Integrated metabolomics and transcriptomics analysis highlight key pathways involved in the somatic embryogenesis of Darjeeling tea.

BACKGROUND: Darjeeling tea is a globally renowned beverage, which faces numerous obstacles in sexual reproduction, such as self-incompatibility, poor seed germination, and viability, as well as issues with vegetative propagation. Somatic embryogenesis (SE) is a valuable method for rapid clonal propagation of Darjeeling tea. However, the metabolic regulatory mechanisms underlying SE in Darjeeling tea remain largely unknown. To address this, we conducted an integrated metabolomics and transcriptomics analysis of embryogenic callus (EC), globular embryo (GE), and heart-shaped embryo (HE). RESULTS: The integrated analyses showed that various genes and metabolites involved in the phenylpropanoid pathway, auxin biosynthesis pathway, gibberellin, brassinosteroid and amino acids biosynthesis pathways were differentially enriched in EC, GE, and HE. Our results revealed that despite highly up-regulated auxin biosynthesis genes YUC1, TAR1 and AAO1 in EC, endogenous indole-3-acetic acid (IAA) was significantly lower in EC than GE and HE. However, bioactive Gibberellin A4 displayed higher accumulation in EC. We also found higher BABY BOOM (BBM) and Leafy cotyledon1 (LEC1) gene expression in GE along with high accumulation of castasterone, a brassinosteroid. Total flavonoids and phenolics levels were elevated in GE and HE compared to EC, especially the phenolic compound chlorogenic acid was highly accumulated in GE. CONCLUSIONS: Integrated metabolome and transcriptome analysis revealed enriched metabolic pathways, including auxin biosynthesis and signal transduction, brassinosteroid, gibberellin, phenylpropanoid biosynthesis, amino acids metabolism, and transcription factors (TFs) during SE in Darjeeling tea. Notably, EC displayed lower endogenous IAA levels, conducive to maintaining differentiation, while higher IAA concentration in GE and HE was crucial for preserving embryo identity. Additionally, a negative correlation between bioactive gibberellin A4 (GA4) and IAA was observed, impacting callus growth in EC. The high accumulation of chlorogenic acid, a phenolic compound, might contribute to the low success rate in GE and HE formation in Darjeeling tea. TFs such as BBM1, LEC1, FUS3, LEA, WOX3, and WOX11 appeared to regulate gene expression, influencing SE in Darjeeling tea.

Assessment of Occupational Noise Generation and Associated Noise-Induced Hearing Loss among Employees of a Black Tea Processing Factory in Darjeeling District, India.

Introduction: Exposure to high levels of noise is a problem among tea factory workers worldwide, but it is poorly studied in India. Aims: This study aimed to assess noise generation in various parts of a black tea factory and find out prevalence of occupational noise-induced hearing loss (ONIHL) and its determinants among employees. Materials and Methods: An observational cross-sectional study was performed in a black tea processing factory of Darjeeling District. Noise levels and exposure data at different parts of the factory were measured using a sound level meter. Participant characteristics were obtained using a questionnaire and noise-induced hearing loss data obtained by audiometry. A sound map was generated based on noise exposure data and a multivariable logistic regression performed to assess determinants of ONIHL. Results: Sound pressure levels ranged from 58.7 to 90.3 dBA, with the highest levels in the crushing-tearing-curling (CTC) room. Noise exposure of workers was the highest during curling process and the lowest during packaging in the packing room. The prevalence of ONIHL was found to be 28.3%, most of which were of moderate degree, and the highest prevalence was among CTC room workers. Multivariable analysis showed significant association only between daily noise exposure and the presence of ONIHL (AOR 1.68, P value = 0.018). None of the study participants used any hearing protection equipment during work. Conclusions: Generation of high levels of noise is a pertinent problem in the black tea factory, which, coupled with non-use of personal protective equipment, led to a high risk and prevalence of ONIHL.

Use of headspace GC/MS combined with chemometric analysis to identify the geographic origins of black tea.

Some black teas demand high market prices. Black tea samples (306) collected from 10 geographic origins, including China (Guxi, Likou, Jinzipai, Guichi, Dongzhi, Changning, Wuyishan, Shaowu), India (Darjeeling), and Sri Lanka (Kandy), were analyzed using headspace volatilization followed by GC/MS (HS-GC/MS). Forty-eight volatile compounds were identified. The aroma compounds were mainly identified as alcohols, aldehydes, ketones, and esters. Analysis of either full-spectrum data or 22 tea compounds shared among the samples with k-Nearest Neighbor (k-NN) and Random Forest (RF) models discriminated all origins at 100% using KNN and 95% with RF using either data set. The discrimination rates using 2 key aroma compounds (linalool and geraniol) by k-NN were 100% for nine origins, with the rate for Guxi area at 89%, because 3 samples were classified to Jinzipai. The findings support the use of HS-GC/MS combined with chemometrics as a tool to identify the origin of black tea.

A new species of emCephalaeschna/em Selys, 1883 (Odonata: Anisoptera: Aeshnidae) from Neora Valley National Park, West Bengal, India, with notes on emC. acanthifrons/em Joshi amp; Kunte, 2017 and emC. viridifrons/em (Fraser, 1922).

A new species Cephalaeschna patrai sp. nov. is described from Neora Valley National Park, Darjeeling Himalays as the eighth species of the genus from India. This new species is characterized by bright green markings on overall black body color, black is replaced with brown in female. Anterolateral thoracic stripe separated in two patches connected with a narrow line. The cerci are uniformly broad towards end, without any constriction in the lateral view; tip of the same prominently curved upwards to form blunt tubercle which appears to be projected inwards in the dorsal view. An updated key for all the Indian species is provided here. A short note about the affinities among congenerics distributed across Himalayas (particularly C. acanthifrons Joshi Kunte, 2017 and C. viridifrons (Fraser, 1922)) is also included.

Genome-wide SNP discovery from Darjeeling tea cultivars - their functional impacts and application toward population structure and trait associations.

Genotyping by sequencing and identification of functionally relevant nucleotide variations in crop accessions are the key steps to unravel genetic control of desirable traits. Elite cultivars of Darjeeling tea were undergone SNP genotyping by double-digest restriction-site associated DNA sequencing method. This study reports a set of 54,206 high-quality SNP markers discovered from ~10.4 GB sequence data, encompassing 15 chromosomes of the reference tea genome. Genetic relatedness among the accessions conforms to the analyses of Bayesian clustering, UPGMA, and PCoA methods. Genomic positions of the discovered SNPs and their putative effect on annotated genes designated a thoughtful understanding of their functional aspects in tea system biology. A group of 95 genes was identified to be affected by high impact variants. Genome-wide association analyses of 21 agronomic and biochemical phenotypes resulted in trait-linked polymorphic loci with strong confidence (p < 0.05 and 0.001).

HLA-A -B and -DRB1 distribution in Kami: A caste population of Gorkha community from the sub-Himalayan region of West Bengal, India.

The present investigation is the first of its kind to understand the HLA profile of Kami population from the Indian Gorkha community of sub-Himalayan West Bengal, India. A total of 158 individuals from Kami population were genotyped at first field resolution by HLA ABDRB1 PCR SSP typing kit. The genotype assignment to the individuals was performed by Ready Gene V.1.0.0.0' software. The data were analysed by PopWin32-0.7.0 software. All the loci typed were in Hardy-Weinberg equilibrium. The genotype data is accessible at Allele Frequencies Net Database with the name India, sub-Himalayan West Bengal, Kami number 3720.

Phytochemical analysis of mite-infested tea leaves of Darjeeling Hills, India.

INTRODUCTION: Darjeeling tea of India is one of the most famous beverages globally. However, a large amount of tea crop is damaged every year by the attack of mites. OBJECTIVES: The study aimed to determine the changes in different pigments and biochemical components of tea leaves due to mite infestation. MATERIALS AND METHODS: We used UV-visible and Fourier-transform infrared (FTIR) spectroscopy simultaneously to understand the damages in pigment contents of the leaves of tea (Camellia sinensis (L.) Kuntze) due to attack of phytophagus mite, Oligonychus coffeae Nietner. Furthermore, chemical analysis of infested tea leaves was also performed to compare the nutrients of the plants, namely total phenol, protein and soluble sugar. RESULTS: The UV-visible study reveals severe reduction of the pigments such as chlorophyll (Chl), carotenoids and xanthophylls in the tea leaf due to mite infestation. The findings of the FTIR study, also shows variation in different physiochemical components in the leaf Chl. The sugar and protein content of the infested leaves have been reduced compared to uninfested ones. Results in the case of tea leaves plucked during first (March) and third (November) flushes show similar trends. CONCLUSION: The increase in phenolic and alcoholic components and decrease in Chl contents may affect the quality of Darjeeling tea. The extent of damages done by the pests measured here could aid the pest management in tea gardens.

Sustainability assessment for the transportation environment of Darjeeling, India.

Darjeeling is an important tourist hill town of West Bengal, India. It suffers from an acute problem of transportation, particularly during its peak tourist seasons due to limited road space, inadequate public transport facilities and indiscriminate use of automobiles. This hill town was originally designed for a population of 10,000, but over the years, it has come face-to-face with rapid urbanization, a rising population of both tourists and residents and intensifying motor vehicle usage. These factors together are posing a threat to its transport environment. This study identifies the Sustainable Transport Indicators (STIs) available in the existing literature to identify the critical stretches using Analytical Hierarchy Process (AHP) based on experts' consensus. It was found that the experts placed emphasis on the mobility of the town, talking about vehicular impact on air pollution and encroachment of roads as the main issues affecting the sustainability of the transport environment. Thereafter, policy-level interventions have been suggested in accordance with the identified sustainability issues. We trust that other tourist hill towns with issues similar to Darjeeling could easily emulate the study methodology to assess their transport environment sustainability, or replicate on the lines of the recommended policy interventions.

A review of the genus Lordiphosa Basden in India, with descriptions of four new species from the Himalayan region (Diptera, Drosophilidae).

All Indian species of the genus Lordiphosa Basden are reviewed, with descriptions of four new species, L. curva Fartyal & Toda, sp. n. of the denticeps species group and L. ayarpathaensis Kandpal & Singh, sp. n., L. makaibarensis Pradhan & Chatterjee, sp. n. and L. srinagarensis Sati & Fartyal, sp. n. of the nigricolor species group. Two of the new species, L. ayarpathaensis and L. makaibarensis, were found visiting flowers of Hedychium spicatum and Datura suaveolens, respectively. This is the first record of flower visitation in Lordiphosa flies. In addition, L. parantillaria (Kumar & Gupta, 1990), syn. n. is synonymized with L. antillaria (Okada, 1984). Supplementary and revised descriptions for L. antillaria and L. neokurokawai (Singh & Gupta, 1981) and a key to all Indian species of Lordiphosa are provided.

Biocontrol efficacy and plant growth promoting activity of Bacillus altitudinis isolated from Darjeeling hills, India.

A total of 18 bacterial isolates were obtained from the rhizosphere of Sechium edule growing in the lower foothills of Darjeeling, India. The bacterial isolates were tested for PGPR traits in vitro such as phosphate solubilization, HCN, siderophore, IAA, chitinase, protease production as well as inhibition of pthytopathogens. Of all the bacterial isolates, one bacterium designated as BRHS/S-73 was found to possess all the tested characters which was identified on the basis of 16S rRNA gene sequence analysis as Bacillus altitudinis and was selected for in vivo studies. A significant improvement in growth measured in terms of increase in root length, shoot length, and increase in root and shoot biomass was observed when seeds of Vigna radiata, Cicer arietinum, and Glycine max were bacterized prior to sowing in field condition. Besides, the bacterium could also solubilize soil phosphate. Apart form growth promotion, root rot disease of Vigna radiata caused by Thanatephorus cucumeris was also significantly reduced by 74% when the bacterium was applied to the rhizosphere prior to pathogen challenge. The biocontrol efficacy of the bacterium was found to be 66.6% even after 30 days of pathogen inoculation. Activities of key defense related enzymes such as phenylalanine ammonia lyase, peroxidase, ß-1,3-glucanase, and chitinase in both roots and leaves of treated plants were also enhanced. Results clearly suggest that B. altitudinis (BRHS/S-73) is a potential PGPR which can be used as efficient microorganism for enhancement of plant growth and suppression of fungal disease.

Antioxidants and ROS scavenging ability in ten Darjeeling tea clones may serve as markers for selection of potentially adapted clones against abiotic stress.

Ten Darjeeling tea clones (BT15/263, RR17/144, B777, T253, B157, Sundaram, HV39, AV2, K1/1 and TTV1) were collected from the experimental garden of Darjeeling Tea Research and Development Centre, Kurseong. Total phenol, flavonoids and two antioxidating enzymes (peroxidase and superoxide dismutase) were estimated. The total phenol ranged between 241 and 28 GAE mg g(-1) of leaf dry weight. The highest amount obtained in four clones, B15/263 (241.47), RR17/144 (221.2), B777 (154.54) and B157 (140.23 mg g(-1)). Flavonoids were estimated as Catechin equivalent (CE) and ranged between 56.88 and 20.81 CE mg g(-1) leaf dry weight. Higher amounts occurred in BT15/263 (56.88 mg g(-1)), B777 (56.69) and RR17/144 (48.63). Antioxidant activities were measured following DPPH and ABTS free radicle scavenging procedures and the results were well according to total polyphenol content among the clones (in total phenols, ranges of correlation in DPPH assay were r (2) = 0.990-0.989, p ≤ 0.05; in flavonoids r (2) = 0.954, p ≤ 0.01-0.987, p ≤ 0.05). Similarly, ABTS percent scavenging results were quiet significant. The IC50 values were determined for both DPPH and ABTS assay. PAGE expressions of isoforms in two antioxidative enzymes and quantification of them also varied much among the investigated clones. The incidence of total phenols, flavonoids, PRX and SOD and ROS scavenging assay in in-situ condition, might be used as biochemical markers towards the superior adaptability against abiotic stress. In the present work, four clones (B15/263, B777, RR17/144 and B157) would be designated as comparatively better suited to the predicted abiotic stress.