Types Of Plants Research Articles

Physiological adjustments of temperate tree species and herbs in response to low root temperatures

Abstract Hydraulic constraints induced by low root temperature might be a major cause for the low temperature limit of plants. However, up to date most of our knowledge on the physiological effects of low root temperatures derived from short-term lab experiments, with very limited information on potential adjustments to continuous low temperature stress. In this study, we quantified the cold sensitivity of root water uptake and transport to leaves in seedlings of different functional plant types (conifers, broadleaved trees and annual herbs) by 2H-H2O labelling after exposure to three constant root temperatures (15°C, 7°C and 2°C) but the same higher aboveground temperatures (between 20-25 °C). We investigated changes in the cold sensitivity of roots after 0, 10 and 20-days prolonged exposure to the respective root temperatures. Plant water uptake and transport was decreased by lowered root temperature in all species, with a stronger effect at 2°C compared to 7°C. The water uptake and transport capacity of tree species gradually declined over the 20-day treatment, while the two investigated herbs exhibited immediately strong decreases that were kept at the same low level throughout the entire experiment time. The speed of the water uptake reduction across the 20 days observation period differed among the tree species and was faster in species that reach their natural upper distribution limits at lower elevations compared to species that occur at subalpine regions. The restricted root water uptake and transport was accompanied by reductions in leaf water potential, stomatal conductance and growth. Overall, our study showed increasingly reduced capacity for water uptake and transport across functional plant groups at continuous cold root conditions. This result might indicate accumulative negative effects on cell membrane permeability for water in roots, or a controlled reduction of root water conductivity of temperate trees in preparation for winter dormancy.

Root rot in medicinal plants: a review of extensive research progress

Root rot is a general term for soil-borne diseases that cause the necrosis and decay of underground plant parts. It has a wide host range and occurs in various types of plants, including crops, horticultural crops and medicinal plants. Due to the fact that medicinal plants generally have a long growth cycle and are primarily the root and rhizome herbs. This results in root rot causing more serious damage in medicinal plant cultivation than in other plants. Infected medicinal plants have shrivel or yellowed leaves, rotting rhizomes, and even death of the entire plant, resulting in a sharp decline in yield or even total crop failure, but also seriously reduce the commercial specifications and effective ingredient content of medicinal plants. The pathogens of root rot are complex and diverse, and Fusarium fungi have been reported as the most widespread pathogen. With the expansion of medicinal plant cultivation, root rot has occurred frequently in many medicinal plants such as Araliaceae, Fabaceae, Ranunculaceae, and Solanaceae and other medicinal plants. This article reviews recent research progress on root rot in medicinal plants, covering various aspects such as disease characteristics, occurrence, pathogen species, damage to medicinal plants, disease mechanisms, control measures, and genetic factors. The aim is to provide reference for better control of root rot of medicinal plants.

Load Frequency Control Design for Complex Power Systems Implementing Integral Single-Phase Sliding Mode Control

This paper proposes a Decentralized Integral Single-phase Sliding Mode Control (DISSMC) for Load Frequency Control (LFC) in Complex Power Systems with Multi-Source generation (CPSMS), integrating reheat, hydro, gas, and wind turbines. A generalized structure is employed to model Multi-Area Linked Power Systems (MALPS), providing a realistic representation of diverse power plants. The proposed method formulates an integral Sliding Surface (SS) to mitigate the chattering phenomena and ensures finite-time stability through a continuous control law. Additionally, a single-phase technique eliminates the reaching phase, ensuring immediate trajectory control. The MATLAB/Simulink simulations validate the DISSMC's effectiveness in stabilizing frequency fluctuations and managing load variations across three interconnected regions, each hosting different power plant types. The results highlight the proposed controller's robustness and adaptability to dynamic load and renewable energy source fluctuations.

The difference of organophosphate esters (OPEs) uptake, translocation and accumulation mechanism between four varieties in Poaceae.

To explore variation patterns of uptake, translocation, and accumulation processes responding to organophosphate esters (OPEs) among Poaceae plants, hydroponic and computer simulation experiments were executed. Plant growth, OPEs' concentration, and bioinformation and transcript of lipid transporters in the three terrestrial barley, wheat, and maize and aquatic rice seedlings were studied after exposure to seven OPE congeners. Four types of plants could accumulate seven OPE congeners. OPEs could promote rice growth by upregulating IAA27 hormone gene. However, maize growth was inhibited due to upregulating IAA17 hormone gene. In general, OPEs with log Kow > 4 tended to accumulate in roots of the four types of plants. Furthermore, the uptake, translocation, and accumulation mechanism of OPEs in different plants showed species-specific, depending on chemical properties of OPEs and biological factors specifically referring to the binding ability and gene expression of lipid transporters. The uptake and accumulation of OPE in aquatic rice roots were mainly influenced by biological factors. On the contrary, terrestrial plants relied on log Kow more than biological factors. Meanwhile, TIL of Poaceae plants could be a common and key protein that contributed to OPEs accumulation.

Manipulating Propagule Type and Interrow Ground Cover to Influence Flowering Time, Yield, Fruit Quality, and Harvest Dates in the Day-neutral Strawberry ‘Albion’

We examined methods of producing day-neutral strawberries in a north temperate climate using alternatives to standard bare-root propagules and clean cultivation between plant rows. Fragaria ×ananassa ‘Albion’ were planted in plastic-covered raised beds in Ithaca, NY, USA, for each of the 2022 and 2023 growing seasons. Plants were selected from the following four propagule types from different developmental stages: standard bare-root plants set in early May; bare-root plants started in the greenhouse in February and planted in early May; bare-root plants started in the greenhouse in March and planted in early May; and plug plants set in the field in fall (Aug 2021 and Oct 2022) of the previous year. To determine if pollination could be enhanced, each type of plant was grown in plots in the field with one of the following between rows: bare ground; a diverse flowering groundcover; or exclusion netting on hoops over the strawberry plants when they were flowering. Pollinators visiting strawberries were observed weekly and identified to species when possible. Fruits were collected weekly and marketable and unmarketable yields were measured through the harvest season. Fall-planted plugs produced significantly higher marketable yields than those of other propagule types in both years. Bare-root plants set in early May had the lowest yield. Percent marketable yield varied depending on the growing year because of drastically different weather conditions. There was no evidence that flowering groundcover attracted pollinators to the strawberry plants because strawberries had few pollinator visits, regardless of the surrounding vegetation. Exclusion netting had significantly higher percent marketable yield and total yield than the those of other groundcover types despite lower percent fruit set, likely because of the benefits of tarnished plant bug exclusion.

Genetic Diversity Analysis and Comprehensive Evaluation of “M82” in EMS-Mutagenized Tomato

Background: Ethyl methyl sulfonate (EMS) mutagenesis is widely used because of its advantages of inducing point mutations and no need for genetic transformation. To identify germplasm resources of processed tomatoes with superior comprehensive traits suitable for cultivation in Xinjiang. Methods: In this study, tomato seeds were treated with 2% EMS reagent for 12 h, 21 quality traits and 20 quantitative traits of 33 processed tomatoes derived from EMS-mutagenized“M82”were evaluated. Results: The results indicated that for traits such as hypocotyl color, growth habit, plant type, leaf type, and leaf shape, the range of quantitative trait variation was 8.45–37.25%, with a genetic diversity index ranging from 1.25 to 2.07. Conclusions: Cluster analysis of quantitative traits categorized the 33 EMS-mutagenized “M82” processed tomato resources into five groups: Group I contained 22 robust germplasm samples; Group II consisted of a single potential high-quality germplasm; Group III comprised five germplasm with a small and extreme plant type; Group IV included four high-yield germplasm; and Group V represented one moderate, conventional germplasm. Raw data from 15 quantitative traits across the 33 accessions were standardized using the “extreme method” to extract six comprehensive factors. The top 10 germplasm resources based on the comprehensive score were 76, 137, 97, 102, 19, 104, 21, 108, 17, and 147. It provides some theoretical basis for realizing the high-yield and high-quality cultivation and variety breeding of processed tomatoes in Xinjiang.

Robust counting for multi-species plants based on Few-Shot learning

Accurate counting of plant organs at various growth stages is crucial for crop growth monitoring, phenotypic assessment, and yield prediction. Traditional plant counting models, typically designed for specific plant types, often exhibit poor generalization capabilities. In this research, an improved model, Field-CounTR, was proposed to accurately count multiple plant organs. The Field-Count dataset, utilizing a Few-Shot method, was introduced to enhance accuracy in plant counting. Additionally, a mixed salient module was developed to improve the feature fusion capability of sample images by exploiting their high similarity in Few-Shot counting tasks. During the downsampling process, Shuffle Attention was integrated to reduce redundant information in the feature fusion process. Furthermore, a hybrid convolution module combining Do-Conv and dilated convolutions was developed to increase the speed of convolutional inference and expand the receptive field through over-parameterized and dilation operations. To assess the effectiveness of the proposed approach, tests were conducted using the Field-Count dataset, which includes Sorghum, Wheat, Maize, and Rice. The results demonstrated a mean absolute error (MAE) of 14.49 and a root mean square error (RMSE) of 21.14. Compared with the CounTR model, the Field-CounTR model reduced the MAE and RMSE by 2.01 and 1.33, respectively. The enhanced Field-CounTR model exhibited superior feature extraction performance, high detection accuracy, and excellent generalization capabilities. This model can accurately count multiple plant types in complex field or orchard conditions and offers a wide range of applications.

Bicarbonate use reduces the photorespiration in Ottelia alismoides adapting to the CO2-fluctuated aquatic systems.

Underwater CO2 concentration fluctuates extremely in natural water bodies. Under low CO2, the unique CO2 concentrating mechanism in aquatic plants, bicarbonate use, can suppress photorespiration. However, it remains unknown (1) to what extent bicarbonate use reduces photorespiration, (2) how exactly photorespiration varies between bicarbonate-users and CO2-obligate users under CO2-fluctuated environments, and (3) what are differences in Rubisco characteristics between these two types of aquatic plants. In the present study, the bicarbonate user Ottelia alismoides and its phylogenetically close CO2-obligate user Blyxa japonica were chosen to answer these questions. The results showed that bicarbonate use saved ~13% carbon loss under low CO2 via decreasing photorespiration in O. alismoides. Through bicarbonate use, the photorespiration of O. alismoides was kept stable both under high and low underwater CO2 concentrations, while the photorespiration significantly increased in the CO2-obligate user B. japonica under low CO2. However, B. japonica showed a significantly higher photosynthesis rate than O. alsimoides when CO2 was sufficient. These differences could be related to the kinetic characteristics of Rubisco showing a higher carboxylation turnover rate (Kcat) in B. japonica, and the similar affinity to CO2 (Kc) and specificity factor (Sc/o) in these two species that might be determined by the variation of six amino acid residuals in Rubisco large subunit sequences, especially the site 281 (A vs. S) and 282 (H vs. F). All these differences in photorespiration and kinetic characteristics of Rubisco could explain the distribution patterns of bicarbonate users and CO2-obligate users in the field.

Response of an obligate CAM plant to competition and increased watering intervals.

Climate change has exacerbated precipitation variability, profoundly impacting vegetation dynamics and community structures in arid ecosystems. There remains a notable knowledge gap regarding the ecological effects of altered precipitation on crassulacean acid metabolism (CAM) plants and their interactions with other photosynthetic types. This study investigated the response of the typical obligate CAM plant Orostachys fimbriata to extended watering intervals (WI4-WI8) and various competitive patterns (M1-M4) with the C3 grass Melilotus officinalis and the C4 grass Setaria viridis through greenhouse experiments. The results showed that: (1) In species mixtures, CAM plants had slightly reduced the total biomass (TB) compared to monocultures, yet maintained competitiveness by increasing the root-to-shoot biomass (R:S) ratio, stabilizing plant height, and sustaining their photosynthetic rates. (2) As watering intervals increased, CAM plants adapted by further elevating the R:S ratio, reducing height, and decreasing aboveground biomass. However, their height, CO2 assimilation rate, and above- and below-ground biomass were significantly suppressed, particularly when coexisting with C4 plants. More extreme watering regime caused a 47.6% decrease in TB of CAM plants in M4, while C3 and C4 grasses declined by 53.2% and 37.8%, respectively. (3) Given the predicted extension of drought intervals and the intensification of individual rainfall events under future climate conditions, the competitive pressure from C4 plants with high drought tolerance and resource acquisition advantages may limit the expansion potential of CAM plants in drylands. This study enhances the understanding of adaptive mechanisms of CAM plants competing and coexisting with grasses under variable environments, providing scientific bases for predicting arid ecosystem dynamics.

Correlations of gene expression, codon usage bias, and evolutionary rates of the mitochondrial genome show tissue differentiation in Ophioglossum vulgatum.

Mitochondria are crucial for energy production in plant tissues, but their quantity and activity vary in different tissues and developmental processes. Determining the factors underlying differential molecular evolutionary rates has long been a central question in evolutionary biology, with expression level emerging as the prime predictor. Although we have previously observed an anti-correlation between expression level (E) and evolutionary rate (R) in chloroplast genes, it remains unclear whether such an anti-correlation exists in plant mitochondrial genes. Ophioglossum vulgatum is a typical plant belonging to the Ophioglossaceae, characterized by its unique morphology with only a single leaf above ground. It holds significant scientific and medicinal value. Using the mitochondrial genome and transcriptome data of O. vulgatum, we first analyzed the correlation between mitochondrial gene expression, codon usage bias, and evolutionary rates in different tissues. Our findings indicated that mitochondrial gene expression level was the strongest between stem and leaf, while the weakest was between sporangium and root. Kruskal-Wallis tests revealed significant differences across various tissue types. Codon usage bias was influenced by both mutation and selection, with selection exerting a greater impact. The Spearman's rank correlation coefficients between codon adaptation index and expression levels of sporangium, stem, leaf, and root were 0.1178, 0.3926, 0.4463, and 0.2945, respectively, with significance in stem and leaf (P < 0.05). The correlation coefficients between the nonsynonymous substitution rate (dN) and expression levels in sporangium, stem, leaf, and root were -0.0840, -0.1786, -0.1714, and -0.0857, respectively, yet none are statistically significant. The correlation coefficient between the synonymous substitution rate (dS) and expression levels in sporangium was negative, whereas those between dS and the stem, leaf, and root were positive, although they were not significant. The dN/dS ratio exhibited a significant negative correlation with expression levels in both leaf and root (P < 0.05). For the first time, our study revealed differences in the correlation between mitochondrial gene expression and codon usage bias, as well as evolutionary rates, across various tissues of O. vulgatum. Moreover, we also provide novel insights into understanding the effects of plant mitochondrial gene expression on evolutionary patterns.

Multi-objective optimization and posteriori multi-criteria decision making on an integrative solid oxide fuel cell cooling, heating and power system with semi-empirical model-driven co-simulation

An integrative solid oxide fuel cell combined cooling, heating and power system in green buildings with hydrogen energy of byproduct water enables carbon neutrality transformation. However, underlying mechanisms on capacity sizing of combined cooling, heating and power system devices and its impacts on system techno-economy have not been figured out especially considering dynamic degradation and efficiency of associated devices. In this study, a multi-software optimization platform is established by MATLAB-TRNSYS co-simulation for sizing parametrical analysis, with well balance of modelling complexity and computational efficiency. A self-sufficient combined cooling, heating and power system is modelled integrating with a semi-empirical surrogate model of solid oxide fuel cell to interact with other balance of plant types efficiently. Total energy efficiency and annual total cost are optimized through parametrical analysis on device size of each component (battery, electrolyzer and solid oxide fuel cell) and analysis of variance for contribution ratio quantification. Results indicate that, the size increase in electrolyzer and solid oxide fuel cell will improve system total energy efficiency by 13.635 % and 2.194 %, but promote annual total cost by 4.042 × 104 $ and 2.389 × 103 $, respectively. Besides, sensitivity analysis indicates that the electrolyzer size prioritizes other design parameters in techno-economic performance. Optimal sizes of battery, electrolyzer and solid oxide fuel cell are in cell number range of 333 – 403, 17 – 20, and 26 – 30, respectively, with corresponding optimal total energy efficiency and annual total cost at 70.861 % – 72.147 % and 6.723 × 104 $ – 7.325 × 104 $, respectively. The research results can provide guidance on hydrogen-based cooling, heating and power system design and operation with techno-economic feasibility for low-carbon district energy transition.

Retrieval of nicotine content in cigar leaves by remote analysis of aerial hyperspectral combining machine learning methods

Cigar leaf is a special type of tobacco plant, which is the raw material for producing high-quality cigars. The content and proportion of nicotine and other composite substances of cigar leaves have a crucial impact on their quality and vary greatly with the time of harvest. Hyperspectral remote sensing technology has been widely used in the field of crop monitoring because of its advantages of large area coverage, fast information acquisition, short cycle turnover, strong real-time performance and high efficiency. Therefore, it is important to accurately monitor nicotine content of field crops in a timely manner in the production of high-quality cigar leaf. To this end, this study set out to measure crop reflectance spectra acquired by UAV drones from tobacco field crops by hyperspectral image acquisition. MSC, SG, and SNV were combined and applied to the raw data. The output of these operations was then further processed by CARS, SPA, and UVE algorithms to determine the nicotine sensitive bands. Three machine learning algorithms were then used to analyze the data: PLS, BP, RF, and the SVM. An inversion model of the content of nicotine was established, and the model was evaluated for accuracy. The main research conclusions are as follows: (1) With the increase in the rate of application of nitrogen fertilizer, the nicotine content of cigar leaves increased; (2) Processing data by the CARS, SPA, and UVE methods reduces the degree of data redundancy and information co-linearity in the screening of the content of nicotine sensitive bands; (3) The MSC-SNV-SG-CARS-BP model has the best predictive accuracy on the nicotine content. The prediction accuracy of the testing set was R2 = 0.797, RMSE = 0.078,RPD = 2.182.

Soil-to-plant transfer factors of radium for different types of plants as influenced by clay content, organic matter content and radium partition in the soil

Soil-to-plant transfer factors of radium for different types of plants as influenced by clay content, organic matter content and radium partition in the soil

The TCP transcription factor TAC8 positively regulates the tiller angle in rice (Oryza sativa L.).

The tiller angle, one of the critical factors that determine the rice plant type, is closely related to rice yield. An appropriate rice tiller angle can improve rice photosynthetic efficiency and increase yields. In this study, we identified a transcription factor, TILLRE ANGLE CONTROL 8 (TAC8), that is highly expressed in the rice tiller base and positively regulates the tiller angle by regulating cell length and endogenous auxin content; TAC8 encodes a TEOSINTE BRANCHED1/CYCLOIDEA/PCF transcriptional activator that is highly expressed in the nucleus. RNA-seq revealed that TAC8 is involved mainly in the photoperiod and abiotic stress response in rice. Yeast two-hybrid assays verified that TAC8 interacts with CHLOROPHYLL A/B-BINDING PROTEIN 1, which responds to photoperiod, and haplotype analysis revealed that a 34-bp deletion at position 1516 in the promoter region and a 9-bp deletion at position 153 in the coding region can result in impaired function or loss of function of TAC8. This study provides a new genetic resource for designing ideal plant types with appropriate rice tiller angle.

Respon Pertumbuhan Dan Produksi Tanaman Siomak (Lactuca Sativa L.) Pada Variasi Media Tanam Dan Pupuk Urin Kelinci

Siomak is a type of lettuce plant that has a slightly different leaf shape from lettuce plants in general. This research aims to determine the interaction between planting media treatment and rabbit urine fertilizer concentration on the growth and yield of siomak plants. This research was carried out from April to May 2022 in Rejomulyo Village, Kras District, Kediri Regency, East Java Province. This research used a factorial completely randomized design (CRD) with two factors. The first factor is the planting medium (M), while the second factor is the concentration of rabbit urine fertilizer (K). The results of this research show that the M2K4 treatment combination (planting media ratio 2:1:3 + 40 ml/L urine fertilizer) is the treatment combination with the best results in the observation variables of number of leaves and wet weight per plant. The combination of M2K2 treatment (planting media ratio 2:1:3 +20 ml/L urine fertilizer) is the combination with the best results in increasing the root length of siomak plants. The single treatment of M2 planting media (planting media ratio 2:1:3) showed better results than the results of treatment M1 (planting media ratio 2:1:2) significantly in the observation variables of plant height, number of leaves, leaf area and root volume. . K4 treatment (urine fertilizer 40 ml/L) is the most effective and efficient concentration in increasing plant height and leaf area growth. The results of observing the root volume of the K5 treatment (50 ml/L urine fertilizer) showed the best results.

Kajian Revegetasi Pada Aktivitas Reklamasi Lahan Bekas Tambang Batubara

Before carrying out mining, it must take into account the impact of mining activities, namely changes in the landscape, it is necessary to re-vegetate and replant. This research was conducted to find out and provide a solution to the problem of revegetation failure that often occurs to achieve revegetation success and to identify and improve the factors that cause many dead plants. The location of this research was conducted in Bantuas Village, Palarang District, Samarinda Municipality, East Kalimantan Province, the data collection technique was carried out by direct collection in the field by taking data on plant types and soil pH, data processing was carried out by processing the collected data by entering data into in excel software aims to make the data neatly arranged and the data analysis method used is qualitative. There are several factors that cause plants to die, namely due to an error in selecting plant species and not paying attention to acidic soil pH. The way to overcome this is by choosing plant types that are suitable for the revegetation area and using dolomite to neutralize acidic soil pH and to achieve success it is necessary to pay attention to plant types, maintenance, planting preparation, monitoring.

Defects in the Metal of Welded Joints of Collectors to Steam Generators in Nuclear Power Plants

This article presents a study of the metal of coolant collectors' welded joints to steam generators in nuclear power plants. During the operation of nuclear power plants of the VVER-1000 type, metal defects were found in the collectors' welds to the steam generator body. The general cause for the defects' occurrence and development is the combination of: 1) the influencing stresses, and 2) the corrosively aggressive working environment. The specific manifestation and development of defects differs across different NPPs. This study focuses on examining the on-site working conditions. It describes observations on the occurrence and development of defects in the metal of the welded joints and possible facility degradation scenarios. The resulting data come from actual observations spanning a 30-year-period. This information is important for the safe operation of steam generators in NPPs. The data can be used for probabilistic safety analyses at NPPs as well as for NPP lifetime extension.

Assessing and optimizing the potential for climate change mitigation and carbon sequestration in urban residential green spaces: energizing sustainable cities

IntroductionUrban green spaces play a crucial role in mitigating climate change by sequestering atmospheric carbon dioxide. This study aimed to evaluate the carbon sequestration potential of common plant species in urban residential areas and provide recommendations for optimizing green space design and management.MethodsThe research was conducted in four residential areas of Nanjing, China, where key growth parameters of 20 plant species, including evergreen trees, deciduous trees, evergreen shrubs, and deciduous shrubs, were measured. The assimilation method was employed to calculate carbon sequestration per unit canopy area and for entire plants.ResultsThe results showed that the carbon sequestration capacities of different plant species and types exhibited significant differences, with p-values less than 0.05. In terms of daily carbon sequestration per unit canopy projection area, the ranking was as follows: evergreen trees &amp;gt; evergreen shrubs &amp;gt; deciduous trees &amp;gt; deciduous shrubs. For total plant carbon sequestration, the ranking was: evergreen trees &amp;gt; deciduous trees &amp;gt; evergreen shrubs &amp;gt; deciduous shrubs. Evergreen trees performed excellently in both carbon sequestration metrics, with the average daily carbon sequestration per unit canopy projection area and for the entire plant being 18.0024 g/(m2·d) and 462.28 g/d, respectively. The study also observed seasonal variations, with carbon sequestration rates being higher in autumn and summer compared to spring and winter. During the summer, the average daily carbon sequestration per unit canopy projection area and for the entire plant were 11.975 g/(m2·d) and 161.744 g/d, respectively, while in autumn, these values were 13.886 g/(m2·d) and 98.458 g/d. Seasonal variations were also observed, with autumn and summer exhibiting higher carbon sequestration rates compared to spring and winter. Additionally, CO2 concentrations were monitored across the four residential areas, providing insights into the spatial and temporal dynamics of carbon sequestration.DiscussionBased on the findings, optimization strategies were proposed, such as prioritizing the selection and integration of high-performing evergreen tree species in urban green space design and incorporating diverse plant types to enhance year-round carbon sequestration. This study contributes to the development of sustainable urban planning and landscape management practices, promoting the role of green spaces in mitigating climate change and enhancing urban resilience.

Typical tetra-mediated signaling and plant architectural changes regulate salt-stress tolerance in indica rice genotypes.

Upon exposure to salt stress, calcium signaling in plants activates various stress-responsive genes and proteins along with enhancement in antioxidant defense to eventually regulate the cellular homeostasis for reducing cytosolic sodium levels. The coordination among the calcium signaling molecules and transporters plays a crucial role in salinity tolerance. In the present study, twenty-one diverse indigenous rice genotypes were evaluated for salt tolerance during the early seedling stage, and out of that nine genotypes were further selected for physio-biochemical study. Further analysis identified potential salt-tolerant and salt-sensitive genotypes with tolerant lines exhibiting lower Na+/K+ ratio. Plant phenotype clearly documented the root architectural changes among the most salt-tolerant and sensitive genotypes, while the histo-biochemical DAB and NBT staining and in-gel SOD activity clearly revealed the differential ROS accumulation between the contrasting genotypes and their antioxidant activity. Ultrastructural study depicted stronger UV autofluorescence in the hypodermal and vascular bundle regions, while phloroglucinol staining displayed intense coloration in the vascular bundle region of Bhutmuri, the salt-tolerant genotype, compared to Manipuri Black, the salt-sensitive one showing differential lignification among the contrasting genotype to combat salt stress. Based on expression study, our proposed model depicted immediate upregulation (short-term) of OsSOS3 and OsNHX1 along with gradual upregulation of OsHKT and downregulation of OsSOS1 throughout the stress period to protect the tolerant plant through signaling cascade, while the inadequate upregulation of OsSOS3, OsNHX1, and OsHKT under early stress, coupled with poor coordination between the expression of OsSOS1 and OsSOS3 genes, makes the plant salt sensitive.

Interaction between arbuscular mycorrhizal fungi and dark septate endophytes in the root systems of Populus euphratica and Haloxylon ammodendron under different drought conditions in Xinjiang, China

Background and AimsArbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) are known to enhance the tolerance of host plants to biotic and abiotic stresses, but the mechanism of their interaction under natural conditions has not been extensively studied.MethodsWe analyzed the endophytic fungal diversity and colonization characteristics in the typical desert plants Populus euphratica and Haloxylon ammodendron and the relationship between them and environmental factors.ResultsExcept for DSE in the roots of H. ammodendron, the colonization rates of AMF and DSE were significantly positively correlated with drought severity. The abundance of AMF and DSE under medium and mild drought conditions was greater than that under severe drought conditions. The root colonization rate and abundance of AMF were lower than those of DSE under the same drought conditions. The species diversity and abundance of AMF and DSE in P. euphratica were greater than those in H. ammodendron. AMF were more susceptible to soil factors such as soil water content, soil nitrogen and phosphorus content, and urease, whereas DSE were more affected by pH.ConclusionDrought stress has different effects on AMF and DSE in the roots of P. euphratica and H. ammodendron. DSE have a greater advantage in extremely arid environments. This study demonstrates the interaction between AMF and DSE with the host plants P. euphratica and H. ammodendron as well as their effects on the adaptation of host plants to the desert environment, which can provide a basis for strengthening desert vegetation management.