Search Results (34)

Low-temperature stress severely restricts the growth, development, and yield of bitter gourd (Momordica charantia L.), a warm-loving crop with inherent low cold tolerance. NAC transcription factors (TFs) serve as crucial regulators in plant responses to abiotic stresses like cold, while their roles in coping with cold stress in bitter gourd remain unclear. This study identified cold-responsive genes in bitter gourd and characterized the candidate NAC TF McNAC087 through transcriptome analysis. Transcriptome sequencing of cold-tolerant (R) and cold-sensitive (S) bitter gourd inbred lines under 5 °C stress (0 h, 6 h, 12 h, 24 h) revealed 1157 co-expressed differentially expressed genes (DEGs), enriched via Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis in cold tolerance-related pathways (signal transduction, carbohydrate/amino acid metabolism). RT-qPCR showed higher McNAC087 expression in R than S under cold stress, and subcellular localization confirmed it as a nucleus-localized protein. McNAC087 overexpression in Arabidopsis enhanced cold tolerance after sequential stress (−14 °C for 1.5 h, 4 °C for 16 h, and 22 °C recovery for 2 days), with less damage compared to wildtype (WT). Physiologically, overexpressing lines had higher proline, elevated superoxide dismutase/peroxidase/catalase (SOD/POD/CAT) activities, lower malondialdehyde/hydrogen peroxide/superoxide anion (MDA/H₂O₂/O₂⁻) accumulation under cold stress, and upregulated ICE-CBF-COR pathway marker genes (CBF1, DREB2A, RD29A, COR47). In conclusion, McNAC087 enhances Arabidopsis cold tolerance by regulating physiology and activating cold-responsive genes, providing insights for bitter gourd cold tolerance mechanisms and crop breeding. Full article

Cold stress severely limits legume productivity, threatening global food security, particularly in climate-vulnerable regions. This review synthesizes advances in understanding and enhancing cold tolerance in key legumes (chickpea, soybean, lentil, and cowpea), addressing three core questions: (1) molecular/physiological foundations of cold tolerance; (2) how emerging technologies accelerate stress dissection and breeding; and (3) integration strategies and deployment challenges. Legume cold tolerance involves conserved pathways (e.g., ICE-CBF-COR, Inducer of CBF Expression, C-repeat Binding Factor, Cold-Responsive genes) and species-specific mechanisms like soybean’s GmTCF1a-mediated pathway. Multi-omics have identified critical genes (e.g., CaDREB1E in chickpea, NFR5 in pea) underlying adaptive traits (membrane stabilization, osmolyte accumulation) that reduce yield losses by 30–50% in tolerant genotypes. Technologically, AI and high-throughput phenotyping achieve >95% accuracy in early cold detection (3–7 days pre-symptoms) via hyperspectral/thermal imaging; deep learning (e.g., CNN-LSTM hybrids) improves trait prediction by 23% over linear models. Genomic selection cuts breeding cycles by 30–50% (to 3–5 years) using GEBVs (Genomic estimated breeding values) from hundreds of thousands of SNPs (Single-nucleotide polymorphisms). Advanced sensors (LIG-based, LoRaWAN) enable real-time monitoring (±0.1 °C precision, <30 s response), supporting precision irrigation that saves 15–40% water while maintaining yields. Key barriers include multi-omics data standardization and cost constraints in resource-limited regions. Integrating molecular insights with AI-driven phenomics and multi-omics is revolutionizing cold-tolerance breeding, accelerating climate-resilient variety development, and offering a blueprint for sustainable agricultural adaptation. Full article

Drought stress is a devastating natural stress that threatens crop productivity and quality. Mitigating the adverse effects of drought stress on wheat is a key object in agriculture. C-repeat binding transcription factor/DROUGHT RESPONSE ELEMENT BINDING FACTOR 1 (CBF/DREB1) transcription factors are well known for their role in cold acclimation. However, the involvement of CBF genes in drought stress and the mechanisms underlying their function remain poorly understood. In this study, 81 CBFs were identified in wheat, which were further clustered into four distinct lineages based on phylogenetic analysis. Chromosomal localization indicated that most CBF genes were dispersed across chromosome 5. We identified three homoeologous genes (TaCBF14A, TaCBF14B, and TaCBF14D) that were simultaneously upregulated under drought stress based on RNA-seq analysis. According to the high expression after drought stress, TaCBF14B was selected for further functional analysis. Subcellular localization and transcriptional activation activity analysis indicated that TaCBF14B likely functions as a transcription factor involved in drought stress tolerance. Overexpression of TaCBF14B in Arabidopsis enhanced the primary root growth by 13.49% (OE1), 12.56% (OE2), and 19.53% (OE3) under 200 mM mannitol treatment, and 21.65% (OE1), 16.63% (OE2), and 28.13% (OE3) under 250 mM mannitol treatment compared to WT. Meanwhile, the water loss rate of transgenic lines was 56% in WT leaves, but only 44%, 50%, and 40% in OE1, OE2, and OE3 lines, respectively. Compared to the wild type, POD activities of OE1, OE2, and OE3 were significantly increased by 42.94%, 29.41%, and 62.52%, respectively. And the Pro activities in OE1, OE2, and OE3 were significantly increased by 16.33%, 5.18%, and 29.09%, respectively, compared to the wild type. Additionally, the MDA content in OE1, OE2, and OE3 was significantly reduced by 40.53%, 15.81%, and 54.36%, respectively. Further analysis showed that the transgenic lines were hypersensitive to abscisic acid (ABA), and exhibited increased expression of AtABI3. We speculate that TaCBF14B plays an important role in enhancing drought tolerance. In summary, our findings provide new insights into the functional roles of CBF genes in drought stress tolerance. Full article

Alfalfa (Medicago sativa) is a globally distributed economic legume crop used for forage and ecological restoration. We aimed to explore the mechanisms underlying the cold acclimation observed in this species. Our results for fall plant growth showed that non-dormant alfalfa (SD) maintained a vigorous growth rate compared to that of fall-dormant alfalfa (ZD); however, the winter survival rate of ZD was higher than that of SD. Among the ZD samples, the starch content first accumulated and then decreased; the sucrose content was consumed first along with simultaneous raffinose accumulation, which was followed by sucrose content accumulation, with consistent changes in the corresponding related synthase and hydrolase activity. SD exhibited the opposite trend. The transcriptome data showed that most of the differentially expressed genes were involved in carbon metabolism (ko01200), amino acid biosynthesis (ko01230), and starch and sucrose metabolism (ko00500). Our data clearly show that alfalfa’s cold acclimation mechanism is a complex process, with the establishment of stable carbon homeostasis; sucrose is first converted into starch and raffinose, and then, starch is converted into sucrose, which enables alfalfa’s cold resistance. The process is accompanied by CBF/DREB1A TF regulation. This study provides important insights into the cold acclimation mechanisms of alfalfa. Full article

Low temperature significantly contributes to the medicinal quality of Conyza blinii. The CBF/DREB1-dependent cold-responsive signaling pathway is a major contributor to plant cold stress resistance. However, whether the CBF/DREB1 signaling pathway affects the terpenoid metabolism of C. blinii under cold stress remains to be explored. Here, we systematically identified and analyzed the impact of CbCBFs on the terpenoid metabolism of C. blinii. The results showed that three CbCBFs and CbICE1 were identified based on the transcriptome. The functions significantly correlated with CbCBFs encompass plant hormones and stress responses. Co-expression analysis revealed that key genes in BR and JA signaling pathways were correlated with CbCBFs. Among them, CbCBF2 is the predominant factor under low-temperature conditions and is significantly positively correlated with oleanolic acid. Overexpression of CbCBF2 significantly upregulated the catalase gene CbβAS and increased oleanolic acid content in the leaves. These results indicate that CbCBF2 can act as a major regulatory factor to promote the synthesis of oleanolic acid by integrating JA and BR signaling under low temperature conditions. Full article

Olea europaea, native to the Mediterranean region, has been widely cultivated for the nutritional content of its fruits and leaves. To adapt to climates beyond the Mediterranean, research on the climatic adaptation of O. europaea is urgently needed. Therefore, in this study, the CBF/DREB1 family genes in olives, which are related to cold tolerance, were genome-wide characterized. In total, four OeCBFs were screened; their open reading frame (ORF) were 552~684 bp in length, the encoded proteins were 20,786.60~25,235.16 Da, with 183~227 amino acids, and the theoretical isoelectric point (pI) were 4.91~9.13. The transcription of four OeCBFs was significantly different in olive tissues, especially OeCBF2 and OeCBF4, which were substantially more highly-expressed in aboveground tissues (terminal buds, young leaves, old leaves, and stems) than in underground tissues (thick and fine roots). Exposed to cold stress, OeCBF2 and OeCBF4 were up-regulated more obviously in olive leaves and stems, while OeCBF3 was induced to higher levels in the roots, implying the adaptation potential of the OeCBFs to low temperature stress. A comparison of the expression of the four OeCBFs in two varieties, Picholine (more tolerant to the other one) and Arbequina, found that the expression of OeCBFs was higher in most tissues of Picholine than that of Arbequina. When exposed to cold stress, the expression of the OeCBFs was also higher in the leaves and roots of Picholine than in Arbequina, further confirming the correlation between OeCBFs and cold tolerance of olive trees. This study not only deepens our understanding of the CBF gene family in olives, but also provides significant genetic information for olive breeding and improvement. Full article

Winter rapeseed (Brassica rapa) has a good chilling and freezing tolerance. inducer of CBF expression 1 (ICE1) plays a crucial role in cold signaling in plants; however, its role in Brassica rapa remains unclear. In this study, we identified 41 ICE1 homologous genes from six widely cultivated Brassica species. These genes exhibited high conservation, with evolutionary complexity between diploid and allotetraploid species. Cold stress induced ICE1 homolog expression, with differences between strongly and weakly cold-tolerant varieties. Two novel ICE1 paralogs, BrICE1 and BrICE2, were cloned from Brassica rapa Longyou 6. Subcellular localization assays showed that they localized to the nucleus, and low temperature did not affect their nuclear localization. The overexpression of BrICE1 and BrICE2 increased cold tolerance in transgenic Arabidopsis and enhanced reactive oxygen species’ (ROS) scavenging ability. Furthermore, our data demonstrate that overexpression of BrICE1 and BrICE2 inhibited root growth in Arabidopsis, and low temperatures could induce the degradation of BrICE1 and BrICE2 via the 26S-proteasome pathway. In summary, ICE1 homologous genes exhibit complex evolutionary relationships in Brassica species and are involved in the C-repeat/DREB binding factor (CBF) pathway and ROS scavenging mechanism in response to cold stress; these regulating mechanisms might also be responsible for balancing the development and cold defense of Brassica rapa. Full article

To elucidate the function of the cold-resistance regulatory gene FmNAC1 from Fraxinus mandshurica Rupr., this study identified the role that overexpression of the FmNAC1 gene plays in tobacco growth and cold-stress regulation. The cloned FmNAC1 gene from F. mandshurica is 891 bp in length and encodes 296 amino acids. Our subcellular localization analysis confirmed that FmNAC1 is primarily located in the nucleus and functions as a transcription factor. FmNAC1 is responsive to cold and NaCl stress, as well as to the induction of IAA, GA, and ABA hormone signals. To further elucidate its function in cold resistance, four transgenic tobacco lines expressing FmNAC1 (FmNAC1-OE) were generated through tissue culture after the Agrobacterium-mediated transformation of wild-type (WT) Nicotiana tabacum L. These FmNAC1-OE plants exhibited accelerated growth after transplantation. When exposed to low-temperature conditions at −5 °C for 24 h, the rates of wilting and yellowing of the FmNAC1-OE plants were significantly lower than those of the WT tobacco plants. Additionally, the membrane integrity, osmotic regulation, and reactive oxygen species (ROS)-scavenging abilities of the FmNAC1-OE tobacco lines were better than those of the WT plants, indicating the potential of the FmNAC1 gene to improve plant cold resistance. The gene expression results further revealed that the FmNAC1 transcription factor exhibits regulatory interactions with growth-related genes such as IAA and AUX1; cold-resistance-related genes such as ICE, DREB, and CBF1; and genes involved in the clearance of reactive oxygen species (ROS), such as CAT and SOD. All of this evidence shows that the FmNAC1 transcription factor from F. mandshurica plays a key role in contributing to the enhancement of growth, cold resistance, and ROS clearance in transgenic tobacco plants. Full article

MYB (myoblast) protein comes in large quantities and a wide variety of types and plays a role in most eukaryotes in the form of transcription factors (TFs). One of its important functions is to regulate plant responses to various stresses. However, the role of MYB TFs in regulating stress tolerance in strawberries is not yet well understood. Therefore, in order to investigate the response of MYB family members to abiotic stress in strawberries, a new MYB TF gene was cloned from Fragaria vesca (a diploid strawberry) and named FvMYB108 based on its structural characteristics and evolutionary relationships. After a bioinformatics analysis, it was determined that the gene belongs to the R2R3-MYB subfamily, and its conserved domain, phylogenetic relationships, predicted protein structure and physicochemical properties, subcellular localization, etc. were analyzed. After qPCR analysis of the expression level of FvMYB108 in organs, such as the roots, stems, and leaves of strawberries, it was found that this gene is more easily expressed in young leaves and roots. After multiple stress treatments, it was found that the target gene in young leaves and roots is more sensitive to low temperatures and salt stimulation. After these two stress treatments, various physiological and biochemical indicators related to stress in transgenic Arabidopsis showed corresponding changes, indicating that FvMYB108 may be involved in regulating the plant’s ability to cope with cold and high-salt stress. Further research has found that the overexpression of this gene can upregulate the expression of AtCBF1, AtCOR47, AtERD10, and AtDREB1A related to low-temperature stress, as well as AtCCA1, AtRD29a, AtP5CS1, and AtSnRK2.4 related to salt stress, enhancing the ability of overexpressed plants to cope with stress. Full article

Phosphatidylinositol 4-phosphate 5-kinases (PIP5Ks), essential enzymes in the phosphatidylinositol signaling pathway, are crucial for the abiotic stress responses and the overall growth and development of plants. However, the GhPIP5Ks had not been systematically studied, and their function in upland cotton was unknown. This study identified a total of 28 GhPIP5Ks, and determined their chromosomal locations, gene structures, protein motifs and cis-acting elements via bioinformatics analysis. A quantitative real-time PCR (qRT‒PCR) analysis showed that most GhPIP5Ks were upregulated under different stresses. A virus-induced gene silencing (VIGS) assay indicated that the superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities were significantly decreased, while malondialdehyde (MDA) content were significantly increased in GhPIP5K2- and GhPIP5K22-silenced upland cotton plants under abiotic stress. Furthermore, the expression of the stress marker genes GhHSFB2A, GhHSFB2B, GhDREB2A, GhDREB2C, GhRD20-1, GhRD29A, GhBIN2, GhCBL3, GhNHX1, GhPP2C, GhCBF1, GhSnRK2.6 and GhCIPK6 was significantly decreased in the silenced plants after exposure to stress. These results revealed that the silencing of GhPIP5K2 and GhPIP5K22 weakened the tolerance to abiotic stresses. These discoveries provide a foundation for further inquiry into the actions of the GhPIP5K gene family in regulating the response and resistance mechanisms of cotton to abiotic stresses. 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

The pivotal role of CBF/DREB1 transcriptional factors in Triticeae crops involved in the abiotic stress response has been highlighted. The CBFs represent an important hub in the ICE-CBF-COR pathway, which is one of the most relevant mechanisms capable of activating the adaptive response to cold and drought in wheat, barley, and rye. Understanding the intricate mechanisms and regulation of the cluster of CBF genes harbored by the homoeologous chromosome group 5 entails significant potential for the genetic improvement of small grain cereals. Triticeae crops seem to share common mechanisms characterized, however, by some peculiar aspects of the response to stress, highlighting a combined landscape of single-nucleotide variants and copy number variation involving CBF members of subgroup IV. Moreover, while chromosome 5 ploidy appears to confer species-specific levels of resistance, an important involvement of the ICE factor might explain the greater tolerance of rye. By unraveling the genetic basis of abiotic stress tolerance, researchers can develop resilient varieties better equipped to withstand extreme environmental conditions. Hence, advancing our knowledge of CBFs and their interactions represents a promising avenue for improving crop resilience and food security. Full article

Vegetatively propagating aquatic angiosperms, the Lemnaceae family (duckweeds) represents valuable genetic resources for circular bioeconomics and other sustainable applications. Due to extremely fast growth and laborious cultivation of in vitro collections, duckweeds are an urgent subject for cryopreservation. We developed a robust and fast DMSO-free protocol for duckweed cryopreservation by vitrification. A single-use device was designed for sampling of duckweed fronds from donor culture, further spin-drying, and subsequent transferring to cryo-tubes with plant vitrification solution 3 (PVS3). Following cultivation in darkness and applying elevated temperatures during early regrowth stage, a specific pulsed illumination instead of a diurnal regime enabled successful regrowth after the cryopreservation of 21 accessions of Spirodela, Landoltia, Lemna, and Wolffia genera, including interspecific hybrids, auto- and allopolyploids. Genome size measurements revealed no quantitative genomic changes potentially caused by cryopreservation. The expression of CBF/DREB1 genes, considered as key factors in the development of freezing tolerance, was studied prior to cooling but was not linked with duckweed regrowth after rewarming. Despite preserving chlorophyll fluorescence after rewarming, the rewarmed fronds demonstrated nearly zero photosynthetic activity, which did not recover. The novel protocol provides the basis for future routine application of cryostorage to duckweed germplasm collections, saving labor for in vitro cultivation and maintaining characterized reference and mutant samples. Full article

Freezing stress is one of the main factors limiting the growth and yield of wheat. In this study, we found that TaMYB4 expression was significantly upregulated in the tillering nodes of the strong cold-resistant winter wheat variety Dongnongdongmai1 (Dn1) under freezing stress. Weighted gene co-expression network analysis, qRT-PCR and protein–DNA interaction experiments demonstrated that monodehydroascorbate reductase (TaMDHAR) is a direct target of TaMYB4. The results showed that overexpression of TaMYB4 enhanced the freezing tolerance of transgenic Arabidopsis. In TaMYB4 overexpression lines (OE-TaMYB4), AtMDHAR2 expression was upregulated and ascorbate-glutathione (AsA–GSH) cycle operation was enhanced. In addition, the expression of cold stress marker genes such as AtCBF1, AtCBF2, AtCBF3, AtCOR15A, AtCOR47, AtKIN1 and AtRD29A in OE-TaMYB4 lines was significantly upregulated. Therefore, TaMYB4 may increase freezing tolerance as a transcription factor (TF) in Arabidopsis through the AsA–GSH cycle and DREB/CBF signaling pathway. This study provides a potential gene for molecular breeding against freezing stress. Full article