Dehydrin Gene Research Articles

Drought-responsive dynamics of H3K9ac-marked 3D chromatin interactions are integrated by OsbZIP23-associated super-enhancer-like promoter regions in rice

BackgroundIn response to drought stress (DS), plants undergo complex processes that entail significant transcriptome reprogramming. However, the intricate relationship between the dynamic alterations in the three-dimensional (3D) genome and the modulation of gene co-expression in drought responses remains a relatively unexplored area.ResultsIn this study, we reconstruct high-resolution 3D genome maps based on genomic regions marked by H3K9ac, an active histone modification that dynamically responds to soil water variations in rice. We discover a genome-wide disconnection of 3D genome contact upon DS with over 10,000 chromatin loops lost, which are partially recovered in the subsequent re-watering. Loops integrating promoter–promoter interactions (PPI) contribute to gene expression in addition to basal H3K9ac modifications. Moreover, H3K9ac-marked promoter regions with high affinities in mediating PPIs, termed as super-promoter regions (SPRs), integrate spatially clustered PPIs in a super-enhancer-like manner. Interestingly, the knockout mutation of OsbZIP23, a well-defined DS-responsive transcription factor, leads to the disassociation of over 80% DS-specific PPIs and decreased expression of the corresponding genes under DS. As a case study, we show how OsbZIP23 integrates the PPI cluster formation and the co-expression of four dehydrin genes, RAB16A–D, through targeting the RAB16C SPR in a stress signaling-dependent manner.ConclusionsOur high-resolution 3D genome maps unveil the principles and details of dynamic genome folding in response to water supply variations and illustrate OsbZIP23 as an indispensable integrator of the yet unique 3D genome organization that is essential for gene co-expression under DS in rice.

Role of Trichoderma asperelloides and Trichoderma brevicompactum in improving drought tolerance in rice

Drought is considered as one of the major abiotic stresses affecting rice production under rainfed ecologies of Bangladesh hampering the country's self-sufficiency in rice production through reduced crop yield and quality. In the present study, we studied the effect of two species of plant growth promoting Trichoderma v iz; Trichoderma asperelloides and Trichoderma brevicompactum on rice plant development under drought stress and their role in inducing tolerance to drought at physiological and biochemical level. Results reveal that both species are capable of inducing plant tolerance to drought stress when tested on drought tolerant (BRRI dhan56) and drought susceptible (IR64) varieties. As the number of drought stress days increased, there was an increase in root length of both the varieties but increase in root length was more in BRRI dhan56 as compared to IR 64 when seeds of both varieties were primed with Trichoderma. There was significant change in proline, malondialdehyde (MDA), total Phenolic content (TFC), H2O2 content in Trichoderma treated versus non-treated plants for both varieties. These biochemical changes were verified with the expression of aquaporin (AQU), dehydrin (DHN) and DREB genes in both rice varieties treated with both Trichoderma species. Interaction studies of Trichoderma species with two rice genotypes suggested that AQU-2 expressed more in tolerant variety (BRRI dhan56) when primed with Trichoderma asperelloides whereas, both Trichoderma spp. up regulated the expression of DHN-4 and DREB genes in both rice genotypes under drought conditions. The present findings suggest that the both Trichoderma asperelloides and Trichoderma brevicompactum are most effective in improving drought tolerance in rice, and its prospective application will contribute to the advancement of rice genotypes to sustain crop productivity under drought stress.

Assessment of the changes in growth, photosynthetic traits and gene expression in Cynodon dactylon against drought stress

Drought stress considered a key restrictive factor for a warm-season bermudagrass growth during summers in China. Genotypic variation against drought stress exists among bermudagrass (Cynodon sp.), but the selection of highly drought-tolerant germplasm is important for its growth in limited water regions and for future breeding. Our study aimed to investigate the most tolerant bermudagrass germplasm among thirteen, along latitude and longitudinal gradient under a well-watered and drought stress condition. Current study included high drought-resistant germplasm, “Tianshui” and “Linxiang”, and drought-sensitive cultivars; “Zhengzhou” and “Cixian” under drought treatments along longitude and latitudinal gradients, respectively. Under water deficit conditions, the tolerant genotypes showed over-expression of a dehydrin gene cdDHN4, antioxidant genes Cu/ZnSOD and APX which leads to higher antioxidant activities to scavenge the excessive reactive oxygen species and minimizing the membrane damage. It helps in maintenance of cell membrane permeability and osmotic adjustment by producing organic osmolytes. Proline an osmolyte has the ability to keep osmotic water potential and water use efficiency high via stomatal conductance and maintain transpiration rate. It leads to optimum CO2 assimilation rate, high chlorophyll contents for photosynthesis and elongation of leaf mesophyll, palisade and thick spongy cells. Consequently, it results in elongation of leaf length, stolon and internode length; plant height and deep rooting system. The CdDHN4 gene highly expressed in “Tianshui” and “Youxian”, Cu/ZnSOD gene in “Tianshui” and “Linxiang” and APX gene in “Shanxian” and “Linxiang”. The genotypes “Zhongshan” and “Xiaochang” showed no gene expression under water deficit conditions. Our results indicate that turfgrass show morphological modifications firstly when subjected to drought stress; however the gene expression is directly associated and crucial for drought tolerance in bermudagrass. Hence, current research has provided excellent germplasm of drought tolerant bermudagrass for physiological and molecular study and future breeding.

Genome-wide identification and salt stress-expression analysis of the dehydrin gene family in Chenopodium quinoa

Dehydrins (DHNs) are essential proteins in the embryonic development and abiotic stress responses of plants. Due to their remarkable ability to confer tolerance to plants in conditions of drought, salinity and extreme temperatures, DHNs have garnered considerable interest. Quinoa (Chenopodium quinoa Willd.), a facultative halophyte plant, can thrive in a wide range of agroecosystems, making it a promising candidate for stress tolerance studies. In this study, we identified eleven DHN genes in the quinoa genome belonging to Y-, F- and H-orthologous groups found in angiosperms. Notably, the H-DHNs lack the K-segment, a feature observed in all Amaranthaceae species, but not in other angiosperms. We identified four DHN structural subgroups: FSKn, YnSKn, SKn-DHNs and the atypical HS-DHN. Phylogenetic analysis indicated that each structural subgroup, except for SK2-DHN, presents two paralogous genes, in accordance with the allotetraploid character of C. quinoa. Quantitative real-time PCR expression analysis revealed that DHN1s (FSK2) and DHN3s (Y2SK2) were expressed in all tissues, while DHN2s (FSK3) were predominant in roots and DHN4s (Y4SK2 and SK2) were predominant in flowers. Salt-response gene expression analysis in seedlings showed that CqDHN4s increase their expression in response to salt stress in all varieties studied, while CqDHN1s reduce their expression in a more salt stress-tolerant variety, suggesting a possible adaptive advantage. In silico analysis of the promoters of CqDHN1s and CqDHN4s supports the involvement of these DHNs in responding to abiotic stress.

Prokaryotic expression, purification, and the in vitro and in vivo protection study of dehydrin WDHN2 from Triticum aestivum.

Dehydrins proteins accumulate and play important protective roles in most plants during abiotic stresses. The objective of this study was to characterize a YSK2-type dehydrin gene, WDHN2, isolated from Triticum aestivum previously. In this work, wheat dehydrin WDHN2 was expressed in Escherichia coli and purified by immobilized metal affinity chromatography, which exhibited as a single band by sodium dodecyl sulfonate polyacrylamide gel electrophoresis and western blotting. We show that WDHN2 is capable of alleviating lactate dehydrogenase inactivation from heat and desiccation in vitro enzyme activity protection assay. In vivo assay of Escherichia coli viability demonstrates the enhancement of cell survival by the overexpression of WDHN2. The protein aggregation prevention assay explores that WDHN2 has a broad protective effect on the cellular proteome. The results show that WDHN2 is mainly accumulated in the nucleus and cytosol, suggesting that this dehydrin may exert its function in both cellular compartments. Our data suggest that WDHN2 acts as a chaperone molecular in vivo.

Dehydrin genes allelic variations in some genotypes of local wild and cultivated barley (Hordeum L.) in Syria

Dehydrin genes allelic variations in some genotypes of local wild and cultivated barley (Hordeum L.) in Syria

Water productivity and growth parameters of Fawn-tall fescue and Tekapo-orchard grass under deficit irrigation in arid zones.

This study aimed to determine the drought stress response of Fawn-tall fescue and Tekapo-orchard grass and investigate a drought stress resistance marker. Grass genotypes were grown under four Irrigation treatments I1 equivalent to 0.3 standard crop evapotranspiration (ETc), I2 equivalent to 0.65 ETc, I3 equivalent to 0.75 ETc, and I4 equivalent to 1.2 ETc. Plant height, fresh weight, dry weight were measured and the Water productivity (WP) were calculated. The results showed a reduction in the growth of both grass genotypes as the drought stress increased as indicated by the shorter plants and reduction in fresh and dry weight. However, the WP results showed that the Fawn-tall fescue endured the drought stress better than the Tekapo-orchard grass as indicated by the constant values of the plant WP across the tested irrigation treatments. The results was confirmed by the amplification of dehydrin genes where Fawn-tall fescue was found to be homozygous for dehydrin genes.

Biochemical, physiological, and molecular responses of diverse olive cultivars to different irrigation regimes

Olive is an essential industrial crop in the Mediterranean region with valuable economic and agricultural concerns. Despite its drought resistance, its productivity is restricted by extreme drought stress. Olive cultivars display considerable variation in response mechanisms to drought stress. Accordingly, the impact of mild and extreme water deprivation over two seasons compared to full irrigation requirements on growth and physiological characteristics of three diverse olive cultivars. Three olive cultivars, ‘Manzanillo’, ‘Eggizi-Shami’, and ‘Tofaahi’, were evaluated under three irrigation regimes 100% ETc, 75% ETc, and 50% ETc. Characteristics of shoot and root, as well as physio-chemical constituents, were determined. Besides, the gene expression of dehydration-responsive element binding (DREB), dehydrin (DHN), and catalase (CAT) genes in olive cultivars were explored under different irrigation regimes. The results indicated a substantial impact of irrigation level on all studied parameters. The mild and extreme drought stress treatments caused a gradual reduction in nitrogen, phosphorus, and potassium content, relative water content, root and shoot length, root and leaf numbers, branch count, and leaf area across both seasons. Conversely, proline content was considerably increased under drought treatments compared to well-watered conditions. Similarly, the assessed cultivars exhibited significant variation in all studied parameters, with ‘Eggizi-Shami’ demonstrating superiority. Under mild and extreme drought stress conditions, the cultivar ‘Eggizi-Shami’ displayed the highest proline content and most growth characteristics. Besides, the real-time quantitative PCR (RT-qPCR) analysis displayed significant alterations in gene expression of the tested three genes related to drought response (DHN, DREB, and CAT). The RT-qPCR analysis revealed that under drought stress conditions (75% and 50% ETc), ‘Eggizi-Shami’ exhibited higher expression compared to the other two cultivars (‘Tofaahi’ and ‘Manzanillo’). Combining the results of morphological and physiological parameters with gene expression analysis of drought-related genes can offer highly validated information about drought-tolerant olive cultivars. This integrated approach serves as an innovative methodology to identify and confirm genes involved in abiotic stress.

Nitric Oxide (NO) Improves Wheat Growth under Dehydration Conditions by Regulating Phytohormone Levels and Induction of the Expression of the TADHN Dehydrin Gene

Nitric oxide (NO) is a universal signaling molecule with important regulatory functions in the plant’s life cycle and adaptation to a wide spectrum of environmental stresses including drought. The effect of pre-sowing seed treatment with the donor of NO sodium nitroprusside (SNP, 200 μM) on wheat Triticum aestivum L. plants subjected to dehydration (PEG-8000, 12%) was investigated. SNP pretreatment stimulated germination and seedling growth in normal conditions and protected them under dehydration. These effects were confirmed by percentage of seed germination, changes in fresh and dry weight of 5–6-day-old seedlings, as well as by seedlings’ linear dimensions, visual appearance, and mitotic index of the root apical meristem. Assessment of the transpiration intensity (TI) and relative water content (RWC) showed that SNP pretreatment helped to maintain the water status of seedlings subjected to dehydration stress. The data obtained by enzyme-linked immunosorbent assay (ELISA) suggested that the positive effects of SNP may be due to its influence on the phytohormonal system. SNP pretreatment induced an increase in the level of indolylacetic acid (IAA) and especially cytokinins (CK), while essential changes in ABA content were not detected. Water deficiency caused a substantial increase in ABA content and a decrease in the levels of CK and IAA. Pre-sowing SNP treatment decreased stress-induced fluctuations in the content of all studied phytohormones. Using reverse-transcription PCR (RT-PCR), we obtained data on the increase in expression of the TADHN dehydrin gene in SNP-pretreated seedlings under normal and, especially, under dehydration conditions. These findings may indicate the participation of dehydrins in NO-induced defense reactions in wheat plants under water stress. Furthermore, exogenous NO had a stabilizing effect on membrane cellular structures, as evidenced by the reduction of electrolyte leakage (EL) levels and malondialdehyde (MDA) content in dehydrated wheat seedlings under the influence of pre-sowing SNP treatment.

Heterologous expression of bacterial dehydrin gene in Arabidopsis thaliana promotes abiotic stress tolerance.

The online version contains supplementary material available at 10.1007/s12298-023-01358-w.

Salt Stress Tolerance of Pyrus spp. and Cydonia oblonga Genotypes Assessed by Morphological, Biochemical and Dehydrin Gene Expression Analysis

Salt Stress Tolerance of Pyrus spp. and Cydonia oblonga Genotypes Assessed by Morphological, Biochemical and Dehydrin Gene Expression Analysis

Intrinsic disordered nature and prediction of the secondary structure in wheat dehydrins

Dehydrins are well known stress responsive proteins in plants. However, the analysis of dehydrin gene family correlating the intrinsic disordered nature with their secondary structure is lacking in wheat. The wheat genome sequence from IWGSC was used to identify 48 dehydrin genes which encode for 48 dehydrin proteins. The identified dehydrin proteins had molecular weights ranging from 9.65 kDa to 101.60 kDa. The identified proteins were named as TaDHN where Ta indicates Triticum aestivum while DHN indicated dehydrin and this was followed by predicted molecular weight and the chromosome number. PONDR database was used to predict intrinsic disordered nature in these proteins and the results revealed that all the proteins are highly disordered. Among the identified proteins, TaDHN14-6-5A showed maximum disordered nature (88.81%) whereas TaDHN28-1-6D was found to be the least disordered protein (57.25 %). The secondary structure prediction using GOR database revealed the presence of random coils, helix, sheets and turns in all the proteins. Based upon these findings, it can be asserted that this will help in genome wide analysis of dehydrins along with the functional analysis and structure modelling.

Molecular Characterization of Dehydrin in Azraq Saltbush among Related Atriplex Species

Atriplex spp. (saltbush) is known to survive extremely harsh environmental stresses such as salinity and drought. It mitigates such conditions based on specialized physiological and biochemical characteristics. Dehydrin genes (DHNs) are considered major players in this adaptation. In this study, a novel DHN gene from Azrak (Jordan) saltbush was characterized along with other Atriplex species from diverse habitats. Intronless DHN-expressed sequence tags (495-761 bp) were successfully cloned and sequenced. Saltbush dehydrins contain one S-segment followed by three K-segments: an arrangement called SK3-type. Two substantial insertions were detected including three copies of the K2-segemnet in A. canescens. New motif variants other than the six-serine standard were evident in the S-segment. AhaDHN1 (A. halimus) has a cysteine residue (SSCSSS), while AgaDHN1 (A. gardneri var. utahensis) has an isoleucine residue (SISSSS). In contrast to the conserved K1-segment, both the K2- and K3-segment showed several substitutions, particularly in AnuDHN1 (A. nummularia). In addition, a parsimony phylogenetic tree based on homologs from related genera was constructed. The phylogenetic tree resolved DHNs for all of the investigated Atriplex species in a superclade with an 85% bootstrap value. Nonetheless, the DHN isolated from Azraq saltbush was uniquely subclustred with a related genera Halimione portulacoides. The characterized DHNs revealed tremendous diversification among the Atriplex species, which opens a new venue for their functional analysis.

Intracellular trehalose modulates oxidative responses and dehydrin gene expression in Arabidopsis thaliana (L.) Heynh during dehydration

Intracellular trehalose modulates oxidative responses and dehydrin gene expression in Arabidopsis thaliana (L.) Heynh during dehydration

Accumulation of Dehydrin Transcripts Correlates with Tolerance to Drought Stress in Sunflower

Present study was focused on the analyses of phenotypic traits (across field and laboratory trials) and transcriptional changes in cotyledons and roots of sunflower hybrids, exposed to different levels of drought stress. By comparing the level of dehydrins genes (DHNs) expression in tolerant and sensitive genotypes as response to drought and of the correlations between physiologic responses in laboratory and field screening, an efficient and easily manageable experimental test system for sunflower seedlings was established. Thus, DHNs genes (Rab18-like, Xero1 and COR47-like) differentially expressed under induced hydric stress could be used as a proceeding for estimation of plant drought survival, hence, improving the pre-screening trials in the breeding programs aimed on plant tolerance to water-deficit stresses.

Isolation and Characterization of Dehydrin Gene from Egyptian Gray Mangrove in Nabq Protectorate

ABSTRACT: Dehydrins have a key role in protecting plants, especially in the grey mangrove tree Avicennia marina (Forssk.) Vierh. from salt stress. Understanding the mangrove plants at the molecular level will be necessary for developing such highly salt-tolerant crops. The full-length cDNA of the DHN gene sequence AmDHN was isolated from Avicennia marina and contained a 588bp open reading frame (ORF) encoding a 195 amino acid protein with a molecular weight of about 19.746k Da. As well as, multiple alignment sequences and phylogenetic relationships were analyzed for sequences using MEGA7 software revealing that AmDHN has a high identity with other DHNs plants and suggesting that AmDHN belongs to group II (LEA) proteins. Using bioinformatics analysis tools, we have investigated characterize and gene expression to better understand the structure and function analysis prediction of the AmDHN protein. AmDHN protein contains motifs (SYK2), Sn, Yn segment, and at least one copy of a lysine-rich conserved sequence known as K-segment (consensus EKKGIME/DKIKEKLPG) near the C terminal, the 3D predicted the structure protein sequence of the secondary structure, the top 5 final models using by I-TASSER server and several parameters computed by the software were obtained. Our results indicate that the AmDHN gene plays an essential role in salt stress remediation in the Avicennia marina. They could be used for further studies to understand the molecular mechanisms of salinity tolerance in plants and can be potentially utilized in transforming other plants to improve tolerance to salinity stress.

大白菜脱水素基因的鉴定和特征分析

大白菜脱水素基因的鉴定和特征分析

Overexpression of ZmDHN15 Enhances Cold Tolerance in Yeast and Arabidopsis.

Maize (Zea mays L.) originates from the subtropical region and is a warm-loving crop affected by low-temperature stress. Dehydrin (DHN) protein, a member of the Group 2 LEA (late embryogenesis abundant proteins) family, plays an important role in plant abiotic stress. In this study, five maize DHN genes were screened based on the previous transcriptome sequencing data in our laboratory, and we performed sequence analysis and promoter analysis on these five DHN genes. The results showed that the promoter region has many cis-acting elements related to cold stress. The significantly upregulated ZmDHN15 gene has been further screened by expression pattern analysis. The subcellular localization results show that ZmDHN15 fusion protein is localized in the cytoplasm. To verify the role of ZmDHN15 in cold stress, we overexpressed ZmDHN15 in yeast and Arabidopsis. We found that the expression of ZmDHN15 can significantly improve the cold resistance of yeast. Under cold stress, ZmDHN15-overexpressing Arabidopsis showed lower MDA content, lower relative electrolyte leakage, and less ROS (reactive oxygen species) when compared to wild-type plants, as well as higher seed germination rate, seedling survival rate, and chlorophyll content. Furthermore, analysis of the expression patterns of ROS-associated marker genes and cold-response-related genes indicated that ZmDHN15 genes play an important role in the expression of these genes. In conclusion, the overexpression of the ZmDHN15 gene can effectively improve the tolerance to cold stress in yeast and Arabidopsis. This study is important for maize germplasm innovation and the genetic improvement of crops.

Arabidopsis AtLTI30 and AtHIRD11 dehydrin genes and their contribution to cadmium tolerance in transgenic tobacco plants

Arabidopsis AtLTI30 and AtHIRD11 dehydrin genes and their contribution to cadmium tolerance in transgenic tobacco plants

Low Temperature Conditioning Reduced the Chilling Injury by Regulating Expression of the Dehydrin Genes in Postharvest Huangguan Pear (Pyrus bretschneideri Rehd. cv. Huangguan)

‘Huangguan’ pear (Pyrus bretschneideri Rehd. cv. Huangguan) fruit is sensitive to chilling injury (CI), which exhibits peel browning spots (PBS) during cold storage. Dehydrin (DHN) is considered to be related to cold tolerance in plants, but its function in postharvest pear fruit during storage remains unclear. In this study, six PbDHNs (PbDHN1–6) genes were identified and characterized, and the PbDHN proteins were sorted into YnKn, SKn and YnSKn according to the major conserved motifs related to the number and location of K-segments, S-segments, and Y-segments. In addition, there were five cold-responsive related cis-acting elements in the promoter region of the PbDHNs. The analysis of fruit quality suggested that compared with a storage temperature at 20 °C, a storage temperature of 0 °C results in CI in ‘Huangguan’ pear fruit, while a storage temperature of 10 °C and low temperature conditioning (LTC) alleviates the CI. Moreover, gene expression results indicated that the six PbDHNs were markedly enhanced at low temperatures, especially at 0 °C. The transcripts of PbDHN1, PbDHN4, PbDHN5 and PbDHN6 were also increased in the fruit stored at 10 °C, but they were lower than that at 0 °C except PbDHN5. Compared with low temperature storage at 0 °C, LTC treatment significantly depressed the expression of PbDHN1, PbDHN2, PbDHN3, PbDHN4, and PbDHN6, while enhanced the mRNA amount of PbDHN5. In conclusion, PbDHN1, PbDHN4, PbDHN5, and PbDHN6 were closely related to the CI, and LTC lowered the CI by down-regulating the expression of PbDHN1, PbDHN4, and PbDHN6 and by up-regulating PbDHN5 in ‘Huangguan’ pear fruit.