Background: Pinellia ternata is a major medicinal herb widely utilized in traditional medicine, but is sensitive to high temperature, which often triggers a severe “sprout tumble” phenomenon. Methods: To elucidate the molecular mechanisms of heat tolerance in P. ternata, we screened two contrasting germplasms: the heat-tolerant JBX1 and the heat-sensitive XBX4. In the present study, a combined analysis of physiology, transcriptome, and metabolome was performed on JBX1 and XBX4 under heat stress at 40 °C. Results: JBX1 exhibited significantly greater leaf thickness, higher basal chlorophyll content, more stable antioxidant enzyme activities, and lower oxidative damage than XBX4 under heat stress. Transcriptomically, JBX1 maintained elevated basal expression of genes encoding key enzymes in carbon fixation, amino acid metabolism, and phenylpropanoid biosynthesis, as well as those encoding heat shock transcription factors (HSFs), heat shock proteins (HSPs), and the thermosensor Thermo-With ABA-Response 1 (TWA1). Metabolomically, JBX1 accumulated higher levels of key primary metabolites, antioxidants, and protective phenylpropanoids under both control and heat conditions. Notably, a “polarity reversal” emerged in nitrogen metabolism, where core amino acids accumulated in JBX1 but were depleted in XBX4. Integrated analysis revealed a more coordinated gene–metabolite network in JBX1 involving the phenylpropanoid, ATP-binding cassette (ABC) transporter, and glutathione pathways. Conclusions: Our findings demonstrate that JBX1 possessed stronger basal thermotolerance, which is derived from coordinated establishment of higher constitutive metabolic reserves and efficient dynamic metabolic reprogramming. This study provides insights into the molecular mechanisms of heat stress in P. ternata.

Extreme high temperatures severely affect the cultivation of octoploid strawberry seedlings. However, the molecular mechanisms of heat stress response in strawberry seedlings remain unclear. The results demonstrated that when strawberry seedlings were subjected to 40 °C treatment for 6 hours, the proline content and activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) all exhibited significant increases compared to the control group maintained at 25 °C. Consequently, strawberry seedlings exposed to either 25 °C or 40 °C for 6h and 24h were selected for subsequent transcriptomic analysis. A total of 11,526 heat stress-responsive genes were identified. Multiple metabolic pathways associated with heat stress were uncovered by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Sixty-six FaHSF genes were identified in octoploid strawberries, among which FaHSFA2/A3/A7/B1/B2 were significantly up-regulated under heat stress according to transcriptomic analysis, and were further validated by quantitative reverse transcription polymerase chain reaction (RT-qPCR) assay, confirming the reliability of the transcriptome data generated in this study. Collectively, these results facilitate the identification of key heat stress resistance genes in octoploid strawberry and offer valuable insights into the mechanisms of heat tolerance, providing candidate targets for the breeding of heat-resistant varieties.

Integration of conventional bioinformatics approaches with advanced machine learning and explainable AI identified 45 candidate genes and 21 top features (10 positive and 11 negative regulations) influencing heat stress tolerance. Heat stress is a significant threat to Brassica napus cultivation, a globally important oilseed crop for vegetable oil production. However, identifying the genes associated with heat stress tolerance is challenging using large-scale transcriptomic datasets with traditional approaches. This study combined conventional bioinformatics approaches with advanced machine learning (ML) models to elucidate the heat tolerance mechanism in the seed, flower, leaf, and silique. A total of 1,179 differentially expressed genes (DEGs) were identified, primarily related to detoxification, protein folding, response to heat, and heat shock protein binding, as well as pathways such as alpha-linolenic acid metabolism, glutathione metabolism, and phenylpropanoid biosynthesis. In addition, WGCNA identified 45 candidate hub genes across three modules, associated with four tissues. Interestingly, we trained three ML models, of which the random forest (RF) showed higher performance in terms of ROC (0.98) and accuracy (0.89) than the other two models. Further, we utilized explainable ML, applying SHAP analysis of RF model, and ranked 21 top features (genes) influencing heat stress tolerance, including 10 positive and 11 negative regulators. Among 21 top features, 13 overlapped with traditional bioinformatics approaches (DEGs and WGCNA), whereas eight (38.09%) were uniquely detected via ML models. Finally, expression of seven positive and one negative regulator were validated through RT-qPCR, supporting the findings of integrative meta-transcriptomic and ML results. Our findings provide the valuable resource and highlight the power of ML in genomics to predict the key regulators involved in heat resilience, providing valuable insights into the underlying mechanism of heat stress.

Morchella is a nutritious and artificially cultivable rare ascomycete, and its growth and development regulation mechanisms are a current research hotspot. High-temperature stress severely limits the annual yield of Morchella, and this challenge is intensifying with global warming. However, previous studies have lacked systematic screening for heat-tolerant Morchella strains, and their molecular response mechanisms to heat stress remain unclear. In this study, we conducted a comprehensive analysis of phenotypic characteristics, physiological metabolism, and transcriptomics on 19 Morchella strains under normal (25 °C) and high-temperature (30 °C) conditions. The heat-tolerant strain HLM exhibited superior performance in mycelial growth, morphology, and field cultivation. It maintained cell homeostasis under heat stress through mild osmotic regulation (elevated levels of proline, soluble sugars, and proteins), a robust antioxidant system (increased activities of CAT, POD, and SOD), and reduced malondialdehyde accumulation. Transcriptomic analysis identified a novel regulatory model of "stress perception-metabolic preparation-terminal detoxification" in the heat-tolerant strain HLM under heat stress. The rapid upregulation of the SMPD1 gene may mediate ceramide signal generation, promoting G6PDH expression to drive carbon flow into the pentose phosphate pathway, thereby increasing NADPH output. As the detoxification terminal, AKR4C uses this reducing power to eliminate toxic carbonyl end products like malondialdehyde, completing the defense loop. These findings offer new insights into the heat-tolerance mechanisms of large ascomycetes, provide a theoretical foundation for stress-resistant Morchella breeding and cultivation in high-temperature areas, and serve as valuable resources for exploring heat-tolerance mechanisms and molecular breeding in other edible fungi.

Cyrtorhinus lividipennis, a key natural enemy of the brown planthopper, Nilaparvata lugens, has been observed to tolerate short-term high-temperature exposure; however, the physiological and molecular mechanisms underlying this heat tolerance remain unclear, which may hinder its effective conservation and utilization. Here, we combined physiological and biochemical assays with transcriptome sequencing to elucidate the physiological and molecular mechanisms of heat tolerance in C. lividipennis following 1 h exposure to three temperatures: 26 °C (control), 33 °C (moderate heat stress), and 40 °C (severe heat stress). At 40 °C, sorbitol, trehalose, lipid, and glycogen contents increased significantly, whereas glycerol levels declined. Transcriptomic profiling revealed temperature-dependent DEGs enriched in starch and sucrose metabolism, galactose metabolism, glycerolipid metabolism, oxidative phosphorylation, and protein folding, sorting, and degradation, with pronounced temperature-dependent upregulation of heat shock protein (HSP) gene families. Together, these results demonstrate that C. lividipennis coordinates its heat stress response through soluble polyol accumulation, which is known to act as a compatible osmolytes that help stabilize proteins and membranes and mitigate thermal damage, energy metabolic reprogramming, and HSP-mediated proteostasis, thereby providing a theoretical basis for its conservation and utilization in sustainable paddy agroecosystems.

Heat stress profoundly affects the growth and developmentof non-headingChinese cabbage (NHCC) and usually results in great losses in yieldand quality. In this study, we observed a significant increase inCHH methylation, specifically within gene promoter regions, in NHCCupon heat stress exposure. Furthermore, application of DNA methylationinhibitor 5-azacytidine was found to significantly exacerbating heatstress-induced NHCC wilting. Integrative analysis of DNA methylomeand transcriptome identified several heat stress-inhibited regulators,such as IQD21, SMR1, and PCR2, which negatively regulates the heat tolerance, andsilencing these genes significantly enhanced the heat tolerance ofNHCC. Our findings demonstrated that heat stress triggers hypermethylationof CHH within promoters of some negative heat stress regulators, thusimproving the heat adaptation of NHCC. These findings provide newinsights into the mechanism of NHCC adapting to heat stress and suggesta crucial role of DNA methylation in regulating the heat toleranceof NHCC.

Maize is one of the most widely cultivated cereal crops globally and serves as a staple food, feed and industrial raw material. Rising global temperatures and increased frequency of heat waves due to climate change pose a serious threat to maize productivity, particularly in tropical and subtropical regions. Heat stress adversely affects maize growth, phenology, reproductive development, physiological processes and grain yield. The sensitivity of maize to high temperature is especially pronounced during flowering and grain filling stages. Heat tolerance in maize is a complex trait governed by physiological, biochemical, molecular and genetic mechanisms. This review synthesizes current knowledge on the impact of heat stress on maize, mechanisms of heat tolerance, screening approaches, genetic and molecular strategies and agronomic interventions to enhance heat resilience. Understanding these aspects is essential for developing climate-resilient maize cultivars and ensuring food security under changing climatic scenarios.

Heat stress is a major threat to global wheat (Triticum aestivum L.) production, adversely affecting crop yields and grain quality. Understanding wheat's heat tolerance mechanisms is crucial for developing resilient cultivars. This study used targeted proteomics to validate heat-induced changes to protein abundances in seedling and flag leaves of heat-tolerant (Vixen-T) and heat-sensitive (HD2329-S) wheat genotypes. Proteomics samples were collected on days 1, 3 and 5 of heat exposure (32/16°Cday/night for 3hours per day over 5days) and day 12 post-recovery. Flag leaf gas exchange was studied under heat treatment during ear peep and significant genotype × heat treatment interactions were observed for all traits. Significant protein abundance changes occurred under heat stress for 15 and 14 proteins at the seedling and ear peep stages, respectively. Two key proteins-DM2 domain-containing protein (r=0.99) and Rubisco activase (r=0.96)-showed consistent responses across both developmental stages. Redox homeostasis and protein chaperone pathways emerged as major contributors to wheat heat tolerance. These findings highlight critical protein biomarkers that can support breeding efforts to develop heat-tolerant wheat varieties, offering valuable strategies for sustaining wheat productivity under climate change. SIGNIFICANCE: This study identifies and validates novel protein biomarkers associated with heat tolerance in wheat. These proteins were discovered in our previous study in the flag leaves of four genotypes with contrasting heat responses (tolerant: RAJ3765, HD2932; susceptible: HD2329, HD2733) under short-term heat stress at the ear peep stage. These biomarkers were further validated in two genotypes (tolerant: Vixen; susceptible: HD2329) under short-term heat stress at both seedling and ear peep stages. The validated protein isoforms span key biological processes, including photosynthesis, redox regulation, chromatin remodelling, protein folding, and carbohydrate and secondary metabolism. This panel of protein biomarkers offers a novel molecular framework for breeding heat-tolerant wheat, providing a strategic avenue, utilising targeted proteomics, to sustain yield under rising temperatures.

Overexpressing PURPLE ACID PHOSPHATASE 2 inhibits primary root elongation in response to heat stress.

Heat stress caused a stagnation in the growth and development of Passiflora edulis Sims. To investigate the effects of high-temperature stress, this study subjected P. edulis to 40 °C treatment for different durations; the changes in chlorophyll content, chlorophyll fluorescence parameters, photosynthetic parameters, transcriptome profiles, and photosynthesis-related genes of P. edulis under high-temperature stress were analyzed. The results showed that after 5 h of heat stress, the chlorophyll content of the leaves decreased by 31%, variable fluorescence/maximum fluorescence (Fv/Fm) decreased by 26.91%, photochemical performance index (PIabs) by 99.28%, comprehensive performance index (PItotal) by 94.20%, light energy absorbed per unit area (ABS/CSm) by 13.56%, light energy captured per unit area (TRo/CSm) by 17.90% and quantum yield of electron transfer per unit area (ETo/CSm) by 92.61%. The net photosynthetic rate (Pn), transpiration rate (Tr) and stomatal conductance (Gs) decreased by 47%, 41% and 38%, respectively, while intercellular CO2 concentration (Ci) increased by 1.34 times. Transcriptome sequencing results of P. edulis under heat stress identified 2336 differentially expressed genes (DEGs), which were significantly enriched in pathways including chloroplast function and plant hormone signal transduction. GO enrichment analysis demonstrated that DEGs were significantly enriched in terms related to catalytic activity and chloroplast components. Concurrently, KEGG pathway analysis revealed that carbon fixation in photosynthetic organisms was among the key pathways showing significant enrichment of these DEGs. The expression levels of photosynthesis-related genes, including PePSAE, PeMADs, PebHLH, PeFAR1, PePSBS, PePnsB4, PebZIP and PeC2H2, exhibited a significant increase after 3 h of high-temperature stress and rapidly declined following 5 h. These findings lay a foundation for further research on the high-temperature stress response mechanism and photosynthetic regulation of heat tolerance in P. edulis.

Identification of loci and linked markers enable the marker-assisted selection for transferring the reproductive phase heat tolerance in rice. Microsatellite marker-based bulked segregant analysis (BSA) for heat tolerance was performed in F3 progenies of the cross between temperature sensitive high yielding variety Uma and tolerant variety N22. Hightemperature stress ranged from 23.33 to 38.99 °C at the booting-stage, and spikelet-fertility was considered as a direct measure of tolerance. N22 has exhibited a high spikelet-fertility of 90.92 per cent against 2.62 per cent, 44.78 per cent in Uma and F3 plants, respectively. Of the 197 microsatellite markers screened, 41 were found to be polymorphic and used for BSA of tolerant and susceptible F3 bulk along with both the parents. Marker RM5749 on chromosome 4 had co-segregated with tolerance, whereas, previously reported markers for heat tolerance in rice did not have an effect in the study population. The LOD value obtained during single marker analysis for the linkage between marker RM5749 and spikelet fertility was 6.86, indicating a strong linkage with the spikelet fertility under heat stress. The failure of the reported markers in our population suggests that the reproductive phase heat tolerance mechanisms in rice vary across the populations and the markers have to be validated for each population before being employed in MAS

Cucumber is an important vegetable crop with thermophilic but heat-sensitive growth characteristics. Heat stress threatens cucumber growth and development, leading to a decline in both quality and yield. However, the evaluation system and molecular mechanism of long-term heat tolerance remain unclear. Here, an evaluation system in response to long-term heat stress was established, and chlorophyll a content and catalase (CAT) activity were identified as key evaluation indices for determining the heat tolerance of cucumber seedlings. Transcriptomic and physiological analyses revealed that sugar metabolism played a pivotal role in the heat response. Notably, the expression of CsIAGLU (Indoleacetic Acid glucosyltransferase) was significantly upregulated in heat-tolerant genotype PS76, whereas it was not induced in the heat-sensitive genotype PWRG. Loss of function of CsIAGLU by gene editing resulted in increased sensitivity to heat stress along with higher sugar contents, accelerated stomatal closure, and chlorophyll degradation. Furthermore, CsDREB2C.L, a positive regulator of heat stress response, directly bound to the CsIAGLU promoter to enhance its expression. Overexpression of CsDREB2C.L and CsIAGLU maintained stable sugar contents, thereby keeping stomatal opening and sustaining leaf greening to resist heat stress. Taken together, our findings provide valuable insights into the mechanism of heat resistance in cucumber.

Transcriptome mapping of unfertilized pea flowers under high temperature: insights into gene regulatory networks genomics resources.

Abstract Breeding for heat tolerance in soybean [ Glycine max (L.) Merr.] is constrained by limited genetic diversity for heat tolerance, lack of efficient selection criteria, and incomplete knowledge of heat tolerance mechanisms. The objectives of this study were to characterize the heat tolerance of a soybean recombinant inbred line (RIL) population based on physiological traits defining leaf function, pollen viability, and yield, and identify genotypes and traits that can be included in breeding programs for heat tolerance selection. Field trials were conducted in South Carolina in 2022 and 2023 to test 192 RILs (derived from DS 25‐1 [heat‐tolerant] × DT97‐4290 [heat‐susceptible]), parental lines, and 12 check genotypes. Plants were initially grown at ambient temperatures, and the heat stress treatment (38°C–42°C for at least 4 h during the daytime) was established using heat tents for 14 days during the R2–R4 growth stages. RILs 22, 26, 38, 54, 78, and 115 were identified as the most heat‐tolerant, and the RILs 174, 182, and 192 as the most heat‐sensitive based on leaf physiological traits (chlorophyll index, chlorophyll fluorescence, lipid peroxidation, and photosynthesis), pollen viability, aboveground biomass, seed number, seed yield, and 100‐seed weight. Seed yield was positively correlated with chlorophyll index, photosynthesis, aboveground biomass, and seed number under heat stress. Aboveground biomass had the highest heritability ( H 2 = 0.48), reinforcing its significance as a key selection criterion for heat tolerance in soybean. New heat‐tolerant germplasms identified in this research and the three physiological traits for improving selection efficiency provide valuable resources for soybean varietal development programs.

Chickpea (Cicer arietinum L.), a vital cool-season pulse crop, experiences significant yield losses when exposed to heat stress during its reproductive stages, a vulnerability exacerbated by weather extremes. Chickpea plants synthesize numerous metabolites when subjected to heat stress; however, the underlying metabolomic mechanisms of heat tolerance remain poorly understood. In this study, we employed widely targeted metabolomics to identify key metabolites and potential biomarkers in the flower buds of two contrasting chickpea genotypes: the heat-tolerant PI518255 and the heat-sensitive PI598080. The tolerant genotype showed improved chlorophyll index, photochemical efficiency, antioxidant activity, along with low electrolyte leakage and malondialdehyde content. In contrast, the sensitive genotype exhibited low chlorophyll index, photochemical efficiency and low antioxidant activity, and high electrolyte leakage and malondialdehyde content, under heat stress conditions (35/20 °C day/night). Volcano plot analysis identified 86 up-regulated and 230 down-regulated metabolites in response to heat stress. Heatmap analysis revealed that elevated levels of specific flavonoids, phenolic acids, lignans, coumarins, alkaloids, quinones, and terpenoids characterized the heat-tolerant genotype, suggesting their potential as biomarkers for screening heat stress tolerance. KEGG enrichment and pathway analysis highlighted isoflavonoid biosynthesis, flavonoid metabolism, lysine degradation, and butanoate metabolism as key pathways affected by heat stress. Future targeted metabolomics studies may provide deeper insights into the biochemical mechanisms underlying chickpea acclimation to heat stress.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-21697-w.

The complex and dynamic microenvironments of pathological sites, including infections, tumors, and neurological disorders, impose formidable challenges on conventional therapies due to features such as iron dysregulation, localized acidity, biofilm barriers, and thermal adaptation. Harnessing these microenvironmental cues to design light-activated, microenvironment-responsive therapeutic platforms offers a promising strategy for precise, spatiotemporally controlled treatments. Nutritional immunity restricts iron availability to suppress pathogen proliferation, while bacteria deploy specialized siderophore-mediated uptake systems to circumvent this restriction. By exploiting this vulnerability, "Trojan horse" nanoplatforms such as a multifunctional nanocomposite (Ga-CT@P) can hijack bacterial iron uptake pathways, induce iron starvation, and exert potent antimicrobial effects. DFT calculations revealed that Ga3+ exhibits stronger, more uniform binding to enterobactin than Fe3+, leading to stable, redox-inert complexes that mislead bacterial transport systems. Beyond metal ion interference, acid-responsive photodynamic therapy (PDT) offers spatiotemporally precise activation at infectious sites while minimizing off-target toxicity. Our development of DHTPA, a pH-responsive AIE photosensitizer, enables robust reactive oxygen species (ROS) generation exclusively under mildly acidic conditions, enhancing bactericidal efficacy. This platform demonstrated strong antibacterial effects against drug-resistant pathogens and effectively promoted wound healing in vivo, showcasing the potential of lesion-specific "on-demand" PDT.To address biofilm barriers, OMV-camouflaged nanodisguisers synergistically integrate photothermal heating, ion interference, and ROS generation to dismantle biofilms while inducing metabolic collapse in pathogens. Simultaneously, OMV-coated nanodisguisers exploit bacterial adhesion pathways for targeted delivery, enabling photonic disruption of pathogen metabolism. In thermosensitive microenvironments, where heat-shock-protein-mediated thermal tolerance limits photothermal therapy (PTT), we developed dual-laser PTT strategies using NIR-II AIEgens (PM331@F127) to achieve precise, stepwise thermal regulation. This strategy rapidly suppresses heat tolerance mechanisms at higher temperatures and maintains moderate thermal ablation, maximizing efficacy while reducing collateral damage. In high-barrier systems such as the central nervous system (CNS), crossing the blood-brain barrier (BBB) is essential for effective phototherapy. We designed DK@RA-PEG, an NIR-II photosensitizer platform functionalized with RVG peptides and nucleic acid aptamers, to enable BBB penetration, virus-specific targeting, and ROS-mediated viral eradication under NIR light. This approach demonstrated effective treatment of rabies virus infection in vivo while maintaining neurocompatibility. Collectively, these advances establish a versatile framework for microenvironment-responsive, light-controlled therapies that decode and harness biochemical and physical signatures within diseased tissues, achieving spatiotemporal precision beyond conventional modalities. By integrating chemical signaling modulation, smart molecular design, and physiological barrier penetration, these platforms illuminate a path toward intelligent, personalized phototherapies for complex disease landscapes.

ABSTRACTUnderstanding species‐specific salt and heat tolerance mechanisms provides valuable insights into colonization and zonation patterns in saline environments. To explore these mechanisms, this study investigated the effects of selected salinity and thermoperiod on seed germination in the African haplotypes of the common reeds, P. australis and P. mauritianus. The effect of salinity was determined by germinating seeds in 0%, 5%, 10%, 20%, and 50% seawater at alternating night/day temperatures of 15°C/25°C and 20°C/30°C for 21 days. In both species, the highest germination, seedling vigor, root length, and number of leaves were obtained in the non‐saline control treatment. In P. australis, there was 100% seed germination in the non‐saline controls in both thermoperiods, while in P. mauritianus, germination was 36% and 45% lower, respectively. Salinity did not affect the germination of P. australis at 15°C/25°C, but at 20°C/30°C, germination decreased. In P. mauritianus, seed germination decreased significantly with an increase in salinity in both thermoperiods. Salinity and 20°C/30°C thermoperiod significantly reduced biomass, leaf production, culm height, and root elongation in both species. Phragmites australis was more salt‐tolerant than P. mauritianus, as germination percentage, biomass, root length, and seedling vigor index were higher in both thermoperiods. Neither species germinated at 5°C and 35°C/40°C thermoperiods; however, P. australis seeds exhibited higher viability as indicated by a greater germination recovery percentage compared to P. mauritianus. Phragmites australis seeds are lighter, fluffier, more viable, disperse easily, and may contribute to its ability to colonize a greater diversity of habitats compared to P. mauritianus.

Comparative analysis of photosynthetic heat tolerance mechanisms in select Rubus subgenus Idaeobataus species using a numerical modeling and partitioning approach

Despite an increase in global food availability, food insecurity remains a pressing global challenge affecting millions across developed and developing nations. This issue is particularly severe in developing countries in tropical regions, where harsh climatic conditions, low agricultural productivity, and limited access to resources intensify the challenge of food insecurity. Africa exemplifies these challenges, with approximately 20% of the total population undernourished. East Africa is no stranger to these statistics with 31.8% of the country’s children under 5 years old being malnourished. Many livestock production systems in tropical East Africa operate significantly below their potential due to constraints including climate vulnerability, endemic diseases, and low genetic production capacity of indigenous breeds. Improving livestock productivity has been an area of focus for improving food security for many years. Applying our knowledge of environmental adaptations such as heat tolerance mechanisms like the SLICK gene in cattle and fat tails in sheep and disease resistance traits like trypanotolerance is a foundational step in the development of breed improvement programs for the tropics. Crossbreeding programs have utilized this knowledge for decades resulting in great success stories such as the Girolando cattle of Brazil, which are responsible for producing 80% of the country’s milk today. With the development and use of assisted reproductive technologies (ARTs) like artificial insemination, in vitro fertilization & embryo transfer we have the ability to achieve genetic gain at an unprecedented speed. Many cases have demonstrated promising applications of these technologies, with one such study reporting IVF and ET implementation in Kenyan dairy herds could increase monetary gain by 184% while reducing generation intervals by 47%. Overall, strategic implementation of genetic improvement programs, when adapted to the diverse livestock production systems of the developing tropics hold the key to significantly enhancing livestock productivity, improving food security, and overall contributing to more sustainable agricultural systems in East Africa.

Thermal priming and epigenetic changes improve heat-tolerance mechanisms of tropical seagrasses under warming ocean along Palk Bay region, southeast coast of India.