Salt-stressed Plants Research Articles

Convergent and divergent signaling pathways in C3 rice and C4 foxtail millet crops in response to salt stress

Salt stress is a global constraint on agricultural production. Therefore, the development of salt tolerant plants has become a current research hotspot. Salt tolerance evolves more frequently in C4 grass lineages. However, few studies have been carried out to explore the molecular bases underlying salt stress tolerance in C4 crop foxtail millet. In this study, we performed a multi-pronged approach spanning the omics analyses of transcriptomes and physiological analysis of C3 crop rice and C4 model crop foxtail millet in response to salt stress. Our results revealed specifically compared to C3 rice, C4 foxtail millet has upregulated ABA and notably reduced CK biosynthesis and signaling transduction under salt stress. Salt stress in C3 rice plants triggered rapid downregulation of photosynthesis related genes, which was coupled by severely decreased net photosynthetic rates. In the salt-threatened C3 rice and C4 foxtail millet, some stress responsive transcription factors (TFs), such as AP2/ERF, WRKY and MYB underwent strong and distinct transcriptional changes. Based on weighted gene co-expression network analysis (WGCNA), an AP2/ERF transcription factor Rice Starch Regulator1 SiRSR1 (Seita.3G044600) was identified as a key regulator of salt stress response. To confirmed its function, we generated OsRSR1-knockout lines with CRISPR/Cas9 genome editing in rice and its upstream repressor SiMIR172a-overexpressing (172a-OE) transgenic plants in foxtail millet, which increased salt tolerance. Overall, our study not only provided new insights into the convergent regulation of salt stress responses of foxtail millet and rice, but also shed light on the divergent signaling networks between them in response to salt stress.

The Impact of Salinity on Crop Yields and the Confrontational Behavior of Transcriptional Regulators, Nanoparticles, and Antioxidant Defensive Mechanisms under Stressful Conditions: A Review.

One of the most significant environmental challenges to crop growth and yield worldwide is soil salinization. Salinity lowers soil solution water potential, causes ionic disequilibrium and specific ion effects, and increases reactive oxygen species (ROS) buildup, causing several physiological and biochemical issues in plants. Plants have developed biological and molecular methods to combat salt stress. Salt-signaling mechanisms regulated by phytohormones may provide additional defense in salty conditions. That discovery helped identify the molecular pathways that underlie zinc-oxide nanoparticle (ZnO-NP)-based salt tolerance in certain plants. It emphasized the need to study processes like transcriptional regulation that govern plants' many physiological responses to such harsh conditions. ZnO-NPs have shown the capability to reduce salinity stress by working with transcription factors (TFs) like AP2/EREBP, WRKYs, NACs, and bZIPs that are released or triggered to stimulate plant cell osmotic pressure-regulating hormones and chemicals. In addition, ZnO-NPs have been shown to reduce the expression of stress markers such as malondialdehyde (MDA) and hydrogen peroxide (H2O2) while also affecting transcriptional factors. Those systems helped maintain protein integrity, selective permeability, photosynthesis, and other physiological processes in salt-stressed plants. This review examined how salt stress affects crop yield and suggested that ZnO-NPs could reduce plant salinity stress instead of osmolytes and plant hormones.

Humic acid supplementation improves salt tolerance in chili by modulating morpho-physio-biochemical variables

As agricultural challenges related to soil salinity continue to grow, incorporation of humic acid into cultivation practices could contribute significantly to global food security and sustainable agriculture. This study assessed the effects of different doses of soil applied humic acid (0, 50, 100, and 200 mg/kg w/w soil) on the growth, photosynthetic pigments, and antioxidant potential of chili grown under varying concentrations of salt (0, 50 and 100 mM of NaCl). The results showed that a linear decrease was noticed in the growth, biomass, and photosynthetic pigment attributes of the chili plants by increasing salt level. More reduction was noticed at the higher levels of salt stress as compared to the control, primarily due to lowering of total chlorophyll concentrations and increased sodium accumulation in leaves. Dry biomass significantly increased with humic acid treatments, regardless of the stress level. The reduced enzymatic activities associated with ROS detoxification underscored the pivotal role of humic acid in maintaining redox homeostasis. Optimal use of humic acid (200 mg/kg) showed promising results in comparison with the rest of the treatments in minimizing Na+ uptake in the chili plants. This study demonstrates that the application of humic acid activates physio-biochemical defense responses against salt stress in chili plants and provides a significant pavement for the cultivation of chili in soils containing moderate levels of salt.

Halotolerant and plant growth-promoting endophytic fungus Aspergillus terreus CR7 alleviates salt stress and exhibits genoprotective effect in Vigna radiata.

Soil salinity is one of the major environmental stresses that results in reduction of cultivable land and decreased productivity. In the present study, halotolerant and plant growth-promoting endophytic fungi were isolated from Catharanthus roseus, and their effect in mitigating salt stress in Vigna radiata was evaluated. An isolate CR7, identified to be Aspergillus terreus, showing plant growth promotion activities, viz. IAA production (23.43 ± 0.79 μg/ml), phosphate solubilization (133.63 ± 6.40 μg/ml), ACC deaminase activity (86.36 ± 2.70 μmol α-ketobutyrate/h/mg protein) etc. and ability to grow at 15% NaCl was selected for further in vivo studies. Colonization of CR7 was carried out in V. radiata which was subjected to different concentrations of salt (150, 200, and 250 mM NaCl). Under salt stress, A. terreus CR7 inoculated plants showed substantially improved root and shoot length, biomass, chlorophyll content, relative water content, phenolics, protein content, and DPPH scavenging activity. Endogenous IAA level was enhanced by 5.28-fold in treated plants at maximum salt stress. Inoculation of A. terreus CR7 affected oxidative stress parameters, exhibiting an increase in catalase and superoxide dismutase and reduction in proline, electrolyte leakage, and malondialdehyde content. Fluorescent microscopic analysis of roots revealed improved cell viability and decreased levels of glutathione and hydrogen peroxide under salt stress in treated plants. The isolate A. terreus CR7 also protected against DNA damage induced by salt stress which was evaluated using comet assay. A decrease in DNA tail length, tail moment, and olive tail moment to the extent of 19.87%, 19.76%, and 24.81%, respectively, was observed in A. terreus CR7-colonized plants under salt stress. It can be concluded that A. terreus CR7 can be exploited for alleviating the impact of salt stress in crop plants.

The dual role of methylglyoxal in plant stress response and regulation of DJ-1 protein.

Methylglyoxal (MG) is a highly reactive metabolic intermediate that plays important roles in plant salt stress response. This review explores the sources of MG in plants, how salt stress promotes MG production, and the dual role of MG under salt stress conditions. Both the positive role of low concentrations of MG as a signalling molecule and the toxic effects of high concentrations of MG in plant response to salt stress are discussed. The MG detoxification pathways, especially the glyoxalase system, are described in detail. Special attention is given to the novel role of the DJ-1 protein in the glyoxalase system as glyoxalase III to remove MG, and as a deglycase to decrease glycation damage caused by MG on DNA, proteins, and other biomolecules. This review aims to provide readers with comprehensive perspectives on the functions of MG in plant salt stress response, the roles of the DJ-1 protein in MG detoxification and repair of glycation-damaged molecules, as well as the broader functional implications of MG in plant salt stress tolerance. New perspectives on maintaining plant genome stability, breeding for salt-tolerant crop varieties, and improving crop quality are discussed.

OsBCAT2, a gene responsible for the degradation of branched-chain amino acids, positively regulates salt tolerance by promoting the synthesis of vitamin B5.

Salt stress negatively affects rice growth, development and yield. Metabolic adjustments contribute to the adaptation of rice under salt stress. Branched-chain amino acids (BCAA) are three essential amino acids that cannot be synthesized by humans or animals. However, little is known about the role of BCAA in response to salt stress in plants. Here, we showed that BCAAs may function as scavengers of reactive oxygen species (ROS) to provide protection against damage caused by salinity. We determined that branched-chain aminotransferase 2 (OsBCAT2), a protein responsible for the degradation of BCAA, positively regulates salt tolerance. Salt significantly induces the expression of OsBCAT2 rather than BCAA synthesis genes, which indicated that salt mainly promotes BCAA degradation and not de novo synthesis. Metabolomics analysis revealed that vitamin B5 (VB5) biosynthesis pathway intermediates were higher in the OsBCAT2-overexpressing plants but lower in osbcat2 mutants under salt stress. The salt stress-sensitive phenotypes of the osbcat2 mutants are rescued by exogenous VB5, indicating that OsBCAT2 affects rice salt tolerance by regulating VB5 synthesis. Our work provides new insights into the enzymes involved in BCAAs degradation and VB5 biosynthesis and sheds light on the molecular mechanism of BCAAs in response to salt stress.

ZnO quantum dots alleviate salt stress in Salvia miltiorrhiza by enhancing growth, scavenging reactive oxygen species, and modulating stress-responsive genes

Experiments were conducted to investigate the alleviating effects of ZnO quantum dots (ZnO QDs) on salt stress in Salvia miltiorrhiza by comparing them with conventional ZnO nanoparticles (ZnO NPs). The results demonstrated that compared with salt stress alone, foliar application of ZnO QDs significantly improved the biomass as well as the total chlorophyll and carotenoids contents under salt stress. ZnO QDs reduced H2O2 and MDA levels, decreased non-enzymatic antioxidant (ASA and GSH) content, and improved antioxidant enzyme (POD, SOD, CAT, PAL, and PPO) activity under salt stress. Metal elemental analysis further demonstrated that the ZnO QDs markedly increased Zn and K contents while decreasing Na content, resulting in a lower Na/K ratio compared to salt stress alone. Finally, RNA sequencing results indicated that ZnO QDs primarily regulated genes associated with stress-responsive pathways, including plant hormone signal transduction, the MAPK signaling pathway, and metabolic-related pathways, thereby alleviating the adverse effects of salt stress. In comparison, ZnO NPs did not exhibit similar effects in terms of improving plant growth, enhancing the antioxidant system, or regulating stress-responsive genes under salt stress. These findings highlight the distinct advantages of ZnO QDs and suggest their potential as a valuable tool for mitigating salt stress in plants.

Physiological and Molecular Responses of Pyrus pyraster Seedlings to Salt Treatment Analyzed by miRNA and Cytochrome P450 Gene-Based Markers.

Physiological and molecular marker-based changes were studied in the tissues of two-year-old Pyrus pyraster (L.) Burgsd. seedlings under salt treatment. For 60 days, 5 mL of 100 mM NaCl solution was applied to each plant per day to a cumulative volume of 300 mL in the substrate. In response to osmotic stress, the seedlings increased their water use efficiency (WUE) on day 20 of regular NaCl application and maintained a stable net photosynthetic rate (An) per unit area. Under conditions of increasing salinity, the young plants maintained a balanced water regime of the leaf tissues (Ψwl). The seedlings invested mass to their root growth (R/S), retained a substantial portion (72%) of Na+ ions in the roots, and protected their leaves against intoxication and damage. A significant decrease in the leaf gas exchange parameters (gs, E, An) was manifested on day 60 of the experiment when the cumulative NaCl intake was 300 mL per plant. The variability in the reactions of the seedlings to salinity is related to the use of open-pollinated progeny (54 genotypes) in the experiment. Lus-miR168 showed tissue- and genotype-specific genome responses to the applied stress. Polymorphic miRNA-based loci were mostly detected in the root samples on the 20th and 35th days of the experiment. The cumulative effect of the salt treatment was reflected in the predominance of polymorphic loci in the leaves. We can confirm that miRNA-based markers represent a sensitive detection tool for plant stress response on an individual level. The screening and selection of the optimal type of miRNA for this type of research is crucial. The cytochrome P450-Based Analog (PBA) techniques were unable to detect polymorphism among the control and treated seedlings, except for the primer pair CYP2BF+R, where, in the roots of the stressed plant, insertions in the amplicons were obtained. The expression ratios of cytochrome P450 in the salt-stressed plants were higher in the roots in the case of 20/100 mL and in the leaves with higher doses. The observed physiological and molecular responses to salinity reflect the potential of P. pyraster seedlings in adaptation to osmotic and ionic stress.

Exogenous melatonin induces salt and drought stress tolerance in rice by promoting plant growth and defense system

Due to global climate change, crops are certainly confronted with a lot of abiotic and biotic stress factors during their growth that cause a serious threat to their development and overall productivity. Among different abiotic stresses, salt and drought are considered the most devastating stressors with serious impact on crop’s yield stability. Here, the current study aimed to elucidate how melatonin works in regulating plant biomass, oxidative stress, antioxidant defense system, as well as the expression of genes related to salt and drought stress in rice plants. Eight groups of rice plants (3 replicates, 5 plants each) underwent varied treatments: control, melatonin, salt, drought, salt + drought, salt + melatonin, drought + melatonin, and salt + drought + melatonin. Melatonin (100 µM) was alternately applied a week before stress exposure; salt stress received 100 mM NaCl every 3 days for 3 weeks, and drought stress involved 10% PEG. Young leaves were randomly sampled from each group. The results showed that melatonin treatment markedly reduces salt and drought stress damage by promoting root, shoot length, fresh and dry weight, increasing chlorophyll contents, and inhibiting excessive production of oxidative stress markers. Salt and drought stress significantly decreased the water balance, and damaged cell membrane by reducing relative water contents and increasing electrolyte leakage. However, melatonin treated rice plants showed high relative water contents and low electrolyte leakage. Under salt and drought stress conditions, exogenous application of melatonin boosted the expression level of salt and drought stress responsive genes like OsSOS, OsNHX, OsHSF and OsDREB in rice plants. Taken together, our results reveal that melatonin treatment significantly increases salt and drought tolerance of rice plants, by increasing plant biomass, suppressing ROS accumulation, elevating antioxidants defense efficiency, and up-regulating the expression of salt and drought stress responsive genes.

Salt-excluder rootstock improves physio-biochemical responses of grafted grapevine plants subjected to salinity stress

This study tests the hypothesis that a more salt-excluder rootstock can attenuate salt stress in grapevine plants by enhancing photosynthesis and providing ionic and oxidative protection. Plants of ‘BRS Vitória’ variety, grafted with the rootstocks IAC 313 (salt-excluder) and SO4, were subjected to salinity by adding NaCl (0, 50, and 100 mM) for 30 days. Plants with SO4 showed more severe salt toxicity symptoms in leaves and lower chlorophyll content under salinity. Conversely, plants with IAC 313 showed improved photosynthesis and stomatal conductance, along with higher carboxylation efficiency under salt compared to SO4. Under salinity, plants with SO4 showed higher losses of K+ in stems, roots, and petioles, as well as increased accumulation of Na+ in these organs, relative to IAC 313. Furthermore, plants with IAC 313 had lower leaf Na+ content under salinity and reduced leaf Cl− content at 50 mM NaCl, a response associated with a higher Na+ allocation in petioles of IAC 313. At 50 mM, IAC 313 exhibited better photochemical activity, as indicated by electron transport rate and non-photochemical quenching. However, at 100 mM, both rootstocks showed similar trends, suggesting that the photosynthetic restriction was primarily due to stomatal disturbances. Plants with IAC 313 showed better APX activity and ascorbate balance under salinity. IAC 313 showed more salt-resistance traits than SO4, although the growth was similarly affected in both rootstocks. This response could be due to the reduced time of salt treatment (30 days). In summary, our data indicate that IAC 313 rootstock possesses better salt tolerance traits than SO4.

Optimization of preparation and transformation of protoplasts from Populus simonii × P. nigra leaves and subcellular localization of the major latex protein 328 (MLP328)

BackgroundPopulus simonii × P. nigra is an ideal material for studying the molecular mechanisms of woody plants. In recent years, research on Populus simonii × P. nigra has increasingly focused on the application of transgenic technology to improve salt tolerance. However, the rapid characterization of gene functions has been hampered by the long growth cycle and exceedingly poor transformation efficiency. Protoplasts are an important tool for plant gene engineering, which can assist with challenging genetic transformation and the protracted growth cycle of Populus simonii × P. nigra. This study established an optimized system for the preparation and transformation of protoplasts from Populus simonii × P. nigra leaves, making genetic research on Populus simonii × P. nigra faster and more convenient. Major Latex Protein (MLP) family genes play a crucial role in plant salt stress response. In the previous study, we discovered that PsnMLP328 can be induced by salt treatment, which suggested that this gene may be involved in response to salt stress. Protein localization is a suggestion for its function. Therefore, we conducted subcellular localization analysis using protoplasts of Populus simonii × P. nigra to study the function of the PsnMLP328 gene preliminarily.ResultsThis study established an optimized system for the preparation and transformation of Populus simonii × P. nigra protoplasts. The research results indicate that the optimal separation scheme for the protoplasts of Populus simonii × P. nigra leaves included 2.5% cellulase R-10, 0.6% macerozyme R-10, 0.3% pectolyase Y-23, and 0.8 M mannitol. After enzymatic digestion for 5 h, the yield of obtained protoplasts could reach up to 2 × 107 protoplasts/gFW, with a high viability of 98%. We carried out the subcellular localization analysis based on the optimized transient transformation system, and the results indicated that the MLP328 protein is localized in the nucleus and cytoplasm; thereby proving the effectiveness of the transformation system.ConclusionIn summary, this study successfully established an efficient system for preparing and transforming leaf protoplasts of Populus simonii × P. nigra, laying the foundation for future research on gene function and expression of Populus simonii × P. nigra.

Mitigação do estresse salino em mudas de maracujá com aplicação de H2O2

ABSTRACT Hydrogen peroxide (H2O2) can be indicated as a strategy to mitigate salt stress in plants, so the objective of this study was to evaluate the effect of different concentrations and methods of application of H2O2 as a mitigator of salt stress on the growth, physiology, and quality of seedlings of yellow passion fruit. The experiment was carried out in a protected environment (screened) belonging to UFERSA, in Caraúbas - RN, Brazil, in a randomized block design and analyzed in a 2 × 4 × 3 factorial scheme, with four replications and one plant per plot. The treatments consisted of levels of electrical conductivity of irrigation water - ECw (0.5 and 3.2 dS m-1), H2O2 concentrations (0, 12, 24, and 36 μM), and H2O2 application methods (M1 = seed soaking, M2 = foliar spraying, and M3 = seed soaking + foliar spraying). Increased levels of salinity in irrigation water negatively affect seedling quality. Hydrogen peroxide at an average concentration of 24 µM mitigates salt stress in passion fruit seedlings cv. BRS Gigante Amarelo. H2O2 application to seeds associated with foliar spraying mitigates the effects of salt stress on the absolute growth rate of the leaf area of passion fruit seedlings irrigated with an ECw of 3.2 dS m-1.

The overlooked ion: Unraveling the effects of magnesium-specific toxicity on willows under sulphate salinity

Among all the current stressors on global agricultural systems, soil salinity is one of the most significant and continues to escalate. Traditionally, sodium chloride is the salt employed for studying salt stress in plants, but for many regions, sulphates are the predominant salts that cause soil degradation and curtail agricultural production. Willow trees (Salix spp.) have been identified as potential candidates for multipurpose establishment on salinity-affected marginal agriculture fields. To compare the impacts of sodium and magnesium sulphate salts, 12 native and hybrid willow genotypes were subjected to four sodium and magnesium sulphate salt treatments for 12 weeks. Magnesium sulphate treated willows showed more significant growth impacts, and displayed treatment-specific inhibition of photosynthesis, increased disruption of mineral nutrient balance, and greater inhibition of sulphur assimilation, compared to the trees treated with same level of sodium and same treatment osmolality. In addition, it was apparent that sulphate treatments encouraged sulphur uptake and translocation to the leaves, where it was partitioned to organic sulphur, but did not pool in small organic sulphur-containing compounds. The advantages and disadvantages of two different salt tolerance strategies were compared through a case study with two native willows, a sodium excluder and a sodium accumulator.

Phytohormone Production by the Endophyte Bacillus safensis TS3 Increases Plant Yield and Alleviates Salt Stress.

Endophytic bacteria can be used to overcome the effect of salinity stress and promote plant growth and nutrient uptake. Bacillus safensis colonizes a wide range of habitats due to survival in extreme environments and unique physiological characteristics, such as a high tolerance for salt, heavy metals, and ultraviolet and gamma radiations. The aim of our study was to examine the salt resistance of the endophytic strain TS3 B. safensis and its ability to produce phytohormones and verify its effect on plant yield in field trials and the alleviation of salt stress in pot experiments. We demonstrate that the strain TS3 is capable of producing enzymes and phytohormones such as IAA, ABA and tZ. In pot experiments with radish and oat plants in salinization, the strain TS3 contributed to the partial removal of the negative effect of salinization. The compensatory effect of the strain TS3 on radish plants during salinization was 46.7%, and for oats, it was 108%. We suppose that such a pronounced effect on the plants grown and the salt stress is connected with its ability to produce phytohormones. Genome analysis of the strain TS3 showed the presence of the necessary genes for the synthesis of compounds responsible for the alleviation of the salt stress. Strain B. safensis TS3 can be considered a promising candidate for developing biofertilizer to alleviate salt stress and increase plant yield.

Diversity of halotolerant endophytes from wheat (Triticum aestivum) and their response to mitigate salt stress in plants

Soil salinity is one of the major limiting factors that decline crop production. About 20% of irrigated land soil is presently affected by high salinity worldwide reducing the crop yield by 20–50%. Endophytes play an important role in coping with the salinity stress in plants. In present study, 224 bacterial endophytes exhibiting discrete salt tolerance ranging from 0.5 M to 4.0 M were isolated from the shoot and root of wheat. Endophytic isolates showed varying salt tolerance potential and only a few (7.14%) possess the capability to tolerate high salt concentration (≥3.0 M NaCl). The 16S rRNA gene sequence exhibited 65 discrete OTUs recovered from the root (53.85%) and shoot tissue (46.15%) of the wheat plant. The 16S rRNA gene sequencing revealed the majority of phylum were Firmicutes (81.54%), Proteobacteria (13.85%), and Actinobacteria (4.62%) and dominated by Bacillus (63.08%), Priestia (13.85%), Pseudomonas (10.77%), Exiguobacterium and Curtobacterium (3.08% each). Moreover, this study is the first report for the abundance of certain bacterial species as endophytes from wheat cultivated under saline-affected regions like Bacillus australimaris, B. vallismortis, B. haynesii, Rossellomorea marisflavi, Exiguobacterium undae, Curtobacterium pusillum. The selected endophytes significantly reduced the detrimental influence of salt stress and enhanced various growth parameters like root length, shoot length, fresh weight, and dry weight of salt susceptible wheat variety ‘HD 2733’ as compared to the control. The present study might be beneficial to restore soil fertility and reduce the loss of crop productivity under saline stress conditions.

The Role of Chloride Channels in Plant Responses to NaCl.

Chloride (Cl-) is considered a crucial nutrient for plant growth, but it can be a challenge under saline conditions. Excessive accumulation of Cl- in leaves can cause toxicity. Chloride channels (CLCs) are expressed in the inner membranes of plant cells and function as essential Cl- exchangers or channels. In response to salt stress in plants, CLCs play a crucial role, and CLC proteins assist in maintaining the intracellular Cl- homeostasis by sequestering Cl- into vacuoles. Sodium chloride (NaCl) is the primary substance responsible for causing salt-induced phytotoxicity. However, research on plant responses to Cl- stress is comparatively rare, in contrast to that emphasizing Na+. This review provides a comprehensive overview of the plant response and tolerance to Cl- stress, specifically focusing on comparative analysis of CLC protein structures in different species. Additionally, to further gain insights into the underlying mechanisms, the study summarizes the identified CLC genes that respond to salt stress. This review provides a comprehensive overview of the response of CLCs in terrestrial plants to salt stress and their biological functions, aiming to gain further insights into the mechanisms underlying the response of CLCs in plants to salt stress.

Halotolerant Rhizobacteria Promote Plant Growth and Decrease Salt Stress in Carya illinoinensis (Wangenh.) K. Koch

Pecan cultivation holds significant global importance. Salinity negatively affects the physiology and metabolism of the plant. However, certain plant growth-promoting rhizobacteria (PGPR) have the ability to reduce salt stress in plants. The objective was to analyze the effects of the rhizobacteria Bacillus paralicheniformis strain LBEndo1 on the development of pecan seedlings under salinity stress conditions. Two factors were analyzed: the presence of saline stress and the bacterial inoculation. The bacterial application was conducted at a concentration of 1 × 108 CFU/mL, and irrigation was administered every third day with 80 mL of water containing 50 mM NaCl. The results show that the rhizobacteria has a maximum tolerance of 15% salinity. Furthermore, the inoculation of PGPR significantly increased the biomass of the seedlings, including the dry weight of leaves, stem, and roots, as well as the stem diameter and height. Furthermore, seedlings that interacted with the rhizobacteria exhibited superior development under saline conditions, with significant increases of 105.5% in chlorophyll concentration and 112% in proline accumulation compared to non-inoculated seedlings. Additionally, a remarkable reduction in leaf damage caused by salt stress was observed. In conclusion, the LBEndo1 rhizobacteria, being a strain resistant to salinity and possessing multiple mechanisms to promote growth while mitigating salt stress, has the potential to be utilized in pecan seedlings to alleviate stress caused by salinity and increases biomass.

Using Bacillus megaterium as a bio-fertilizer alleviates salt stress, improves phosphorus nutrition, and increases cauliflower yield

The traditional crop production system involves the use of large amounts of chemical fertilizers, which negatively impacts the ecological environment by increasing soil degradation and salinity, threatening sustainable agricultural production. Therefore, there is an urgent need for agricultural practices that increase plant productivity and reduce negative impacts on the environment. Phosphate-solubilizing microorganisms can enhance nutrient availability and plant uptake. This study investigated the effect of Bacillus megaterium as a bio-fertilizer (inoculated and non-inoculated) combined with phosphorus fertilizer (40, 60, and 80 kg. ha−1) on the growth and yield of cauliflower grown under saline conditions, saline soil (9.68 dS.m−1) and saline irrigation water (7.12 dS.m−1). Salt-stressed cauliflower inoculated with Bacillus and fertilized with 60 or 80 kg. ha−1 P2O5 showed improved growth and higher yield compared to other treatments, without significant differences between them. However, Bacillus-treated plants fertilized with 60 P2O5 showed increases in superoxide dismutase (SOD) by 29.3%, catalase (CAT) by 13.9, chlorophyll by 10.4%, N by 7.8%, and P by 8.6%, while Na decreased by 7.8%, resulting in significant increases in cauliflower yield (head weight by 9.3%, and total yield by 8.3%) compared with the control treatment (recommended P fertilizer, 80 kg P2O5. ha−1). The results indicated that the inoculation of salt-stressed plants with Bacillus megaterium is a promising and feasible approach to reduce phosphorus fertilizer use by up to 25% and enhance membrane stability (MSI), relative water content (RWC), nutrient availability, and growth performance, thus mitigating the adverse effects of salt stress exacerbated by climate change.

In-silico identification and characterization of sucrose transporter genes and their differential expression pattern under salinity stress in Glycine max

Plant sucrose transporters, involved in sugar transport, are key in facilitating sugar flux across the plant cell membranes. However, external stress stimuli significantly impact these sucrose transporters (SWEET/MST/SUT) and, ultimately, the distribution of photosynthates. This has importance as sucrose is a prime energy source, a signaling molecule, and an osmolyte playing a key role in growth and development processes. This study aims to identify and comprehensive in silico characterization and involvement of soybean sucrose transporters GlymaSWEET, GlymaMST, and GlymaSUT in plant development and salt stress responses in an important oilseed crop soybean (Glycine max L.). A genome-wide screening of soybean revealed 13 GlymaSWEET, 6 GlymaMST, and 5 GlymaSUT orthologues as confirmed from the eggNOG database. Probable sites of these proteins were found to be the membranes of cells and organelles, as suggested by their sub-cellular localization. The cis-regulatory elements of these transporters’ promoters indicated their involvement in environmental stress responses. MicroRNA interactions with these transporters were also studied, besides 3-D protein structure prediction using in silico approaches. To gain an insight into the functional divergence of GlymaSWEET, GlymaMST, and GlymaSUT transporters, qRT-PCR-based gene expression analysis was done both in control and salt-treated root and leaf tissues of two contrasting Indian soybean varieties MAUS-47 (salt-tolerant) and Gujosoya-2 (salt-sensitive). Differential gene expression was observed with varying degrees amongst the varieties and the treatments. Overall, we can conclude that the identified GlymaSWEET, GlymaMST, and GlymaSUT have the potential to be explored as candidate genes for engineering salinity stress tolerance in soybean and other plants.

Complete Genome Sequence of Pseudomonas promysalinigenes Strain RL-WG26, a PGPR Isolated from the Rice Rhizosphere for Studying the Promotion of Plant Growth Under Salt Stress

The Pseudomonas promysalinigenes strain RL-WG26, which was previously isolated from the rhizosphere of Sea Rice 86 (SR86), could promote the plant growth and alleviate the plant salt stress of SR86 by regulating the ion concentration in plants, increasing the dry weight and chlorophyll content of plants, and reducing the proline and malondialdehyde content in roots. Here, we report the complete genome sequence of Pseudomonas promysalinigenes strain RL-WG26 to lay a foundation for deciphering the molecular mechanisms of strain RL-WG26-mediated plant salt tolerance and to further the application potential of this strain. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .