Cloning, induction pattern and prokaryotic expression of a small heat shock protein SmHSP21.8 gene from Salvia miltiorrhiza / 药学学报

In order to reveal the molecular mechanism of the small heat shock proteins (sHSPs) involved in stress resistance and active ingredients accumulation in Salvia miltiorrhiza, a small heat shock protein gene was cloned from Salvia miltiorrhiza by reverse transcription PCR according to the transcriptome data of orange root Salvia miltiorrhiza. The gene is named SmHSP21.8 based on the molecular weight of the protein, and it contains an open reading frame of 585 bp, which encodes 194 amino acids. The results of phylogenetic analysis and amino acid sequence alignment showed that SmHSP21.8 protein belongs to the endoplasmic reticulum (ER) subfamily, and contains a conserved endoplasmic reticulum-specific DPFR-I/V-LE-H/Q-x-P motif at N-terminus. The prokaryotic expression vector pMAL-c2X-SmHSP21.8 was constructed and transformed into E. coli BL21 competent cells. The recombinant protein was successfully expressed after inducted. Temporal and spatial expression analysis showed that SmHSP21.8 gene was the highest expressed in flowers and had significant tissue specificity. The relative expression of the gene was significantly increased in seedlings after induction by 38 ℃, PEG6000, abscisic acid(ABA), and indole-3-acetic acid (IAA), indicating that SmHSP21.8 gene may be involved in abiotic stress such as high temperature and drought, as well as the response to exogenous hormones ABA and IAA. These results lay the foundation for further research on the molecular mechanism of small heat shock proteins involved in adversity stress.

Genome-wide identification and expression analysis of CSLA gene family of Dendrobium catenatum / 中国中药杂志

Glucomannan is the key active ingredient of Dendrobium catenatum, and CSLA family is responsible for glucomannan biosynthesis. In order to systematically evaluate the CSLA family members of D. catenatum, the bioinformatics methods were performed for genome-wide identification of DcCSLA gene family members through the genomic data of D. catenatum downloaded from the NCBI database, and further analyses of their phylogenetic relationship, gene structure, protein conserved domains and motifs, promoter cis-elements and gene expression profiles in response to stresses. The results showed that D. catenatum contains 13 CSLA members, all of which contain 9-10 exons. In the evolutionary relationship, CSLA genes were clustered into 5 groups, DcCSLA genes were distributed in all branches. Among which the ancestral genes of groupI existed before the monocot-dicot divergence, and groupⅡ-Ⅴ only existed in the monocot plants, indicating that group Ⅰ represents the earliest origin group. CSLA proteins are characteristic of the signature CESA_CaSu_A2 domain. Their promoter regions contain cis elements related to stresses and hormones. Under different stress treatments, low temperature induces the expression of DcCSLA5 and inhibits the expression of DcCSLA3. Infection of Sclerotium delphinii inhibits DcCSLA3/4/6/8/9/10 expression. Under the treatment of jasmonic acid, DcCSLA11 expression was significantly up-regulated, and DcCSLA2/5/7/12/13 were significantly down-regulated. These results laid a foundation for further study on the function of DcCSLA genes in glucomannan biosynthesis and accumulation.

Expression pattern analysis of terpene synthases of endangered Aquilaria sinensis under different stresses / 中草药

Objective: To analyze the expression of terpene synthases of Aquilaria sinensis, an endangered south medicine, and to predict the influences of the environmental factors and stresses on the synthesis of terpene in A. sinensis. Methods: Two-year old seedlings and calli were treated by different stresses. The gene expression patterns of terpene synthases were analyzed by real-time qPCR. Results: Wounding and cauterizing could induce the transcriptional expression of terpene synthases in the stems, and the effect of cauterizing was more significant. Low temperature inhibited the transcription of terpene synthases. In calli, methyl jasmonate (MeJA) treatment had the most effective induction. Conclusion: Both wounding and cauterizing could induce the synthesis of terpenes in stems, while the cauterizing treatment might have better effect. Low temperature has negative influence on agarwood formation. For calli, different treatments could induce the terpene synthesis, while MeJA has the best efficacy.