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The phytohormone jasmonate (JA) coordinates stress and growth responses to increase plant survival in unfavorable environments. Although JA can enhance plant UV‐B stress tolerance, the mechanisms underlying the interaction of UV‐B and JA in this response remain unknown. In this study, we demonstrate that the UV RESISTANCE LOCUS 8 ‐ TEOSINTE BRANCHED1, Cycloidea and PCF 4 ‐ LIPOXYGENASE2 (UVR8‐TCP4‐LOX2) module regulates UV‐B tolerance dependent on JA signaling pathway in Arabidopsis thaliana. We show that the nucleus‐localized UVR8 physically interacts with TCP4 to increase the DNA‐binding activity of TCP4 and upregulate the JA biosynthesis gene LOX2. Furthermore, UVR8 activates the expression of LOX2 in a TCP4‐dependent manner. Our genetic analysis also provides evidence that TCP4 acts downstream of UVR8 and upstream of LOX2 to mediate plant responses to UV‐B stress. Our results illustrate that the UV‐B‐dependent interaction of UVR8 and TCP4 serves as an important UVR8‐TCP4‐LOX2 module, which integrates UV‐B radiation and JA signaling and represents a new UVR8 signaling mechanism in plants. [ABSTRACT FROM AUTHOR]

The flowering of Amorphophallus bulbifer (A. bulbifer) plays an important role in its reproduction. The flowers and leaves of A. bulbifer cannot grow at the same time. However, the physiological and molecular mechanisms involved in flower bud and leaf bud formation are still unclear. In this study, the flower buds and leaf buds of A. bulbifer in the early stage of growth were used as research materials, transcriptome and metabolome analyses were carried out, and the soluble sugar and starch contents of A. bulbifer corms were determined. Transcriptome analysis revealed 5542 differentially expressed genes (DEGs) between flower buds and leaf buds, 3107 of which were upregulated and 2435 of which were downregulated. Enrichment analysis of the KEGG pathway showed that these differential genes were enriched mainly in the plant hormone signal transduction, DNA replication and fatty acid elongation pathways. A total of 5296 significant differentially abundant metabolites were screened out by nontargeted metabolomics analysis. The differentially abundant metabolites were functionally classified in the HMDB, and 118 were successfully matched, including 17 that were highly expressed in flower buds. The differentially abundant metabolites in the flower buds were mainly enriched in pathways such as amino acid metabolism, isoquinoline alkaloid biosynthesis and pyrimidine metabolism. Targeted metabolomics analysis revealed that the contents of ABA, ZT and iPA in flower buds were significantly greater than those in leaf buds, while the opposite trend was observed for IAA. The analysis of soluble sugar and starch contents showed that the starch and soluble sugar contents in flower buds were significantly greater than those in leaf buds. The results of this study showed that flower bud development in A. bulbifer was regulated by amino acids, starch, ABA, ZT, iPA, IAA and other hormones. These findings could lead to valuable genetic resources for further study of A. bulbifer flowering and provide a deeper understanding of the molecular basis of A. bulbifer flowering. [ABSTRACT FROM AUTHOR]

Nitric oxide (NO) plays an important role in plant growth, development, and stress responses. The exogenous NO donor sodium nitroprusside (SNP) increased the plant height, root length, and biomass of tomato seedlings under nitrate stress, especially 100 μM SNP. The reactive oxygen species (ROS) and malondialdehyde (MDA) contents were decreased, while the antioxidant enzyme activities, ascorbate and glutathione contents, and expression of SlTrxh, SlNTRB, SlTpx were increased in tomato after SNP and nitrate stress treatment, compared with nitrate stress. The tomato plants showed shorter root length, more MDA and ROS contents after the NADPH-dependent thioredoxin reductase (NTR) inhibitor Auranofin (ANF) was added, suggesting that ANF inhibited the alleviating effect of NO under nitrate stress. The NO and S-nitrosothiol (SNO) contents and the SlNR transcript levels were decreased and the expression of SlGLB, SlGSNOR was increased after NO and nitrate stress treatment. The S-nitrosylated level in tomato roots was increased after nitrate stress. The SlMDHAR, SlTrxh, and SlNTRB protein were S-nitrosylated after NO and nitrate stress treatment. These results suggested that key enzymes in ascorbate-glutathione cycle and Trx system played an important role in alleviating the effect of NO in tomato seedlings under nitrate stress involving the S-nitrosylation modification. [ABSTRACT FROM AUTHOR]

Salinity is a prominent environmental stressor that significantly impacts plant growth and development. Here, we conducted research on the physiological and transcriptomic mechanism of a wild cucumber, Cucumis hystrix Chakr, under NaCl stress. Physiological data showed that contents of malondialdehyde, peroxide (H2O2), proline, soluble sugar, and activities of antioxidant enzymes of superoxide dismutase, peroxidase, ascorbate peroxidase, and glutathione reductase in wild cucumber plants were increased significantly after NaCl treatment. Transcriptomic analysis revealed that 3509 transcripts were differentially expressed in leaves and 5516 transcripts in roots after NaCl treatment. Numerous genes were related to the signal transduction, transcription factor, ion transport, osmotic metabolism, and reactive oxygen species scavenging. Moreover, the thioredoxin H type gene of Cucumis hystrix Chakr (ChTrxh) was isolated and characterized. Our study demonstrated that the transgenic tobacco plants overexpressing ChTrxh exhibited enhanced tolerance to NaCl stress compared to wild-type plants. These findings contribute valuable insights into the functional characteristics of important genes in wild cucumber under NaCl stress. [ABSTRACT FROM AUTHOR]

Nitric oxide (NO) modulates plant response by post-translationally modifying proteins, mainly through S-nitrosylation. Ascorbate peroxidase (APX) in the ascorbate-glutathione (AsA-GSH) cycle participates in the removal of hydrogen peroxide (H2O2). However, the relationship between S-nitrosylation and the role of tomato APX (SlAPX) under nitrate stress is still unclear. In this study, the enzyme activity, mRNA expression, and S-nitrosylation level of SlAPX were significantly increased in tomato roots after nitrate treatment. SlAPX protein could be S-nitrosylated by S-nitrosoglutathione in vitro, and APX activity was significantly increased after S-nitrosylation. The SlAPX overexpressed tobacco plants grew better than the wild type (WT) plants under nitrate stress. Meanwhile, the transgenic plants showed lower reactive oxygen species and malondialdehyde content, higher APX, monodehydroascorbate reductase, glutathione reductase activities, ascorbic acid/dehydroascorbic acid, and reduced glutathione/oxidized glutathione ratio, proline, and soluble sugar contents than those in the WT plants under nitrate treatment. Moreover, overexpressed transgenic seeds showed higher tolerance to methyl viologen induced oxidative stress compared with the WT. The NO accumulation and S-nitrosylation APX level were higher in transgenic plants than in WT plants after nitrate stress treatment. Our results provide novel insights into the mechanism of SlAPX modulation excess nitrate stress tolerance involving the S-nitrosylation modification. [ABSTRACT FROM AUTHOR]

Myelocytomatosis (MYC) transcription factors are crucial mediators of the jasmonate signaling pathway, which mediates the growth and developmental processes of plants. However, the function of MYC genes in tomato, Solanum lycopersicum (SlMYC), remains poorly understood. In this study, we have identified 14 non-redundant SlMYC genes across the genome of tomatoes. Six of the twelve chromosomes included these genes, and four syntenic pairs of SlMYC were identified. According to the results of phylogenetic analysis, 14 SlMYC genes were clustered into classes I, II, III, and IV, and their functional domains were predicted. The SlMYC upstream promoter region contained a variety of light-, stress-, and hormone-response regulatory elements. The expression of the 14 SlMYC genes differed significantly across organs. SlMYCs primarily showed an upregulation trend after methyl jasmonate (MeJA) treatment. In contrast, after treatment with sodium chloride (NaCl), SlMYCs showed a trend of downregulation. However, there were differences in the expression patterns of SlMYCs after mannitol treatment. Using clustered regularly interspaced short palindromic repeats/Cas 9 (CRISPR/Cas 9) technology, the loss-of-function of SlMYC1 (slmyc1) was obtained. The slmyc1 tomato plants demonstrated reduced resistance to NaCl and mannitol stress compared to wild-type plants due to their shorter root length and higher reactive oxygen species (ROS) content. In brief, this study provides valuable information about the taxonomy of the SlMYC genes in tomato. It establishes a foundation for future research on the mechanism by which SlMYC influences plant development and stress response. [ABSTRACT FROM AUTHOR]

Nitrogen (N) is one of the essential macronutrients that play important roles in plant growth and development. To better understand the response of antioxidant system and Nmetabolism under Nstarvation and re-supply condition, physiological and transcriptomic analyses were performed in tomato (Solanum lycopersicum L.). The malondialdehyde (MDA) and reactive oxygen species (ROS) contents increased significantly, while the superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and monodehydroascorbate reductase (MDHAR) activities, the ratio of ASA/DHA and GSH/GSSG, the NO3− contents, nitrate reductase (NR) activities decreased after Nstarvation treatment. Compared with the control, 1766 genes were up-regulated and 2244 genes were down-regulated after Nstarvation. These differentially expressed genes (DEGs) are mainly enriched in functional items such as cellular process, metabolic process and catalytic activity. The KEGG pathways revealed that the DEGs were mainly involved in phenpropane biosynthesis, amino sugar and nucleotide sugar metabolism, and Nmetabolism. The expression of SlSOD, SlCAT, SlAPX, SlMDHAR, SlTrxh, SlPrx, SlGrx, SlNRT2.4, SlNR, SlGS2, and SlNiR decreased after Nstarvation and increased after Nre-supply, which were validated by qRT-PCR. Our results provide abasis for understanding the response of tomato to Ndeficiency and resupply and atheoretical reference for cultivation regulation. [ABSTRACT FROM AUTHOR]

A symbiotic relationship is observed between Armillaria and the Chinese herbal medicine Gastrodia elata (G. elata). Armillaria is a nutrient source for the growth of G. elata, and its nutrient metabolism efficiency affects the growth and development of G. elata. Auxin has been reported to stimulate Armillaria species, but the molecular mechanism remains unknown. We found that naphthalene acetic acid (NAA) can also promote the growth of A. gallica. Moreover, we identified a total of 2071 differentially expressed genes (DEGs) by analyzing the transcriptome sequencing data of A. gallica at 5 and 10 hour of NAA treatment. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that these unigenes were significantly enriched in the metabolism pathways of arginine, proline, propanoate, phenylalanine and tryptophan. The expression levels of the general amino acid permease (Gap), ammonium transporter (AMT), glutamate dehydrogenase (GDH), glutamine synthetase (GS), Zn(II) 2Cys6 and C2H2 transcription factor genes were upregulated. Our transcriptome analysis showed that the amino acid and nitrogen metabolism pathways in Armillaria were rapidly induced within hours after NAA treatment. These results provide valuable insights into the molecular mechanisms by which NAA promotes the growth of Armillaria species. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H2O2) is an important signaling molecule that involved in multiple physiological metabolic processes in plants. Excess H2O2 can destroy biological macromolecules to poison the cell. Thioredoxin peroxidase (Tpx) plays an important role in protecting plants from oxidative damage by clearing H2O2. In this study, tomato Tpx (SlTpx) gene was cloned and bioinformatic analysis was done. The mRNA transcript level of SlTpx in tomato root and leaf was increased significantly after NaCl stress treatment for 12 h. SlTpx overexpression transgenic tobacco plants were obtained to study its function under NaCl stress. The seed germination rate of SlTpx overexpression plants was higher than that in wild type (WT) plants under NaCl treatment. The malondialdehyde (MDA) content and reactive oxygen species (ROS) accumulation in transgenic tobacco were less than in WT under NaCl stress. Transgenic plants had significantly higher antioxidant enzyme activities, proline and total soluble sugar contents, and expression of Na+ metabolism genes in transgenic plants than the WT. Moreover, The SlTpx transgenic seeds showed higher tolerance to H2O2 and methyl viologen (MV) treatment, compared with the WT. Besides, the growth of prokaryotic strain of pET-28a-SlTpx was better than the pET-28a strain with H2O2 treatment. The above results indicate that the SlTpx gene improves the plant salt tolerance by scavenging H2O2. Key message: Overexpression of tomato SlTpx gene in tobacco enhances the salt stress tolerance. [ABSTRACT FROM AUTHOR]

Phenolic glycosides are the important bioactive molecules, and their bioavailability can be influenced by enzyme hydrolysis, such as β-glucosidases (EC3.2.1.21) and other glycosyl hydrolases (GHs). Wood rotting fungi possess a superfamily of GHs, but little attention has been paid to the GHs and their potential applications in biotransformation of phenolic glycosides. In this study, two GH3 gene family members of Trametes trogii S0301, mainly expressed in the carbon sources conversion stage were cloned, and TtBgl3 coded by T_trogii _12914 showed β-glucosidase activity toward 4-nitrophenyl β-D-glucopyranoside (p NPG). The recombinant TtBgl3 preferred an intermediately neutral optimum pH with >80% of the maximum activity at pH 5.0–7.0 and was stable at a wide range of pH (5.0–10.0). Phenolic glycosides transformation experiments showed that TtBgl3 was a dual-activity enzyme with both activities of aryl-β-D-glucosidase and β-glucuronidase, and could hydrolyze the β-glucoside/glucuronide bond of phenolic glycosides. Under optimized conditions, the recombinant TtBgl3 had much higher transformation efficiency toward the β-glucoside bond of gastrodin, esculin and daidzin than β-glucuronide bond of baicalin, with the transformation rate of 100 and 50%, respectively. Our homology modeling, molecular docking, and mutational analysis demonstrated that His85 and Lys467 in the acceptor-binding pocket of TtBgl3 were the potential active sites. The point mutation of His85 and Lys467 leads to the significantly impaired catalytic activity toward p NPG and also the weak transformation efficiency toward gastrodin. These findings provide insights for the identification of novel GH3 β-glucosidases from T. trogii and other wood-rotting fungi. Furthermore, TtBgl3 might be applied as green and efficient biological catalysts in the deglycosylation of diverse phenolics to produce bioactive glycosides for drug discovery in the future. [ABSTRACT FROM AUTHOR]

SUMMARY: To survive, sessile plants must adapt to grow and develop when facing water‐deficit stress. However, the molecular mechanisms underlying fine‐tuning of the antagonistic action between stress response and growth remain to be determined. Here, plants overexpressing Lateral Organ Boundaries Domain 15 (LBD15) showed abscisic acid (ABA) hypersensitivity and tolerance of water‐deficit stress, whereas the loss‐of‐function mutant lbd15 presented decreased sensitivity to ABA and increased sensitivity to water‐deficit stress. Further analysis revealed that LBD15 directly binds to the promoter of the ABA signaling pathway gene ABSCISIC ACID INSENSITIVE4 (ABI4) to activate its expression, thereby forming an LBD15–ABI4 cascade to optimally regulate ABA signaling‐mediated plant growth and tolerance of water‐deficit stress. In addition, drought stress‐induced ABA signaling promoted LBD15 expression, which directly activates expression of ABI4 to close stomata. As a result, water loss is reduced, and then water‐deficit stress tolerance is increased. The results of this study reveal a molecular mechanism by which LBD15 coordinates and balances plant growth and resistance to water‐deficit stress. [ABSTRACT FROM AUTHOR]

A thermo-activation and thermostable laccase isoenzyme (Lac 37 II) produced by Trametes trogii S0301 at 37°C was purified to apparent homogeneity by anionic exchange chromatography and sephadex G-75 chromatography, with 12.3% of yeiled and a specific activity of 343.1 U mg–1. The molecular weight of the purified Lac 37 II was estimated to be approximately 56 kDa in 12% sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The optimal pH and temperature for the protein was 2.7 and 60°C, respectively. The purified Lac 37 II showed higher resistance to all tested metal ions and organic solvents except for Fe2+ and Cd2+ at 37°C and the activity of the purified Lac 37 was significantly enhanced by Cu2+ at 50 mM. The K cat , K m , and K cat / K m of Lac 37 II were 2.977 s–1, 16.1 μM, and 184.9 s–1 μM–1, respecively, in the condition of pH 2.7 and 60°C using ABTS as a substrate. Peptide-mass fingerprinting analysis showed that the Lac 37 II matched to the gene-deduced sequences of lcc3 in T. trogii BAFC 463, other than Lcc1 , Lcc 2 , and Lcc 4. Compared with laccase prepared at 28°C, the onset of thermo-activation of Lac 37 II activity occurred at 30°C with an increase of 10%, and reached its maximum at the temperatures range of 40–60°C with an increase of about 40% of their original activity. Furthermore, Lac 37 II showed the efficient decolorization ability toward triphenylmethane dyes at 60°C, with decolorization rates of 100 and 99.1% for 25 mg L–1 malachite and crystal violet in 5 h, respectively, when hydroxybenzotriazole (HBT) was used as a mediator. In conclusion, it is the first time to report a thermo-activation laccase from a thermophilic T. trogii strain, which has a better enzyme property and higher decolorization ability among fungal laccases, and it also has a further application prospective in the field of biotechnology. [ABSTRACT FROM AUTHOR]

To investigate the function of 14-3-3 protein in response to excess nitrate stress, a 14-3-3 protein, designated as So14-3-3 , was isolated from spinach. Phylogenetic analysis demonstrated that So14-3-3 belongs to non-ε group of 14-3-3 superfamily. Real time-quantitative RT-PCR and western blot analysis showed that So14-3-3 was induced by excess nitrate stress in spinach roots and leaves. After nitrate treatment, the phosphorylated H + -ATPase and nitrate reductase (NR) increased and decreased respectively. Co-Immunoprecipitation (Co-IP) suggested that the interaction of So14-3-3 with the phosphorylated H + -ATPase enhanced, but reduced with phosphorylated NR in spinach roots after nitrate treatment. Besides, 5 proteins interacted with So14-3-3 were found by Co-IP and LC-MS/MS analysis. So14-3-3 overexpressing transgenic tobacco plants showed enhanced tolerance to nitrate treatment at the germination and young seedlings stage. The transgenic plants showed longer root length, lower malondialdehyde (MDA), H 2 O 2 , protein carbonyl contents, relatively higher soluble sugar and protein contents, than the WT plants after nitrate treatment. The phosphorylation levels of H + -ATPase in transgenic plants were higher than the WT plants after nitrate treatment, whereas NR were lower. Additionally, in transgenic plants, the interaction of So14-3-3 with phosphorylated H + -ATPase and NR increased and decreased more than the WT plants under nitrate stress, leading to higher H + -ATPase and NR activities in transgenic plants. These data suggested that So 14-3-3 might be involved in nitrate stress response by interacting with H + -ATPase and NR. [ABSTRACT FROM AUTHOR]

Plant sterols are important multifunctional lipids, which are involved in determining membrane properties. Sterol C24 methyltransferase2 (SMT2) governs the pattern of phytosterols synthesized in higher plants. In this study, the spinach sterol C24 methyltransferase2 ( SoSMT2 ) cDNA was cloned by RT-PCR and RACE-PCR. The full length of SoSMT2 consists of 1614 bp, including a 278 bp 5′-untranslated region (UTR), a 1086 bp open reading frame (ORF), and a 250 bp 3′-UTR. The SoSMT2 gene encodes a polypeptide of 361 amino acid residues with a predicted molecular mass of 40.47 kDa. RT-PCR analysis indicated that the expression of SoSMT2 was induced by excess nitrate in the root and shoot of spinach. The transcript level of SoSMT2 was decreased by NaCl treatment. In contrast, dehydration, and H 2 O 2 treatment increased the transcript levels of SoSMT2 . To examine the biological roles of SoSMT2 in stress responses, transgenic Arabidopsis plants that constitutively overexpress SoSMT2 under the control of cauliflower mosaic virus 35S promoter were generated. The germination rate of transgenic seeds was higher than wild type (WT) in MS medium supplemented with 160 mM nitrate. When seedlings were transferred to MS liquid medium with 160 mM nitrate for 0, 8, 24 and 48 h, the transgenic plants showed lower levels of MDA and H 2 O 2 contents, compared with WT plants. Additionally, transgenic plants had relatively higher SOD, CAT and POD activities and soluble sugar contents than WT plants under nitrate stress with the increasing of treatment time. These data suggest that SoSMT2 is involved in nitrate tolerance in spinach. [ABSTRACT FROM AUTHOR]

Effect of nitrate (NO3 −) on lipid peroxidation, activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), soluble sugar, and proline accumulation were investigated in cucumber [Cucumis sativus L. cv. ‘Xintaimici’ (salt-tolerant) and ‘Shennongchunwu’ (salt-sensitive)] seedlings treated with 14 (control) and 140 mM NO3 − for seven days. The results showed that excess NO3 − increased malondialdehyde (MDA) content and electrolyte leakage in cucumber roots of both cultivars, and the degree of increase was higher in ‘Shennongchunwu’. The activities of SOD, CAT, POD, and APX increased in the roots of ‘Xintaimici’, but decreased in roots of ‘Shennongchunwu’, with respect to the control plants. Compared to the control, the soluble sugar and proline content increased in the cucumber roots of both cultivars, especially in ‘Xintaimici’. These results suggested that ‘Xintaimici’ tolerance to NO3 − stress may partly be due to higher activities of antioxidant enzymes and accumulation of osmotic regulation substances. [ABSTRACT FROM AUTHOR]

Abstract: Mitogen-activated protein kinase (MAPK) cascades play a key role in plant growth and development as well as biotic and abiotic stress response. To unravel the roles of MAPK in cucumber, its expression in transgenic cucumber plants was reduced by an antisense approach. For this purpose, a 1113bp cDNA fragment of cucumber MAPK gene (CsNMAPK) was expressed in antisense orientation driven by the 35S promoter of cauliflower mosaic virus. The pBI-CsNMAPK plasmid DNA was introduced into cucumber embryo by the pollen-tube pathway method. All seeds were sown in the soil and screened for transformants with kanamycin, polymerase chain reaction (PCR), Northern blot and real-time quantitative reverse transcriptative PCR (RT-PCR) analysis. Two independent transgenic plants were obtained and analyzed. The results showed that the transgenic cucumber plants exhibited retarded growth. The transgenic plant height was shorter and the leaves were smaller. Transgenic cucumber plants suppression CsNMAPK were more sensitive to salt stress than the wild-type (WT) plants. The fresh weight of shoot of the transgenic plants decreased more than WT after 50mM NaCl treatment for 7 days. The malondialdehyde (MDA) content was higher, while the superoxide dismutase (SOD) activity and proline accumulation were lower in the transgenic plants than the WT plants after NaCl stress treatment. The evidence indicated that CsNMAPK was involved in positive regulation of reactive oxygen species (ROS) scavengence and osmotic adjustment under salt stress. [ABSTRACT FROM AUTHOR]

Manganese peroxidases (MnPs), gene family members of white-rot fungi, are necessary extracellular enzymes that degrade lignocellulose and xenobiotic aromatic pollutants. However, very little is known about the diversity and expression patterns of the MnP gene family in white-rot fungi, especially in contrast to laccases. Here, the gene and protein sequences of eight unique MnP genes of T. trogii S0301 were characterized. Based on the characteristics of gene sequence, all TtMnPs here belong to short-type hybrid MnP (type I) with an average protein length of 363 amino acids, 5–6 introns, and the presence of conserved cysteine residues. Furthermore, analysis of MnP activity showed that metal ions (Mn2+ and Cu2+) and static liquid culture significantly influenced MnP activity. A maximum MnP activity (>14.0 U/mL) toward 2,6-DMP was observed in static liquid culture after the addition of Mn2+ (1 mM) or Cu2+ (0.2 or 2 mM). Moreover, qPCR analysis showed that Mn2+ obviously upregulated the Group I MnP subfamily (T_trogii_09901, 09904, 09903, and 09906), while Cu2+ and H2O2, along with changing temperatures, mainly induced the Group II MnP subfamily (T_trogii_11984, 11971, 11985, and 11983), suggesting diverse functions of fungal MnPs in growth and development, stress response, etc. Our studies here systematically analyzed the gene structure, expression, and regulation of the TtMnP gene family in T. trogii, one of the important lignocellulose-degrading fungi, and these results extended our understanding of the diversity of the MnP gene family and helped to improve MnP production and appilications of Trametes strains and other white-rot fungi. [ABSTRACT FROM AUTHOR]

Abstract: Mitogen-activated protein kinases (MAPKs) play important roles in the transduction of extracellular signals to the intracellular targets in all eukaryotes. Here, a cucumber cDNA designated CsNMAPK, encoding a mitogen-activated protein kinase was isolated using RT-PCR, 3′ and 5′ RACE. The full-length cDNA sequence contains 1636bp and an open reading frame (ORF) of 1113bp, which encodes 370 amino acid residues. According to the phylogenetic analysis, CsNMAPK belongs to subgroup I MAPK in plants. Northern blot analysis revealed that CsNMAPK expressed differently in response to excess NO3 −. And the CsNMAPK expression kinetics between a salt-resistant cultivar (Xintaimici) and a salt-sensitive cultivar (Shennongchunwu) was slightly different under 182mmolL−1 NO3 − treatment. The mRNA levels also increased after 24h treatments with H2O2 and salicylic acid (SA), but decreased with abscisic acid (ABA) and low-temperature. However, there was no significant induction of CsNMAPK gene after 24h drought and high-temperature treatments. Our results suggested that a MAP kinase cascade may function in excess NO3 − and other abiotic stresses in cucumber. [Copyright &y& Elsevier]

Introduction: Introduction: hypertension and diabetes are chronic disorders associated with an increased risk of cardiovascular disease. Objectives: to evaluate the effect of 52 % low-sodium salt applied to the Chinese-modified DASH (CM-DASH) diet on risk of atherosclerotic cardiovascular disease (ASCVD) in patients with hypertension and type-2 diabetes. Methods: the low-sodium salt group (LSSG) took 5 g/day of 52 % low-sodium salt plus CM-DASH diet for 8 weeks, while the normal-sodium salt group (NSSG) took the same dose of normal-sodium salt plus CM-DASH diet for 8 weeks. Blood tests, 24-hour urine tests, anthropometric measurements, and 10-year risk of ASCVD prediction were assessed. Results: compared with baseline, both LSSG and NSSG showed a significant reduction in 10-year risk of ASCVD, but we did not find any statistically significant differences in 10-year risk of ASCVD between LSSG and NSSG. Conclusions: our study shows that salt limits and DASH diets reduce the risk of cardiovascular disease whereas low-sodium salt containing 52 % sodium chloride did not significantly lower the risk of cardiovascular disease when compared to regular salt. Due to the limitations of the research, additional studies will be necessary to confirm our findings. [ABSTRACT FROM AUTHOR]

Abstract Hydrogen sulfide (H 2 S) is emerging as a potential messenger molecule involved in modulation of physiological processes in plants. Mitogen-activated protein kinase (MAPK) and nitric oxide (NO) are essential for abiotic stress signaling. This work investigated the effects of H 2 S and the crosstalk between H 2 S, MAPK and NO in cucumber roots under nitrate stress. The inhibitory effect of 140 mM nitrate on the growth of shoot and root was substantially alleviated by treatment with H 2 S donor sodium hydrosulfide (NaHS), especially 100 μM NaHS. Treatment with 100 μM NaHS reduced malondialdehyde (MDA) and H 2 O 2 contents, ROS accumulation and increased the activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX). CsNMAPK transcript level was up-regulated by NaHS treatment, while significantly decreased by propargylglycine (PAG, specific inhibitor of H 2 S biosynthesis) and hypotaurine (HT, H 2 S scavenger) in cucumber roots under nitrate stress. NO accumulation was increased by NaHS treatment under nitrate stress, but reduced by HT, PAG and PD98059, indicating that NO might function downstream of MAPK and H 2 S. MAPK inhibitor PD98059 and NO scavenger (cPTIO) reversed the alleviating effect of H 2 S by increasing MDA and H 2 O 2 contents, and decreasing antioxidant enzyme activities of SOD, CAT, POD, APX, and the endogenous H 2 S contents and LCD activities under nitrate stress. In conclusion, H 2 S played a protective role in cucumber seedlings under nitrate stress and MAPK/NO signaling were involved in the process by regulating antioxidant enzyme activities. Highlights • H 2 S could alleviate the oxidative damage caused by excess nitrate stress by enhancing antioxidant enzyme activities. • CsNMAPK transcript level and NO accumulation were increased by NaHS treatment under nitrate stress. • MAPK inhibitor PD98059 and NO scavenger (cPTIO) reversed the alleviating effect of H 2 S. [ABSTRACT FROM AUTHOR]

Soil secondary salinization caused by excess nitrate addition is one of the major obstacles in greenhouse vegetable production. Excess nitrate inhibited the growth of tomato plants, while application of 100 μM H 2 S donor NaHS efficiently increased the plant height, fresh and dry weight of shoot and root, root length, endogenous H 2 S contents and L-cysteine desulfhydrases activities. NaHS altered the oxidative status of nitrate-stressed plants as inferred by changes in reactive oxygen species (ROS) accumulation and lipid peroxidation accompanied by regulation of the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX). Besides, NaHS increased the nitric oxide (NO) and total S-nitrosothiols (SNOs) contents, nitrate reductase (NR) activities and decreased the S-nitrosoglutathione reductase (GSNOR) activities under nitrate stress. Furthermore, microarray analysis using the Affymetrix Tomato GeneChip showed that 5349 transcripts were up-regulated and 5536 transcripts were down-regulated under NaHS and excess nitrate stress treatment, compared to the excess nitrate stress alone. The differentially expressed genes (log 2 fold change >2 or <  −2) of up-regulated (213) and down-regulated (271) genes identified were functionally annotated and subsequently classified into 9 functional categories. These categories included metabolism, signal transduction, defence response, transcription factor, protein synthesis and protein fate, transporter, cell wall related, hormone response, cell death, energy and unknown proteins. Our study suggested exogenous NaHS might enhance excess nitrate stress tolerance of tomato plants by modulating ROS and reactive nitrogen species (RNS) signaling and downstream transcriptional adjustment, such as defence response, signal transduction and transcription factors. [ABSTRACT FROM AUTHOR]

In this study, the role of nitric oxide (NO) in response to excess nitrate stress in spinach was investigated. The results showed that excess nitrate stress provoked a significant reduction in the seedling growth and an increase in lipid peroxidation and H 2 O 2 content in spinach. The gene and protein expression of nitrate reductase and non-symbiotic hemoglobin were up-regulated, while S-nitrosoglutathione reductase (GSNOR) was down-regulated with the accumulation of NO and total S -nitrosothiols (SNOs) after 160 mM nitrate treatment for 24 h. Nitrate stress treatment increased the S -nitrosylation level of spinach. Using biotin-switch coupled with LC–MS/MS method, several proteins were identified as targets of S -nitrosylation including ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit, phosphoglycerate kinase, 23 kDa oxygen-evolving protein (OEC), 16 kDa protein of the photosynthetic OEC, and ribulose-1,5-bisphosphate carboxylase oxygenase. We further demonstrated that exogenous NO donor (SNP) increased the superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR) and GSNOR activities, which would reduce reactive oxygen species (ROS) and reactive nitrogen species (RNS) contents and thereby enhance spinach tolerance to nitrate stress. Suppressing NO accumulation by NR inhibitor, NOS inhibitor, and NO scavenger aggravated the damage to spinach under nitrate stress. These results suggest that NO acts as an essential signal to enhance spinach tolerance to nitrate stress via reducing ROS and RNS toxicity. [ABSTRACT FROM AUTHOR]

Abstract: Phospholipase D (PLD; EC3.1.4.4) is thought to have a crucial role in plant signal transduction. Here, a full-length cDNA clone encoding PLD was isolated from cucumber (Cucumis sativus L.) by RT-PCR and RACE. The 2756-bp full-length cDNA sequence of cucumber PLD (CsPLD) contains an open reading frame of 2427bp encoding 808 amino acids. The deduced amino acid sequence showed high sequence similarities with PLDs from other plant species. According to the phylogenetic analysis, CsPLD belongs to PLDα group and contains two characteristic HKD motifs, one IYIENQFF motif and one C2 domain. The tertiary structure of the CsPLD protein was also predicted and found to be composed mainly of random coils. In both the salt-tolerant ‘Xintaimici’ and salt-sensitive ‘Shennongchunwu’ cultivars, CsPLD expression differed among roots, stems, leaves, flowers and mature fruit; expression was highest in leaves and lowest in fruit. The transcript level of CsPLD in salt-tolerant cucumber was higher than that in the salt-sensitive cucumber plants after 182mmolL−1 nitrate treatment. CsPLD expression in both Xintaimici and Shennongchunwu increased with increasing nitrate concentration, although CsPLD mRNA expression in roots of Shennongchunwu peaked at 140mmolL−1 nitrate and then decreased. In addition, CsPLD expression was induced in leaves of both cultivars by various treatments, including abscisic acid, salicylic acid, NaCl, drought and low temperature; however, there was no significant induction in its expression following treatment for 30min with either H2O2 or high temperature. In roots, there was a significant increase in CsPLD expression following all treatments in both cultivars, except in the roots of Xintaimici in response to H2O2. These results suggest that, in cucumber, PLD functions under conditions of excess nitrate and other abiotic stresses. [Copyright &y& Elsevier]

Abstract: The effects of silicon (Si) application on plant growth, pigments, photosynthetic parameters, chlorophyll a (Chl a) fluorescence parameters and nitrogen metabolism were studied in Cucumis sativus L. under cadmium (Cd) toxicity. Compared with the control, 100μM CdCl2 treatment caused dramatic accumulation of Cd in cucumber leaves, greatly induced chlorosis, and the transmission electron microscope (TEM) analysis indicated that Cd treatment cucumber chloroplast showed obvious swollen, thylakoids and chloroplast membrane were seriously damaged, and could not be observed clearly. Application of Si reversed the chlorosis, protected the chloroplast from disorganization, and significantly increased the pigments contents, which might be mainly responsible for the higher photosynthetic rate and accumulation of biomass under Cd stress. Further investigation of chlorophyll a fluorescence indicated that Cd treatment decreasing photosynthesis was not due to stomatal restriction, while was closely related integrity damage or function lost of the photosynthetic machinery which can be concluded from the higher intercellular CO2 concentration (Ci) and lower F v/F m and ΦPSII. Application of Si alleviated the inhibited level of photosynthesis and F v/F m and ΦPSII by Cd, which might imply that Si plays important roles in protecting photosynthetic machinery from damaging. The Cd treatment also greatly inhibited the enzymes of nitrogen metabolism including nitrogen reductase (NR), glutamine synthetase (GS), glutamate synthase (GOGAT) and glutamate dehydrogenase (GDH), and Si supply decreased the inhibiting effects of Cd. [Copyright &y& Elsevier]

• Cys54 is important for SlTrxh activity. • SlTrxh overexpression tobacco enhance nitrate stress tolerance. • SlTrxh interacte with SlPrx. The thioredoxin (Trx) system plays a vital function in cellular antioxidative defense. However, little is known about Trx in tomato under excess nitrate. In this study, we isolated the tomato gene encoding h-type Trx gene (SlTrxh). The mRNA transcript of SlTrxh in roots and leaves of tomato was induced incrementally under excess nitrate for 24 h. Subcellular localization showed that SlTrxh might localize in the cytoplasm, nucleus and plasma membrane. Enzymatic activity characterization revealed that SlTrxh protein possesses the disulfide reductase function and Cysteine (Cys) 54 is important for its activity. Overexpressing SlTrxh in tobacco resulted in increasing seed germination rate, root length and decreasing H 2 O 2 and O 2 − accumulation, compared with the wild type (WT) tobacco under nitrate stress. While overexpressing SlTrxhC54S (Cysteine 54 mutated to Serine) in tobacco showed decreased germination rate and root length compared with the WT after nitrate treatment. After nitrate stress treatment, SlTrxh overexpressing transgenic tobacco plants have lower malonaldehyde (MDA), H 2 O 2 contents and Reactive Oxygen Species (ROS) accumulation, and higher mRNA transcript level of NtP5CS , NtDREB2 , higher ratio of ASA/DHA and GSH/GSSG, higher activities of ascorbate peroxidase and NADP thioredoxin reductase. Besides, SlTrxh overexpressing plants showed higher tolerance to Methyl Viologen (MV) in the seed germination and seedling stage. The yeast two-hybrid, pull-down, Co-immunoprecipitation and Bimolecular luciferase complementation assay confirmed that SlTrxh physically interacted with tomato peroxiredoxin (SlPrx). These results suggest that SlTrxh contributes to maintaining ROS homeostasis under excess nitrate stress interacting with SlPrx and Cys54 is important for its enzyme activity. [ABSTRACT FROM AUTHOR]

• Proper NaHS concentration can promote the growth of tomato seedlings. • NaHS increase activities of key enzymes of nitrogen metabolism and the content of nitrate in tomato seedlings. • The molecular mechanism of 100 μM NaHS promoting tomato growth was revealed by microarray. • NaHS improves growth of tomato seedlings involving the MAPK signaling through microarray and MAPK inhibitor analysis. As a signal molecule, hydrogen sulfide (H 2 S) plays an important role in plant growth. In this study, the effect of different concentration of H 2 S donor, sodium hydrosulfide (NaHS), on growth of tomato seedlings was tested in hydroponic culture. The effects of 50 μM NaHS on tomato seedlings were not significant, compared with the control. After 100 μM NaHS treatment, plant height, shoot fresh weight and dry weight increased significantly. However, 300, 500 and 1000 μM NaHS had inhibitory effect on tomato seedlings, especially 1000 μM NaHS. 100 μM NaHS could increase chlorophyll a, chlorophyll b, and total chlorophyll content, stomatal conductance, net photosynthetic rate, transpiration rate and intercellular CO 2 concentration. The activities of nitrate reductase, glutamate synthase and glutamine synthase, and L-cysteine demethylase (LCD), and nitrate content, were increased significantly after 100 μM NaHS treatment. The microarray results showed that 9122 genes changed after treated with 100 μM NaHS for 3 h, and 430 genes changed more than 2 times. These genes were grouped into metabolism, signal transduction, stress resistance, transcription factors, transport, protein synthesis and degradation, hormone response, and cell wall related genes in tomato seedlings. RT-PCR analysis showed that the expression of some MAPK family genes changed significantly when exogenous NaHS was added, especially SlMAPK3 and SlMAPK13. The MAPK inhibitor PD98059 reduce the LCD activity and H 2 S content in tomato seedlings, which indicated that MAPK signaling pathway was involved in the process of H 2 S promoting tomato seedling growth. [ABSTRACT FROM AUTHOR]

Introduction: Dandelion is widely used in clinical practice due to its beneficial effects. Polyphenolic compounds are considered the main anti-inflammatory active ingredient of dandelion, but the gene expression patterns of polyphenolic compounds in different dandelion tissues are still unclear., Methods: In this study, we combined a nontargeted metabolome, PacBio Iso-seq transcriptome, and Illumina RNA-seq transcriptome to investigate the relationship between polyphenols and gene expression in roots, flowers, and leaves of flowering dandelion plants., Results: Eighty-eight flavonoids and twenty-five phenolic acids were identified, and 64 candidate genes involved in flavonoid biosynthesis and 63 candidate genes involved in chicoric acid biosynthesis were identified. Most flavonoid and chicoric acid-related genes demonstrated the highest content in flowers. RNA-seq analysis revealed that genes involved in polyphenol biosynthesis pathways, such as CHS, CHI, F3H, F3'H, FLS, HQT, and CAS, which are crucial for the accumulation of flavonoids and chicoric acid, were upregulated in flowers., Discussion: The combination of transcriptomic and metabolomic data can help us better understand the biosynthetic pathways of polyphenols in dandelion. These results provide abundant genetic resources for further studying the regulatory mechanism of dandelion polyphenol biosynthesis., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Zhao, Li, Huang, Shen, Xu and Li.)

Nitric oxide (NO) is a redox-dependent signaling molecule that plays a crucial role in regulating a wide range of biological processes in plants. It functions by post-translationally modifying proteins, primarily through S-nitrosation. Thioredoxin (Trx), a small and ubiquitous protein with multifunctional properties, plays a pivotal role in the antioxidant defense system. However, the regulatory mechanism governing the response of tomato Trxh (SlTrxh) to excessive nitrate stress remains unknown. In this study, overexpression or silencing of SlTrxh in tomato led to increased or decreased nitrate stress tolerance, respectively. The overexpression of SlTrxh resulted in a reduction in levels of reactive oxygen species (ROS) and an increase in S-nitrosothiol (SNO) contents; conversely, silencing SlTrxh exhibited the opposite trend. The level of S-nitrosated SlTrxh was increased and decreased in SlTrxh overexpression and RNAi plants after nitrate treatment, respectively. SlTrxh was found to be susceptible to S-nitrosation both in vivo and in vitro , with Cysteine 54 potentially being the key site for S-nitrosation. Protein interaction assays revealed that SlTrxh physically interacts with SlGrx9, and this interaction is strengthened by S-nitrosation. Moreover, a combination of yeast one-hybrid (Y1H), electrophoretic mobility shift assay (EMSA), chromatin immunoprecipitation-quantitative PCR (ChIP-qPCR), and transient expression assays confirmed the direct binding of SlMYB86 to the SlTrxh promoter, thereby enhancing its expression. SlMYB86 is located in the nucleus and SlMYB86 overexpressed and knockout tomato lines showed enhanced and decreased nitrate stress tolerance, respectively. Our findings indicate that SlTrxh functions downstream of SlMYB86 and highlight the potential significance of S-nitrosation of SlTrxh in modulating its function under nitrate stress., Competing Interests: We declare the absence of any conflicts of interest., (© The Author(s) 2024. Published by Oxford University Press on behalf of Nanjing Agricultural University.)

Introduction: Background and purpose: the Dietary Approaches to Stop Hypertension (DASH) diet has multifunctional health benefits. We evaluated the effects of low-sodium salt applied to Chinese modified DASH diet on arterial stiffness in older patients with hypertension and type 2 diabetes. Methods: sixty-one older adults with hypertension and type 2 diabetes were randomly allocated to low sodium salt group (n = 31) or normal sodium salt group (n = 30). They were given the Chinese modified DASH diet plus low-sodium salt (52 % sodium chloride) or same diet plus regular salt (99 % sodium chloride) for eight weeks, respectively. Brachial and ankle pulse wave conduction velocity, ankle brachial index and atherosclerosis-related indices were measured at baseline and week 8. In addition, 24-hour urine and blood samples were measured at baseline, the 4th week and the end of the intervention. Results: as compared with the baseline, the low sodium salt group significantly decreased in ankle brachial index (-0.09 ± 0.11, p < 0.001) and brachial and ankle pulse wave conduction velocity (-133.07 ± 265.99 cm/s, p = 0.010) at week 8 while the normal sodium salt group only decreased significantly in ankle brachial index (-0.06 ± 0.12, p = 0.010) at week 8. Conclusion: the low-sodium salt applied to Chinese modified DASH diet may improve arterial stiffness in patients with hypertension and type 2 diabetes. Further research with an extended follow-up is needed.

Introduction: Aim: to investigate the effects of low sodium formula salt combined with the Chinese Modified Dietary Approaches to Stop Hypertension (DASH) diet on cerebrovascular function in patients with hypertension and type 2 diabetes. Methods: an eight-week single-arm trial was conducted in 66 patients with hypertension and type 2 diabetes to investigate effects of low sodium formula salt (potassium chloride 56 %, sodium chloride 23 %, 5 g/day) combined with Chinese Modified DASH diet on cerebrovascular function (measured by transcranial Doppler sonography), indicators of chronic diseases (blood pressure, blood glucose and blood lipids) and urinary excretion. The above indicators were performed before and after intervention. Results: fifty-nine subjects completed the study. Peak systolic velocity, mean flow velocity, end-diastolic velocity, pulsatility index and resistance index of internal cerebral artery and vertebral artery decreased significantly (p < 0.05); pulsatility index and resistance index of anterior cerebral artery and middle cerebral artery decreased significantly (p < 0.05); and end-diastolic velocity and pulsatility index of basilar artery decreased significantly (p < 0.05). Systolic blood pressure, diastolic blood pressure, fasting blood glucose and postprandial blood glucose decreased significantly (p < 0.001; p < 0.001; p < 0.001; p < 0.001). Blood pressure and blood glucose control rates increased significantly (p < 0.001). Conclusions: based on the study, 23 % low-sodium formula combined with CM-DASH diet pattern can improve cerebrovascular function in community patients with hypertension complicated with diabetes and has a good short-term benefit of blood pressure and glucose control.

Introduction: Introduction: hypertension and diabetes are chronic disorders associated with an increased risk of cardiovascular disease. Objectives: to evaluate the effect of 52 % low-sodium salt applied to the Chinese-modified DASH (CM-DASH) diet on risk of atherosclerotic cardiovascular disease (ASCVD) in patients with hypertension and type-2 diabetes. Methods: the low-sodium salt group (LSSG) took 5 g/day of 52 % low-sodium salt plus CM-DASH diet for 8 weeks, while the normal-sodium salt group (NSSG) took the same dose of normal-sodium salt plus CM-DASH diet for 8 weeks. Blood tests, 24-hour urine tests, anthropometric measurements, and 10-year risk of ASCVD prediction were assessed. Results: compared with baseline, both LSSG and NSSG showed a significant reduction in 10-year risk of ASCVD, but we did not find any statistically significant differences in 10-year risk of ASCVD between LSSG and NSSG. Conclusions: our study shows that salt limits and DASH diets reduce the risk of cardiovascular disease whereas low-sodium salt containing 52 % sodium chloride did not significantly lower the risk of cardiovascular disease when compared to regular salt. Due to the limitations of the research, additional studies will be necessary to confirm our findings.

Introduction: Objectives: to evaluate the effect of sodium reduction based on a modified DASH diet on blood pressure in hypertensive patients with type 2 diabetes. Material and methods: sixty-one hypertensive patients with type 2 diabetes were selected from the community and randomly allocated to a common salt group and low sodium salt group receiving the 8-week dietary intervention, in which weeks 1-2 was the dietary guidance phase, weeks 3-4 was the centralized feeding phase, and weeks 5-8 was the home medical care phase. Participants were followed up in the hospital once a week to collect information on outpatient blood pressure, salt, and drug use. Physical examinations were conducted at 4 weeks and the end of the intervention, as well as at baseline. Results: after the intervention, the blood pressure of both the low sodium group (SBP: -14.32 mmHg, p < 0.001; DBP: -6.32mmHg, p < 0.001) and the common salt group (SBP: -10.98 mmHg, p < 0.001; DBP: -5.24 mmHg, p = 0.001) decreased significantly with a more pronounced decrease in the low sodium group but no statistically significant differences between the two groups (SBP: -0.28 mmHg, p = 0.929; DBP: -3.32 mmHg, p = 0.093). At the end of the intervention, sodium intake was significantly decreased, but potassium intake was increased in the low sodium group (p < 0.05); however, the common salt group had no significant change. Conclusion: reducing sodium intake based on the modified DASH diet had a good effect on systolic and diastolic blood pressure in hypertensive patients with type 2 diabetes. Sodium reduction based on the modified DASH diet is safe and effective, and can be used as a guide for healthy living in hypertensive patients.

White-rot fungi, especially Trametes strains, are the primary source of industrial laccases in bioenergy and bioremediation. Trametes strains express members of the laccase gene family with different physicochemical properties and expression patterns. However, the literature on the expression pattern of the laccase gene family in T. trogii S0301 and the response mechanism to Cu 2+ , a key laccase inducer, in white-rot fungal strains is scarce. In the present study, we found that Cu 2+ could induce the mRNAs and proteins of the two alternative splicing variants of heat shock transcription factor 2 ( TtHSF2 ). Furthermore, the overexpression of alternative splicing variants TtHSF2α and TtHSF2β-I in the homokaryotic T. trogii S0301 strain showed opposite effects on the extracellular total laccase activity, with the maximum laccase activity of approximately 0.6 U mL -1 and 3.0 U mL -1 , respectively, on the eighth day, which is 0.4 and 2.3 times that of the wild type strain. Similarly, TtHSF2α and TtHSF2β-I play opposite roles in the oxidation tolerance to H 2 O 2 In addition, the direct binding of TtHSF2α to the promoter regions of the representative laccase isoenzymes ( TtLac1 and TtLac13 ) and protein-protein interactions between TtHSF2α and TtHSF2β-I were detected. Our results demonstrate the crucial roles of TtHSF2 and its alternative splicing variants in response to Cu 2+ We believe that these findings will deepen our understanding of alternative splicing of HSFs and their regulatory mechanism of the laccase gene family in white-rot fungi. Importance The members of laccase gene family in Trametes strains are the primary source of industrial laccase and have gained widespread attention. Increasing the yield and enzymatic properties of laccase through various methods has always been a topic worthy of attention, and there is no report on the regulation of laccase expression through HSF transcription factor engineering. Here, we found that two alternative splicing variants of TtHSF2 functioned oppositely in regulating the expression of laccase genes, and copper can induce the expression of almost all members of the laccase gene family. Most importantly, our study suggested that TtHSF2 and its alternative splicing variants are vital for copper-induced production of laccases in T. trogii S0301., (Copyright © 2021 American Society for Microbiology.)