Zooplankton Diversity Indices for the Assessment of Perennial Freshwater Body in Bishnupur, Bankura, West Bengal

The status of health of any aquatic ecosystem is largely dependent on the diversity and density of zooplankton inhabiting the water body. Zooplankton are considered to be the most vital primary consumer in any aquatic ecosystem. At the same time, they also influence to a greater extent in determining the total productivity of an aquatic body. The present study is an attempt to estimate the diversity of zooplankton and to find out the richness, evenness, of the freshwater perennial aquatic body, Lalbundh of Bishnupur, Bankura.The study was carried out during December 2018 to November 2019. The whole period of study was divided into four major seasons viz winter (December2018 to February2018), Summer (March2019to May 2019), Monsoon (June 2019 to August 2019) and post monsoon (September 2019 to November 2019). Collection of the zooplankton samples and their quantitative analysis was done following the standard procedures. During the whole period of study 18 different species of zooplankton have been identified from the study area. Out of them 7 species belong to the Rotifera group, 6 species belong to Cladocera group, 3 species of Copepoda group and 2 species of Ostracoda group. Rotifera group comprise the dominant of all the groups constituting 39% of the total zooplankton species, followed by Cladocera (33%), Copepoda(18%) and Ostracoda (11%). The range of Shannon diversity index value of zooplankton varies from 2.76 to 2.88. The species richness value varies from 2.45 (winter) to 2.56 (monsoon). Evenness value varies from 0.95 in summer to0.98in monsoon. Zooplankton diversity indices values of Lalbundh give a clear indication of light condition of pollution level of the water body. The main reason behind the pollution of this perennial water body may be the floating dead and decomposed macrophytes in it. They should be removed as far as possible at regular intervals so that the pollution level can be reduced and the water body can be more efficiently used for pisciculture practices.

Effects of Light Intensity on Root Development in a D-Root Growth System

Plant development is highly affected by light quality, direction, and intensity. Under natural growth conditions, shoots are directly exposed to light whereas roots develop underground shielded from direct illumination. The photomorphogenic development strongly represses shoot elongation whereas promotes root growth. Over the years, several studies helped the elucidation of signaling elements that coordinate light perception and underlying developmental outputs. Light exposure of the shoots has diverse effects on main root growth and lateral root (LR) formation. In this study, we evaluated the phenotypic root responses of wild-type Arabidopsis plants, as well as several mutants, grown in a D-Root system. We observed that sucrose and light act synergistically to promote root growth and that sucrose alone cannot overcome the light requirement for root growth. We also have shown that roots respond to the light intensity applied to the shoot by changes in primary and LR development. Loss-of-function mutants for several root light-response genes display varying phenotypes according to the light intensity to which shoots are exposed. Low light intensity strongly impaired LR development for most genotypes. Only vid-27 and pils4 mutants showed higher LR density at 40 μmol m–2 s–1 than at 80 μmol m–2 s–1 whereas yuc3 and shy2-2 presented no LR development in any light condition, reinforcing the importance of auxin signaling in light-dependent root development. Our results support the use of D-Root systems to avoid the effects of direct root illumination that might lead to artifacts and unnatural phenotypic outputs.

Morphological and Chemical Evaluations of Leaf Surface on Particulate Matter2.5 (PM2.5) Removal in a Botanical Plant-Based Biofilter System

Particulate matter has been increasing worldwide causing air pollution and serious health hazards. Owing to increased time spent indoors and lifestyle changes, assessing indoor air quality has become crucial. This study investigated the effect of watering and drought and illumination conditions (constant light, light/dark cycle, and constant dark) on particulate matter2.5 (PM2.5) removal and surface characterization of leaf in a botanical plant-based biofilter system. Using Ardisia japonica and Hedera helix as experimental plants in the plant-based biofilter system, PM2.5, volatile organic carbon, and CO2, as the evaluators of indoor air quality, were estimated using a sensor. Morphological and chemical changes of the leaf surface (i.e., roughness and wax) associated with PM2.5 removal were characterized via scanning electron microscopy, Fourier transform infrared spectroscopy, and atomic force microscopy. The highest PM2.5 removal efficiency, stomata closure, high leaf roughness, and wax layer were observed under drought with constant light condition. Consequently, PM2.5 removal was attributed to the combined effect of leaf roughness and wax by adsorption rather than stomatal uptake. These results suggest that operating conditions of indoor plant-based biofilter system such as watering (or drought) and illumination may be applied as a potential strategy for enhancing PM2.5 removal.

Citrulline Accumulation Mechanism of Pediococcus acidilactici and Weissella confusa in Soy Sauce and the Effects of Phenolic Compound on Citrulline Accumulation

Citrulline is one of the major precursors of ethyl carbamate in soy sauce, and the accumulation of citrulline is attributed to the metabolism of arginine by bacteria with the arginine deiminase (ADI) pathway. However, key strains and factors affecting citrulline accumulation are not yet clear. In this study, two key strains of Pediococcus acidilactici and Weissella confusa were isolated from soy sauce moromi, and the regularity of citrulline formation was studied. Results showed that the conversion rates from arginine to citrulline (A/C rate) and the citrulline accumulation ability of W. confusa and P. acidilactici significantly increased in the presence of different concentrations of NaCl, indicating that salt stress was the main factor for citrulline accumulation. The inconsistent expression of arc genes by salt stress was the reason for citrulline accumulation for P. acidilactici, but for W. confusa, it may be due to the influence of arginine/citrulline on the transportation system: the intracellular citrulline could neither transport to extracellular space nor convert into ornithine. Environmental factors greatly influenced citrulline accumulation of the two key bacteria; A/C rate and citrulline formation in both strains decreased at low temperature (15°C) under high salt stress, but opposite effects were observed for the two key strains under anaerobic light condition. Moreover, quercetin and gallic acid significantly decreased the A/C rate and citrulline accumulation ability of the two key strains. The optimal quercetin and gallic acid as suggested by simulation experiment were 100 and 10 mg/l, respectively, and the lowest A/C rate of 28.4% and citrulline level of 1326.7 mg/l were achieved in the simulation system. This study explored the main factors for citrulline formation by the two key strains and proposed a targeted way to control citrulline in soy sauce.

Insights into Factors Affecting Traffic Accident Severity of Novice and Experienced Drivers: A Machine Learning Approach

Traffic accidents have significant financial and social impacts. Reducing the losses caused by traffic accidents has always been one of the most important issues. This paper presents an effort to investigate the factors affecting the accident severity of drivers with different driving experience. Special focus was placed on the combined effect of driving experience and age. Based on our dataset (traffic accidents that occurred between 2005 and 2021 in Shaanxi, China), CatBoost model was applied to deal with categorical feature, and SHAP (Shapley Additive exPlanations) model was used to interpret the output. Results show that accident cause, age, visibility, light condition, season, road alignment, and terrain are the key factors affecting accident severity for both novice and experienced drivers. Age has the opposite impact on fatal accident for novice and experienced drivers. Novice drivers younger than 30 or older than 55 are prone to suffer fatal accident, but for experienced drivers, the risk of fatal accident decreases when they are young and increases when they are old. These findings fill the research gap of the combined effect of driving experience and age on accident severity. Meanwhile, it can provide useful insights for practitioners to improve traffic safety for novice and experienced drivers.

MSD2, an apoplastic Mn-SOD, contributes to root skotomorphogenic growth by modulating ROS distribution in Arabidopsis

Reactive oxygen species (ROS) play essential roles as a second messenger in various physiological processes in plants. Due to their oxidative nature, ROS can also be harmful. Thus, the generation and homeostasis of ROS are tightly controlled by multiple enzymes. Membrane-localized NADPH oxidases are well known to generate ROS during developmental and stress responses, but the metabolic pathways of the superoxide (O2⋅−) generated by them in the apoplast are poorly understood, and the identity of the apoplastic superoxide dismutase (SOD) is unknown in Arabidopsis. Here, we show that a putative manganese SOD, MSD2 is secreted and possesses a SOD activity that can be inhibited by nitration at tyrosine 68. The expression of MSD2 in roots is light condition-dependent, suggesting that MSD2 may act on ROS metabolism in roots during the light-to-dark transition. Root architecture is governed by ROS distribution that exhibits opposite gradient of H2O2 and O2⋅−, which is indeed altered in etiolated msd2 mutants and accompanied by changes in the onset of differentiation. These results provide a missing link in our understanding of ROS metabolism and suggest that MSD2 plays a role in root skotomorphogenesis by regulating ROS distribution, thereby playing a pivotal role in plant growth and development.

A tonoplast-localized magnesium transporter is involved in stomatal opening in Arabidopsis

Plant stomata play an important role in CO2 uptake for photosynthesis and transpiration, but the mechanisms underlying stomatal opening and closing are still not completely understood. Here, through large-scale screening, we identified an Arabidopsis mutant (cst2 for closed stomata2) defective in stomatal opening under light condition. A map-based cloning combined with complementation test revealed that the mutant phenotype was caused by a nucleotide substitution of a gene, which domains show similarity to human Mg efflux transporter ACDP/CNNM. Functional analysis showed that CST2 encodes a tonoplast-localized transporter for Mg. This protein is constitutively and highly expressed in the guard cells. Furthermore, CST2 is phosphorylated by calcineurin B-like protein (CBL)-interacting protein kinases 26 (CIPK26) in vitro, which is probably required for its activation. Knockout of this gene resulted in stomatal closing and growth retardation under high Mg concentration conditions, while over-expression of this gene increased tolerance to high Mg. Our results indicate that CST2 plays an important role in maintaining Mg homeostasis in plant cells through sequestering Mg into vacuoles especially in guard cells and that this homeostasis is required for stomatal opening, which provide a novel insight into mechanism of stomatal opening in plants.

Investigation of the growth of Chlorella vulgaris and Chlamydomonas reinhardtii cultivated in pre-treated palm oil mill effluent (POME) as the culture medium

The application of microalgae in wastewater treatment has attracted the attention of researchers since a few decades ago. Palm oil industry is one of the lucrative main exporting industry in Malaysia which has drawn the attention of researchers in mitigating the polluting impacts caused by the palm oil mill effluent (POME) released from the oil palm processing. In this study, the growth of the green algae Chlorella vulgaris and Chlamydomonas reinhardtii in the pre-treated POME was studied for 7 continuous days. The number of microalgae cells, chlorophylls and carotenoids contents were monitored throughout the cultivation period. The potential of both strains of microalgae as the water polisher for post-treatment of POME was investigated as well. The findings revealed that both microalgae showed lag phase at the beginning of cultivation and grew exponentially later. When monitoring the chlorophyll content, chlorophyll a and chlorophyll b played a role in photosynthesis when the microalgae detected environmental changes. The carotenoids in the microalgae acted as the accessory pigments which assisted in light harvesting under poor light condition and as the antioxidant protecting the cells when there was excess light. C. vulgaris was able to remove 98.1 % of phosphate and 53.1 % of ammoniacal nitrogen while C. reinhardtii removed 90.1 % and 37.3 %, respectively. This study indicated that two microalgae species have a high potential to be integrated in the post-treatment for POME.

Identification of Differentially Expressed Genes and Pathways Involved in Growth and Development of Mesona chinensis Benth Under Red- and Blue-Light Conditions

Mesona chinensis Benth (MCB) is an important Chinese herbal medicine. The plant factories might be one of the ways to solve the shortage of MCB supply. In this study, the MCB seedlings were treated under the red (R) and blue (B) lights in the plant factory. Results showed that the red light promoted the growth and development of MCB in comparison with the blue light. Under the red-light condition, the biomass, plant height, and root characteristics were significantly higher than those under blue-light condition, while the soil and plant analyzer development (SPAD) under the red-light treatment was significantly lower than that under the blue-light treatment. Red light also significantly promoted the content of soluble sugar and pectin of MCB compared with blue light. Transcriptome analysis showed that a total of 4,165 differentially expressed genes (DEGs) were detected including 2,034 upregulated and 2,131 downregulated. Of these, 1,112 DEGs including 410 upregulated and 702 downregulated genes were associated with 111 pathways. Moreover, a total of 8,723 differentially expressed transcription factors (TFs) were identified in R vs. B, and these TFs were distributed in 56 gene families. Metabonomic results revealed that a total of 184 metabolites and 99 differentially expressed metabolites (DEMs) (42 upregulated and 57 downregulated) were identified in the red- and blue-light treatments. Integrative analysis of transcriptome and metabolome unveiled that a total of 24 pathways included 70 compounds (metabolites) and were associated with 28 unigenes. In particular, these pathways included starch and sucrose metabolism, phenylpropanoid biosynthesis, cysteine and methionine metabolism, glycolysis/gluconeogenesis, and pentose and glucuronate interconversions. The unigenes included asparagine synthetase (AS), thymidine kinase (TK), alpha, alpha-trehalose-phosphate synthase (TPS), phosphatase IMPL1 (IMPL1), dihydroflavonol 4-reductase (D4R), and 4-coumarate-CoA ligase-like 6 (4CL6), bifunctional aspartokinase-homoserine dehydrogenase 1 (thrA), and abscisic acid 8′-hydroxylase 2 isoform X1 (ABA8). It was indicated that these pathways and genes might play important roles in the growth and development of MCB. This study laid a foundation for the future research of MCB.

Radiation dimming induced modifications in radiation utilization of wheat (Triticumaestivum) crop

Global dimming has many environmental and climatic implications. India has also experienced a steady and continuous radiation dimming since 1960s due to increasing load of dust and aerosol in the atmosphere. Radiation interception, temperature, humidity and wind profile are altered under reduced light condition which are determining factor for crop phenology, leaf area index, biomass production, grain yield and radiation use efficiency of crops.In this experiment, three wheat cultivars (HD 2967, WR 544 and PBW 502) were grown under five solar radiation treatments i.e. R1 (no shading), R2 (20% shading), R3 (35% shading), R4 (50% shading) and R5 (75% shading) during rabi season of 2014-15 and 2015-16 at research farm of ICAR-Indian Agricultural Research Institute (ICAR-IARI), New Delhi to study the effect of radiation dimming on performance of selected wheat cultivars.In both the years the canopy temperature of wheat from crop vegetative stage to maturity was decreased with increase of shading level. The effect of reduced solar radiation significantly decreased the biomass production and yield.The radiation use efficiency (RUE) for biomass was increased due to shading treatments whereas the RUE for yield decreased with radiation reduction.The RUE for yield was the highest for no shading treatment (0.85 and 0.75 g MJ-1 in 2014-15 and 2015-16, respectively). Among the cultivars, the radiation use efficiency for biomass as well as yield was the highest in HD 2967 followed by WR 544 and PBW 502,respectively.