Search Results (21)

Soil salinization is a major abiotic stressor that significantly reduces wheat yield. Identifying novel salt-tolerance genes and integrating them into wheat breeding programs can enhance wheat productivity in saline soils. Ethylene response factor (ERF) plays an important role in plant response to salt stress, and thus far, four wheat ERF genes have been identified to be involved in salt stress response. To systematically identify salt tolerance-related ERF genes in wheat, in this study, 213 ERF sequences were isolated from the whole genome of common wheat and classified into 54 members based on subgenome homology, named TaERF1 to TaERF54. Transcriptome sequencing results showed different expression patterns of TaERF members in leaves after 1, 6, 24, and 48 h of NaCl treatment. Based on association analysis, nine TaERF genes were correlated with the leaf salt injury index. Among them, five SNPs of TaERF16-B formed two haplotypes: Hap1 and Hap2. RT-qPCR results showed that the expression level of TaERF16-B was significantly higher in Hap2-typed germplasms than that in Hap1-typed germplasms after 1 and 6 h of NaCl treatment. A Kompetitive Allele-Specific PCR marker K52 was developed for genotyping TaERF16-B haplotypes, which further confirmed the significant correlation between TaERF16-B and salt tolerance-related phenotypes in mapping population and wheat germplasms. This study provides new genes and molecular markers for improving salt tolerance in wheat. Full article

Ubiquitin-specific proteases (UBPs), the largest subfamily of deubiquitinating enzymes (DUBs), are critical for plant growth and development as well as abiotic-stress responses. In this study, we discovered that the expression of the ubiquitin-specific protease 15 (UBP15) gene was induced by salt, mannitol and abscisic acid (ABA) treatments. Further research revealed that UBP15 is involved in modulation of salt, drought tolerance and ABA signaling during seed germination, early seedling development, post-germination root growth or adult-plant stage. Enrichment analysis showed that many genes related to abiotic stresses and metabolic pathways were altered in the ubp15-1 mutant. Through the joint analysis of the quantitative real-time polymerase chain reaction (qRT-PCR) and differentially-expressed gene relationship network, we found that UBP15 may mainly regulate salt-stress tolerance by modulating the dwarf and delayed flowering 1 (DDF1) pathway through a cascade reaction. In the regulation of drought-stress responses, ring domain ligase1 (RGLG1) may be a direct substrate of UBP15. Moreover, we cannot exclude the possibility that UBP15 acts in a feed-forward loop mechanism in the regulation of drought-stress responses via ethylene response factor 53 (ERF53) and its ubiquitin (Ub) ligase RGLG1. In ABA signal transduction, UBP15 may play a role in at least three aspects of the ABA signaling pathway: ABA synthesis, stomatal closure regulated by ABA signaling, and transcription factors in the ABA pathway. Taken together, our results suggest that UBP15 is involved in salt, osmotic, and drought-stress tolerance and the ABA signaling pathway by directly regulating the stability of key substrates or indirectly affecting the expression of genes related to abiotic stresses in Arabidopsis thaliana. Our research provides new germplasm resources for stress-resistant crops cultivation. These results demonstrate that UBP15 is a key regulator of salt, drought and ABA tolerance in Arabidopsis. Full article

Rice (Oryza sativa L.) serves as a substitute for bread and is a staple food for half of the world’s population, but it is heavily affected by insect pests. The fall armyworm (Spodoptera frugiperda) is a highly destructive pest, threatening rice and other crops in tropical regions. Despite its significance, little is known about the molecular mechanisms underlying rice’s response to fall armyworm infestation. In this study, we used transcriptome analysis to explore the global changes in gene expression in rice leaves during a 1 h and 12 h fall armyworm feeding. The results reveal 2695 and 6264 differentially expressed genes (DEGs) at 1 and 12 h post-infestation, respectively. Gene Ontology (GO) and KEGG enrichment analyses provide insights into biological processes and pathways affected by fall armyworm feeding. Key genes associated with hormone regulation, defense metabolic pathways, and antioxidant and detoxification processes were upregulated, suggesting the involvement of jasmonic acid (JA) signaling, salicylic acid biosynthesis pathways, auxin response, and heat shock proteins in defense during 1 h and 12 h after fall armyworm infestation. Similarly, key genes involved in transcriptional regulation and defense mechanisms reveal the activation of calmodulins, transcription factors (TFs), and genes related to secondary metabolite biosynthesis. Additionally, MYB, WRKY, and ethylene-responsive factors (ERFs) are identified as crucial TF families in rice’s defense response. This study provides a comprehensive understanding of the molecular dynamics in rice responding to fall armyworm infestation, offering valuable insights for developing pest-resistant rice varieties and enhancing global food security. The identified genes and pathways provide an extensive array of genomic resources that can be used for further genetic investigation into rice herbivore resistance. This also suggests that rice plants may have evolved strategies against herbivorous insects. It also lays the groundwork for novel pest-resistance techniques for rice. Full article

The present review is focused on current findings on the involvement of ethylene in seed biology. The responsiveness of seeds to ethylene depends on the species and the dormancy status, improving concentrations ranging from 0.1 to 200 μL L⁻¹. The signaling pathway of ethylene starts with its binding to five membrane-anchored receptors, which results in the deactivation of Constitutive Triple Response 1 (CTR1, a protein kinase) that does not exert its inhibitory effect on Ethylene Insensitive 2 (EIN2) by phosphorylating its cytosolic C-terminal domain. An analysis of germination in the presence of inhibitors of ethylene synthesis or action, and using seeds from mutant lines altered in terms of the genes involved in ethylene synthesis (acs) and the signaling pathway (etr1, ein2, ein4, ctr1 and erf1), demonstrates the involvement of ethylene in the regulation of seed dormancy. The promoting effect of ethylene is also regulated through crosstalk with abscisic acid (ABA) and gibberellins (GAs), essential hormones involved in seed germination and dormancy, and Reactive Oxygen Species (ROS). Using a mutant of the proteolytic N-degron pathway, Proteolysis (PRT6), the Ethylene Response Factors (ERFs) from group VII (HRE1, HRE2, RAP 2.2, RAP2.3 and RAP 2.12) have also been identified as being involved in seed insensitivity to ethylene. This review highlights the key roles of EIN2 and EIN3 in the ethylene signaling pathway and in interactions with different hormones and discusses the responsiveness of seeds to ethylene, depending on the species and the dormancy status. Full article

This study investigated the transcriptomic mechanisms underlying melatonin accumulation and the enhancement of salt tolerance in hull-less barley seeds subjected to zinc sulphate stress. Following zinc sulphate treatment, hull-less barley seeds demonstrated increased melatonin accumulation and improved salt tolerance. Through transcriptome analysis, the study compared gene expression alterations in seeds (using the first letter of seed, this group is marked as ‘S’), seeds treated with pure water (as the control group, is marked as ‘C’), and germinated seeds exposed to varying concentrations of zinc sulphate (0.2 mM and 0.8 mM, the first letter of zinc sulphate, ‘Z’, is used to mark groups ‘Z1’ and ‘Z2’). The analysis revealed that 8176, 759, and 622 differentially expressed genes (DEGs) were identified in the three comparison groups S.vs.C, C.vs.Z1, and C.vs.Z2, respectively. Most of the DEGs were closely associated with biological processes, including oxidative-stress response, secondary metabolite biosynthesis, and plant hormone signaling. Notably, zinc sulphate stress influenced the expression levels of Tryptophan decarboxylase 1 (TDC1), Acetylserotonin O-methyltransferase 1 (ASMT1), and Serotonin N-acetyltransferase 2 (SNAT2), which are key genes involved in melatonin synthesis. Furthermore, the expression changes of genes such as Probable WRKY transcription factor 75 (WRKY75) and Ethylene-responsive transcription factor ERF13 (EFR13) exhibited a strong correlation with fluctuations in melatonin content. These findings contribute to our understanding of the mechanisms underlying melatonin enrichment in response to zinc sulphate stress. Full article

Ethylene-Responsive Factor (ERF) is a key element found in the middle and lower reaches of the ethylene signal transduction pathway. It is widely distributed in plants and plays important roles in plant growth and development, hormone signal transduction, and various stress processes. Although there is research on AP/ERF family members, research on AP2/ERF in Osmanthus fragrans is lacking. Thus, in this work, AP2/ERF in O. fragrans was extensively and comprehensively analyzed. A total of 298 genes encoding OfAP2/ERF proteins with complete AP2/ERF domains were identified. Based on the number of AP2/ERF domains and the similarity among amino acid sequences between AP2/ERF proteins from A. thaliana and O. fragrans, the 298 putative OfAP2/ERF proteins were divided into four different families, including AP2 (45), ERF (247), RAV (5), and SOLOIST (1). In addition, the exon–intron structure characteristics of these putative OfAP2/ERF genes and the conserved protein motifs of their encoded OfAP2/ERF proteins were analyzed, and the results were found to be consistent with those of the population classification. A tissue-specific analysis showed the spatiotemporal expression of OfAP2/ERF in the stems and leaves of O. fragrans at different developmental stages. Specifically, 21 genes were not expressed in any tissue, while high levels of expression were found for 25 OfAP2/ERF genes in several tissues, 60 genes in the roots, 34 genes in the stems, 37 genes in young leaves, 34 genes in old leaves, 32 genes in the early flowering stage, 18 genes in the full flowering stage, and 37 genes in the late flowering stage. Quantitative RT-PCR experiments showed that OfERF110a and OfERF110b had the highest expression levels at the full-bloom stage (S4), and this gradually decreased with the senescence of petals. The expression of OfERF119c decreased first and then increased, while the expression levels of OfERF4c and OfERF5a increased constantly. This indicated that these genes may play roles in flower senescence and the ethylene response. In the subsequent subcellular localization experiments, we found that ERF1-4 was localized in the nucleus, indicating that it was expressed in the nucleus. In yeast self-activation experiments, we found that OfERF112, OfERF228, and OfERF23 had self-activation activity. Overall, these results suggest that OfERFs may have the function of regulating petal senescence in O. fragrans. Full article

Salinity stress poses a significant threat to crop productivity worldwide, necessitating effective mitigation strategies. This study investigated the phytochemical composition and potential of grape seed extract (GSE) to mitigate salinity stress effects on faba bean plants. GC–MS analysis revealed several bioactive components in GSE, predominantly fatty acids. GSE was rich in essential nutrients and possessed a high antioxidant capacity. After 14 days of germination, GSE was applied as a foliar spray at different concentrations (0, 2, 4, 6, and 8 g/L) to mitigate the negative effects of salt stress (150 mM NaCl) on faba bean plants. Foliar application of 2–8 g/L GSE significantly enhanced growth parameters such as shoot length, root length, fresh weight, and dry weight of salt-stressed bean plants compared to the control. The Fv/Fm ratio, indicating photosynthetic activity, also improved with GSE treatment under salinity stress compared to the control. GSE effectively alleviated the oxidative stress induced by salinity, reducing malondialdehyde, hydrogen peroxide, praline, and glycine betaine levels. Total soluble proteins, amino acids, and sugars were enhanced in GSE-treated, salt-stressed plants. GSE treatment under salinity stress modulated the total antioxidant capacity, antioxidant responses, and enzyme activities such as peroxidase, ascorbate peroxidase, and polyphenol oxidase compared to salt-stressed plants. Gene expression analysis revealed GSE (6 g/L) upregulated photosynthesis (chlorophyll a/b-binding protein of LHCII type 1-like (Lhcb1) and ribulose bisphosphate carboxylase large chain-like (RbcL)) and carbohydrate metabolism (cell wall invertase I (CWINV1) genes) while downregulating stress response genes (ornithine aminotransferase (OAT) and ethylene-responsive transcription factor 1 (ERF1)) in salt-stressed bean plants. The study demonstrates GSE’s usefulness in mitigating salinity stress effects on bean plants by modulating growth, physiology, and gene expression patterns, highlighting its potential as a natural approach to enhance salt tolerance. Full article

As a commercial potato sprout suppressant, ethylene (Eth) is usually used under a low temperature for long-term storage of potato tubers. However, in many cases, potato tubers are usually transferred from a refrigeration house and sold at room temperature. In the present research, Eth’s inhibitory effects on tuber sprouting at room temperature were investigated. The potential molecular mechanisms of Eth-induced sprout suppression were revealed by phytohormone and transcriptome analyses. Results showed that exogenous Eth significantly suppressed sprout growth in potato tubers during two weeks of storage. The endogenous plant hormone levels of abscisic acid (ABA) and auxin (Aux) were markedly reduced by Eth treatment. Transcriptomic analysis revealed that more transcriptional changes occurred in the early stage of sprouting. The differentially expressed genes (DEGs) assigned to the pathways of plant hormone signal transduction, photosynthesis, starch and sucrose metabolism and phenylpropanoid biosynthesis, which were closely associated with sprouting, were extensively down-regulated by Eth treatment. In addition, the heat map of six hormone signal transduction pathways showed that the expression of most DEGs annotated into the Aux signal transduction pathway was suppressed by Eth treatment, while the expression of many DEGs annotated as ETR (Eth receptor) and ERF1/2 (Eth-responsive transcription factor 1 and 2) in the Eth signal transduction pathway was enhanced by Eth treatment. Taken together, our results indicated that Eth-induced sprout inhibition might be closely related to the suppression of internal Aux production and signal transduction and the activation of Eth signal transduction. Full article

‘Huangguan’ pear (Pyrus bretschneideri Rehd. cv. Huangguan) is a widely planted cultivar in China. However, it is susceptible to core browning after harvest. In this study, aminoethoxyvinylglycine (AVG) was applied at 200 mg L⁻¹ one and two weeks prior to harvest, and its effects on fruit quality, ripening and core browning were investigated during fruit storage at ambient temperature (25 ± 1 °C). The results showed that there was higher firmness, soluble solids content (SSC) and titratable acid (TA) content, but a lower ethylene production rate and core browning index in AVG-treated fruit than in control (water). Compared with the control fruit, AVG treatment decreased the malondialdehyde (MDA) content and polyphenol oxidase (PPO) activity, delayed the peak of chlorogenic acid (CGA) content in the core tissue, and significantly inhibited the expression of genes such as ACC synthase (PbACS2, PbACS3a, PbACS5a and PbASC5b), ACC oxidase (PbACO1 and PbACO2), ethylene receptors (PbETR2 and PbERS1), ethylene response factor (PbERF1), phenylalanine ammonia lyase (PbPAL1), cinnamate 4-hydroxylase (PbC4H4), 4-hydroxycinnamoyl- CoA ligase (Pb4CL2), hydroxycinnamoyl- CoA shikimate hydroxycinnamoyl transferase (PbHCT1 and PbHCT3), and polyphenol oxidase (PbPPO1 and PbPPO5), as well as phospholipase D (PbPLD) and lipoxygenase (PbLOX1 and PbLOX5). Thus, these results suggested that the reduction in core browning by preharvest application of AVG might be due to an inhibitory effect on the expression of genes associated with ethylene biosynthesis and signaling pathways, CGA biosynthesis, PPO and cell membrane degradation in ‘Huangguan’ pear. Full article

(1) The phytohormones gibberellins (GAs) play a crucial role in plant growth and development, such as seed germination, flowering, fruiting, and stem elongation. Although many biological roles of GAs have been studied intensively, the molecular mechanisms of GAs in woody plants are still unclear. (2) In this study, we investigated the effects of exogenous application of GAs on Neolamarckia cadamba. (3) The height and biomass of N. cadamba increased after 7 days of GA treatment, especially on the second internode. Transcriptome analysis showed that although the majority of genes involved in the GA signaling pathway were up-regulated, the expression of GA20 oxidase (GA20ox) and GA3 oxidase (GA3ox) was down-regulated in the 3 days GA-treated group compared to the CK group. The expression of the cell elongation-related basic helix-loop-helix genes bHLH74 and bHLH49 was up-regulated in the GA-treated group compared with the CK group. Transcriptional expression levels of transcription factors involved in hormone signaling were changed, mainly including bHLH, ethylene response factor (ERF), and WRKY families. In addition, the transcriptional expression level of the key enzymes engaged in the phenylalanine pathway was downregulated after GA treatment. (4) In brief, our findings reveal the physiological and molecular mechanisms of exogenous GA treatment stimulation in N. cadamba. Full article

Abiotic stresses adversely influence crop productivity and salt stress is one limiting factor. Plants need to evolve their defense mechanisms to survive in such fluctuating scenarios at either the biochemical, physiological, or molecular level. The analytical/critical investigations of cotton (Gossypium hirsutum) plants that involve looking into transcriptomic and metabolomic profiles could give a comprehensive picture of the response of the cotton plant to salt stress. This study was conducted on pre-treated cotton seeds by soaking them in a 3% sodium chloride (NaCl) solution at room temperature for 0.5, 1, and 1.5 h. In total, 3738 and 285 differentially expressed genes (DEGs) and metabolites, respectively, were discovered. The prominent DEGs included AtCCC1, EP1, NHE, AtpOMT, GAST1, CLC-c, ARP, AtKIN14, AtC3H2, COP9, AtHK-2, and EID1 to code for the regulation of seed growth, abscisic acid receptor PYR/PYL, a cellular response regarding stress tolerance (especially to salt) and germination, jasmonic acid, salicylic acid, and auxin-activated signaling pathways. A more significant amount of transcription factors, including the ethylene-responsive TFs ERF (205), bHLH (252), ZF-domains (167), bHLH (101), MYB (92), NAC (83), GATA (43), auxin-responsive proteins (30), MADs-box (23), bZIP (27), and HHO (13) were discovered in samples of NaCl-pretreated cotton seedlings under different treatments. The functional annotations of DEGs exposed their important roles in regulating different phytohormones and signal-transduction-mediated pathways in salt-treated seeds. The metabolites analysis revealed differential accumulation of flavonols, phenolic acid, amino acids, and derivatives in seedling samples treated for 0.5 h with NaCl. The conjoint analysis that showed most of the DEGs were associated with the production and regulation of glucose-1-phosphate, uridine 5′-diphospho-D-glucose, and 2-deoxyribose 1-phosphate under salt stress conditions. These results indicated positive effects of NaCl 0.5 h treatments on seedlings’ germination and growth, seemingly by activating specific growth-promoting enzymes and metabolites to alleviate adverse effects of salt stress. Hence, seed pre-treatment with NaCl can be beneficial in future cotton management and breeding programs to enhance growth and development under salt stress. Full article

The first line of plant defence responses against pathogens can be induced by the bacterial flg22 and can be dependent on various external and internal factors. Here, we firstly studied the effects of daytime and ethylene (ET) using Never ripe (Nr) mutants in the local and systemic defence responses of intact tomato plants after flg22 treatments. Flg22 was applied in the afternoon and at night and rapid reactions were detected. The production of hydrogen peroxide and nitric oxide was induced by flg22 locally, while superoxide was induced systemically, in wild type plants in the light period, but all remained lower at night and in Nr leaves. Flg22 elevated, locally, the ET, jasmonic acid (JA) and salicylic acid (SA) levels in the light period; these levels did not change significantly at night. Expression of Pathogenesis-related 1 (PR1), Ethylene response factor 1 (ERF1) and Defensin (DEF) showed also daytime- and ET-dependent changes. Enhanced ERF1 and DEF expression and stomatal closure were also observable in systemic leaves of wild type plants in the light. These data demonstrate that early biotic signalling in flg22-treated leaves and distal ones is an ET-dependent process and it is also determined by the time of day and inhibited in the early night phase. Full article

Fragaria × ananassa Duch, which among the youngest fruit crops, comprises many popular cultivars that are famous for their favored color and aroma. The regulation roles of AP2/ERF (APETALA2/ethylene-responsive element-binding factor) transcription factors in fruit flavor and color regulation have been studied in several fruit crops. The AP2 family of strawberry, which was ignored in recent AP2/ERF identification studies, was explored in this study. A total of 64 FaAP2 (Fragaria × ananassa AP2) transcription factors belonging to the euAP2, euANT (AINTEGUMENTA), and baselANT groups were identified with canonical insertion motifs in two AP2 domains. The motif identification illustrated that motifs 1, 5, and 2 indicated a corresponding AP2 domain repeat 1 with a linker region, and motifs 6, 4, 3 indicated a corresponding AP2 domain repeat 2, all of which were highly conserved. By synteny analysis, FaAP2 paralogs were identified in each sub-genome, and FaAP2 gene duplication and loss explained the unequal AP2 loci of sub-genomes. The expression profile in three cultivars indicated that six FaAP2 paralogs—four WRI (WRINKLED) gene homologs and two AP2 gene homologs—were candidate regulators of red fruit color and/or special fruit aroma. All these finds provide a basis for further investigations into role of AP2 in fruit color and aroma and would be helpful in the targeted selection of strawberry fruit quality to improve breeding. Full article

Since the advent of Huanglongbing (HLB) disease, Florida’s citrus production has dropped by 70%. HLB-affected trees decline rapidly under high pH growing conditions. Limited nutrient availability at high soil pH has been speculated to be the cause of such rapid decline in HLB-affected trees; however, such decline is not observed in healthy citrus trees. Therefore, the objective of this study was to understand the nutrient uptake, physiological, and molecular responses of healthy (HLY) and HLB-affected (HLB) sweet orange (Citrus sinensis (L.) Osbeck) trees when grown in media maintained at different pH levels 6.0, 7.0, or 8.0. Overall, the performance of HLY and HLB trees decreased with the increase in pH conditions. HLB trees showed a significant inverse correlation between growth parameters (leaf number, shoot growth, SPAD value, stem water potential) and growing media pH whereas no such correlation was observed for HLY trees. Interesting, superior performance of HLB trees at pH 6.0 coincided with higher accumulation of Fe, Mn, and N in whole plant body as compared to high pH treatments. In contrast, HLY tree performance was significantly better at pH 7.0 compared to other pH conditions. At pH 7.0, stress related genes were upregulated in HLB leaves as compared to HLY leaves, indicating the stress response in terms of leaf abscission, reduced growth, and natural aging process was exacerbated in HLB trees at higher pH treatments. Altogether, all the physiological and molecular observations supports an interaction between HLB trees and pH, where HLB trees at pH 6.0 perform better than at higher pH. Full article

Ethylene-responsive elements (EREs), such as the GCC box, are critical for ethylene-regulated transcription in plants. Our previous work identified a 19-bp AC-rich element (ACE) in the promoter of bean (Phaseolus vulgaris) metal response element-binding transcription factor 1 (PvMTF-1). Ethylene response factor 15 (PvERF15) directly binds ACE to enhance PvMTF-1 expression. As a novel ERF-binding element, ACE exhibits a significant difference from the GCC box. Here, we demonstrated that ACE serves as an ERE in Arabidopsis. It conferred the minimal promoter to respond to the ethylene stress and inhibition of ethylene. Moreover, the cis-acting element ACE could specifically bind the nuclear proteins in vitro. We further revealed that the first 9-bp sequence of ACE (ACE_core) is importantly required by the binding of nuclear proteins. In addition, PvERF15 and PvMTF-1 were strongly induced by ethylene in bean seedlings. Since PvERF15 activates PvMTF-1 via ACE, ACE is involved in ethylene-induced PvMTF-1 expression. Taken together, our findings provide genetic and biochemical evidence for a new ERE. Full article