Search Results (49)

Glycyrrhiza uralensis is an important medicinal plant exhibiting strong tolerance to abiotic stresses, including drought and salinity. DREB (Dehydration-Responsive Element-Binding) transcription factors, key members of the AP2/ERF family, play crucial roles in plant growth, development, and stress responses. Based on transcriptome data, we identified 18 DREB transcription factors in G. uralensis, designated GuDREB1 to GuDREB18. Bioinformatics analysis revealed genomic sequences ranging from 534 to 2864 bp and coding sequence (CDS) lengths between 525 and 1509 bp. All GuDREB proteins contain a single AP2 domain, including the conserved YRG and RAYD elements, and were predicted to localize to the nucleus. Phylogenetic analysis clustered the G. uralensis DREBs with 61 Arabidopsis thaliana DREBs into five subgroups, indicating evolutionary conservation. Promoter analysis detected seventeen stress-responsive cis-acting elements, encompassing hormone-responsive and abiotic stress-responsive motifs, suggesting diverse biological functions. Tissue-specific expression profiling revealed GuDREB transcription in both aerial and underground parts. Drought stress induced varying degrees of GuDREB expression, confirming their involvement in stress responses. Notably, GuDREB10 expression increased significantly in underground parts, while GuDREB15 showed pronounced upregulation in aerial parts under drought; the GuDREB15 promoter contained the highest number of light-responsive elements (23), potentially explaining its aerial tissue specificity. Drought stress significantly increased abscisic acid (ABA) content. Underground parts exhibited higher initial sensitivity to drought, whereas aerial parts displayed a more sustained response; ABA levels overall showed an initial increase followed by a decline. This study expands the G. uralensis DREB gene database, provides a foundation for selecting stress-resistance genes, and offers insights into DREB functional roles in abiotic stress responses in this key medicinal species. Full article

Rice (Oryza sativa), a crucial global staple, grapples with environmental stress and resource constraints, necessitating sustainable farming. This review explores the transformative role of transcription factors (TFs) in revolutionizing rice agriculture and their potential impact on global food security. It underscores TFs’ pivotal role in gene expression, particularly in responding to environmental stimuli, presenting a promising avenue for enhancing rice resilience. Delving into key TF families in rice, it highlights their multifaceted roles in abiotic stress responses, defense mechanisms, yield improvement, nutrient uptake, seed development, photosynthesis, and flowering regulation. Specific TFs, including DREB (Dehydration-Responsive Element-Binding), WRKY, NAC, MYB (Myeloblastosis), AP2/ERF (APETALA2/Ethylene Responsive Factor), and bHLH (basic Helix–Loop–Helix), are examined for their contributions to stress resilience, defense mechanisms, and yield enhancement. Concrete examples from cutting-edge research illustrate the tangible benefits of harnessing these molecular regulators. However, manipulating TFs presents challenges, necessitating innovative approaches such as predictive models, collaborative field testing, and transparent communication to navigate intricate regulatory networks and regulatory hurdles. Ultimately, a promising future emerges where manipulating rice TFs leads to the development of resilient, high-yielding, and nutritious varieties. Embracing research advancements and addressing existing challenges is imperative to unlock the full potential of these concealed regulators, ensuring sustainable food security for a growing global population. Full article

Dehydration response element binding proteins (DREBs) have been identified as major regulators of cold acclimatization in many angiosperms. Cold stress is one of the primary abiotic stresses affecting kiwifruit growth and development. However, kiwifruit is currently one of the most widely consumed fruits worldwide because of its high nutritional value. 5-Aminolevulinic acid (5-ALA) is a nonprotein amino acid known for its distinct promotional effects on plant resistance, growth, and development. However, studies on the function of the kiwifruit DREB gene in alleviating low-temperature stress in its seedlings via exogenous 5-ALA have not been reported. Therefore, in this study, we performed a genome-wide identification of DREB gene family members in kiwifruit and analyzed the regulatory effects of exogenous 5-ALA on kiwifruit DREB genes under low-temperature stress. A total of 193 DREB genes were identified on 29 chromosomes. Phylogenetic analysis classified these genes into six subfamilies. Although there were some differences in cis-elements among subfamilies, all of them contained more biotic or abiotic stresses and hormone-related cis-acting elements. GO and KEGG enrichment analyses revealed that AcDREB plays an essential role in hormone signaling, metabolic processes, and the response to adverse stress. Under low-temperature stress, the application of exogenous 5-ALA inhibited the accumulation of APX and DHAR, promoted an increase in chlorophyll, and increased the accumulation of enzymes and substances such as 5-ALA, MDHAR, GR, ASA, GAH, and GSSH, thereby accelerating ROS scavenging and increasing the cold hardiness of kiwifruits. Functional analysis revealed that 46 differentially expressed DREB genes, especially those encoding AcDREB69, AcDREB92, and AcDREB148, which are involved in ethylene signaling and defense signaling, and, after the transcription of downstream target genes is activated, are involved in the regulation of low-temperature-stressed kiwifruits by exogenous 5-ALA, thus improving the cold tolerance of kiwifruits. Notably, AcDREB69, AcDREB92, and AcDREB148 could serve as key genes for cold tolerance. This study is the first to investigate the function of AcDREB genes involved in the role of exogenous 5-ALA in regulating low-temperature stress, revealing the regulatory mechanism by which DREB is involved in the ability of exogenous 5-ALA to alleviate low-temperature stress. Full article

Rice genome encodes ten OsDREB1 proteins that regulate tolerance to abiotic stresses such as cold and drought. OsDREB1s can bind to the C-repeat (CRT) element, dehydration response element (DRE), and GCC-box in gene promoters for transcription regulation. However, the recognition mechanism of OsDREB1s to these DNA elements remains unclear. Here, the structures of OsDREB1s were modelled using AlphaFold 3, which revealed a typical AP2 domain and a disordered KRP/RAGR motif adjacent to AP2 in all OsDREB1s. Structure modeling of OsDREB1A binding to CRT, DRE, and GCC-box showed that four Arg residues and a Glu (E66) from AP2 play important roles in binding to the major groove of DNA, while R40 in the KRP/RAGR motif was predicted to interact with the minor groove. The structure models revealed a few differences in the binding details for CRT, DRE, and GCC-box. Consistent with these predictions, OsDREB1A was evidenced to bind with the three DNA elements in slightly different affinities through EMSA experiments. Mutation analysis verified the key role of R40 and E66 in binding to CRT. Considering the highly conserved structure and sequence of the KRP/RAGR motif and AP2, we speculate that the DNA recognition mechanism found for OsDREB1A may be common for all OsDREB1s. Full article

The APETALA2/ethylene response factor (AP2/ERF) is a class of plant-specific transcription factors, among which the dehydration-responsive element-binding protein (DREB) subfamily has been widely reported to enhance plant resistance to abiotic stresses. A high-temperature-related gene, Apium graveolens DREBA6b (AgDREBA6b; accession number: OR727346), was previously cloned from a heat-tolerant celery variety. In this study, we transformed this gene into Arabidopsis thaliana using an Agrobacterium rhizogenes-mediated method to explore its function. The results showed that overexpressing AgDREBA6b in Arabidopsis thaliana significantly improved plant growth under high-temperature stress (38 °C) compared to the dreb mutant and wild-type (WT) plants. The anatomical structure of the leaves revealed that the number and degree of stomatal openings in the overexpressed plants were significantly higher than those in the WT and dreb plants, suggesting that AgDREBA6b enhances stomatal opening. Additionally, the chlorophyll content, chlorophyll fluorescence properties, proline (Pro), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activities were higher in the transgenic plants, indicating better stress tolerance. qPCR analysis showed that four heat tolerance-related genes (AtHSP98.7, AtHSP70-1, AtAPX1, and AtGOLS1) were upregulated in the transgenic plants, with higher expression levels than in WT and mutant plants. This study provides valuable genetic resources for understanding the molecular mechanisms of celery’s heat tolerance and offers insights for breeding heat-tolerant celery varieties. Full article

Dehydration-responsive element-binding (DREB) transcription factors are ubiquitous in plants and regulate plant growth, development, signal transduction, and responses to stress, particularly drought stress. However, DREB genes in flax have not previously been studied. This study conducted a comprehensive and systematic analysis of the DREB gene family in flax (Linum usitatissimum L.). A total of 59 LuDREB genes were identified in Longya-10 (a breeding variety), with an uneven distribution across all 15 chromosomes. Further analysis revealed significant variations among LuDREB members, with predictions indicating that these proteins are hydrophilic and localized in the nucleus and cytoplasm. A phylogenetic analysis classified the LuDREB genes into six subgroups, a classification further supported by gene structure and motif composition. Members within the same subgroup exhibited structural conservation, suggesting functional redundancy. The duplication analysis identified 30 pairs of segmentally duplicated LuDREB genes and one pair of tandemly duplicated genes, indicating that segmental duplication was the primary driver of LuDREB gene expansion. A comparative collinearity analysis revealed that most LuDREB genes had orthologs in other plant species, suggesting that this gene family has remained relatively conserved throughout evolution. Cis-acting element analysis identified numerous hormone- and stress-responsive elements in LuDREB promoters, and the quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) results confirmed the role of all LuDREB genes in drought stress response. In addition, transcriptome analysis revealed that LuDREB49 and LuDREB56 exhibited high expression levels in the capsules, whereas LuDREB3 and LuDREB36 showed significantly higher expression levels in the stems, suggesting that these LuDREB genes may have specialized functions in capsule or stem development. Collectively, this study provides a comprehensive overview of LuDREB genes, offering valuable insights into their roles in flax growth, development, and stress responses. Full article

Salinity causes widespread crop loss and prompts plants to adapt through changes in gene expression. In this study, we aimed to investigate the function of the non-tandem CCCH zinc-finger (non-TZF) protein gene AtC3H3 in response to salt stress in Arabidopsis. AtC3H3, a gene from the non-TZF gene family known for its RNA-binding and RNase activities, was up-regulated under osmotic stress, such as high salt and drought. When overexpressed in Arabidopsis, AtC3H3 improved tolerance to salt stress, but not drought stress. The expression of well-known abscisic acid (ABA)-dependent salt stress-responsive genes, namely Responsive to Desiccation 29B (RD29B), RD22, and Responsive to ABA 18 (RAB18), and representative ABA-independent salt stress-responsive genes, namely Dehydration-Responsive Element Binding protein 2A (DREB2A) and DREB2B, was significantly higher in AtC3H3-overexpressing transgenic plants (AtC3H3 OXs) than in wild-type plants (WT) under NaCl treatment, indicating its significance in both ABA-dependent and -independent signal transduction pathways. mRNA-sequencing (mRNA-Seq) analysis using NaCl-treated WT and AtC3H3 OXs revealed no potential target mRNAs for the RNase function of AtC3H3, suggesting that the potential targets of AtC3H3 might be noncoding RNAs and not mRNAs. Through this study, we conclusively demonstrated that AtC3H3 plays a crucial role in salt stress tolerance by influencing the expression of salt stress-responsive genes. These findings offer new insights into plant stress response mechanisms and suggest potential strategies for improving crop resilience to salinity stress. Full article

Bananas are one of the most important cash crops in the tropics and subtropics. Drought and low-temperature stress affect the growth of banana. The DREB (dehydration responsive element binding protein) gene family, as one of the major transcription factor families, plays crucial roles in defense against abiotic stress. Currently, systematic analyses of the banana DREB (MaDREB) gene family have not yet been reported. In this study, 103 members of the MaDREB gene family were identified in the banana genome. In addition, transcriptomic analysis results revealed that MaDREBs responded to drought and cold stress. The expression of MaDREB14/22/51 was induced by drought and cold stress; these geneswere selected for further analysis. The qRT-PCR validation results confirmed the transcriptome results. Additionally, transgenic Arabidopsis plants overexpressing MaDREB14/22/51 exhibited enhanced resistance to drought and cold stress by reducing MDA content and increasing PRO and soluble sugar content. This study enhances our understanding of the function of the MaDREB gene family, provides new insights into their regulatory role under abiotic stress, and lays a good foundation for improving drought and cold stress-tolerant banana verities. Full article

Drought poses a significant challenge to plant growth and productivity, particularly in arid regions like northern Kazakhstan. Dehydration-responsive element-binding (DREB) transcription factors play an important role in plant response to drought and other abiotic stresses. In Arabidopsis thaliana, the DREB subfamily consists of six groups, designated DREB1 to DREB6. Among these, DREB2 is primarily associated with drought and salinity tolerance. In the chickpea genome, two DREB genes, CaDREB2c and CaDREB2h, have been identified, exhibiting high sequence similarity to Arabidopsis DREB2 genes. We investigated the nucleotide sequences of CaDREB2c and CaDREB2h genes in several chickpea cultivars commonly grown in northern Kazakhstan. Interestingly, the CaDREB2h gene sequence was identical across all varieties and corresponded to the sequence deposited in the GenBank. However, the CaDREB2c gene sequence exhibited variations among the studied varieties, categorized into three groups: the first group (I), comprising 20 cultivars, contained a CaDREB2c gene sequence identical to the GenBank (Indian cultivar CDC Frontier). The second group (II), consisting of 4 cultivars, had a single synonymous substitution (T to C) compared to the deposited CaDREB2c gene sequence. The third group, encompassing 5 cultivars, displayed one synonymous substitution (C to T) and two non-synonymous substitutions (G to T and G to A). Furthermore, we assessed the gene expression patterns of CaDREB2c and CaDREB2h in different chickpea varieties under drought conditions. Chickpea cultivars 8 (III), 37 (I), 6 (III), and 43 (I) exhibited the highest drought resistance. Our analysis revealed a strong positive correlation between drought resistance and CaDREB2h gene expression under drought stress. Our findings suggest that the chickpea’s adaptive responses to water deprivation are associated with changes in CaDREB2 gene expression. To further elucidate the mechanisms underlying drought tolerance, we propose future research directions that will delve into the molecular interactions and downstream targets of CaDREB2 genes. Full article

The NAC family of transcription factors (TFs) regulate plant development and abiotic stress. However, the specific function and response mechanism of NAC TFs that increase drought resistance in Picea wilsonii remain largely unknown. In this study, we functionally characterized a member of the PwNAC family known as PwNAC31. PwNAC31 is a nuclear-localized protein with transcriptional activation activity and contains an NAC domain that shows extensive homology with ANAC072 in Arabidopsis. The expression level of PwNAC31 is significantly upregulated under drought and ABA treatments. The heterologous expression of PwNAC31 in atnac072 Arabidopsis mutants enhances the seed vigor and germination rates and restores the hypersensitive phenotype of atnac072 under drought stress, accompanied by the up-regulated expression of drought-responsive genes such as DREB2A (DEHYDRATION-RESPONSIVE ELEMENT BINDING PROTEIN 2A) and ERD1 (EARLY RESPONSIVE TO DEHYDRATION STRESS 1). Yeast two-hybrid and bimolecular fluorescence complementation assays confirmed that PwNAC31 interacts with DREB2A and ABF3 (ABSCISIC ACID-RESPONSIVE ELEMENT-BINDING FACTOR 3). Yeast one-hybrid and dual-luciferase assays showed that PwNAC31, together with its interaction protein DREB2A, directly regulated the expression of ERD1 by binding to the DRE element of the ERD1 promoter. Collectively, our study provides evidence that PwNAC31 activates ERD1 by interacting with DREB2A to enhance drought tolerance in transgenic Arabidopsis. Full article

Mediator is a multiprotein complex integral to the transcription machinery, mediated by RNA polymerase II. Some Mediator subunits have been found to have critical functions in plants’ responses to abiotic stresses. However, the role of plant Mediator subunits in drought responses remains largely enigmatic. Here, we identified a Mediator subunit, RhMED15a, in roses (Rosa hybrida). Its expression was greatly and swiftly induced by dehydration treatment in the root. The promoter sequence of RhMED15a contains cis-acting elements that respond to abscisic acid (ABA) and methyl jasmonate (MeJA). In addition, the expression of RhMED15a was significantly up-regulated with ABA treatment and inversely down-regulated with MeJA treatment. Silencing RhMED15a using virus-induced gene silencing (VIGS) in roses significantly reduced drought tolerance in rose plants. This resulted in a significant increase in the malondialdehyde (MDA) level and a decreased survival rate in comparison to TRV controls. Moreover, we found that the expression of five drought-related genes, including dehydration responsive element binding factor 1B (DREB1B), responsive to desiccation stress 29A (RD29A), responsive to desiccation stress 29B (RD29B), early response to dehydration 14 (ERD14), and 9-cis-epoxycarotenoid dioxygenase 1 (NCED1), was considerably suppressed in RhMED15a-silenced plants during drought stress. Taken together, our results present that the Mediator tail module subunit RhMED15a serves as an enhancer of drought tolerance in rose, probably through the modulation of the expression of some drought-related genes. Full article

Plants monitor day length and memorize changes in temperature signals throughout the day, creating circadian rhythms that support the timely control of physiological and metabolic processes. The DEHYDRATION-RESPONSE ELEMENT-BINDING PROTEIN 1/C-REPEAT BINDING FACTOR (DREB1/CBF) transcription factors are known as master regulators for the acquisition of cold stress tolerance, whereas PHYTOCHROME INTERACTING FACTOR 4 (PIF4) is involved in plant adaptation to heat stress through thermomorphogenesis. Recent studies have shown that circadian clock genes control plant responses to temperature. Temperature-responsive transcriptomes show a diurnal cycle and peak expression levels at specific times of throughout the day. Circadian clock genes play essential roles in allowing plants to maintain homeostasis by accommodating temperature changes within the normal temperature range or by altering protein properties and morphogenesis at the cellular level for plant survival and growth under temperature stress conditions. Recent studies revealed that the central oscillator genes CIRCADIAN CLOCK ASSOCIATED 1/LATE ELONGATED HYPOCOTYL (CCA1/LHY) and PSEUDO-RESPONSE REGULATOR5/7/9 (PRR5/7/9), as well as the EVENING COMPLEX (EC) genes REVEILLE4/REVEILLE8 (REV4/REV8), were involved in the DREB1 pathway of the cold signaling transcription factor and regulated the thermomorphogenesis gene PIF4. Further studies showed that another central oscillator, TIMING OF CAB EXPRESSION 1 (TOC1), and the regulatory protein ZEITLUPE (ZTL) are also involved. These studies led to attempts to utilize circadian clock genes for the acquisition of temperature-stress resistance in crops. In this review, we highlight circadian rhythm regulation and the clock genes involved in plant responses to temperature changes, as well as strategies for plant survival in a rapidly changing global climate. Full article

Significant progress has been made in the functions of auxin efflux transporter PIN-FORMED (PIN) genes for the regulation of growth and development in rice. However, knowledge on the roles of OsPIN genes in abiotic stresses is limited. We previously reported that the mutation of OsPIN1b alters rice architecture and root gravitropism, while the role of OsPIN1b in the regulation of rice abiotic stress adaptations is still largely elusive. In the present study, two homozygous ospin1b mutants (C1b-1 and C1b-2) were employed to investigate the roles of OsPIN1b in regulating abiotic stress adaptations. Low temperature gradually suppressed OsPIN1b expression, while osmotic stress treatment firstly induced and then inhibited OsPIN1b expression. Most OsPIN genes and auxin biosynthesis key genes OsYUC were up-regulated in ospin1b leaves, implying that auxin homeostasis is probably disturbed in ospin1b mutants. The loss of function of OsPIN1b significantly decreased rice chilling tolerance, which was evidenced by decreased survival rate, increased death cells and ion leakage under chilling conditions. Compared with the wild-type (WT), ospin1b mutants accumulated more hydrogen peroxide (H₂O₂) and less superoxide anion radicals $\left({\mathrm{O}}_2^{-}\right)$ after chilling treatment, indicating that reactive oxygen species (ROS) homeostasis is disrupted in ospin1b mutants. Consistently, C-repeat binding factor (CBF)/dehydration-responsive element binding factor (DREB) genes were downregulated in ospin1b mutants, implying that OsDREB genes are implicated in OsPIN1b-mediated chilling impairment. Additionally, the mutation of OsPIN1b led to decreased sensitivity to abscisic acid (ABA) treatment in seed germination, impaired drought tolerance in the seedlings and changed expression of ABA-associated genes in rice roots. Taken together, our investigations revealed that OsPIN1b is implicated in chilling and drought tolerance in rice and provide new insight for improving abiotic stress tolerance in rice. Full article

Dehydration-responsive element-binding (DREB) transcription factors (TFs) of the A1 and A2 subfamilies involved in plant stress responses have not yet been reported in Allium species. In this study, we used bioinformatics and comparative transcriptomics to identify and characterize DREB A1 and A2 genes redundant in garlic (Allium sativum L.) and analyze their expression in A. sativum cultivars differing in the sensitivity to cold and Fusarium infection. Eight A1 (AsaDREB1.1–1.8) and eight A2 (AsaDREB2.1–2.8) genes were identified. AsaDREB1.1–1.8 genes located in tandem on chromosome 1 had similar expression patterns, suggesting functional redundancy. AsaDREB2.1–2.8 were scattered on different chromosomes and had organ- and genotype-specific expressions. AsaDREB1 and AsaDREB2 promoters contained 7 and 9 hormone- and stress-responsive cis-regulatory elements, respectively, and 13 sites associated with TF binding and plant development. In both Fusarium-resistant and -sensitive cultivars, fungal infection upregulated the AsaDREB1.1–1.5, 1.8, 2.2, 2.6, and 2.8 genes and downregulated AsaDREB2.5, but the magnitude of response depended on the infection susceptibility of the cultivar. Cold exposure strongly upregulated the AsaDREB1 genes, but downregulated most AsaDREB2 genes. Our results provide the foundation for further functional analysis of the DREB TFs in Allium crops and could contribute to the breeding of stress-tolerant varieties. Full article

During the early seedling stage, rice (Oryza sativa L.) must overcome low-temperature stress. While a few cold-tolerance genes have been characterized, further excavation of cold-resistance genes is still needed. In this study, we identified a cold-induced transcription factor—LUX ARRHYTHMO (LUX)—in rice. OsLUX was found to be specifically expressed in leaf blades and upregulated by both cold stress and circadian rhythm. The full-length OsLUX showed autoactivation activity, and the OsLUX protein localized throughout the entire onion cell. Overexpressing OsLUX resulted in increased cold tolerance and reduced ion leakage under cold-stress conditions during the seedling stage. In contrast, the knockout of OsLUX decreased seedling cold tolerance and showed higher ion leakage compared to the wild type. Furthermore, overexpressing OsLUX upregulated the expression levels of oxidative stress-responsive genes, which improved reactive oxygen species (ROS) scavenging ability and enhanced tolerance to chilling stress. Promoter analysis showed that the OsLUX promoter contains two dehydration-responsive element binding (DREB) motifs at positions −510/−505 (GTCGGa) and −162/−170 (cCACCGccc), which indicated that OsDREB1s and OsDREB2s probably regulate OsLUX expression by binding to the motif to respond to cold stress. Thus, OsLUX may act as a downstream gene of the DREB pathway. These results demonstrate that OsLUX serves as a positive regulatory factor of cold stress and that overexpressing OsLUX could be used in rice breeding programs to enhance abiotic stress tolerance. Full article