A wound inducible chalcone synthase gene from Dysoxylum gotadhora (DbCHS) regulates flavonoid biosynthesis.

Chalcone synthase (CHS) is a type III polyketide synthase and a key enzyme of the phenylpropanoid pathway that generates precursors for flavonoid biosynthesis. The tree species D. gotadhora is known for having an abundance of rohitukine, which has anti-inflammatory and immune-modulating effects. In this study, we used the leaves of D. gotadhora to clone CHS gene (DbCHS). The 1188-bp open reading frame (ORF) was part of the 1373-bp full-length DbCHS clone. Compared to other parts of the plant, DbCHS is expressed more in the leaves and fruits. This is linked to anti-microbial action against a panel of microbes in these tissues. The leaves and seeds extracts inhibit Bacillus subtilis, Streptococcus pyogenes, Bacillus cereus, and Candida albicans. When a plant is hurt, it leaves its tissues open to attack by microbes. To protect themselves, plants often make chemicals that kill microbes. We found that wounding had a big effect on the production of DbCHS. Based on these tests and the results of phylogenetic analysis and molecular docking, we believe that DbCHS is a wound-inducible enzyme that is needed to make flavonoids, which may give the plant antimicrobial properties. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-023-01344-2.

Critical review on biogeochemical dynamics of mercury (Hg) and its abatement strategies.

Mercury (Hg) is among the naturally occurring heavy metal with elemental, organic, and inorganic distributions in the environment. Being considered a global pollutant, high pools of Hg-emissions ranging from >6000 to 8000 Mg Hg/year get accumulated by the natural and anthropogenic activities in the atmosphere. These toxicants have high persistence, toxicity, and widespread contamination in the soil, water, and air resources. Hg accumulation inside the plant parts amplifies the traces of toxic elements in the linking food chains, leads to Hg exposure to humans, and acts as a potential genotoxic, neurotoxic and carcinogenic entity. However, excessive Hg levels are equally toxic to the plant system and severely disrupt the physiological and metabolic processes in plants. Thus, a plausible link between Hg-concentration and its biogeochemical behavior is highly imperative to analyze the plant-soil interactions. Therefore, it is requisite to bring these toxic contaminants in between the acceptable limits to safeguard the environment. Plants efficiently incorporate or absorb the bioavailable Hg from the soil thus a constructive understanding of Hg uptake, translocation/sequestration involving specific heavy metal transporters, and detoxification mechanisms are drawn. Whereas recent investigations in biological remediation of Hg provide insights into the potential associations between the plants and microbes. Furthermore, intense research on Hg-induced antioxidants, protein networks, metabolic mechanisms, and signaling pathways is required to understand these bioremediations techniques. This review sheds light on the mercury (Hg) sources, pollution, biogeochemical cycles, its uptake, translocation, and detoxification methods with respect to its molecular approaches in plants.

Protective effect of Bacillus species associated with Rumex dentatus against postharvest soil borne disease in potato tubers and GC-MS metabolite profile.

Potato is constantly exposed to various kinds of phytopathogens which cause diseases during the developmental stage and post-harvest storage. This investigation was designed to assay the anti-phytopathogen activity of bacterial endophytes and their suppressive effects on rot disease in potato. The study also aimed to screen isolates for their plant growth-promoting traits and establish GC-MS-based metabolite profile of the potent isolate. Endophytes were isolated from Rumex dentatus and identified based on 16S rRNA gene. They were screened in dual culture assay against fungal phytopathogens and the potent isolate was tested for its capability to suppress Fusarium rot disease in potato tubers. The mechanism of action of endophytes on the phytopathogens was assessed using scanning electron microcopy. Isolates were also screened in vitro to assay their capability to produce phytohormones, hydrolytic enzymes, and to solubilize phosphates. Endophytic isolates produced proteases with a diameter of halo zone ranging from 7 to 32 mm. Bacillus sp. KL5 exhibited the highest production of indole acetic acid (IAA) with the amount of 104.28 µg/mL and was the most potent antagonist of Fusarium oxysporum and Verticillium dahliae with an inhibitory percentage of 61.53 and 100%, respectively. It showed a reduction of potato rot disease severity by more than 50%. GC-MS of active fractions of KL5 showed the presence of dibutylphthalate and 2,4-di-tert-butylphenol as major metabolites. From this study, it is evident that endophytic Bacillus species from R. dentatus are potent antagonists of F. oxysporum and V. dahliae. Bacillus sp. KL5 is a potent inhibitor of pathogenic F. oxysporum in potato tubers and can be developed as a biocontrol agent.

Plant growth promoting potential of butyl isobutyl phthalate and Streptomyces sp. from Rumex dentatus on rice.

Rice (Oryza sativa L.) is one of the most important staple foods consumed in many countries of the world. It is mostly consumed in developing countries where different chemical fertilizers are used to improve the productivity of the crop plant. In the present study, endophytic actinomycetes isolated from Rumex dentatus were identified morphologically and by scanning electron microscopy. Butyl isobutyl phthalate (BIBP) was isolated from the root endophyte Streptomyces sp. JR9 using column chromatography and HPLC methods. The compound was tested for its effect on rice seed germination. BIBP, extracts, and isolates were evaluated for their plant growth effect on rice in a growth chamber. Isolates were also screened in vitro for phosphate solubilization activity and enzyme production. Indole-3-acetic acid (IAA) and BIBP produced in extracts were quantified and detected using high performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) methods, respectively. BIBP was found to increase the germination of rice seeds by 6 to 12% in treated samples and displayed potent effect at lowest concentration (0.437 µM). Both the compound and the extract depicted significant increases in almost all growth parameters at lowest concentration of 0.125 µg/mL and 62.5 µg/mL, respectively. BIBP also increased significantly shoot length, fresh root, fresh shoot, and dried shoot weight at high concentrations and was more potent than the standard phytohormone IAA. HPLC quantification showed 7.952 µg/mg and 0.371 µg/mg of IAA in extracts of Streptomyces sp. JR9 and the stem endophyte Streptomyces sp. KS3, respectively. IAA containing extract of JR9 increased significantly most growth parameters at lowest concentration (125 µg/mL). The extract of KS3 depicted significant increases in almost all growth parameters at high concentration (500 µg/mL). Our investigation showed that streptomycetes isolated from R. dentatus and BIBP are potent growth promoting agents and can be used in agriculture as bio-fertilizer to improve the growth and productivity of rice. KEY POINTS: • Butyl isobutyl phthalate (BIBP) isolated from endophytic Streptomyces sp. JR9 is a potent rice seed germination activator and promotes significantly the growth of rice • Isolated endophytes showed the ability to produce enzymes and phytohormone IAA • Isolates enhanced significantly the growth of rice.

Comprehensive Review of Endophytic Flora from African Medicinal Plants.

Many people in different African countries are suffering from different diseases many of which result in serious life threat and public health problems with high risk of infection and mortality. Due to less accessibility and high cost of modern drugs, people of this continent often depend on traditional medicine using medicinal plants to manage the diseases. Africa has large tropical rain forests, which are very rich in medicinal plants. Many of them have been scientifically proven for their medicinal values. These medicinal plants which constitute a large repertoire of endophytes have not been significantly explored for the isolation of these microorganisms and their bioactive secondary metabolites. This review summarizes the research on endophytes isolated from medicinal plants of Africa, their pharmacological potential and some of their biotechnological aspects. Novel compounds reported from endophytes from Africa with their biological activities have also been reviewed. Information documented in this review might serve as starting point for future researches on endophytes in different African countries.

Rohitukine inhibits NF-κB activation induced by LPS and other inflammatory agents.

Rohitukine (referred to as RHK) is a bioactive chromone alkaloid isolated from the leaves of plant Dysoxylum binectariferum, which has been reported to possess diverse pharmacological properties for the treatment of inflammatory bowel disease (IBD), diarrhoea and anti-lipidemic. However, the underlying mechanism by which RHK exerts its anti-inflammatory activity has not yet demonstrated. This study aimed to elucidate the anti-inflammatory mechanism of RHK using lipopolysaccharide (LPS) - stimulated J774A.1 macrophage cells and in-vivo inflammatory models. Results demonstrated that RHK treatment could significantly decrease the LPS-induced production of nitric oxide, prostaglandin E2 (PGE2), interleukins (ILs) and tumour necrosis factor (TNF)-α in J774A.1 cells. Molecular studies revealed that RHK inhibited the activation of upstream mediator nuclear factor-κB by suppressing the phosphorylation of IκBα and p65. In in-vivo experiments showed prominent anti-inflammatory activity of RHK. Thus, RHK could be considered as a promising candidate for the treatment of inflammatory diseases.

Cloning and expression analysis of chalcone synthase gene from Coleus forskohlii.

Flavonoids are an important class of secondary metabolites that play various roles in plants such as mediating defense, floral pigmentation and plant-microbe interaction. Flavonoids are also known to possess antioxidant and antimicrobial activities. Coleus forskohlii (Willd.) Briq. (Lamiaceae) is an important medicinal herb with a diverse metabolic profile, including production of a flavonoid, genkwanin. However, components of the flavonoid pathway have not yet been studied in this plant. Chalcone synthase (CHS) catalyses the first committed step of flavonoid biosynthetic pathway. Full-length cDNA, showing homology with plant CHS gene was isolated from leaves of C. forskohlii and named CfCHS (GenBank accession no. KF643243). Theoretical translation of CfCHS nucleotide sequence shows that it encodes a protein of 391 amino acids with a molecular weight of 42.75 kDa and pI 6.57. Expression analysis of CfCHS in different tissues and elicitor treatments showed that methyl jasmonate (MeJA) strongly induced its expression. Total flavonoids content and antioxidant activity of C. forskohlii also got enhanced in response to MeJA, which correlated with increased CfCHS expression. Induction of CfCHS by MeJA suggest its involvement in production of flavonoids, providing protection from microbes during herbivory or mechanical wounding. Further, our in silico predictions and experimental data suggested that CfCHS may be posttranscriptionally regulated by miR34.

Evaluation of amylase and lipase levels in blunt trauma abdomen patients.

BACKGROUND: There are studies to prove the role of amylase and lipase estimation as a screening diagnostic tool to detect diseases apart from acute pancreatitis. However, there is sparse literature on the role of serum and urine amylase, lipase levels, etc to help predict the specific intra-abdominal injury after blunt trauma abdomen (BTA). AIM: To elucidate the significance of elevation in the levels of amylase and lipase in serum and urine samples as reliable parameters for accurate diagnosis and management of blunt trauma to the abdomen. MATERIALS AND METHODS: A prospective analysis was done on the trauma patients admitted in Jai Prakash Narayan Apex Trauma Center, AIIMS, with blunt abdomen trauma injuries over a period of six months. Blood and urine samples were collected on days 1, 3, and 5 of admission for the estimation of amylase and lipase, liver function tests, serum bicarbonates, urine routine microscopy for red blood cells, and complete hemogram. Clinical details such as time elapsed from injury to admission, type of injury, trauma score, and hypotension were noted. Patients were divided into groups according to the single or multiple organs injured and according to their hospital outcome (dead/discharged). Wilcoxon's Rank sum or Kruskal-Wallis tests were used to compare median values in two/three groups. Data analysis was performed using STATA 11.0 statistical software. RESULTS: A total of 55 patients with median age 26 (range, 6-80) years, were enrolled in the study. Of these, 80% were males. Surgery was required for 20% of the patients. Out of 55 patients, 42 had isolated single organ injury [liver or spleen or gastrointestinal tract (GIT) or kidney]. Patients with pancreatic injury were excluded. In patients who suffered liver injuries, urine lipase levels on day 1, urine lipase/amylase ratio along with aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) on days 1, 3, and 5, were found to be significant. Day 1 serum amylase, AST, ALT, hemoglobin, and hematocrit levels were found significant in patients who had spleen injury. Serum amylase levels on day 5 and ALP on day 3 were significant in patients who had GIT injury. Urine amylase levels on day 5 were found to be statistically significant in patients who had kidney injury. In patients with isolated organ injury to the liver or spleen, the levels of urine amylase were elevated on day 1 and gradually decreased on days 3 and 5, whereas in patients with injury to GIT, the urine amylase levels were observed to gradually increase on days 3 and 5. CONCLUSION: Although amylase and lipase levels in the serum and urine are not cost-effective clinical tools for routine diagnosis of extra-pancreatic abdominal injuries in BTA, but when coupled with other laboratory tests such as liver enzymes, they may be significant in predicting specific intra-abdominal injury.