Assembly and comparative analysis of the first complete mitochondrial genome of Setaria italica.

MAIN CONCLUSION: In this study, we assembled the first complete mitochondrial genome of Setaria italica and confirmed the multi-branched architecture. The foxtail millet (Setaria italica) holds significant agricultural importance, particularly in arid and semi-arid regions. It plays a pivotal role in diversifying dietary patterns and shaping planting strategies. Although the chloroplast genome of S. italica has been elucidated in recent studies, the complete mitochondrial genome remains largely unexplored. In this study, we employed PacBio HiFi sequencing platforms to sequence and assemble the complete mitochondrial genome. The mitochondrial genome spans a total length of 446,614 base pairs and harbors a comprehensive set of genetic elements, including 33 unique protein-coding genes (PCGs), encompassing 24 unique mitochondrial core genes and 9 variable genes, along with 20 transfer RNA (tRNA) genes and 3 ribosomal RNA (rRNA) genes. Our analysis of mitochondrial PCGs revealed a pronounced codon usage preference. For instance, the termination codon exhibits a marked preference for UAA, while alanine (Ala) exhibits a preference for GCU, and glutamine (Gln) favors CAA. Notably, the maximum Relative Synonymous Codon Usage (RSCU) values for cysteine (Cys) and phenylalanine (Phe) are both below 1.2, indicating a lack of strong codon usage preference for these amino acids. Phylogenetic analyses consistently place S. italica in close evolutionary proximity to Chrysopogon zizanioides, relative to other Panicoideae plants. Collinearity analysis showed that a total of 39 fragments were identified to display homology with both the mitochondrial and chloroplast genomes. A total of 417 potential RNA-editing sites were discovered across the 33 mitochondrial PCGs. Notably, all these editing events involved the conversion of cytosine (C) to uracil (U). Through the employment of PCR validation coupled with Sanger sequencing for the anticipated editing sites of these codons, RNA-editing events were conclusively identified at two specific loci: nad4L-2 and atp6-1030. The results of this study provide a pivotal foundation for advanced genomic breeding research in foxtail millet. Furthermore, they impart essential insights that will be instrumental for forthcoming investigations into the evolutionary and molecular dynamics of Panicoideae species.

Arabidopsis phosphoinositide-specific phospholipase C 4 negatively regulates seedling salt tolerance.

Previous physiological and pharmacological studies have suggested that the activity of phosphoinositide-specific phospholipase C (PI-PLC) plays an important role in regulating plant salt stress responses by altering the intracellular Ca2+ concentration. However, the individual members of plant PLCs involved in this process need to be identified. Here, the function of AtPLC4 in the salt stress response of Arabidopsis seedlings was analysed. plc4 mutant seedlings showed hyposensitivity to salt stress compared with Col-0 wild-type seedlings, and the salt hyposensitive phenotype could be complemented by the expression of native promoter-controlled AtPLC4. Transgenic seedlings with AtPLC4 overexpression (AtPLC4 OE) exhibited a salt-hypersensitive phenotype, while transgenic seedlings with its inactive mutant expression (AtPLC4m OE) did not exhibit this phenotype. Using aequorin as a Ca2+ indicator in plc4 mutant and AtPLC4 OE seedlings, AtPLC4 was shown to positively regulate the salt-induced Ca2+ increase. The salt-hypersensitive phenotype of AtPLC4 OE seedlings was partially rescued by EGTA. An analysis of salt-responsive genes revealed that the transcription of RD29B, MYB15 and ZAT10 was inversely regulated in plc4 mutant and AtPLC4 OE seedlings. Our findings suggest that AtPLC4 negatively regulates the salt tolerance of Arabidopsis seedlings, and Ca2+ may be involved in regulating this process.

Experiment research of cisplatin implants inhibiting transplantation tumor growth and regulating the expression of KLK7 and E-cad of tumor-bearing mice with gastric cancer.

OBJECTIVE: To study the influence of cisplatin implants on transplantation tumor growth and the expression of tissue kallikrein-7 (KLK7) and E-cadherin (E-cad) in tumor-bearing mice with gastric cancer. METHODS: BALB/c nude mice were collected as experimental animal and were randomly divided into model control group (Group A), tail intravenous injection of cisplatin group (Group B), intratumor injection of cisplatin group (Group C) and cisplatin implants treatment group (Group D). After the drugs intervening, the weight and volume of transplantation tumors were measured on Day 20, Day 30 and Day 40 and serum and KLK7 and E-cad contents in transplanted tumor tissue were examined. RESULTS: On Day 20, Day 30 and Day 40 after treatment, the weight and volume of transplantation tumors of tumor-bearing mice in four groups were different (Group A > Group B > Group C > Group D). The contents of KLK-7 and E-cad in tumor tissue and serum of tumor-bearing mice in four groups were different (Group A > Group B > Group C > Group D in KLK-7) and (Group A < Group B < Group C < Group D in E-cad). The weight and volume, and KLK7 and E-cad contents of transplantation tumors in four groups were significant difference (P < 0.05). CONCLUSION: Cisplatin implants can inhibit the growth of transplanted tumor tissue and down-regulated KLK7 expression and up-regulated E-cad expression of tumor-bearing mice with gastric cancer.

Expression of serum Dickkopf-1 in gastric cancer patients.

OBJECTIVE: To explore the expression and clinical significance of DKK-1 protein in patients with gastric cancers. METHODS: Enzyme linked immuno sorbent assay was used to detect expressions of serum DKK-1 protein in 90 cases of gastric cancers, 50 cases of gastric benign disease and 40 healthy cases. The dynamic change in serum DKK-1 protein of gastric cancer patients who accepted radical operation for a month was also observed. RESULTS: The expression of serum DKK-1 protein in gastric cancer groups was significantly higher than that in gastric benign group's (P < 0.01) and in health control (P < 0.01). Serum DKK-1 level was increased gradually along with the progress of the disease. Serum DKK-1 levels were significantly higher in patients at TNM staging III and IV than patients at TNM staging I and II. Level of serum DKK-1 was related to microvascular invasion, differentiation degree and infiltration depth. Level of serum DKK-1 was significantly reduced in patients after radical surgery (P < 0.01). CONCLUSIONS: The expression of serum DKK-1 protein in gastric cancer patients is increased. Level of serum DKK-1 is related to TNM staging, microvascular invasion, differentiation degree and infiltration depth. DKK-1 detection can be used as a reference index in monitoring gastric cancer progress and biological behavior.

Preparation of polyclonal antibody specific for AtPLC4, an Arabidopsis phosphatidylinositol-specific phospholipase C in rabbits.

Phosphoinositide-specific phospholipase Cs (PI-PLCs) are important enzymes in eukaryotes, which catalyze the hydrolysis of phosphatidylinositol 4,5-bisphosphate into the two second messengers inositol 1,4,5-trisphosphate and diacylglycerol. The Arabidopsis genome contains nine putative PI-PLC genes. AtPLC4, an abiotic stress induced gene, has been reported to encode an active PI-PLC isoform. However, the exact roles of putative AtPLC4 in plant remain to be elicited. The first 108 amino acid residues of the N-terminal of AtPLC4, referred to as AtPLC4 N, was expressed as a recombinant protein in Escherichia coli and used as antigen in generating antibody. Purified recombinant proteins including AtPLC1 to AtPLC5, AtPLC8, AtPLC9 and AtPLC4 N were transferred onto the same blot to test specificity of the prepared antibody. Western blot result shows that only AtPLC4 and AtPLC4 N can be recognized by the antibody. The antibody recognized a protein of approximately 68kDa in the plasma membrane fraction and cytosolic fractions prepared from Arabidopsis thaliana plants. This corresponds very well with the calculated molecular weight of AtPLC4. The results suggest that AtPLC4 may encode a plasma membrane-associated protein.