analyzed using real-time PCR, demonstrated that the genes would response to M. oryzae and the response blindingly different between blast resistant and blast sus- ceptible NILs.     

Differential gene expression profile in ischemic myocardium of Wistar rats with acute myocardial infarction

To determine the differential genes in ischemic myocardium of Wistar rats with acute myocardial infarction （AMI）, we constructed two differential gene expression profiles. AMI model was generated by Iigation of the left anterior descending coronary artery in Wistar rats. Total RNA was extracted from the normal and the ischemic heart tissues under the IigaUon point at the 8th day after the operation. Differential gene expression profiles of the two samples were constructed by using long serial analysis of gene expression （LongSAGE）. Real time fluorescence quantitative PCR （Q-PCR） was used to confirm the expression changes of partial target genes. The main results were as follows： a total of 15966 tags were screened from the normal and the ischemic LongSAGE maps, and 9646 tags in the normal tissue and 9563 tags in the ischemic tissue were obtained. Among them, 7665 novel tags were identified by NCBI BLAST search. In the ischemic tissue, 142 genes significantly changed compared to those in the normal tissue （P〈0.05）. These differentially expressed genes may play important roles in the pathways of oxidation and phosphorylation, ATP synthesis and glycolysis and so on. Partial genes identified by the LongSAGE were confirmed by Q-PCR. The results show that AMI causes a series of gene expression changes in the regulation of the pathways related to energy metabolism.     

Cloning and expression profiles of 15 genes encoding WRKY transcription factor in wheat (Triticum aestivem L.)

WRKY proteins are involved in various physiological processes, including biotic and abiotic stress responses, hormone responses and development. However, no systematic identification, expression and function analysis of WRKY genes in wheat were reported. In this study, we isolated 15 wheat cDNAs with complete open reading frame (ORF) encoding putative WRKY proteins using in silico cloning. Phylogenetic analysis indicated that the 15 wheat WRKY genes belonged to three major WRKY groups. Expression analysis revealed that most genes expressed drastically in leaf, except TaWRKY10 which expressed in crown intensively. Four genes were strongly up-regulated with the senescence of leaves. Eight genes were responsive to low temperature, high temperature, NaCl or PEG treatment. Moreover, differential expression patterns were also observed between wheat hybrid and its parents, and some genes were more responsive to PEG treatment in the hybrid. These results demonstrated that wheat WRKY genes are involved in leaf senescing and abiotic stresses. And the changed expression of these WRKY genes in hybrid might contribute to the heterosis by improving the stress tolerance in hybrids.     

Cloning and expression pro?les of 15 genes encoding WRKY transcription factor in wheat (Triticum aestivem L.)

WRKY proteins are involved in various physiological processes, including biotic and abiotic stress responses, hormone responses and development. However, no systematic identi?cation, expression and function analysis of WRKY genes in wheat were reported. In this study, we isolated 15 wheat cDNAs with complete open reading frame (ORF) encoding putative WRKY proteins using in silico cloning. Phylogenetic analysis indicated that the 15 wheat WRKY genes belonged to three major WRKY groups. Expression analysis revealed that most genes expressed drastically in leaf, except TaWRKY10 which expressed in crown intensively. Four genes were strongly up-regulated with the senescence of leaves. Eight genes were responsive to low temperature, high temperature, NaCl or PEG treatment. Moreover, differential expression patterns were also observed between wheat hybrid and its parents, and some genes were more responsive to PEG treatment in the hybrid. These results demonstrated that wheat WRKY genes are involved in leaf senescing and abiotic stresses. And the changed expression of these WRKY genes in hybrid might contribute to the heterosis by improving the stress tolerance in hybrids. 2007 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited and Science in China Press. All rights reserved.     

Cloning and expression pro?les of 15 genes encoding WRKY transcription factor in wheat (Triticum aestivem L.)

WRKY proteins are involved in various physiological processes, including biotic and abiotic stress responses, hormone responses and development. However, no systematic identi?cation, expression and function analysis of WRKY genes in wheat were reported. In this study, we isolated 15 wheat cDNAs with complete open reading frame (ORF) encoding putative WRKY proteins using in silico cloning. Phylogenetic analysis indicated that the 15 wheat WRKY genes belonged to three major WRKY groups. Expression analysis revealed that most genes expressed drastically in leaf, except TaWRKY10 which expressed in crown intensively. Four genes were strongly up-regulated with the senescence of leaves. Eight genes were responsive to low temperature, high temperature, NaCl or PEG treatment. Moreover, differential expression patterns were also observed between wheat hybrid and its parents, and some genes were more responsive to PEG treatment in the hybrid. These results demonstrated that wheat WRKY genes are involved in leaf senescing and abiotic stresses. And the changed expression of these WRKY genes in hybrid might contribute to the heterosis by improving the stress tolerance in hybrids. 2007 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited and Science in China Press. All rights reserved.     

Comparative proteomics analysis of <Emphasis Type="Italic">OsNAS1</Emphasis> transgenic <Emphasis Type="Italic">Brassica napus</Emphasis> under salt stress

Salt stress is one of the major abiotic stresses in agricultural plants worldwide. We used proteomics to analyze the differential expression of proteins in transgenic OsNAS1 and non-transformant Brassica napus treated with 20 mmol/L Na₂CO₃. Total protein from the leaves was extracted and separated through a high-resolution and highly repetitive two-dimensional electrophoresis (2-DE) technology system. Twelve protein spots were reproducibly observed to be upregulated by more than 2-fold between transgenic and non-transformant B. napus. These 12 spots were digested in-gel with trypsin and characterized by matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) to obtain the peptide mass fingerprints. Protein database searching revealed that 5 of these proteins are involved in salt tolerance: dehydrogenase, glutathione S-transferase, peroxidase, 20S proteasome beta subunit, and ribulose-1,5-bisphosphate carboxylase/oxygenase. The potential functions of these identified proteins in substance and energy metabolism, stress tolerance, protein degradation, and cell defense are discussed. The salt tolerance of the transgenic rapeseed was significantly improved by the introduction of the OsNAS1 gene from Brazilian upland rice of Oryza sativa (cv. IAPAR 9).     

Microwave sintering of Ca<Subscript>0.6</Subscript>La<Subscript>0.2667</Subscript>TiO<Subscript>3</Subscript> microwave dielectric ceramics

Ca_0.6La_0.2667TiO₃ ceramics were prepared by conventional and microwave sintering techniques and their sinterability, microstructure, and microwave dielectric properties were investigated in detail for comparison. Densified Ca_0.6La_0.2667TiO₃ ceramics were obtained by microwave sintering at 1350°C for 30 min and by conventional sintering at 1450°C for 4 h. An unusual phenomenon was found that some larger grains (grain size range: 8–10 μm) inclined to assemble in one area but some smaller ones (grain size range: 2–4 μm) inclined to gather in another area in the microwave sintered ceramics. The microwave dielectric properties of Ca_0.6La_0.2667TiO₃ ceramics prepared by microwave sintering at 1350°C were as follows: dielectric constant (ɛ _r) = 119.6, quality factor (Qf) = 17858.5 GHz, and temperature coefficient of resonant frequency (τ _f) = 155.5 ppm/°C. In contrast, the microwave dielectric properties of the ceramics prepared by conventional sintering at 1450°C were ɛ _r = 117.4, Qf = 13375 GHz, and τ _f = 217.2 ppm/°C.