Sheng wu gong cheng xue bao = Chinese journal of biotechnology最新文献

Prunus mume is an ecologically and economically valuable plant with both medicinal and edible values. However, drought severely limits the promotion and cultivation of P. mume in the arid and semi-arid areas in northern China. In this study, we treated P. mume 'Meiren' with natural drought and then assessed photosynthetic and physiological indexes such as osmoregulatory substances, photosynthetic parameters, and antioxidant enzyme activities. Furthermore, we employed transcriptome sequencing to explore the internal regulatory mechanism of P. mume under drought stress. As the drought stress aggravated, the levels of chlorophyll a (Chla), chlorophyll b (Chlb), chlorophyll (a+b)[Chl(a+b)], and soluble protein (SP) in P. mume first elevated and then declined. The net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), maximum photochemical efficiency (Fv/Fm), effective photochemical quantum yield [Y(Ⅱ)], photochemical quenching (qP), and relative electron transport rate (ETR) all kept decreasing, while the levels of malondialdehyde, superoxide dismutase (SOD), peroxidase (POD), and osmoregulatory substances rose. Transcriptome sequencing revealed a total of 24 853 high-quality genes. Gene ontology (GO) enrichment showed that differentially expressed genes (DEGs) were the most under severe drought. Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis showed that the DEGs during the four drought periods were mainly involved in the biosynthesis of secondary metabolites, plant-pathogen interaction, plant hormone signal transduction, starch and sucrose metabolism, and mitogen-activated protein kinase signaling pathways. Furthermore, we identified 16 key genes associated with the drought tolerance of P. mume 'Meiren'. This study discovered that P. mume might up-regulate or down-regulate the expression of drought tolerance-related genes such as SUS, P5CS, LEA, SOD, POD, SOD1, TPPD, and TPPA via transcription factors like MYB, ERF, bHLH, NAC, and WRKY to promote the accumulation of osmoregulatory substances like sucrose and enhance the activities of antioxidant enzymes such as SOD and POD, thus reducing the harm of reactive oxygen species and protecting the structure and function of the membrane system under drought stress. The findings provide theoretical references for further exploration of candidate genes of P. mume in response to drought stress and breeding of drought-tolerant varieties.

Soil cadmium pollution can adversely affect the cultivation of the ornamental plant, Coleus scutellarioides. Upon cadmium contamination of the soil, the growth of C. scutellarioides is impeded, and it may even succumb to the toxic accumulation of cadmium. In this study, we investigated the effects of arbuscular mycorrhizal fungi (AMF) on the adaptation of C. scutellarioides to cadmium stress, by measuring the physiological metabolism and the degree of root damage of C. scutellarioides, with Aspergillus oryzae as the test fungi. The results indicated that cadmium stress increased the activity of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), and the content of malondialdehyde (MDA) and proline (Pro) within the cells of C. scutellarioides, but inhibited mycorrhizal infestation rate, root vigour and growth rate to a great degree. With the same cadmium concentration, the inoculation of AMF significantly improved the physiological indexes of C. scutellarioides. The maximum decrease of MDA content was 42.16%, and the content of secondary metabolites rosemarinic acid and anthocyanosides could be increased by up to 27.43% and 25.72%, respectively. Meanwhile, the increase of root vigour was as high as 35.35%, and the DNA damage of the root system was obviously repaired. In conclusion, the inoculation of AMF can promote the accumulation of secondary metabolites, alleviate root damage, and enhance the tolerance to cadmium stress in C. scutellarioides.

Lateral organ boundaries (LOB) domain (LBD) genes encode a family of transcription factors ubiquitous in higher plants, playing crucial roles in the growth, development, and stress responses. Hippophae rhamnoides, known for its drought, cold, and saline-alkali tolerance, offers significant economic benefits and ecological values. Utilizing the whole genome data and bioinformatics approaches, this study identified and analyzed the LBD gene family in H. rhamnoides. Additionally, we examined the expression pattern of HrLBD genes by integrating the transcriptome data from male and female flower buds in development. Eleven LBD genes were identified in H. rhamnoides, and these genes were distributed on five chromosomes. The HrLBD proteins showed the lengths ranging from 159 aa to 302 aa, the molecular weights between 18 249.91 Da and 33 202.01 Da, and the subcellular localization in the nucleus or chloroplasts. LBD protein domains and gene structures were highly conserved, featuring similar motifs. The phylogenetic analysis of HrLBD genes and the LBD genes in Arabidopsis thaliana and Hordeum vulgare revealed that HrLBD genes falled into two major categories: Class Ⅰ and Class Ⅱ. The transcriptome data and RT-qPCR showed that HrLBD genes were highly expressed in male flower buds, with up-regulated expression levels throughout bud development, indicating a role in the specific stage of male flower bud development. This study lays a theoretical foundation for exploring the roles of HrLBD genes in the growth, development, and sex differentiation of H. rhamnoides flower buds.

Ergothioneine is a natural antioxidant known for its potent anti-inflammatory and antioxidative properties. It has been applied in various sectors such as food, cosmetics, and pharmaceuticals. Edible fungi, both wild and cultivated, stand as the primary natural sources capable of synthesizing ergothioneine. This paper reviews the research progress in the content, physiological functions, extraction and detection methods, synthetic genes and pathways, mycelium fermentation, and engineering strain construction for ergothioneine production. The aim is to provide a comprehensive reference for advancing the research and industrial development related to ergothioneine in edible fungi.

Cucumber (Cucumis sativus L.) is one of the most widely cultivated vegetables in the world. High temperature and other stress conditions can affect the growth and development of this plant, even leading to the decreases in yield and quality. The mitogen-activated protein kinase (MAPK) family plays a crucial role in plant stress responses. However, the role of MPK4 in the stress response of cucumber remains to be reported. In this study, we cloned CsMPK4, which encoded 383 amino acid residues. The qRT-PCR results showed that the expression level of CsMPK4 was the highest in leaves and flowers, moderate in roots, and the lowest in stems and tendrils. CsMPK4 was located in the nucleus and cytoplasm, and it had a close relationship with CmMPK4 in muskmelon. The cucumber plants overexpressing CsMPK4 became stronger and shorter, with reduced length and quantity of tendrils. Moreover, the transgenic seedlings were more resistant to high temperatures, with decreased malondialdehyde (MDA) content and increased activities of peroxidase (POD) and superoxide dismutase (SOD) in young leaves. Furthermore, the protein-protein interaction between CsMPK4 and CsVQ10, a member of the valine-glutamine family, was confirmed by yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assays. The results suggested that CsVQ10 cooperated with CsMPK4 in response to the high temperature stress in cucumber. This study laid a foundation for the further study on the stress response mechanism of CsMPK4 and the breeding of stress-resistant cucumber varieties.

Biosynthesized selenium nanoparticles (SeNPs) have attracted much attention because of their unique physical, chemical, and biological properties. The microbial reduction of selenium salts to SeNPs has great potential, while there is a lack of elite strains. In this study, we explored the reduction of Na₂SeO₃ by Streptomyces avermitilis into SeNPs. The colonies and hyphae of the strain and the synthesized SeNPs were characterized by optical microscopy, scanning electron microscopy (SEM), transmission electron microscope (TEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). At the same time, the inhibitory activity of SeNPs on Fusarium oxysporum, the main pathogen causing root rot of Lycium barbarum, was studied. The results showed that S. avermitilis converted Na₂SeO₃ into SeNPs and tolerated 300 mmol/L Na₂SeO₃, demonstrating strong tolerance. S. avermitilis synthesized spherical SeNPs in the cytoplasm, and most of SeNPs had a diameter of about 100 nm and were released by hyphal fracture. The SeNPs synthesized by S. avermitilis were amorphous, and their surfaces were dominated by C and Se, with the existence of O, N and other elements. SeNPs had functional groups such as -OH, C=O, C-N, and C-H, which were closely related to the stability and biological activity of SeNPs. The SeNPs synthesized by S. avermitilis showcased significant inhibitory activity on F. oxysporum, and 25.0 μmol/mL SeNPs showcased the inhibition rate of 77.61% and EC₅₀ of 0.556 μmol/mL. In conclusion, S. avermitilis can tolerate high Na₂SeO₃ stress and mediate the synthesis of SeNPs. The synthesized SeNPs have good stability and strong inhibitory activity, demonstrating the potential application value in the preparation of SeNPs and the control of L. barbarum root rot.

We studied the genetic diversity and established the DNA molecular identify for Prunus mume with both ornamental and edible values, aiming to collect, identify, evaluate, and breed new varities of this plant and promote the upgrading of the P. mume industry chain in northern China. We employed 13 pairs of primers with good polymorphism, clear bands, and good repeatability to analyze the genetic diversity and establish the molecular identify of 68 germplasm accessions of P. mume with both ornamental and edible values from Xingtai, Hebei Province. We then employed the unweighted pair-group method with arithmetic means (UPGMA) to perform the cluster analysis based on genetic distance. After that, we analyzed the genetic structure of the 68 germplasm accessions based on a Bayesian model. The 13 pairs of SSR primers amplified a total of 124 alleles from 68 P. mume germplasm accessions, with the mean number of alleles (Na) of 9.538 5, the minor allele frequency (MAF) of 0.369 3, the mean number of effective alleles (Ne) of 4.483 5, and the mean Shannon genetic diversity index (I) of 1.712 4. The mean Nei's gene diversity index (H) of 0.763 7, the mean observed heterozygosity (Ho) of 0.719 5, the mean expected heterozygosity (He) of 0.769 3, the mean polymorphism information content (PIC) of 0.733 6, and the mean genetic similarity (GS) of 0.772 9 suggested that there were significant genetic differences and rich genetic diversity among the studied P. mume germplasm accessions. The cluster analysis revealed that the 68 accessions were classified into three groups, with the mean genetic distance of 0.622 6. The population structure analysis classified the germplasm accessions into two populations. According to the PIC of primers, we selected primers for combination and constructed the combination with the fewest primers required for germplasm differentiation of P. mume with both ornamental and edible values. This study provides a theoretical basis for the innovation and industrial upgrading of P. mume with both ornamental and edible values in gardening and the improvement of breeding efficiency.

Picea mongolica, known for its remarkable tolerance to cold, drought, and salinity, is a key species for ecological restoration and urban greening in the "Three Norths" region of China. MYB transcription factors are involved in plant responses to abiotic stress and synthesis of secondary metabolites. However, studies are limited regarding the MYB transcription factors in P. mongolica and their roles in salt stress tolerance. In this study, 196 MYBs were identified based on the genome of Picea abies and the transcriptome of P. mongolica. Phylogenetic analysis classified the MYB transcription factors into seven subclasses. The R2R3-MYB subclass contained the maximum number of genes (84.77%), while the R-R and R1R2R3 subclasses each represented the smallest proportion, at about 0.51%. The MYB transcription factors within the same subclass were highly conserved, exhibiting similar motifs and gene structures. Experiments with varying salt stress gradients revealed that P. mongolica could tolerate the salt concentration up to 1 000 mmol/L. From the transcriptome data of P. mongolica exposed to salt stress (1 000 mmol/L) for 0, 3, 6, 12, and 24 h, a total of 34 differentially expressed MYBs were identified, which suggested that these MYBs played a key role in regulating the response to salt stress. The proteins encoded by these differentially expressed genes varied in length from 89 aa to 731 aa, with molecular weights ranging from 10.19 kDa to 79.73 kDa, isoelectric points between 4.80 and 9.91, and instability coefficients from 41.20 to 70.99. Subcellular localization analysis indicated that most proteins were localized in the nucleus, while three were found in the chloroplasts. Twelve MYBs were selected for quantitative real-time PCR (qRT-PCR), which showed that their expression patterns were consistent with the RNA-seq data. This study provides valuable data for further investigation into the functions and mechanisms of MYB family members in response to salt stress in P. mongolica.

Ensuring food security requires new green pesticides. Double-stranded RNA (dsRNA) pesticides trigger RNA interference by exogenous dsRNA specifically targeting pests and diseases. They can inhibit the expression of key genes in pathogens or pests, thereby achieving effective control of specific pests and diseases. DsRNA pesticides are environmentally friendly, with strong specificity and efficient gene silencing ability, while they have problems such as high production costs. Using engineering strains to produce dsRNA is a feasible strategy, whereas currently there is no cost-effective engineering strain for producing dsRNA. This article reviews the research progress and production strategies of using microorganisms to produce dsRNA, hoping to provide reference for dsRNA production.

Sweet-tasting proteins demonstrate application potential in foods and beverages due to their high sweetness, low calorie, and non-toxicity. So far, eight natural sweet-tasting proteins have been obtained from natural plants. This paper briefs the sweetness properties of the eight proteins and the molecular mechanism of the sweetness, reviews the progress in the genetic engineering, heterologous expression, and molecular modification of three representative sweet-tasting proteins (monellin, brazzein, and thaumatin), and summarizes their expression yields in different hosts and sweetness properties. Lastly, this paper prospects the research, application, and industrial development of sweet-tasting proteins. This review provides a reference for further research and development of new proteinaceous sweeteners.