Priming avocado with sodium hydrosulfide prior to frost conditions induces the expression of genes involved in protection and stress responses.

Priming plants with chemical agents has been extensively investigated as a means for improving their tolerance to many biotic and abiotic stresses. Earlier, we showed that priming young avocado (Persea americana Mill cv. 'Hass') trees with sodium hydrosulfide (NaHS), a donor of hydrogen sulfide, improves the response of photosynthesis to simulated frost (cold followed by high light) conditions. In the current study, we performed a transcriptome analysis to gain insight into the molecular response of avocado 'Hass' leaves to frost, with or without NaHS priming. The analysis revealed 2144 (down-regulated) and 2064 (up-regulated) differentially expressed genes (DEGs) common to both non-primed and primed trees. Non-primed trees had 697 (down) and 559 (up) unique DEGs, while primed trees exhibited 1395 (down) and 1385 (up) unique DEGs. We focus on changes in the expression patterns of genes encoding proteins involved in photosynthesis, carbon cycle, protective functions, biosynthesis of isoprenoids and abscisic acid (ABA), as well as ABA-regulated genes. Notably, the differential expression results depict the enhanced response of primed trees to the frost and highlight gene expression changes unique to primed trees. Amongst these are up-regulated genes encoding pathogenesis-related proteins, heat shock proteins, enzymes for ABA metabolism, and ABA-induced transcription factors. Extending the priming experiments to field conditions, which showed a benefit to the physiology of trees following chilling, suggests that it can be a possible means to improve trees' response to cold stress under natural winter conditions.

Low light-regulated intramolecular disulfide fine-tunes the role of PTOX in Arabidopsis.

Disulfide-based regulation links the activity of numerous chloroplast proteins with photosynthesis-derived redox signals. The plastid terminal oxidase (PTOX) is a thylakoid-bound plastoquinol oxidase that has been implicated in multiple roles in the light and in the dark, which could require different levels of PTOX activity. Here we show that Arabidopsis PTOX contains a conserved C-terminus domain (CTD) with cysteines that evolved progressively following the colonization of the land by plants. Furthermore, the CTD contains a regulatory disulfide that is in the oxidized state in the dark and is rapidly reduced, within 5 min, in low light intensity (1-5 µE m-2 sec-1 ). The reduced PTOX form in the light was reoxidized within 15 min after transition to the dark. Mutation of the cysteines in the CTD prevented the formation of the oxidized form. This resulted in higher levels of reduced plastoquinone when measured at transition to the onset of low light. This is consistent with the reduced state of PTOX exhibiting diminished PTOX oxidase activity under conditions of limiting PQH2 substrate. Our findings suggest that AtPTOX-CTD evolved to provide light-dependent regulation of PTOX activity for the adaptation of plants to terrestrial conditions.

Redox regulation of PGRL1 at the onset of low light intensity.

PGR5-LIKE PHOTOSYNTHETIC PHENOTYPE1 (PGRL1) regulates photosystem I cyclic electron flow which transiently activates non-photochemical quenching at the onset of light. Here, we show that a disulfide-based mechanism of PGRL1 regulated this process in vivo at the onset of low light levels. We found that PGRL1 regulation depended on active formation of key regulatory disulfides in the dark, and that PGR5 was required for this activity. The disulfide state of PGRL1 was modulated in plants by counteracting reductive and oxidative components and reached a balanced state that depended on the light level. We propose that the redox regulation of PGRL1 fine-tunes a timely activation of photosynthesis at the onset of low light.

Fever, Rash, and Shortness of Breath in a 69-Year-Old.

A 69-year-old had fever, fatigue, rash, right periorbital swelling, and shortness of breath. Chest computed tomography revealed numerous small, bilateral pulmonary nodules; laboratory testing revealed mean corpuscular volume, 96.1 fL; hemoglobin level, 12.4 mg/dL; and leukopenia. What is the diagnosis and what would you do next?

The transcriptional regulatory mechanism of the peroxisomal ascorbate peroxidase (pAPX) gene cloned from an extreme halophyte, Salicornia brachiata.

Peroxisomal ascorbate peroxidase detoxifies H2O2 leaching out from peroxisomes into the cytoplasm. The present study describes transcript expression and cis-regulation of the SbpAPX gene cloned from an extreme halophyte, Salicornia brachiata, in the steady state and under different stresses. About 2-fold elevated transcript expression was found in salt- and drought-treated shoots at 12 h compared with control, while 1.9-fold increased expression was observed under heat treatment. In roots, the transcript level was down-regulated at 2 h, thereafter increasing with the time of exposure and reaching a maximum at the control level. The SbpAPX promoter has characteristic cis-regulatory ABA-dependent abiotic stress-responsive elements. The full-length promoter (1,024 bp, PP1) and deletion constructs -838 (PP2), -697 (PP3), -433 (PP4) and -185 bp (PP5) were fused with the GUS (ß-glucuronidase) gene and transformed into tobacco for functional validation. Expression of GUS increased significantly in transgenic plants under stress. Quantitative expression analysis of GUS in T1 plants revealed that promoter PP5 is efficient for gene expression. In planta transient expression further suggested that the promoter PP5 contains efficient stress-inducible elements. A steep decline in GUS expression in PP3, and thereafter an elevated expression in PP4 and PP5, suggested the presence of a repressor element between -696 and -433 bp, while an enhancer element was predicted between -838 and -697 bp. Further, transient expression analyses and electrophoretic mobility shift assay revealed that the core sequence of cis-acting motifs ATAA and CCTCAA function as enhancer and repressor binding sites, respectively. Based on the study, a model is proposed for the cis-regulation of the SbpAPX gene. The present study provides a useful insight for understanding gene expression regulation in a halophyte with or without stress. Furthermore, potential stress-responsive promoter-driven expression of introgressed gene(s) can be used for engineering crops with enhanced stress tolerance.

Multisystem Inflammatory Syndrome in Children: A Year in Review.

Centers for Disease Control and Prevention published a case definition for the multisystem inflammatory syndrome in children in May 2020 when reports started pouring in about a clinical syndrome in children which was temporally associated with coronavirus disease 2019 infection. It has also been referred to as pediatric inflammatory multisystemic syndrome temporally associated with severe acute respiratory syndrome coronavirus 2. Most of these patients test positive for severe acute respiratory syndrome coronavirus 2 serology or reverse transcription-polymerase chain reaction, although a small number of patients could test negative which would require an epidemiological link to the coronavirus disease 2019 infection. The initial clinical presentation could overlap with Kawasaki disease, severe coronavirus disease 2019 infection, toxic shock syndrome, and macrophage activation syndrome. While multisystem inflammatory syndrome in children is characterized by multisystem involvement with hyper inflammation and severe clinical presentation initially, the prognosis is generally good. Since it was first described, there have been multiple studies describing the demographic characteristics, laboratory features, and treatment paradigm.

Daytime or Edge-of-Daytime Intra-Canopy Illumination Improves the Fruit Set of Bell Pepper at Passive Conditions in the Winter.

Optimal light conditions ensure the availability of sufficient photosynthetic assimilates for supporting the survival and growth of fruit organs in crops. One of the growing uses of light-emitting diodes (LEDs) in horticulture is intra-canopy illumination or LED-interlighting, providing supplemental light for intensively cultivated crops directly within their canopies. Originally developed and applied in environmentally controlled greenhouses in northern latitude countries, this technique is nowadays also being tested and studied in other regions of the world such as the Mediterranean region. In the present work, we applied intra-canopy illumination for bell pepper grown in passive high tunnels in the Jordan Valley using a commercial LED product providing cool-white light. The study included testing of daytime ('LED-D') and edge-of-daytime ('LED-N') illumination, as well as a detailed characterization of fruit set and fruit survival throughout the growth season. We found that both light regimes significantly improved the fruit set and survival during winter, with some benefit of LED-N illumination. Notably, we found that western-facing plants of illuminated sections had a higher contribution toward the increased winter fruit set and spring yield than that of illuminated eastern-facing plants. Greater plant height and fresh weight of western-facing plants of the illuminated sections support the yield results. The differences likely reflect higher photosynthetic assimilation of western-facing plants as compared to eastern-facing ones, due to the higher daily light integral and higher canopy temperature of the former. This study provides important implications for the use of intra-canopy lighting for crops grown at passive winter conditions and exemplifies the significance of geographical positioning, opening additional avenues of investigation for optimization of its use for improving fruit yield under variable conditions.

Physiological characterization of the wild almond Prunus arabica stem photosynthetic capability.

Leaves are the major plant tissue for transpiration and carbon fixation in deciduous trees. In harsh habitats, atmospheric CO2 assimilation via stem photosynthesis is common, providing extra carbon gain to cope with the detrimental conditions. We studied two almond species, the commercial Prunus dulcis cultivar "Um-el-Fahem" and the rare wild Prunus arabica. Our study revealed two distinctive strategies for carbon gain in these almond species. While, in P. dulcis, leaves possess the major photosynthetic surface area, in P. arabica, green stems perform this function, in particular during the winter after leaf drop. These two species' anatomical and physiological comparisons show that P. arabica carries unique features that support stem gas exchange and high-gross photosynthetic rates via stem photosynthetic capabilities (SPC). On the other hand, P. dulcis stems contribute low gross photosynthesis levels, as they are designed solely for reassimilation of CO2 from respiration, which is termed stem recycling photosynthesis (SRP). Results show that (a) P. arabica stems are covered with a high density of sunken stomata, in contrast to the stomata on P. dulcis stems, which disappear under a thick peridermal (bark) layer by their second year of development. (b) P. arabica stems contain significantly higher levels of chlorophyll compartmentalized to a mesophyll-like, chloroplast-rich, parenchyma layer, in contrast to rounded-shape cells of P. dulcis's stem parenchyma. (c) Pulse amplitude-modulated (PAM) fluorometry of P. arabica and P. dulcis stems revealed differences in the chlorophyll fluorescence and quenching parameters between the two species. (d) Gas exchange analysis showed that guard cells of P. arabica stems tightly regulate water loss under elevated temperatures while maintaining constant and high assimilation rates throughout the stem. Our data show that P. arabica uses a distinctive strategy for tree carbon gain via stem photosynthetic capability, which is regulated efficiently under harsh environmental conditions, such as elevated temperatures. These findings are highly important and can be used to develop new almond cultivars with agriculturally essential traits.

High Burden of Burnout on Rheumatology Practitioners.

OBJECTIVE: Burnout among physicians is common and has important implications. We assessed the extent of burnout among rheumatology practitioners and its associations. METHODS: One hundred twenty-eight attendees at the 2019 Rheumatology Winter Clinical Symposium were surveyed using the Maslach Burnout Index (MBI) and a demographics questionnaire. Scores for emotional exhaustion (EE) ≥ 27, depersonalization (DP) ≥ 10, and personal accomplishment (PA) ≤ 33 were considered positive for burnout. Data regarding practitioner characteristics including age, sex, years in practice, and other demographics of interest were also collected. These data were used to determine prevalence and interactions of interest between practitioner characteristics and the risk of burnout. RESULTS: Of the 128 respondents, 50.8% demonstrated burnout in at least 1 MBI domain. Dissatisfaction with electronic health records was associated with a 2.86-times increased likelihood of burnout (OR 2.86, 95% CI 1.23-6.65, P = 0.015). Similar results were found for lack of exercise (OR 5.00, 95% CI 1.3-18.5, P = 0.016) and work hours > 60 per week (OR 2.6, 95% CI 1.16-5.6, P = 0.019). Practitioners in group practice were 57% less likely to burn out (OR 0.43, 95% CI 0.20-0.92, P = 0.029), as were those who spend > 20% of their time in personally satisfying work (OR 0.32, 95% CI 0.15-0.71, P = 0.005). CONCLUSION: In what we believe to be one of the largest studies regarding burnout among rheumatology practitioners, we found a substantial prevalence of burnout, with 51% of all respondents meeting criteria in at least 1 domain defined by the MBI and 54% of physicians meeting these same criteria.

Cloning and functional characterization of the Na+/H+ antiporter (NHX1) gene promoter from an extreme halophyte Salicornia brachiata.

Salinity is one of the major abiotic stresses which affect plant growth and productivity by imposing dual stress, ionic and osmotic stress, on plants. Halophytes which are adapted to complete their life cycle in saline soil keep the transcript expression of stress-responsive genes constitutively higher in the optimum growth environments, which can be further increased by several folds under stress conditions. The transcript expression of SbNHX1 gene, cloned from a leafless succulent halophyte Salicornia brachiata, was up-regulated under salinity stress, but its transcriptional regulation has not been studied so far. In the present study, a 1727 bp putative promoter (upstream to translation start site) of the SbNHX1 gene was cloned using a genome walking method. The bioinformatics analysis identified important stress-responsive cis-regulatory motifs, GT1, MBS, LTR and ARE, in addition to two leaf-specific enhancer motifs. The GUS expression analysis of stable transgenic tobacco plants, transformed with a transcriptional fusion of GUS with the full SbNHX1 promoter (NP1) or any of its five deletion fragments (NP2 to NP6), showed that the deletion of two enhancer motifs resulted in the sudden decrease in GUS expression in leaves but not in the stem or root tissues. In contrast, under salinity stress, the higher induction of GUS expression observed in NP1 and NP2 was correlated by the presence of salt-inducible GT1- and MBS-motifs which is distributed only in NP1 and NP2 deletion promoter fragments. Finally, we concluded that the SbNHX1 promoter has a 624 bp (-1727 to -1103 bp) regulatory region which contains the two leaf-specific enhancer motifs and salinity stress-inducible GT-1 and MBS motifs. We suggest the SbNHX1 gene promoter and fragments as a candidate alternative promoter/s for crop engineering for better stress tolerance, which can be amended according to the desired level of expression needed.

Fold-change Response of Photosynthesis to Step Increases of Light Level.

Plants experience light intensity over several orders of magnitude. High light is stressful, and plants have several protective feedback mechanisms against this stress. Here we asked how plants respond to sudden rises at low ambient light, far below stressful levels. For this, we studied the fluorescence of excited chlorophyll a of photosystem II in Arabidopsis thaliana plants in response to step increases in light level at different background illuminations. We found a response at low-medium light with characteristics of a sensory system: fold-change detection (FCD), Weber law, and exact adaptation, in which the response depends only on relative, and not absolute, light changes. We tested various FCD circuits and provide evidence for an incoherent feedforward mechanism upstream of known stress response feedback loops. These findings suggest that plant photosynthesis may have a sensory modality for low light background that responds early to small light increases, to prepare for damaging high light levels.

A SNARE-Like Superfamily Protein SbSLSP from the Halophyte Salicornia brachiata Confers Salt and Drought Tolerance by Maintaining Membrane Stability, K(+)/Na(+) Ratio, and Antioxidant Machinery.

About 1000 salt-responsive ESTs were identified from an extreme halophyte Salicornia brachiata. Among these, a novel salt-inducible gene SbSLSP (Salicornia brachiata SNARE-like superfamily protein), showed up-regulation upon salinity and dehydration stress. The presence of cis-regulatory motifs related to abiotic stress in the putative promoter region supports our finding that SbSLSP gene is inducible by abiotic stress. The SbSLSP protein showed a high sequence identity to hypothetical/uncharacterized proteins from Beta vulgaris, Spinacia oleracea, Eucalyptus grandis, and Prunus persica and with SNARE-like superfamily proteins from Zostera marina and Arabidopsis thaliana. Bioinformatics analysis predicted a clathrin adaptor complex small-chain domain and N-myristoylation site in the SbSLSP protein. Subcellular localization studies indicated that the SbSLSP protein is mainly localized in the plasma membrane. Using transgenic tobacco lines, we establish that overexpression of SbSLSP resulted in elevated tolerance to salt and drought stress. The improved tolerance was confirmed by alterations in a range of physiological parameters, including high germination and survival rate, higher leaf chlorophyll contents, and reduced accumulation of Na(+) ion and reactive oxygen species (ROS). Furthermore, overexpressing lines also showed lower water loss, higher cell membrane stability, and increased accumulation of proline and ROS-scavenging enzymes. Overexpression of SbSLSP also enhanced the transcript levels of ROS-scavenging and signaling enzyme genes. This study is the first investigation of the function of the SbSLSP gene as a novel determinant of salinity/drought tolerance. The results suggest that SbSLSP could be a potential candidate to increase salinity and drought tolerance in crop plants for sustainable agriculture in semi-arid saline soil.

Functional Characterization of the Tau Class Glutathione-S-Transferases Gene (SbGSTU) Promoter of Salicornia brachiata under Salinity and Osmotic Stress.

Reactive oxygen or nitrogen species are generated in the plant cell during the extreme stress condition, which produces toxic compounds after reacting with the organic molecules. The glutathione-S-transferase (GST) enzymes play a significant role to detoxify these toxins and help in excretion or sequestration of them. In the present study, we have cloned 1023 bp long promoter region of tau class GST from an extreme halophyte Salicornia brachiata and functionally characterized using the transgenic approach in tobacco. Computational analysis revealed the presence of abiotic stress responsive cis-elements like ABRE, MYB, MYC, GATA, GT1 etc., phytohormones, pathogen and wound responsive motifs. Three 5'-deletion constructs of 730 (GP2), 509 (GP3) and 348 bp (GP4) were made from 1023 (GP1) promoter fragment and used for tobacco transformation. The single event transgenic plants showed notable GUS reporter protein expression in the leaf tissues of control as well as treated plants. The expression level of the GUS gradually decreases from GP1 to GP4 in leaf tissues, whereas the highest level of expression was detected with the GP2 construct in root and stem under control condition. The GUS expression was found higher in leaves and stems of salinity or osmotic stress treated transgenic plants than that of the control plants, but, lower in roots. An efficient expression level of GUS in transgenic plants suggests that this promoter can be used for both constitutive as well as stress inducible expression of gene(s). And this property, make it as a potential candidate to be used as an alternative promoter for crop genetic engineering.

An efficient method of agrobacterium-mediated genetic transformation and regeneration in local Indian cultivar of groundnut (Arachis hypogaea) using grafting.

Groundnut (Arachis hypogaea L.) is an industrial crop used as a source of edible oil and nutrients. In this study, an efficient method of regeneration and Agrobacterium-mediated genetic transformation is reported for a local cultivar GG-20 using de-embryonated cotyledon explant. A high regeneration 52.69 ± 2.32 % was achieved by this method with 66.6 µM 6-benzylaminopurine (BAP), while the highest number of shoot buds per explant, 17.67 ± 3.51, was found with 20 µM BAP and 10 µM 2,4-dichlorophenoxyacetic acid (2,4-D). The bacterial culture OD, acetosyringone and L-cysteine concentration were optimized as 1.8, 200 µM and 50 mg L(-1), respectively, in co-cultivation media. It was observed that the addition of 2,4-D in co-cultivation media induced accumulation of endogenous indole-3-acetic acid (IAA). The optimized protocol exhibited 85 % transformation efficiency followed by 14.65 ± 1.06 % regeneration, of which 3.82 ± 0.6 % explants were survived on hygromycin after selection. Finally, 14.58 ± 2.95 % shoots (regenerated on survived explants) were rooted on rooting media (RM3). In grafting method, regenerated shoots (after hygromycin selection) were grafted on the non-transformed stocks with 100 % survival and new leaves emerged in 3 weeks. The putative transgenic plants were then confirmed by PCR, Southern hybridization, reverse transcriptase PCR (RT-PCR) and ß-glucuronidase (GUS) histochemical assay. The reported method is efficient and rapid and can also be applied to other crops which are recalcitrant and difficult in rooting.

Introgression of the SbASR-1 gene cloned from a halophyte Salicornia brachiate enhances salinity and drought endurance in transgenic groundnut (arachis hypogaea)and acts as a transcription factor [corrected].

The SbASR-1 gene, cloned from a halophyte Salicornia brachiata, encodes a plant-specific hydrophilic and stress responsive protein. The genome of S. brachiata has two paralogs of the SbASR-1 gene (2549 bp), which is comprised of a single intron of 1611 bp, the largest intron of the  abscisic acid stress ripening [ASR] gene family yet reported. In silico analysis of the 843-bp putative promoter revealed the presence of ABA, biotic stress, dehydration, phytohormone, salinity, and sugar responsive cis-regulatory motifs. The SbASR-1 protein belongs to Group 7 LEA protein family with different amino acid composition compared to their glycophytic homologs. Bipartite Nuclear Localization Signal (NLS) was found on the C-terminal end of protein and localization study confirmed that SbASR-1 is a nuclear protein. Furthermore, transgenic groundnut (Arachis hypogaea) plants over-expressing the SbASR-1 gene constitutively showed enhanced salinity and drought stress tolerance in the T1 generation. Leaves of transgenic lines exhibited higher chlorophyll and relative water contents and lower electrolyte leakage, malondialdehyde content, proline, sugars, and starch accumulation under stress treatments than wild-type (Wt) plants. Also, lower accumulation of H2O2 and O2.- radicals was detected in transgenic lines compared to Wt plants under stress conditions. Transcript expression of APX (ascorbate peroxidase) and CAT (catalase) genes were higher in Wt plants, whereas the SOD (superoxide dismutase) transcripts were higher in transgenic lines under stress. Electrophoretic mobility shift assay (EMSA) confirmed that the SbASR-1 protein binds at the consensus sequence (C/G/A)(G/T)CC(C/G)(C/G/A)(A/T). Based on results of the present study, it may be concluded that SbASR-1 enhances the salinity and drought stress tolerance in transgenic groundnut by functioning as a LEA (late embryogenesis abundant) protein and a transcription factor.

The SbMT-2 gene from a halophyte confers abiotic stress tolerance and modulates ROS scavenging in transgenic tobacco.

Heavy metals are common pollutants of the coastal saline area and Salicornia brachiata an extreme halophyte is frequently exposed to various abiotic stresses including heavy metals. The SbMT-2 gene was cloned and transformed to tobacco for the functional validation. Transgenic tobacco lines (L2, L4, L6 and L13) showed significantly enhanced salt (NaCl), osmotic (PEG) and metals (Zn++, Cu++ and Cd++) tolerance compared to WT plants. Transgenic lines did not show any morphological variation and had enhanced growth parameters viz. shoot length, root length, fresh weight and dry weight. High seed germination percentage, chlorophyll content, relative water content, electrolytic leakage and membrane stability index confirmed that transgenic lines performed better under salt (NaCl), osmotic (PEG) and metals (Zn++, Cu++ and Cd++) stress conditions compared to WT plants. Proline, H2O2 and lipid peroxidation (MDA) analyses suggested the role of SbMT-2 in cellular homeostasis and H2O2 detoxification. Furthermore in vivo localization of H2O2 and O2-; and elevated expression of key antioxidant enzyme encoding genes, SOD, POD and APX evident the possible role of SbMT-2 in ROS scavenging/detoxification mechanism. Transgenic lines showed accumulation of Cu++ and Cd++ in root while Zn++ in stem under stress condition. Under control (unstressed) condition, Zn++ was accumulated more in root but accumulation of Zn++ in stem under stress condition suggested that SbMT-2 may involve in the selective translocation of Zn++ from root to stem. This observation was further supported by the up-regulation of zinc transporter encoding genes NtZIP1 and NtHMA-A under metal ion stress condition. The study suggested that SbMT-2 modulates ROS scavenging and is a potential candidate to be used for phytoremediation and imparting stress tolerance.

Cloning and transcript analysis of type 2 metallothionein gene (SbMT-2) from extreme halophyte Salicornia brachiata and its heterologous expression in E. coli.

Salicornia brachiata is an extreme halophyte growing luxuriantly in the coastal marshes and frequently exposed to various abiotic stresses including heavy metals. A full length type 2 metallothionein (SbMT-2) gene was isolated using RACE and its copy number was confirmed by southern blot analysis. Transcript expression of SbMT-2 gene was analyzed by semi-quantitative Rt-PCR and real time quantitative (qRT) PCR. Expression of SbMT-2 gene was up-regulated concurrently with zinc, copper, salt, heat and drought stress, down regulated by cold stress while unaffected under cadmium stress. Heterologous expression of SbMT-2 gene enhances metal accumulation and tolerance in E. coli. Metal-binding characteristics of SbMT-2 protein show its possible role in homeostasis and/or detoxification of heavy metals. Significant tolerance was observed by E. coli cells expressing recombinant SbMT-2 for Zn(++), Cu(++) and Cd(++) compared to cells expressing GST only. Sequestration of zinc was 4-fold higher compared to copper and in contrast SbMT-2 inhibits the relative accumulation of cadmium by 1.23-fold compared to GST protein. Fusion protein SbMT-2 showed utmost affinity to zinc (approx. 2.5 fold to Cu(++) and Cd(++)) followed by copper and cadmium ions with same affinity. Halophyte S. brachiata has inherent resilience of varying abiotic tolerance therefore SbMT-2 gene could be a potential candidate to be used for enhanced metal tolerance and heavy metal phytoremediation.

The SbASR-1 gene cloned from an extreme halophyte Salicornia brachiata enhances salt tolerance in transgenic tobacco.

Salinity severely affects plant growth and development. Plants evolved various mechanisms to cope up stress both at molecular and cellular levels. Halophytes have developed better mechanism to alleviate the salt stress than glycophytes, and therefore, it is advantageous to study the role of different genes from halophytes. Salicornia brachiata is an extreme halophyte, which grows luxuriantly in the salty marshes in the coastal areas. Earlier, we have isolated SbASR-1 (abscisic acid stress ripening-1) gene from S. brachiata using cDNA subtractive hybridisation library. ASR-1 genes are abscisic acid (ABA) responsive, whose expression level increases under abiotic stresses, injury, during fruit ripening and in pollen grains. The SbASR-1 transcript showed up-regulation under salt stress conditions. The SbASR-1 protein contains 202 amino acids of 21.01-kDa molecular mass and has 79 amino acid long signatures of ABA/WDS gene family. It has a maximum identity (73 %) with Solanum chilense ASR-1 protein. The SbASR-1 has a large number of disorder-promoting amino acids, which make it an intrinsically disordered protein. The SbASR-1 gene was over-expressed under CaMV 35S promoter in tobacco plant to study its physiological functions under salt stress. T(0) transgenic tobacco seeds showed better germination and seedling growth as compared to wild type (Wt) in a salt stress condition. In the leaf tissues of transgenic lines, Na(+) and proline contents were significantly lower, as compared to Wt plant, under salt treatment, suggesting that transgenic plants are better adapted to salt stress.