摘要:
The wolf spider Lycosa singoriensis is a hunting spider with a widespread distribution in northwest China. The venom gland of spiders, which is a vent specialized secretory tissue, can secrete abundant and complex toxin components. To extensively examine the transcripts expressed in the venom glands of L. singoriensis, we generated 833 expressed sequence tags (ESTs) from a directional cDNA library. Toxin-like sequences account for 69.1% of these ESTs, 17.3% are similar to cellular transcripts and 13.6% have no significant similarity to any known sequences. Here, we identified 223 novel toxin-like sequences, which can be classified into six different. superfamilies; that means a novel potential source of ligands for varied ion channels was discovered. With the aid of Gene Ontology terms and homology to eukaryotic orthologous groups, the annotation of cellular transcripts revealed some cellular processes important for the toxin secretion of venom glands including protein synthesis, protein folding, tuned post-translational processing and trafficking, etc. (C) 2009 Elsevier GmbH. All rights reserved.
作者机构:
中国科学院亚热带农业生态研究所,长沙,410125;中国科学院环江喀斯特生态实验站,广西环江,547200;湖南农业大学生物科学技术学院,长沙,410128;南京农业大学茶学研究所,南京,210095;[宋同清; 王克林; Zeng F.-P.] Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China, Station of Karst Ecology in Huanjiang, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Huanjiang 547200, Guangxi, China
通讯机构:
[Ouyang, Z.-W.] I;Institute of Subtropical Agriculture, , Changsha 410125, China
作者机构:
[Hao, Lin; Xia, Shitou; Li, Xin] Univ British Columbia, Michael Smith Labs, Vancouver, BC V6T 1Z4, Canada.;[Zhu, Zhaohai; Xia, Shitou; Zhang, Yuelin] Natl Inst Biol Sci, Beijing 102206, Peoples R China.;[Xia, Shitou; Xiao, Langtao] Hunan Agr Univ, Hunan Prov Key Lab Phytohormones & Growth & Dev, Changsha 410128, Hunan, Peoples R China.;[Li, Xin; Chen, Jin-Gui] Univ British Columbia, Dept Bot, Vancouver, BC V6T 1Z4, Canada.
通讯机构:
[Li, Xin] U;Univ British Columbia, Michael Smith Labs, Vancouver, BC V6T 1Z4, Canada.
摘要:
Systemic acquired resistance (SAR) is a plant immune response induced by local necrotizing pathogen infections. Expression of SAR in Arabidopsis (Arabidopsis thaliana) plants correlates with accumulation of salicylic acid (SA) and up-regulation of Pathogenesis-Related (PR) genes. SA is an essential and sufficient signal for SAR. In a genetic screen to search for negative regulators of PR gene expression and SAR, we found a new mutant that is hypersensitive to SA and exhibits enhanced induction of PR genes and resistance against the virulent oomycete Hyaloperonospora arabidopsidis Noco2. The enhanced pathogen resistance in the mutant is Nonexpressor of PR genes1 independent. The mutant gene was identified by map-based cloning, and it encodes a protein with high homology to Replication Factor C Subunit3 (RFC3) of yeast and other eukaryotes; thus, the mutant was named rfc3-1. rfc3-1 mutant plants are smaller than wild-type plants and have narrower leaves and petals. On the epidermis of true leaves, there are fewer cells in rfc3-1 compared with the wild type. Cell production rate is reduced in rfc3-1 mutant roots, indicating that the mutated RFC3 slows down cell proliferation. As Replication Factor C is involved in replication-coupled chromatin assembly, our data suggest that chromatin assembly and remodeling may play important roles in the negative control of PR gene expression and SAR.
摘要:
The F-box protein CORONATINE INSENSITIVE1 (COI1) plays a central role in jasmonate (JA) signaling and is required for all JA responses in Arabidopsis (Arabidopsis thaliana). To dissect JA signal transduction, we isolated the partially suppressing coi1 (psc1) mutant, which partially suppressed coi1 insensitivity to JA inhibition of root growth. The psc1 mutant partially restored JA sensitivity in coi1-2 background and displayed JA hypersensitivity in wild-type COI1 background. Genetic mapping, sequence analysis, and complementation tests revealed that psc1 is a leaky mutation of DWARF4 (DWF4) that encodes a key enzyme in brassinosteroid (BR) biosynthesis. Physiological analysis showed that an application of exogenous BR eliminated the partial restoration of JA sensitivity by psc1 in coi1-2 background and the JA hypersensitivity of psc1 in wild-type COI1 background. Exogenous BR also attenuated JA inhibition of root growth in the wild type. In addition, the expression of DWF4 was inhibited by JA, and this inhibition was dependent on COI1. These results indicate that (1) BR is involved in JA signaling and negatively regulates JA inhibition of root growth, and (2) the DWF4 is down-regulated by JA and is located downstream of COI1 in the JA-signaling pathway.
摘要:
Comparison of the volatile constituents of different parts of Cortex magnolia officinalis by GC-MS combined with chemometric resolution method Volatile compositions of different parts (stem, branch and root barks) of Cortex magnolia officinalis, cultivated in China, were investigated for the first time by GC-MS with the help of heuristic evolving latent projection (HELP). Identification of components was conducted by similarity matching to NIST mass library but also assisted by comparison of temperature-programmed retention indices (PTRIs) with the data web available. A total of 90, 82 and 76 volatile compounds in the essential oils of the three samples taken from the same batch aforementioned were qualitatively and quantitatively determined, representing 84.03, 83.68 and 83.10% of the total content, respectively. Among the constituents determined, there were 50 components coexisting. Eudesmol and its isomers were shown to be the principal compounds in the studied samples, accounting for 47.66, 36.74 and 36.31%, respectively. The three kinds of isomers (a-, band c-eudesmol) in houpo volatile oils have been tentatively qualified and quantified simultaneously for the first time. By comparative analysis, significant qualitative and semi-quantitative differences and similarities were observed among the three samples. The results achieved provide a scientific evidence for further exploitation of Magnolia bark and clinical medication.
摘要:
Transposons are effective mutagens alternative to T-DNA for the generation of insertional mutants in many plant species including those whose transformation is inefficient. The current strategies of transposon tagging are usually slow and labor-intensive and yield low frequency of tagged lines. We have constructed a series of transposon tagging vectors based on three approaches: (i) AcTPase controlled by glucocorticoid binding domain/VP16 acidic activation domain/Gal4 DNA-binding domain (GVG) chemical-inducible expression system; (ii) deletion of AcTPase via Cre-lox site-specific recombination that was initially triggered by Ds excision; and (iii) suppression of early transposition events in transformed rice callus through a dual-functional hygromycin resistance gene in a novel Ds element (HPT-Ds). We tested these vectors in transgenic rice and characterized the transposition events. Our results showed that these vectors are useful resources for functional genomics of rice and other crop plants. The vectors are freely available for the community. 2009 Institute of Botany, the Chinese Academy of Sciences.
摘要:
Jingzhaotoxin-34 (JZTX-34) is a 35-residue polypeptide from the venom of Chinese tarantula Chilobrachys jingzhao. Our previous work reported its full-length cDNA sequence encoding a precursor with 87 residues. In this study we report the protein expression and biological function characterization. The toxin was efficiently expressed by the secretary pathway in yeast. Under whole-cell patch-clamp mode, the expressed JZTX-34 was able to inhibit tetrodotoxin-sensitive (TTX-S) sodium currents (IC50 similar to 85 nM) while having no significant effects on tetrodotoxin-resistant (TTX-R) sodium currents on rat dorsal root ganglion neurons. The inhibition of TTX-S sodium channels was completely reversed by strong depolarization (+120 mV). Toxin treatment altered neither channel activation and inactivation kinetics nor recovery rate from inactivation. However, it is interesting to note that in contrast to huwentoxin-IV, a recently identified receptor site-4 toxin from Ornithoctonus huwena venom, 100 nM JZTX-34 caused a negative shift of steady-state inactivation curve of TTX-S sodium channels by approximately 10 mV. The results indicated that JZTX-34 might inhibit mammalian sensory neuronal sodium channels through a mechanism similar to HWTX-IV by trapping the 1154 voltage sensor in the resting conformation, but their binding sites should not overlay completely. (C) 2009 Elsevier Inc. All rights reserved.
摘要:
Expression profiles of nine rice heat shock protein genes (OsHSPs) were analyzed by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). The nine genes exhibited distinctive expression in different organs. Expression of nine OsHSP genes was affected differentially by abiotic stresses and abscisic acid (ABA). All nine OsHSP genes were induced strongly by heat shock treatment, whereas none of them were induced by cold. The transcripts of OsHSP80.2, OsHSP71.1 and OsHSP23.7 were increased during salt tress treatment. Expression of OsHSP80.2 and OsHSP24.1 genes were enhanced while treated with 10% PEG. Only OsHSP71.1 was induced by ABA while OsHSP24.1 was suppressed by ABA. These observations imply that the nine OsHSP genes may play different roles in plant development and abiotic stress responses.
作者机构:
中国科学院亚热带农业生态研究所,长沙,410125;中国科学院环江喀斯特农业生态系统研究观测站,广西环江,547200;湖南农业大学生物科学技术学院,长沙,410128;南京农业大学茶学研究所,南京,210095;[Zeng F.-P.; 宋同清] Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China, Station of Karst Ecology in Huanjiang, Institute of Subtropical Agriculture, Chinese Academy of Scicences, Huanjiang 547200, Cuangxi, China
通讯机构:
[Song, T.-Q.] I;Institute of Subtropical Agriculture, , Changsha 410125, China
作者机构:
[He, Feifei; Chen, Qing; Zhang, Fusuo; Su, Fang; Jiang, Rongfeng] Key Laboratory of Plant-soil Interactions of Ministry of Education, Key Laboratory of Plant Nutrition of Minstry of Agriculture, College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing 100193, China;[He, Feifei] College of Bioscience and Biotechnology, Hunan Agricultural University, Furong District, Changsha 410128, China
通讯机构:
[Su, F.] K;Key Laboratory of Plant-soil Interactions of Ministry of Education, Key Laboratory of Plant Nutrition of Minstry of Agriculture, College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan West Road, China