Search Results (17)

Vacuolar H⁺-ATPases play crucial roles in plant ion homeostasis and stress adaptation, yet the functional characterization of their subunit genes in purslane remains limited. In this study, PoVHA-a3, encoding a tonoplast-localized V-ATPase a3 subunit, was identified as a key salt-responsive gene through transcriptomic analysis. Integrated bioinformatic analysis and molecular docking simulations predicted specific binding of NAC3, MYB1, and bHLH62 to the PoVHA-a3 promoter, suggesting their synergistic role in regulating PoVHA-a3 expression. Under salt stress, PoVHA-a3 transgenic Arabidopsis lines exhibited elevated endogenous abscisic acid levels and upregulation of signaling genes (AtNCED3, AtRD29A, AtCOR15A), while the brassinosteroid signaling pathway was suppressed, as indicated by the reduced expression of AtBZR1 and AtEXPA8. Meanwhile, the transgenic lines demonstrated enhanced ATP levels, respiratory rate, and V-ATPase activity. In addition, PoVHA-a3 expression led to greater accumulation of osmoprotectants (proline, soluble sugars and proteins), higher activities of antioxidant enzymes, and reduced levels of oxidative stress indices. Furthermore, a significantly lower shoot Na⁺/K⁺ ratio was observed in transgenic plants, indicating improved ion homeostasis. In conclusion, this study demonstrates that PoVHA-a3 acts as a pivotal positive regulator of salt tolerance in purslane, providing a valuable genetic resource for enhancing salt tolerance in crops through genetic engineering. Full article

Mitogen-Activated Protein Kinases (MAPKs) play crucial roles in plant stress signaling, but the mechanisms of MAPK genes in Portulaca oleracea remain functionally uncharacterized. In this study, transcriptomic screening of P. oleracea under salt stress identified PoMPK3 as a candidate gene, showing significant root-specific upregulation. Phylogenetic analysis classified it as a Group A MAPK protein, and subcellular localization confirmed its membrane association. Heterologous expression of PoMPK3 in Arabidopsis thaliana significantly enhanced salt tolerance, as evidenced by improved seed germination rates, longer primary roots, increased biomass, and reduced stress symptoms. Mechanistically, PoMPK3 expression activated ABA signaling, leading to increased ABA levels and upregulation of AtNCED3, AtPYR1, and AtABF3. Furthermore, it strengthened the antioxidant defense, as evidenced by elevated antioxidant enzyme activity, leading to a reduction in oxidative stress. The transgenic lines also demonstrated enhanced osmotic adjustment through osmolytes accumulation and ionic homeostasis, evidenced by tissue-specific Na⁺/K⁺ ratios (low in shoots, high in roots) resulting from the concerted upregulation of AtSOS1, AtNHX1, and AtHKT1. In addition, gene co-expression network analysis and molecular docking predicted phosphorylation of WRKY transcription factors, suggesting a novel mechanism for transcriptome reprogramming. Collectively, our findings not only advance the understanding of salt tolerance mechanisms in purslane but also identify PoMPK3 as a key genetic determinant, thereby laying the foundation for its use in breeding programs aimed at enhancing salt stress resilience in crops. Full article

The plant cuticle, a protective barrier against external stresses, and abscisic acid (ABA), a key phytohormone, are crucial for plant growth and stress responses. Heterologous expression of AtNCED3 in plants has been widely studied. In this research, by comparing the japonica rice cultivar Zhonghua 10 and its AtNCED3 over-expressing lines during the vegetative growth stage through multiple methods, we found that AtNCED3 over-expression increased leaf ABA content, enhanced epidermal wax and cutin accumulation, modified wax crystal density, and thickened the cuticle. These changes reduced leaf epidermal permeability and the transpiration rate, thus enhancing drought tolerance. This study helps understand the role of endogenous ABA in rice cuticle synthesis and its mechanism in plant drought tolerance, offering potential for genetic improvement of drought resistance in crops. Full article

The WRKY transcription factor family is a significant family of plant transcription factors (TFs). Plant growth and development are often influenced by abiotic factors, such as salinity and low temperature. Numerous studies have demonstrated that WRKY TFs primarily influence plant responses to adversity. However, there are few studies on the role of WRKY genes in the stress responses of Malus baccata (L.) Borkh. We cloned the MbWRKY33 gene from Malus baccata for this research, and its roles in salt stress tolerance were analyzed. Phylogenetic tree analysis revealed that MbWRKY33 and PbWRKY33 have the highest homology. Subcellular localization revealed that MbWRKY33 was located within the nucleus. An analysis of tissue-specific expression showed that MbWRKY33 had relatively high expression levels in young leaves and roots. Moreover, Arabidopsis thaliana plants overexpressing MbWRKY33 exhibited stronger resistance to salt stress compared with the wild type (WT) and the unloaded line empty vector (UL). Under the treatment of 200 mM NaCl, transgenic Arabidopsis thaliana plants exhibited significantly higher activities of antioxidant enzymes like superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) than the control. In contrast, the WT and the UL lines had elevated levels of malondialdehyde (MDA) and reactive oxygen species (ROS). In addition, MbWRKY33 elevates transgenic plant resistance to salt stress by regulating the expression levels of AtNHX1, AtSOS1, AtSOS3, AtNCED3, AtSnRK2, and AtRD29a. Results indicated that MbWRKY33 in Malus might be linked to high-salinity stress responses, laying a foundation for understanding WRKY TFs’ reaction to such stress. Full article

Cold stress is a significant factor limiting plant growth and development. Pomegranate is particularly susceptible to low temperatures. Calmodulin-binding transcriptional activators (CAMTAs) are key regulators of cold stress tolerance in plants. In this study, we conducted a comprehensive analysis of the CAMTA family proteins across 12 species, including Punica granatum (pomegranate), using bioinformatic methods. Pomegranate CAMTA3 (PgCAMTA3) was isolated and characterized, and it demonstrated enhanced cold tolerance when expressed in Arabidopsis thaliana. Quantitative real-time PCR (qRT-PCR) analysis showed that the expression of PgCAMTA3 was up-regulated under cold and ABA treatments in pomegranates. Two A. thaliana transgenic lines, OE1 and OE2, which overexpress PgCAMTA3, were generated through genetic transformation. The overexpression of PgCAMTA3 enhanced the cold stress tolerance in transgenic A. thaliana. OE1 and OE2 exhibited higher survival rates under cold stress. Furthermore, enzymatic activity assays revealed enhanced peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD) in OE lines. These antioxidant enzymatic activities collectively contribute to better cold stress tolerance by providing more effective reactive oxygen species (ROS) scavenging and cellular protection mechanisms, which was confirmed by lower levels of malondialdehyde (MDA) and ROS production. In addition, the overexpression of PgCAMTA3 led to the upregulation of the expression levels of AtCBF2, AtNCED3, and AtWRKY22, which were modulated by CAMTA3. In summary, we report the significant role of PgCAMTA3 in plant cold tolerance. Our findings provide valuable insights into the CAMATA family in plants and offer new perspectives on the molecular mechanisms underlying cold tolerance in pomegranates. Full article

Paulownia fortunei (Seem.) Hemsl is a Paulownia Sieb.et tree of the family Scrophulariaceae. It has become an important short-to-medium-term fast-growing multi-purpose tree species in China due to its rapid growth, strong adaptability, and excellent material properties. MYB transcription factors in plants have numerous and diverse functions, playing important roles in various aspects such as plant stress response. To investigate the function of MYB transcription factors in Paulownia fortunei, this study used PCR technology to clone the PfMYB44 gene from Paulownia fortunei. The homology of PfMYB44 and SiMYB44 (Sesamum indicum) was the highest. Expression analysis results showed that PfMYB44 was expressed in the root, stem, young leaf, and mature leaf of Paulownia fortunei, with the highest content in the root. Cold, drought, hot, salt, and ABA treatments could increase the expression level of PfMYB44. Overexpression-PfMYB44 plants were constructed, and physiological and molecular analysis showed that PfMYB44 could positively regulate salt and drought stresses. Under drought stress, the expression levels of AtP5CS, AtCAT1, AtNCED3 and AtSnRK2.4 in transgenic lines were significantly induced. Salt stress induced the expression of AtNHX1, AtSOS1, AtSOS2 and AtSOS3 genes, and the relative expression levels of these genes in transgenic Arabidopsis were higher. In conclusion, the functional study of PfMYB44 laid a certain foundation for the study of Paulownia stress resistance, and was helpful to the study of its stress resistance mechanism and the cultivation of new stress resistance varieties. Full article

Foxtail millet is a drought-tolerant cereal and forage crop. The basic leucine zipper (bZIP) gene family plays important roles in regulating plant development and responding to stresses. However, the roles of bZIP genes in foxtail millet remain largely uninvestigated. In this study, 92 members of the bZIP transcription factors were identified in foxtail millet and clustered into ten clades. The expression levels of four SibZIP genes (SibZIP11, SibZIP12, SibZIP41, and SibZIP67) were significantly induced after PEG treatment, and SibZIP67 was chosen for further analysis. The studies showed that ectopic overexpression of SibZIP67 in Arabidopsis enhanced the plant drought tolerance. Detached leaves of SibZIP67 overexpressing plants had lower leaf water loss rates than those of wild-type plants. SibZIP67 overexpressing plants improved survival rates under drought conditions compared to wild-type plants. Additionally, overexpressing SibZIP67 in plants displayed reduced malondialdehyde (MDA) levels and enhanced activities of antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) under drought stress. Furthermore, the drought-related genes, such as AtRD29A, AtRD22, AtNCED3, AtABF3, AtABI1, and AtABI5, were found to be regulated in SibZIP67 transgenic plants than in wild-type Arabidopsis under drought conditions. These data suggested that SibZIP67 conferred drought tolerance in transgenic Arabidopsis by regulating antioxidant enzyme activities and the expression of stress-related genes. The study reveals that SibZIP67 plays a beneficial role in drought response in plants, offering a valuable genetic resource for agricultural improvement in arid environments. Full article

The PHYTOME study investigated the effect of consuming processed meat products on outcomes related to colorectal cancer risk without testing the impact of genetic variability on these responses. This research aims to elucidate the genetic impact on apparent total N-nitroso compound (ATNC) excretion, colonic DNA adduct formation, ex vivo-induced DNA damage, and gene expression changes in colon biopsies of healthy participants. Through a systematic literature review, candidate polymorphisms were selected and then detected using TaqMan and PCR analysis. The effect of genotype on study outcomes was determined via a linear mixed model and analysis of variance. Machine learning was used to evaluate relative allele importance concerning genotoxic responses, which established a ranking of the most protective alleles and a combination of genotypes (gene scores). Participants were grouped by GSTM1 genotype and differentially expressed genes (DEGs), and overrepresented biological pathways were compared between groups. Stratifying participants by ten relevant genes revealed significant variations in outcome responses. After consumption of processed red meat, variations in NQO1 and COMT impacted responses in ATNC levels (µmol/L) (+9.56 for wildtype vs. heterozygous) and DNA adduct levels (pg/µg DNA) (+1.26 for variant vs. wildtype and +0.43 for variant vs. heterozygous), respectively. After phytochemicals were added to the meat, GSTM1 variation impacted changes in DNA adduct levels (−6.12 for deletion vs. wildtype). The gene scores correlated with these responses and DEGs were identified by GSTM1 genotype. The altered pathways specific to the GSTM1 wildtype group included ‘metabolism’, ‘cell cycle’, ‘vitamin D receptor’, and ‘metabolism of water-soluble vitamins and co-factors’. Genotype impacted both the potential genotoxicity of processed red meat and the efficacy of protective phytochemical extracts. Full article

‘Beta’ is a hybrid of Vitis riparia L. and V. labrusca and has a strong ability to adapt to adverse growth environments and is mainly cultivated and used as a resistant rootstock. At present, the most extensively studied MYB TFs are R2R3-type, which have been found to be involved in plant growth, development, and stress response processes. In the present research, VhMYB15, a key transcription factor for abiotic stress tolerance, was screened by bioinformatics in ‘Beta’ rootstock, and its function under salinity and drought stresses was investigated. VhMYB15 was highly expressed in roots and mature leave under salinity and drought stresses. Observing the phenotype and calculating the survival rate of plants, it was found that VhMYB15-overexpressing plants exhibited relatively less yellowing and wilting of leaves and a higher survival rate under salinity and drought stresses. Consistent with the above results, through the determination of stress-related physiological indicators and the expression analysis of stress-related genes (AtSOS2, AtSOS3, AtSOS1, AtNHX1, AtSnRK2.6, AtNCED3, AtP5CS1, and AtCAT1), it was found that transgenic Arabidopsis showed better stress tolerance and stronger adaptability under salinity and drought stresses. Based on the above data, it was preliminarily indicated that VhMYB15 may be a key factor in salinity and drought regulation networks, enhancing the adaptability of ‘Beta’ to adverse environments. Full article

Drought stress is a significant threat to agricultural productivity and poses challenges to plant survival and growth. Research into microbial plant biostimulants faces difficulties in understanding complicated ecological dynamics, molecular mechanisms, and specificity; to address these knowledge gaps, collaborative efforts and innovative strategies are needed. In the present study, we investigated the potential role of Brevundimonas vesicularis (S1T13) as a microbial plant biostimulant to enhance drought tolerance in Arabidopsis thaliana. We assessed the impact of S1T13 on Col-0 wild-type (WT) and atnced3 mutant plants under drought conditions. Our results revealed that the inoculation of S1T13 significantly contributed to plant vigor, with notable improvements observed in both genotypes. To elucidate the underlying mechanisms, we studied the role of ROS and their regulation by antioxidant genes and enzymes in plants inoculated with S1T13. Interestingly, the inoculation of S1T13 enhanced the activities of GSH, SOD, POD, and PPO by 33, 35, 41, and 44% in WT and 24, 22, 26, and 33% in atnced3, respectively. In addition, S1T13 upregulated the expression of antioxidant genes. This enhanced antioxidant machinery played a crucial role in neutralizing ROS and protecting plant cells from oxidative damage during drought stress. Furthermore, we investigated the impact of S1T13 on ABA and drought-stress-responsive genes. Similarly, S1T13 modulated the production of ABA and expression of AO3, ABA3, DREB1A, and DREB2A by 31, 42, 37, 41, and 42% in WT and 20, 29, 27, 38, and 29% in atnced3. The improvement in plant vigor, coupled with the induction of the antioxidant system and modulation of ABA, indicates the pivotal role of S1T13 in enhancing the drought stress tolerance of the plants. Conclusively, the current study provides valuable insights for the application of multitrait S1T13 as a novel strain to improve drought stress tolerance in plants and could be added to the consortium of biofertilizers. Full article

The NAC (NAM, ATAF1/2 and CUC2) transcription factors are ubiquitously distributed in plants and play critical roles in the construction of plant organs and abiotic stress response. In this study, we described the cloning of a Suaeda liaotungensis K. NAC transcription factor gene SlNAC4, which contained 1450 bp, coding a 331 amino acid. We found that SlNAC4 was highly expressed in stems of S. liaotungensis, and the expression of SlNAC4 was considerably up-regulated after salt, drought, and ABA treatments. Transcription analysis and subcellular localization demonstrated that the SlNAC4 protein was located both in the nucleus and cytoplasm, and contained a C-terminal transcriptional activator. The SlNAC4 overexpression Arabidopsis lines significantly enhanced the tolerance to salt and drought treatment and displayed obviously increased activity of antioxidant enzymes under salt and drought stress. Additionally, transgenic plants overexpressing SlNAC4 had a significantly higher level of physiological indices. Interestingly, SlNAC4 promoted the expression of ABA metabolism-related genes including AtABA1, AtABA3, AtNCED3, AtAAO3, but inhibited the expression of AtCYP707A3 in overexpression lines. Using a yeast one-hybrid (Y1H) assay, we identified that the SlNAC4 transcription factor could bind to the promoters of those ABA metabolism-related genes. These results indicate that overexpression of SlNAC4 in plants enhances the tolerance to salt and drought stress by regulating ABA metabolism. Full article

As an excellent grafting material, Malus baccata (L.) Borkh is native to Liaoning, Jilin, Heilongjiang and other regions in China, with a strong adverse environmental adaptability. As a typical transcription factor, the NAC gene acts as a regulator in many molecular pathways responding to abiotic stress. However, research of NAC in the Malus baccata has just begun. In the present research, a new NAC transcription factor, MbNAC22, was obtained from the seedlings of Malus baccata, and its function in drought and salt treatments was studied by heterologous expression. The open reading frame of the MbNAC22 gene is 768, encoding 255 amino acids (aa). Through confocal microscopy, MbNAC22 was found to be located in the nucleus. The heterologous expression of MbNAC22 in Arabidopsis showed that it enhanced the viability of Arabidopsis under drought and salt treatments. Under stresses, the chlorophyll content of the plants decreased, but the decline of the overexpressed-MbNAC22 Arabidopsis was relatively low. Through phenotypic observation and determination of stress-related physiological indicators, it was found that compared with WT Arabidopsis, overexpressed-MbNAC22 Arabidopsis had a higher tolerance to stresses. Under stresses, the overexpression of MbNAC22 positively regulated ion-transport-related genes (AtNHX1 and AtSOS1), the key genes of the ABA pathway (AtNCED3 and AtDREB2A), the proline synthesis gene (AtP5CS2) and the drought-induced gene (AtERD11), while the expression of the leaf senescence-associated gene (AtSAG21) and programmed cell death related gene (AtAEP1) was inhibited. Therefore, we speculate that MbNAC22 responds positively to drought and salt stresses by regulating the expression of stress-related genes. Full article

The MYB transcription factor (TF) family is one of the largest transcription families in plants, which is widely involved in the responses to different abiotic stresses, such as salt, cold, and drought. In the present study, a new MYB TF gene was cloned from Fragaria vesca (a diploid strawberry) and named FvMYB82. The open reading frame (ORF) of FvMYB82 was found to be 960 bp, encoding 319 amino acids. Sequence alignment results and predictions of the protein structure indicated that the FvMYB82 contained the conserved R2R3-MYB domain. Subcellular localization analysis showed that FvMYB82 was localized onto the nucleus. Furthermore, the qPCR showed that the expression level of FvMYB82 was higher in new leaves and roots than in mature leaves and stems. When dealing with different stresses, the expression level of FvMYB82 in F. vesca seedlings changed markedly, especially for salt and cold stress. When FvMYB82 was introduced into Arabidopsis thaliana, the tolerances to salt and cold stress of FvMYB82-OE A. thaliana were greatly improved. When dealt with salt and cold treatments, compared with wild-type and unloaded line (UL) A. thaliana, the transgenic lines had higher contents of proline and chlorophyll, as well as higher activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). However, the transgenic A. thaliana had lower level of malondialdehyde (MDA) and electrolytic leakage (EL) than wild-type and UL A. thaliana under salt and cold stress. Meanwhile, FvMYB82 can also regulate the expression of downstream genes associated with salt stress (AtSnRK2.4, AtSnRK2.6, AtKUP6, and AtNCED3) and cold stress (AtCBF1, AtCBF2, AtCOR15a, and AtCOR78). Therefore, these results indicated that FvMYB82 probably plays an important role in the response to salt and cold stresses in A. thaliana by regulating downstream related genes. Full article

CBF transcription factors (TFs) are key regulators of plant stress tolerance and play an integral role in plant tolerance to adverse growth environments. However, in the current research situation, there are few reports on the response of the CBF gene to Begonia stress. Therefore, this experiment investigated a novel CBF TF gene, named MbCBF2, which was isolated from M. baccata seedlings. According to the subcellular localization results, the MbCBF2 protein was located in the nucleus. In addition, the expression level of MbCBF2 was higher in new leaves and roots under low-temperature and high-salt induction. After the introduction of MbCBF2 into Arabidopsis thaliana, the adaptability of transgenic A. thaliana to cold and high-salt environments was significantly enhanced. In addition, the high expression of MbCBF2 can also change many physiological indicators in transgenic A. thaliana, such as increased chlorophyll and proline content, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activity, and reduced malondialdehyde (MDA) content. Therefore, it can be seen from the above results that MbCBF2 can positively regulate the response of A. thaliana to low-temperature and osmotic stress. In addition, MbCBF2 can also regulate the expression of its downstream genes in transgenic lines. It can not only positively regulate the expression of the downstream key genes AtCOR15a, AtERD10, AtRD29a/b and AtCOR6.6/47, related to cold stress at low temperatures, but can also positively regulate the expression of the downstream key genes AtNCED3, AtCAT1, AtP5CS, AtPIF1/4 and AtSnRK2.4, related to salt stress. That is, the overexpression of the MbCBF2 gene further improved the adaptability and tolerance of transgenic plants to low-temperature and high-salt environments. Full article

Brassinosteroids (BRs) are plant hormones that play an essential role in plant development and have the ability to protect plants against various environmental stresses, such as low and high temperature, drought, heat, salinity, heavy metal toxicity, and pesticides. Mitigation of stress effects are produced through independent mechanisms or by interaction with other important phytohormones. However, there are few studies in which this property has been reported for BRs analogs. Thus, in this work, the enhancement of drought stress tolerance of A. thaliana was assessed for a series of 2-deoxybrassinosteroid analogs. In addition, the growth-promoting activity in the Rice Lamina Inclination Test (RLIT) was also evaluated. The results show that analog 1 exhibits similar growth activity as brassinolide (BL; used as positive control) in the RLIT bioassay. Interestingly, both compounds increase their activities by a factor of 1.2–1.5 when they are incorporated to polymer micelles formed by Pluronic F-127. On the other hand, tolerance to water deficit stress of Arabidopsis thaliana seedlings was evaluated by determining survival rate and dry weight of seedlings after the recovery period. In both cases, the effect of analog 1 is higher than that exhibited by BL. Additionally, the expression of a subset of drought stress marker genes was evaluated in presence and absence of exogenous applied BRs. Results obtained by qRT-PCR analysis, indicate that transcriptional changes of AtDREBD2A and AtNCED3 genes were more significant in A. thaliana treated with analog 1 in homogeneous solution than in that treated with BL. These changes suggest the activation of alternative pathway in response to water stress deficit. Thus, exogenous application of BRs synthetic analogs could be a potential tool for improvement of crop production under stress conditions. Full article