Growth kinetics, improved plant growth and alleviation of water stress in tomato by water stress tolerant bacteria.

Plants are subject to a variety of abiotic stresses contributed to yield losses of up to 50%, posing a significant challenge to global food production. To cope with drought stress, of 205 bacterial cultures investigated for moisture stress tolerant potential, 16 cultures showed promising results in improving the majority of plant growth ameliorating activities under water stress and non-stress conditions. Growth kinetics and plant growth ameliorating activities declined significantly with the increase in water stress level. Most of the isolates tolerant to water stress were Streptomyces and Pseudomonas species. Of these, four strains with the best results were selected for growing tomato under water stress conditions. The imposition of water stress severely inhibited the growth of tomato plants. However, bacterial strains alleviated the stress and enhanced plant growth performance. Antioxidant activity showed a promising result of protection from reactive oxygen species produced in plants because of water stress. Plants treated with bioinoculants also exhibited a substantial decline in lipid peroxidation. Water stress significantly reduced the yield of tomato. However, bioinoculants treated plants demonstrated significantly higher yields than untreated plants. Nutrient uptake and fruit quality also improved in the treated plants. Experiments point to the scope of developing a microbial formulation to alleviate water stress in higher plants.

Influence of photoperiod variations on the mRNA expression pattern of melatonin bio-synthesizing enzyme genes in the pineal organ and retina: A study in relation to the serum melatonin profile in the tropical carp Catla catla.

Surface-dwelling C. catla were exposed to different photoperiods (8L:16D, 12L:12D, 12D:12L and 16L:8D) and the mRNA level profile of enzymes involved in melatonin synthesis was evaluated in the pineal gland and retina. Furthermore, a comparative analysis of the serum melatonin profile with the mRNA level was also performed. The results indicated diurnal variations in the transcripts of tph1, aanat and hiomt in the pineal organ and retina, and these variations change with the change in lighting regime. The serum melatonin profile showed rhythmicity in the natural photoperiod, but the serum melatonin level increased proportionally with increasing daylength. In short photoperiods, the peak value (though lower than in long photoperiods) of melatonin maintains a longer duration in serum. Moreover, the comparative analysis revealed a similar profile of mRNA of pineal aanat1 and aanat2 with serum melatonin under the same lighting conditions. This indicates that serum melatonin is produced by the pineal gland. Our results specify the importance of day length and the timing of onset or offset of the dark for maintaining the oscillating levels of serum melatonin and mRNA levels of melatonin biosynthesizing enzyme genes in the pineal organ and retina as well. The findings in this study highlight the distinctive pattern of mRNA levels in the pineal organ and retina under different photoperiods. The pineal melatonin biosynthesizing enzyme genes showed a similar pattern with serum melatonin levels while the retinal genes changed dramatically with photoperiod. We also revealed a light-dependent transcriptional regulation of pineal aanat genes in C. catla. Moreover, our results suggest that ALAN and skyglow can influence the levels of serum melatonin and its biosynthesis, resulting in desynchronization of the entire biological clock as well as the overall physiology of the animal.

Anticarcinogenic and Antioxidant Action of an Edible Aquatic Flora Jussiaea repens L. Using In Vitro Bioassays and In Vivo Zebrafish Model.

Oxidative stress is the major cause of many health conditions, and regular consumption of antioxidants helped to encounter and prevent such oxidative stress-related diseases. Due to safety concerns over long-term uses of synthetic antioxidants, natural antioxidants are more preferred. The purpose of this study is to investigate the antioxidant and anticancer activities of Jussiaea repens L., a wild edible flora found in Manipur, India. The antioxidant activity was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), Ferric reducing antioxidant power (FRAP) assay and DNA-nicking assay. The anticancer activity was tested using five cancer lines viz., SKOV3 cells (ovarian), HeLa (cervical), MDA-MB-231 (breast), PANC-1 (pancreatic), and PC3 (prostate). The toxicity, developmental effect, antiproliferative activity was further tested using zebrafish embryos. The methanolic plant extract had higher polyphenol content than flavonoids. The in vitro study demonstrated a promising antioxidant capacity and DNA protection ability of this plant. The extract also showed cytotoxic activity against SKOV3, HeLa, MDA-MB-23, and PANC-1 cancer cell lines. The in vivo studies on zebrafish embryos demonstrated the extract's ability to suppress the developmental process and elicited more cytotoxicity to cancer cells than developing zebrafish embryos. Moreover, the in vivo studies on zebrafish embryos also indicated the antiproliferative activity of J. repens L. extract.

Interaction of melatonin and gonadotropin-inhibitory hormone on the zebrafish brain-pituitary-reproductive axis.

Circadian cycles and photoperiod are known to influence reproductive physiology in several animals. Neuropeptides, such as gonadotropin-inhibitory hormone (GNIH) and gonadotropin-releasing hormone (GNRH), are influenced by melatonin in birds and mammals. The present study demonstrates the role of melatonin in oocyte maturation in the zebrafish (Danio rerio), via the brain-pituitary-reproductive axis, under different photic conditions. Melatonin was significantly higher both in the whole brain and ovary under continuous dark (DD) compared to continuous light (LL) conditions. Transcription of gnih in the brain was high in LL, but low in DD; similarly, melatonin exogenous treatment reduced gnih in cultured brain in a dose-dependent manner. Expression of gnrh3, however, was high in both continuous photic conditions (DD and LL), whereas fshb and lhb were high only during DD. kiss2, another neuropeptide, was high in LL, but kiss1 remain unchanged among the conditions. At the gonad level, expression of fshr, lhcgr, mtnr1aa, and mtnr1ab tracked with the expression of their respective ligand in DD and LL. The expression of mprb is high in DD ovary, although intra-ovarian growth factors (tgfb1a and bmp15) were low. The measured increased percentages of germinal vesicle breakdown, expression of Cyclin B1, and reduced Cdc2p34 phosphorylation are consistent with increased maturation in the dark. Our study thus links melatonin to the inhibition of gnih in the brain-pituitary-reproductive axis of zebrafish in response to photic conditions.

Melatonin biosynthesizing enzyme genes and clock genes in ovary and whole brain of zebrafish (Danio rerio): Differential expression and a possible interplay.

The present study on zebrafish (Danio rerio) is the first attempt to demonstrate the circadian mRNA expression of melatonin biosynthesizing enzyme genes (Tph1a, Aanat1, Aanat2 and Hiomt) and clock associated genes (Bmal1a, Clock1a, Per1b, Per2 and Cry2a) in the ovary with a comparison to whole brain in normal (LD=12h L:12h D) and altered photic conditions (continuous dark, DD; continuous light, LL). Moreover, the present study also confirmed the ability of zebrafish ovary to biosynthesize melatonin both in vivo and in vitro with a significant difference at day and night. qRT-PCR analysis of genes revealed a dark acrophase of Aanat2 in both organs while Tph1 is in whole brain in LD condition. On the contrary, Bmal1a and Clock1a giving their peak in light, thereby showing a negative correlation with Tph1a and Aanat2. In LD-ovary, the acrophase of Tph1a, Bmal1a and Clock1a is in light and thus display a positive correlation. This trend of relationship in respect to Tph1a is not changing in altered photic conditions in both organs (except in DD-ovary). On the other hand this association for Aanat2 is varying in ovary under altered photic conditions but only in DD-whole brain. Both in LD and LL the expression of Aanat2 in brain presenting an opposite acrophase with both Bmal1a and Clock1a of ovary and consequently displaying a strong negative correlation among them. Interestingly, all ovarian clock associated genes become totally arrhythmic in DD, representing a loss of correlation between the melatonin synthesizing genes in brain and clock associated genes in ovary. The result is also indicating the formation of two heterodimers namely Clock1a:Bmal1a and Per2:Cry2a in the functioning of clock genes in both organs, irrespective of photic conditions, as they are exhibiting a strong significant positive correlation. Collectively, our data suggest that ovary of zebrafish is working as peripheral oscillator having its own melatonin biosynthesizing machinery and signifying a possible correlation with central oscillating system in various photic conditions.

DNA protection ability, antihyperglycemic potential and in-vivo toxicity assessment of arrowleaf tearthumb (Persicaria sagittata L.), a neglected aquatic plant species of Eastern Asia.

Persicaria sagittata L. (common name arrowleaf tearthumb, American) is an herbaceous edible plant with characteristics sessile leaves mainly found in wetland areas of North America and Eastern Asia. In Eastern Himalayan Region of India, the ethnic communities consumed this plant as vegetables. The present investigation suggests the plant is endowed with bioactive compounds having potential DNA protection ability and antihyperglycemic activity. The DNA nicking assay revealed that the methanolic extract of this plant has the potential to protect plasmid DNA against hydroxyl damage. The α-glucosidase and α-amylase inhibitory assay of this methanolic extract suggest more effectiveness in inhibition of α-amylase than the α-glucosidase. Further, proximate composition, micronutrient, total phenolic and flavonoid content of this underutilised aquatic plant was determined. And lastly the in-vivo cytotoxicity study of Persicaria sagittata L. plant extract suggest that the plant is less toxic to in-vivo system.

Artificial Light at Night (ALAN): A Potential Anthropogenic Component for the COVID-19 and HCoVs Outbreak.

The origin of the coronavirus disease 2019 (COVID-19) pandemic is zoonotic. The circadian day-night is the rhythmic clue to organisms for their synchronized body functions. The "development for mankind" escalated the use of artificial light at night (ALAN). In this article, we tried to focus on the possible influence of this anthropogenic factor in human coronavirus (HCoV) outbreak. The relationship between the occurrences of coronavirus and the ascending curve of the night-light has also been delivered. The ALAN influences the physiology and behavior of bat, a known nocturnal natural reservoir of many Coronaviridae. The "threatened" and "endangered" status of the majority of bat species is mainly because of the destruction of their proper habit and habitat predominantly through artificial illumination. The stress exerted by ALAN leads to the impaired body functions, especially endocrine, immune, genomic integration, and overall rhythm features of different physiological variables and behaviors in nocturnal animals. Night-light disturbs "virus-host" synchronization and may lead to mutation in the genomic part of the virus and excessive virus shedding. We also proposed some future strategies to mitigate the repercussions of ALAN and for the protection of the living system in the earth as well.

Artificial Light at Night (ALAN), an alarm to ovarian physiology: A study of possible chronodisruption on zebrafish (Danio rerio).

The ALAN is drawing the attention of researchers and environmentalists for its ever-increasing evidence on its capacity of "desynchronization" of organismal physiology. Photoperiod and circadian cycles are critical parameters to influence the biology of reproduction in several animals, including fish. The present study is the first proof of the development of an ovarian tumour with the effect of light in zebrafish (Danio rerio), an excellent model for circadian-related studies. Results of three experimental conditions, continuous light for one week, LLW, one month, LLM, and for one year, LLY revealed a clear desynchronization of clock associated genes (Clock1a, Bmal1a, Per2, and Cry2a). Interestingly, loss of rhythmicity and low concentration of melatonin found in these conditions in whole brain, retina, ovary, and serum through ELISA. RNA-Seq data of ovarian samples revealed the upregulation of Mid2, Tfg, Irak1, Pim2, Tradd, Tmem101, Nfkbib genes and ultimately increase the expression of NF-κB, a cellular transformer for tumourigenesis, confirmed by the western blot. The appearance of TNFα, inflammatory cytokines and activator of NF-κB also increased. Histology approved the formation of thecoma and granulosa cell tumour in the one year exposed ovarian sample. The whole transcriptome data analysis revealed 1791 significantly upregulated genes in an ovarian tumour. Among these genes, DAVID functional annotation tool identified 438 genes, directly linked to other physiological disorders. This study evidenced of an ovarian tumour induced by ALAN in zebrafish.

Daily and Seasonal Expression Profile of Serum Melatonin and Its Biosynthesizing Enzyme Genes (tph1, aanat1, aanat2, and hiomt) in Pineal Organ and Retina: A Study under Natural Environmental Conditions in a Tropical Carp, Catla catla.

The tropical carp Catla catla is gaining importance for the studies of the impact of environmental changes on aquatic animals due to its surface dwelling habitat. To date, no information is available on the transcriptional profile of melatonin biosynthesizing enzyme genes in any tropical carp under either natural or artificial photothermal conditions in pineal and retina. The present study is an attempt to demonstrate the temporal pattern of expression of melatonin biosynthesizing enzyme genes, tryptophan hydroxylase 1 (tph1), arylalkylamine N-acetyltransferase (aanat1 and aanat2), and hydroxyindole-O-methyltransferase (hiomt) collectively and simultaneously in pineal organ and retina in tropical fish, C. catla, on a daily and seasonal basis under natural environmental conditions along with the serum melatonin levels. Depending upon the changes of the natural photothermal conditions, in four phases of an annual cycle, the variation and/or shifting of the rhythm parameters of different melatonin biosynthesizing enzyme genes in these two organs are different. Moreover, relative expression of these genes varies based on tissue and season. The serum melatonin levels correspond to the expression pattern of pineal aanat2 and hiomt. This finding indicates a possible organization of melatonin biosynthesizing enzyme genes with reproductive phases differently in these two photoreceptive organs for maintaining its physiological functions.