The Impact of High-Temperature Stress on the Growth and Development of Tuta absoluta (Meyrick).

Insect life processes and reproductive behaviors are significantly affected by extremely high temperatures. This study focused on Tuta absoluta, which poses a severe threat to tomato cultivars. The effects of intense heat stress on the growth, development, oviposition, and longevity of T. absoluta were investigated. This investigation encompassed various developmental stages, including eggs, pupae, and adults. This study revealed that egg hatching and pupa emergence rates were significantly reduced at a temperature of 44 °C maintained for 6 h. The longevity of adults that emerged after the egg and pupal stages were exposed to 44 °C for 6 h was significantly reduced compared to the control. Notably, there was no significant variation in adult fecundity after egg-stage exposure to high temperatures. However, all treatments exhibited significantly reduced fecundity compared to the control after exposure to high temperatures during the pupal stage. Adult survival rates after exposure to 40 °C and 44 °C for 3 h were 74.29% and 22.40%, respectively, dramatically less than that of the control, which was 100%. However, no significant differences were noted in terms of longevity and egg production. These results offer a better understanding of the complex interactions between extreme temperatures and the life history traits of T. absoluta, thereby offering valuable insights for implementing management strategies to alleviate its impact on tomato crops in response to climate change.

Pontibacter harenae sp. nov., isolated from the soil of a Populus euphratica forest.

A Gram-negative, rod-shaped, aerobic and light pink-pigmented bacterium, designated XAAS-A31T, was isolated from the soil of a Populus euphratica forest located near Hotan City, Xinjiang, PR China. Polyphasic, taxonomic and phylogenomic analyses were used to determine the taxonomy position of the strain. Phylogenetic analysis based on 16S rRNA gene sequence analysis indicated that XAAS-A31T belongs to the genus Pontibacter, family Hymenobacteraceae, and shows highest sequence similarity to Pontibacter silvestris XAAS-R86T (96.2 %). The digital DNA-DNA hybridization (22.0 %-19.2 %) and orthologous average nucleotide identity (74.1 %-72.7 %) values relative to closest validly published Pontibacter species were lower than the recommended thresholds of 70 and 96 %, respectively. The cells grew at 4-40 °C (optimum, 28-30 °C), at pH 6.5-8.5 (pH 7.0-7.5) and with 0-8% NaCl (0.5-2.0% NaCl). The main respiratory quinone of XAAS-A31T is MK-7, and the principal cellular fatty acids are iso-C15 : 0, iso-C17 : 0 3OH and summed feature 4 (iso-C17 : 1 I and/or anteiso-C17 : 1 B). The major polar lipids are phosphatidylethanolamine, three unidentified amino-phospholipids, one unidentified glycolipid and eight unidentified lipids. The genome length of strain XAAS-A31T is 5.48 Mbp with a DNA G+C content of 44.2 mol% and 4013 protein-coding genes. Phenotypic and genotypic data suggested that XAAS-A31T represents a novel Pontibacter species, for which we propose the name Pontibacter harenae sp. nov. and type strain XAAS-A31T (=CCTCC AB 2017162T=KCTC 62049T).

Strepolyketide D, a new SEK15-derived polyketide compound from salt-lake-derived Streptomyces sp. DBC5.

A new SEK15-derived polyketide compound, strepolyketide D (1), was isolated from salt-lake-derived Streptomyces sp. DBC5, together with two known analogues (2-3). Their structures were elucidated based on spectroscopic analysis of IR, MS, 1 D and 2 D NMR. Compound 2 elicited moderate antioxidation with IC50 value of 39.26 µg/ml. The results of the study revealed that salt-lake actinomycetes of Lake Dabancheng appear to have immense potential as a source of polyketide compounds.

Hormesis effect of hydrogen peroxide on the promoter activity of neuropeptide receptor PAC1-R.

Pituitary adenylate cyclase-activating polypeptide (PACAP) receptor 1 (PAC1-R) is the neuropeptide PACAP-preferring receptor-mediating neuroprotective activity. In order to clarify the biological mechanism of its expression, we cloned the 2,526 bp promoter fragment from -2,500 to +26 of the transcription initiation site of human ADCYAP1R1 gene and constructed the novel promotor reporter system named pYr-PromDetect-PAC1p. It was found in SH-SY5Y cells low concentration (<10 nM) of hydrogen peroxide (H2 O2 ) significantly promoted the activity of PAC1-R promoter in dose-dependent way, which was significantly inhibited by the transcription factor specificity protein 1 (SP1) inhibitor mithramycin A and was further confirmed in the deletion mutation of the predicted SP1 binding sites. Moreover, higher concentration of H2 O2 (>10 nM) inhibited the activity of PAC1-R in dose-dependent way. The hormesis effect of H2 O2 on PAC1-R promoter would help to further clarify the physiological effect of low-dose reactive oxygen on nervous system. PRACTICAL APPLICATIONS: PAC1-R mediates well-known neuroprotective, neurotrophic, and neurogenesis effects, which is an important drug target for neurodegenerative diseases. The hormesis effects of oxidative stress on PAC1-R expression not only help to explain the hormesis effects of oxidative stress on nerve system, but also offer a novel strategy to increase the expression of PAC1-R for the nerve protection or nerve generation. For example, taking advantage of low degree of oxidative stress to increases the expression of PAC1-R might help prevent subsequent surgical serious injury on the nervous system. The activation of PAC1-R promoter by low concentration of H2 O2 would help to further clarify the physiological effect of low-dose reactive oxygen on nervous system.

The allosteric modulation effects of doxycycline, minocycline, and their derivatives on the neuropeptide receptor PAC1-R.

Class B G-protein coupled receptors (GPCR) PAC1-R is a neuropeptide pituitary adenylate cyclase activating polypeptide (PACAP)-preferring receptor that mediates the effective neuroprotective activity. Based on our previous data showing that doxycycline and minocycline work as the positive allosteric modulator (PAM) of PAC1-R, we used computer molecular docking and isothermal titration calorimetry assay to further determine the bindings of doxycycline/minocycline's derivatives including tetracycline/tigecycline with the N-terminal extracellular domain of PAC1-R (PAC1-EC1). Then the cAMP assay combined with the PAC1-R natural agonist PACAP27 was used to confirm the possible PAM roles of the small-molecule antibiotics. The results showed that tetracycline/tigecycline had significant lower affinity to PAC1-EC1 than doxycycline/minocycline, which was consistent with their non-positive allosteric modulation activity on PAC1-R. Furthermore, by comparing the key residues contributing to the PAM binding with the predicted allosteric site in PAC1-EC1, we characterized four motifs contributing to PAM binding in PAC1-EC1. The site-directed mutation results showed that ASN60 played the most important role in the PAM binding of the small-molecule antibiotics, while ASP116 played a sensitive marginal role in the PAM binding. These results not only help to explain the clinical and experimental neuroprotective effects of doxycycline/minocycline, but also help to characterize the PAM binding site in PAC1-EC1, which will promote the screening and characterization of novel small-molecule PAMs targeting PAC1-EC1 with drug development potency in nerve system disease.

The palmitoylation of the N-terminal extracellular Cys37 mediates the nuclear translocation of VPAC1 contributing to its anti-apoptotic activity.

VPAC1 is class B G protein-coupled receptors (GPCR) shared by pituitary adenylate cyclase activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP). The first cysteine (Cys37) in the N-terminal extracellular domain of mature VPAC1 is a free Cys not involved in the formation of conserved intramolecular disulfide bonds. In order to investigate the biological role of this Cys37 in VPAC1, the wild-type VPAC1 and Cys37/Ala mutant (VPAC1-C37/A) were expressed stably as fusion proteins with enhanced yellow fluorescent protein (EYFP) respectively in Chinese hamster ovary (CHO) cells. Both VPAC1-EYFP and VPAC1-C37/A-EYFP trafficked to the plasma membrane normally, and CHO cells expressing VPAC1-EYFP displayed higher anti-apoptotic activity against camptothecin (CPT) induced apoptosis than the cells expressing VPAC1-C37/A-EYFP, while VPAC1-C37/A-CHO cells showed higher proliferative activity than VPAC1-CHO cells. Confocal microscopic analysis, western blotting and fluorescence quantification assay showed VPAC1-EYFP displayed significant nuclear translocation while VPAC1-C37/A-EYFP did not transfer into nucleus under the stimulation of VIP (0.1 nM). Acyl-biotin exchange assay and click chemistry-based palmitoylation assay confirmed for the first time the palmitoylation of Cys37, which has been predicted by bioinformatics analysis. And the palmitoylation inhibitor 2-bromopalmitate significantly inhibited the nuclear translocation of VPAC1-EYFP and its anti-apoptotic activity synchronously. These results indicated the palmitoylation of the Cys37 in the N-terminal extracellular domain of VPAC1 mediates the nuclear translocation of VPAC1 contributing to its anti-apoptotic activity. These findings reveal for the first time the lipidation-mediating nuclear translocation of VPAC1 produces a novel anti-apoptotic signal pathway, which may help to promote new drug development strategy targeting VPAC1.

Paenibacillus wulumuqiensis sp. nov. and Paenibacillus dauci sp. nov., two novel species of the genus Paenibacillus.

Two Gram-staining-positive, aerobic, motile, endospore-forming, rod-shaped bacteria, designated strains Y24(T) and H9(T) were isolated from cold spring and carrot (Daucus L.) samples, respectively, in Xinjiang Uyghur Autonomous Region, north-western China. The taxonomic positions of the two new isolates were determined by using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences and DNA-DNA hybridizations showed that strains Y24(T) and H9(T) were two different novel species belonging to the genus Paenibacillus, with Paenibacillus hunanensis FeL05(T) as their closest relative. The genomic DNA G + C contents of the two isolates Y24(T) and H9(T) were 48.1 and 46.6 mol %, respectively. The cell wall peptidoglycan contained meso-diaminopimelic acid. The predominant menaquinone was both as MK-7. The major cellular fatty acids were anteiso-C15:0, C16:0, iso-C16:0, anteiso-C17:0 and iso-C15:0. The polar lipid profiles consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and two glycolipids as the major components. On the basis of their phenotypic characteristics, the two isolates represent two different novel species of the genus Paenibacillus, for which the names Paenibacillus wulumuqiensis sp. nov. (type strain Y24(T) = CPCC 100602(T) = JCM 30284(T)) and Paenibacillus dauci sp. nov. (type strain H9(T) = CPCC 100608(T) = JCM 30283(T)) are proposed.