Category: Technology

A group from International Centre for Genetic Engineering and Biotechnology, Trieste, Italy, etc. has reported on effects of Pseudomonas chlororaphis inoculation in Rice rhizosphere.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8309335/

Among the group of Plant Growth-Promoting Rhizobacteria (PGPR), strains belonging to the Pseudomonas chlororaphis species have been found in association with a wide range of plants, both mono- and dicotyledonous, and both wild and cultivated. P. chlororaphis is currently classified into four subspecies, namely chlororaphis, aureofaciens, aurantiaca, and piscium. Several strains of P. chlororaphis have shown potential for application as plant probiotics due to their rhizosphere colonization abilities and plant-associated beneficial phenotypes such as chemotaxis and motility, biofilm formation, P solubilization, aminocyclopropane-1-carboxylic acid (ACC) deaminase, Indole-3-acetic acid (IAA) production and biocontrol.

P. chlororaphis strains produce different antifungal compounds such as Prn (pyrrolnitrin), PCN (phenazine-1-carboxamide), PCA (phenazine-1-carboxylic acid), 2-OH-PHZ (2-hydroxyphenazine), HPR (2-hexyl-5-propyl-alkylresorcinol) and HCN (hydrogen cyanide). These molecules inhibit the growth of various phytopathogens belonging to the Fusarium group and different species of Colletotrichum, Phytophthora, Pythium, Sclerotinia, Magnaporthe oryzae and Rhizoctonia, protecting plants.

In order to determine the effects of P. chlororaphis on plant growth, several phenotypic parameters were assayed. Statistical analyses were carried out on chlorophyll, flavonoid content and nitrogen balance index (NBI) as physiological parameters. In addition, plant height and dry shoot biomass at 90 days post inoculation (dpi) were also established. Results did not show any statistical differences between control and P. chlororaphis inoculated plants, although a tendency on higher NBI and lower flavonoid contents was measured in inoculated plants compared with the control. It was concluded that under the conditions tested, no significant plant beneficial effect was observed upon seed inoculation of P. chlororaphis.

However, there was a possibility that the plant defense system could be primed by P. chlororaphis maintaining a low level of stress.
In P. chlororaphis inoculated plants, it was found that expression of genes associated with defense OsISAP1, encoding for a multiple stress-responsive zinc-finger protein, was up-regulated at 28 dpi, suggesting an activation of the plant defense mechanisms.

A group from University of Medicine “Aldo Moro”, Bari, Italy, etc. has reported on prognostic power of Galectin-3 against severe COVID-19.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8332745/

This is the first study in scientific literature assessing the prognostic role of Galectin-3 in acute respiratory failure secondary to COVID-19 disease. Patients with higher serum levels of Galectin-3 tend to develop a more severe degree of ARDS with a worse prognosis. It is well known that SARS-COV2 infection can lead to the so called “cytokine storm” in some susceptible patients. For instance, our non-survivors group shows increased blood levels of various inflammation markers, which are frequently associated with negative outcomes in COVID-19 disease. Nevertheless, only IL-6, CRP and Galectin-3 remain statistically significant in our multivariate regression model. This finding is not surprising for IL-6 and CRP, which were previously reported as important prognostic markers in COVID-19 disease. On the contrary, this is the first study addressing this role for Galectin-3. Furthermore, among the explored parameters, Galectin-3 shows the best AUC curve in ROC analysis, showing good diagnostic power for severe ARDS (AUC 0.75, p = 0.001) using a cut-off value of 35.3 ng/ml.

In fact, patients with Galectin-3 serum levels above 35.3 ng/ml were not only more prone to develop severe ARDS, but also markedly at higher risk of ICU admission or death. The cohort size of this study was 156 patients.

A group from University of Hertfordshire, Hatfield, UK has reported that Bacillus amyloliquefaciens inoculation singularly increased winter wheat crop biomass and arbuscular mycorrhizal (AM) fungal symbiosis.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8309287/

Microbial associations between plant and soil are highly complex and provide a myriad of interactions with a wide range of plant and soil benefits including increased soil fertility and aggregation, improved plant immunity and defence, increased plant biomass and carbon sequestration. Arbuscular mycorrhizal (AM) fungi are one of the constituent organisms within the rhizosphere of an estimated 80% of terrestrial plants forming mutualistic biotrophic symbiosis with host plants. Mycorrhizal helper bacteria (MHB) stimulate mycorrhizae formation and further enhance plant-fungi symbiosis. The role of MHB and their interaction with AM fungi is poorly understood as is the extent of the tripartite rhizobacteria-AM fungi-host plant relationship. As MHBs, three Gram-positive Bacilli species were used in addition to (Ri) AM fungus R. intraradices in this experiment: (Bs) B. subtilis, (Bp) B. pumilis, and (Ba) B. amyloliquefaciens.

Soil cultivation by conventional tillage (CT) has been shown to directly influence the abundance and diversity of the soil microbiome. The hyphal networks of AM fungi are damaged by CT resulting in decreased root cortical arbuscules. However, the impact of tillage on rhizobacteria is relatively unknown. So, a series of experiments was done under two tillage regimes, CT and zero tillage (ZT).

As a conclusion, it was found that B. amyloliquefaciens (Gram-positive Bacilli) applied singularly increased winter wheat crop biomass and AM fungal symbiosis.

A group from School of Life Sciences, Nanjing University, Nanjing, China, etc. has reported four miRNAs (miR-7-5p, miR-24-3p, miR-145-5p and miR-223-3p) that are remarkably decreased in the elderly and diabetic individuals can inhibit SARS-CoV-2 replication.
https://www.nature.com/articles/s41392-021-00716-y

To comprehensively investigate the differences in circulating miRNA expression patterns in the serum between young and elderly people, age-related non-coding RNA expression profiles obtained by high-throughput sequencing from the NCBI Gene Expression Omnibus database were downloaded. A total of 13 samples (3 young, age <30 and 10 old, age >60) were analyzed, and differentially expressed miRNAs were screened and identified.

Quite interestingly, it was found that four miRNAs (miR-7-5p, miR-24-3p, miR-145-5p and miR-223-3p) through high-throughput sequencing and quantitative real-time PCR analysis, that are remarkably decreased in the elderly and diabetic groups.

Then, it was demonstrated that these miRNAs, either in the exosome or in the free form, can directly inhibit S protein expression and SARS-CoV-2 replication. A figure below shows the case of exosome.

A group from University of Oxford, UK, etc. has reported on mapping of SARS-CoV-2 spike glycoprotein-derived antigens presented by HLA class II on dendritic cells.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8116342/

It is very curious for blog admin whether HLA-II bound glycopeptides presented as SARS-CoV-2-specific antigens on dendritic cells have the same glycosylation as phagocytized SARS-CoV-2 by dendritic cells.

HLA-II-bound glycopeptides were identified from 14 N-linked glycosylation sites in Spike from total 22 glycosylation sites. HLA-II-bound peptides carried predominantly short paucimannosidic-type N-glycans while original Spike carried oligomannosidic- and GlcNAc-capped complex-type N-glycan structures at these sites. The paucimannosylation of the HLA-II-bound peptides comprised both core-fucosylated and fucosylated species. This reveals there is substantial trimming of glycan residues on the glycopeptides during antigen processing in dendritic cells.

The heatmap colors in a figure above indicate the relative frequency of each glycan composition present, and the total number of peptide spectral matches (PSM) is also shown (blue bars).

A group from Chinese Academy of Agricultural Sciences, Shenzhen, China, etc. has reported that high Zn wheat recruit more bacteria relevant to Zn mobilization in the rhizosphere.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8261137/

Around 20% of the world population are suffering from zinc (Zn) deficiency, and the situation will become worse with the increase of atmosphere carbon dioxide. An effective solution to address human Zn deficiency is to increase the grain Zn concentration of staple food crops like wheat, namely, Zn biofortification. The target of wheat Zn biofortification is to increase the current grain Zn concentration of 20 ~ 30 mg/kg to above 40 mg/kg that is sufficient for human Zn nutrition.

Due to the poor mobility of Zn in soil, the absorption of Zn by plant roots mainly occurs in the rhizosphere, where the activities of roots and microorganisms can somewhat increase the amount of available Zn. In the calcareous soils distributed worldwide, Zn availability is restricted by alkaline environment and high carbonate content; and various root exudates like carboxylic acids, amino acids, and low-molecular-weight polypeptides can acidify the rhizosphere and solubilize the Zn immobilized in minerals. Besides, the microbes living on root exudates can also produce organic acids, siderophores, and exopolysaccharides that can mobilize micronutrients in rhizosphere soil.

Comparisons of the relative abundances of rhizosphere-enriched species between High Zn (HZn) and Low Zn (LZn) wheat found that 30 species were significantly enriched in HZn with the abundance ratio of HZn to LZn >1.5 and two species were enriched in LZn with the abundance ratio of HZn to LZn <0.5. Of the 32 species, three HZn-enriched species belong to the reported soil Zn-mobilizing genus Pseudomonas, which is one of the 38 previously published Zn-mobilizing microbial species or genera. Nearly half of the previously reported Zn-mobilizing microbes were enriched in wheat rhizosphere, but most of them showed no significant difference between HZn and LZn. Differently, the 32 HZn- or LZn-enriched species were also enriched in wheat rhizosphere, and they exhibited significant differences between HZn and LZn, such as much higher abundances of Pseudomonas and Massilia species in HZn than those in LZn. Besides, genome functional annotation of the 32 species showed that 28 HZn-enriched and two LZn-enriched species possess the functional genes involved in soil Zn mobilization. Therefore, the previously reported Zn-mobilizing microbes can promote the Zn uptake of all wheat plants, while the identified 30 HZn- or LZn-enriched species may be the potential soil Zn-mobilizing microbes contributing to the variations of shoot Zn uptake and grain Zn concentration among cultivars.

It would be true that the HZn wheat recruit more bacteria relevant to soil Zn mobilization in the rhizosphere, suggesting that the difference between Hzn wheat and LZn wheat cultivars comes from the difference in microbiome of the rhizosphere. However, how HZn wheat recruit Zn mobilization bacteria is still unknown.

A group from National Cancer Institute, Frederick, USA, etc. has reported good Serum cytokine and chemokine markers associated with effective immune response to SARS-CoV-2 in mRNA vaccination.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8299183/

A cohort of 63 health-care workers received the BNT162b2 mRNA vaccine and was monitored for the development of neutralizing antibodies. There were two types of recipients in this cohort. One is individuals without any SARS-CoV-2 infection before the vaccination (58 recipients), and the other was individuals with pre-existing SARS-CoV-2 infection (6 recipients). The 58 recipients showed immune responses first detected 3 weeks after the 1st dose (day 22), which was followed by a significant increase after the 2nd dose by day 36. The neutralizing ability was measured using a surrogate virus neutralization test, and an assay that reached a median of 96% inhibition after the 2nd dose, In contrast, the 5 recipients with pre-existing SARS-CoV-2 immunity showed antibody responses to SARS-CoV-2 at the day of vaccination, followed by an immediate strong anamnestic response after the 1st dose (day 8). The antibody responses did not further increase upon the 2nd vaccination and remained significantly higher than those in the SARS-CoV-2-naive vaccine recipients.

This study highlights important associations of several immunoregulatory molecules induced by vaccination with innate and adaptive immune responses elicited by an mRNA-based vaccine. The early cytokine/chemokine signature featuring IL-15, IFN-γ, and IP-10/CXCL10 may be used to monitor effective vaccination and as a guide to optimize the efficacy of mRNA vaccination strategies.