Overexpression Lines Research Articles

Two pathogen-inducible UDP-glycosyltransferases, UGT73C3 and UGT73C4, catalyze the glycosylation of pinoresinol to promote plant immunity in Arabidopsis.

UDP-glycosyltransferases (UGTs) constitute the largest glycosyltransferase family in the plant kingdom. They are responsible for transferring sugar moieties onto various small molecules to control many metabolic processes. However, their physiological significance in plants is largely unknown. Here, we revealed the function and mechanism of two Arabidopsis UGT genes, UGT73C3 and UGT73C4, which can be strongly induced by Pseudomonas syringae pv. tomato DC3000. Their overexpression significantly enhanced plant immune response, while the loss of their functions in double mutants resulted in the more sensitive phenotype to pathogen infection, although their single mutants had no obvious alteration in pathogen resistance. To understand the regulatory mechanism of UGT3C3/C4 in plant immunity, a completely secondary metabolome analysis and glycoside quantification were conducted. More accumulation of pinoresinol diglucosides was revealed in the UGT73C3 and UGT73C4 overexpression lines than that in wild-type plants whether before or after Pst DC3000 treatment, whereas the double mutants accumulated less pinoresinol diglucosides. Further, the in vitro and in vivo experiments demonstrated that UGT73C3 and UGT73C4 were capable of glycosylating pinoresinol to form pinoresinol monoglucoside and diglucoside. Moreover, we found that pinoresinol glycosylation promoted plant immune response by enhancing ROS production and callose deposition. Additionally, the transcriptional factor HB34 was identified to be responsible for the activation of UGT73C3 and UGT73C4 transcription and play a key role in plant immune responses. Overall, this study revealed a new pathway of plant immune responses via UGT73C3/C4 mediated pinoresinol glycosylation under the HB34 regulation.

A Phosphate-Starvation Enhanced Purple Acid Phosphatase, GmPAP23 Mediates Intracellular Phosphorus Recycling and Yield in Soybean.

Plant internal phosphorus (P) recycling is a complex process, which is vital for improving plant P use efficiency. However, the mechanisms underlying phosphate (Pi) release from internal organic-P form remains to be deciphered in crops. Here, we functionally characterised a Pi-starvation responsive purple acid phosphatase (PAP), GmPAP23 in soybean (Glycine max). GmPAP23 could hydrolyse a series of Pi-containing compounds in vitro, such as trehalose-6-phosphate and glucose-l-phosphate. Moreover, GmPAP23 overexpression led to less P distribution in soybean source organs, including mature leaves and pod shells, but more P distribution in seeds under P sufficient conditions, although no effect was observed for transgenic soybean lines with its suppression. Metabolomic analysis found that a group of P-containing metabolites exhibited differential accumulations in mature leaves between wild type (WT) and GmPAP23 overexpression lines, such as glucose-l-phosphate and trehalose-6-phosphate. Moreover, a MYB transcription factor, GmPHR14 was subsequently found to activate the transcription of GmPAP23 via directly binding to its promoter. Collectively, these findings could highlight that the GmPHR14-GmPAP23 pathway, which controls internal P recycling in soybean, and thus affect yield.

JrMYB44 is required for the accumulation of polyphenols and contributes to drought tolerance in Juglans regia

Juglans regia, an important economic tree species, is planted all over the world, and drought is one of the crucial factors limiting its growth and development. The various polyphenol content in walnut plants constitutes one of the material bases for the differences in stress resistance among various germplasms. However, the molecular mechanism underlying stress response mediated by polyphenol -dependent pathways remains unclear. v-Myb avian myeloblastosis viral oncogene homolog (MYB) protein of transcription factors play important regulatory roles in the process of plant stress responses. Previously, we identified JrMYB44 could be involved in osmotic stress response in walnut. In this study, we confirmed that the drought resistance of four walnut cultivars (‘Chandler’, ‘Xiangling’, ‘Xilin2’ and ‘Xifu1’) is positively correlated with the accumulation of polyphenols. The content and component changes of polyphenols in JrMYB44 overexpression (OE) and suppression (SE) lines in both walnut and Arabidopsis thaliana demonstrated that JrMYB44 positively regulated polyphenols accumulation. The variation of JrMYB44 expression and polyphenol levels under drought treatment indicated significant correlation between JrMYB44-induced drought tolerance and polyphenol accumulation, which was involved in reactive oxidative species (ROS) balance. The differentially expressed genes (DEGs) between OE and WT implied that JrMYB44 could positively activate downstream genes to participate in the drought stress response. Yeast one-hybrid (Y1H), transient GUS expression assay and dual-luciferase reporter assay (DLR) confirmed that JrMYB44 could recognize downstream JrWRKY7 and JrDREB2A, two transcription factors previously reported to be involved in drought response. Meanwhile, it was confirmed by Y2H, GST-pull down and luciferase complementation imaging assay (LCI) that JrMYB44 could interact with JrMYC2 and JrDof1, another two previously reported potential drought response regulators. Collectively, these results indicated that JrMYB44 could activate JrWRKY7, JrDREB2A and interact with JrMYC2 and JrDof1 to promote walnut polyphenol accumulation and improve drought resistance in a ROS dependent manner.

Transcription factors SlNOR and SlNOR-like1 regulate steroidal glycoalkaloids biosynthesis in tomato fruit.

Steroidal glycoalkaloids (SGAs) are specialized metabolites in Solanaceae that serve as defensive compounds and undergo significant compositional changes during fruit ripening. This study explored the roles of transcription factors SlNOR and SlNOR-like1 in SGAs biosynthesis during tomato fruit development. UPLC-MS/MS revealed dynamic changes in four major SGAs: tomatidine, β-tomatine, α-tomatine, and Esculeoside A. Transgenic studies with knockout and overexpression lines demonstrated that both SlNOR and SlNOR-like1 positively regulated SGAs accumulation. RT-qPCR analysis showed that these transcription factors modulated multiple GAME genes in the SGAs biosynthetic pathway. Through EMSA and DLR assays, we established that SlNOR and SlNOR-like1 directly bound to and activated GAME25 and GAME40 promoters, two key genes involved in tomatidine synthesis and α-tomatine conversion, respectively. These findings reveal a previously unknown regulatory mechanism of SGAs metabolism and suggest potential strategies for optimizing tomato fruit quality through molecular breeding.

Metabolomics and transcriptomics analyses revealed overexpression of TaMGD enhances wheat plant heat stress resistance through multiple responses.

Monogalactosyldiacylglycerol (MGDG), as the primary lipid component of thylakoid membranes, has a significant part in plant growth and stress response. The current study employed two transgenic wheat lines (MG1516 and MG1314) overexpressing the MGDG synthase gene (TaMGD) and wild-type cv "JW1" to explore the function of TaMGD in response to high temperature stress during the anthesis stage of wheat. Under high-temperature stress, the overexpressed wheat lines exhibited higher grain weight, increased antioxidant enzyme activity, and lower H2O2 and malondialdehyde contents in leaves. Transcriptomic analysis suggests that overexpression of TaMGD influenced multiple metabolic pathways in response to high-temperature stress, including carbon metabolism, amino acid metabolism, photosynthesis, and lipid-related metabolism. Overall, 146 differentially expressed metabolites (DEMs) were identified in MG1516 and wild-type (WT) under heat stress, with MG1516 exhibiting a higher number of upregulated metabolites, particularly glycolipids, organic acids, and organic oxygen compounds. Furthermore, lipid content and unsaturation analysis revealed that the overexpressing wheat line had a higher lipid content and greater saturation than WT under heat stress. Our findings demonstrate that overexpression of TaMGD in wheat affects multiple metabolic pathways, including photosynthesis, carbon, and amino acid metabolism, in reply to high-temperature stress through the modification of cell membrane lipid content, fatty acid unsaturation and other factors.

ZmHB53, a Maize Homeodomain-Leucine Zipper I Transcription Factor Family Gene, Contributes to Abscisic Acid Sensitivity and Confers Seedling Drought Tolerance by Promoting the Activity of ZmPYL4.

Plant-specific homeodomain-leucine zipper I (HD-Zip I) transcription factors (TFs) crucially regulate plant drought tolerance. However, their specific roles in maize (Zea mays L.) regulating drought tolerance remain largely unreported. Here, we screened a maize HD-Zip I TF family gene, ZmHB53, and clarified its role in drought stress. ZmHB53 overexpression maize plants exhibited sensitivity to abscisic acid (ABA), tolerant to polyethylene glycol (PEG 6000)-induced stress during germination, along with improved seedling drought resistance. Compared to the wild-type, ZmHB53 overexpression lines show higher water retention, biomass, and survival rates, and reduced water loss and stomatal size under drought, suggesting ZmHB53's role in drought adaptation. DNA affinity purification sequencing (DAP-Seq), yeast one hybrid, electrophoretic mobility shift assay (EMSA), and dual luciferase showed that ZmHB53 directly bound to and upregulated the expression of ABA receptor ZmPYL4. Meanwhile, transgenic plants overexpressing ZmPYL4 also exhibit ABA sensitivity and drought tolerance. The research results provide novel insights into the regulatory role of ZmHB53 and ZmPYL4 in enhancing maize's drought tolerance, establishing a foundation for future validation and potential application of ZmHB53 in strategies to improve maize resistance to drought.

Oncogene OSTM1 Promotes Gastric-Cancer Metastasis by Modulating the Metastatic Microenvironment Through Altered Tumor-Cell Autocrine Signaling.

Gastric cancer remains a malignancy with high incidence, mortality rates, and poor prognosis globally. Osteoclastogenesis-associated transmembrane protein 1 (OSTM1), a transmembrane protein overexpressed in various tumors, has unclear functions in gastric-cancer progression. This study explores OSTM1's role in gastric-cancer proliferation and metastasis. OSTM1 expression was analyzed in gastric-cancer and adjacent tissues using immunohistochemistry and RT-qPCR. OSTM1 overexpression and knockdown cell lines were established to assess its effects on cancer-cell behavior through in vitro and in vivo experiments. Western blot and RT-qPCR were used to examine OSTM1's regulation of S100A4 expression. OSTM1 was significantly overexpressed in gastric-cancer tissues, negatively correlating with TNM staging and overall survival. OSTM1 overexpression enhanced cancer-cell proliferation, colony formation, migration, and invasion, while its knockdown showed opposite effects. In vivo studies confirmed increased lung metastatic capability in high OSTM1-expressing cells. Mechanistically, OSTM1 positively regulated S100A4 expression, with S100A4 knockdown reducing OSTM1-enhanced metastasis. Gastric-cancer lung metastases showed higher microvascular density and α-SMA-positive fibroblast infiltration in the OSTM1 high-expression group. OSTM1 promotes gastric-cancer progression by upregulating S100A4 and modifying the tumor microenvironment through enhanced angiogenesis and fibroblast activation. OSTM1 represents a potential diagnostic and prognostic biomarker, with the OSTM1-S100A4 axis offering new therapeutic possibilities for gastric-cancer treatment.

Overexpression of the GmPM35 Gene Significantly Enhances Drought Tolerance in Transgenic Arabidopsis and Soybean

Drought stress is one of the major adversity stresses affecting soybean (Glycine max [L.] Merr.) yield. Late embryogenesis abundant protein (LEA protein) is a large family of proteins widely distributed in various types of organisms, and this class of proteins plays an important role in protecting proteins, membrane lipids, and lipids inside the cell. The soybean GmPM35 gene is a member of the LEA_6 subfamily. The expression of the GmPM35 gene was significantly increased after drought stress in soybeans. A subcellular localization assay confirmed that the gene acts on the cell membrane. Against wild-type Arabidopsis thaliana, we found that Arabidopsis lines overexpressing the GmPM35 gene were significantly more drought-tolerant at germination and seedling stages under drought stress. To further investigate the drought tolerance function of this gene in soybeans, nine overexpression lines of the T3 generation soybean GmPM35 gene and two editing lines of the T3 generation soybean GmPM35 gene were obtained by Agrobacterium-mediated method using a wild-type soybean strain (JN28) as a receptor. Germination rate, root length, chlorophyll (CHL) content, Proline (Pro) content, malondialdehyde (MDA) content, superoxide anion (O2−) content, hydrogen peroxide (H2O2) content, (NBT, DAB) staining, and activities of antioxidant enzymes (CAT, SOD, POD), and photosynthetic physiological indexes of the three different types of strains were measured and analyzed before and after drought stress. Combined with the results of rehydration experiments and physiological and biochemical indices, we found that overexpression of the GmPM35 gene protected the activities of antioxidant enzymes under drought stress. The activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) were increased by an average of 34.28%, 26.12%, and 30.01%, respectively, in soybean plants overexpressing the GmPM35 gene compared with wild-type soybeans. Under drought stress conditions, soybean plants overexpressing the GmPM35 gene showed an average increase of 76.81% in photosynthesis rate (Pn), 39.8% in transpiration rate (Tr), 126% in stomatal conductance (Gs), 47.71% in intercellular CO2 concentration (Ci), and 26.44% in instantaneous water use efficiency (WUEi). The improvement of these indexes helped to reduce the accumulation of reactive oxygen species (ROS) in the plants. In addition, we found that under drought stress, the MDA content was reduced by an average of 18.8%, and the Pro content was increased by an average of 60.14% in soybean plants overexpressing the GmPM35 gene, and the changes in these indexes indicated that the plants had stronger antioxidant and osmoregulatory capacities in response to drought stress. In summary, this experiment demonstrated that the GmPM35 gene plays an important role in soybean tolerance to drought stress, and by overexpressing the GmPM35 gene, soybean plants can better tolerate drought stress and maintain normal physiological functions.

Identification of the Granule-Bound Starch Synthase (GBSS) Genes Involved in Amylose Biosynthesis in Tartary Buckwheat (Fagopyrum tataricum (L.) Gaertn.).

Tartary buckwheat is a nutrient-rich pseudo-cereal whose starch contents, including amylose and amylopectin contents, and their properties hold significant importance for enhancing yield and quality. The granule-bound starch synthase (GBSS) is a key enzyme responsible for the synthesis of amylose, directly determining the amylose content and amylose-to-amylopectin ratio in crops. Although one has already been cloned, the GBSS genes at the genome-wide level have not yet been fully assessed and thoroughly analyzed in Tartary buckwheat. This study comprehensively analyzed the FtGBSSs in Tartary buckwheat. Based on the genome data of Tartary buckwheat, five FtGBSS genes, namely FtGBSS-1 to FtGBSS-5, were identified on three chromosomes, exhibiting about 1800 bp lengths in their CDSs and numerous exons and introns in gene structures. Amino acid analyses revealed high homology in ten GBSS proteins from Tartary buckwheat, rice, maize, and Arabidopsis thaliana, with a specific starch synthase catalytic domain and ten conserved motifs. The Tartary buckwheat GBSS proteins had a closer relationship with GBSS proteins from monocot based on evolutionary relationship analysis. Expression analyses suggested that the FtGBSS genes showed distinct tissue-specific expression patterns in Tartary buckwheat and rice-Tartary buckwheat. Among them, FtGBSS-1, FtGBSS-2, and FtGBSS-4 were higher expressed in the root, stem, or flower, suggesting that they have a role in the amylose synthesis of these tissues. Notably, FtGBSS-3 and FtGBSS-5 were more highly expressed in seeds than in other tissues, suggesting that they have a pivotal role in amylose synthesis of the seeds of Tartary buckwheat. Furthermore, the cis acting elements in the promoters of FtGBSSs and their binding transcription factors (TFs) were investigated. A protein-protein interaction network was constructed and co-expression was analyzed based on the gene expression patterns of the FtGBSSs, and the identified TFs, belonging to bZIP, ERF, bHLH, and MADS-box TF families, were identified within this network, and their expression patterns were significantly correlated to the expression patterns of two seed-specific FtGBSS genes (FtGBSS-3 and FtGBSS-5). Finally, FtGBSS1-5 was successfully transformed into rice through transgenic manipulation, and the FtGBSS1-5 overexpression lines showed an increase in amylose content accompanied by a reduction in amylopectin and total starch contents compared with WT. Overall, this research not only deepens our understanding of the molecular mechanisms of amylose synthesis in Tartary buckwheat, but also provides scientific insights for enhancing crop amylose content and quality through molecular breeding.

OsLdh7 Overexpression in Rice Confers Submergence Tolerance by Regulating Key Metabolic Pathways: Anaerobic Glycolysis, Ethanolic Fermentation and Amino Acid Metabolism.

Lactate dehydrogenase plays a key role in alleviating hypoxia during prolonged submergence. To explore the function of the OsLdh7 gene in enhancing submergence tolerance, we overexpressed this gene in rice (Oryza sativa cv. IR64) and subjected the transgenic lines to complete inundation. The overexpression lines showed enhanced viability, chlorophyll content and photosystem II (PSII) efficiency compared to wild-type (WT) plants under stress and recovery conditions. Additionally, these lines exhibited better starch accumulation and reduced reactive oxygen species (ROS) accumulation. Protein-protein interaction studies revealed that OsLdh7 interacts with OsLos2, OsPdc2, OsAlaAT2 and OsAsp2. Under submergence, enhanced enzyme activities of OsLdh7, OsAsp2 and OsAdh1 led to higher NAD+ levels, sustaining anaerobic glycolytic flux and increasing pyruvate, a critical carbon source for amino acid metabolism as well as anaerobic fermentation pathways. Elevated l-lactate levels resulted in increased activity of OsPdc2, which eventually led to enhanced ethanol production. The overexpression lines also accumulated higher levels of aspartate, glutamate and alanine, crucial for ROS reduction and energy production during recovery. These findings suggest that OsLdh7 overexpression confers tolerance to submergence stress by regulating the important metabolic pathways- anaerobic glycolysis, ethanolic fermentation and amino acid metabolism in rice.

GmGIF5 Promotes Cell Expansion by Negatively Regulating Cell Wall Modification.

Soybean is an important and versatile crop worldwide. Enhancing soybean architecture offers a potential method to increase yield. Plant-specific transcription factors play a crucial, yet often unnoticed, role in regulating plant growth and development. GRF-INTERACTING FACTOR (GIF) genes are plant-specific transcription factors; however, their functions in soybean remain poorly understood. Eight GmGIF members were identified in soybean (Glycine max L.). Phylogenetic analysis divided the eight GmGIF proteins into three groups. In this study, we focused on the role of GmGIF5 owing to its high expression level in the meristem. Subcellular localization and transcriptional activity analysis showed that GmGIF5 was localized to the nucleus and has self-transactivation ability. To elucidate the biological function of GmGIF5, we constructed transgenic Arabidopsis lines overexpressing the gene. Phenotype observations indicated that the overexpression of GmGIF5 contributed to larger leaves, higher plants, wider stems, and larger seeds. The organs of GmGIF5 overexpression lines exhibited larger sizes primarily due to an increase in cell size rather than cell number. RNA sequencing was performed to investigate the underlying mechanism for these effects, showing that differentially expressed genes in overexpression lines were mainly enriched in cell wall modification processes. Our study provides new clues for an understanding of the roles of the GmGIF family in soybean, which can promote the further application of these genes in genetic breeding.

How the Ectopic Expression of the Barley F-Box Gene HvFBX158 Enhances Drought Resistance in Arabidopsis thaliana.

In this study, the drought-responsive gene HvFBX158 from barley was transferred to Arabidopsis thaliana, and overexpression lines were obtained. The phenotypic characteristics of the transgenic plants, along with physiological indicators and transcription level changes of stress-related genes, were determined under drought treatment. Under drought stress, transgenic plants overexpressing HvFBX158 exhibited enhanced drought tolerance and longer root lengths compared to wild-type plants. Additionally, malondialdehyde and hydrogen peroxide contents were significantly lower in transgenic lines, while superoxide dismutase activity was elevated. Quantitative RT-PCR showed that the expression levels of drought and stress response genes, including AtP5CS, AtDREB2A, AtGSH1, AtHSP17.8, and AtSOD, were significantly upregulated. Transcriptome analysis further confirmed that HvFBX158 regulated multiple stress tolerance pathways. In summary, the overexpression of the HvFBX158 gene enhanced drought tolerance in Arabidopsis thaliana by regulating multiple stress response pathways. This study provides a practical basis for improving drought-resistant barley varieties and lays a foundation for subsequent research on F-box family genes for stress resistance in barley.

RPF2 and CARM1 cooperate to enhance colorectal cancer metastasis via the AKT/GSK-3β signaling pathway.

RPF2 plays a crucial role in promoting epithelial-mesenchymal transition (EMT) and regulating metastasis in colorectal cancer (CRC). By analyzing data from the TCGA and GEO databases, we observed significantly elevated RPF2 expression in CRC, which correlated with EMT markers. Further investigations using stable RPF2 overexpression and knockdown cell lines demonstrated that RPF2 facilitates EMT activation through the AKT/GSK-3β signaling pathway. Notably, CARM1 was identified as a key downstream effector of RPF2. Selective inhibition of CARM1 effectively suppressed the activation of the AKT/GSK-3β pathway and EMT induced by RPF2 overexpression. Both in vitro and in vivo experiments confirmed that RPF2 expression levels positively correlate with the metastatic potential of CRC cells. Moreover, treatment with a CARM1 inhibitor significantly reduced the invasive and migratory capabilities of RPF2-overexpressing cells. These findings suggest that RPF2 drives CRC metastasis by modulating EMT via the AKT/GSK-3β pathway, with CARM1 serving as a critical mediator, offering potential therapeutic targets for CRC.

OsFKBP12 transduces the sucrose signal from OsNIN8 to the OsTOR pathway in a loosely binding manner for cell division.

Previously, OsNIN8 initiated a sucrose signal for cell division in radicle and seed development in rice. Here, a set of genes was induced in starved sprouts after sucrose treatment, and 14 genes were screened between ZH11 and nin8 as reporters of sucrose signal. Expressions of reporter depended on levels of OsNIN8 in overexpression and RNAi lines. Further, OsNIN8 interacted with OsFKBP12, a regulator of TOR signal for cell division, and OsFKBP12 interacted with OsTOR (OsTORKD). However, interactions of OsFKBP12 with OsNIN8 or OsTORKD were a loose binding depending on the hydrophobicity of OsFKBP12 C-terminus in Y2H. In addition, OsFKBP12 associating with OsNIN8 was endothermic but with OsNIN8m was exothermic. Knockout OsFKBP12 reappeared nin8 phenotypes and the complementation of the knockout with C-termini of OsFKBP12 worsened the phenotypes. Treatment with TOR inhibitors caused short radicle and OsTOR RNAi repeated low seed-setting of the phenotypes. So, OsFKBP12 transduced sucrose signal from OsNIN8 to the TOR pathway.

Evidence for functional interaction between the CB1 and the mGlu7 receptors mediated signaling in modulation of anxiety behavior and cognition.

Anxiety is a severe social problem. It is a disease entity that occurs alone or accompanies other diseases such as depression, phobia, or post-traumatic stress disorder. Our earlier studies demonstrated that blockage of arachidonic acid (AA) pathway via inhibition of cyclooxygenase-2 (COX-2) enzyme can modulate mGluRs-induced anxiety-like behavior. Here, we hypothesized that modulation of 2-arachidoglycerol (2-AG), a component of the AA pathway, concomitantly with modulation of mGluR7 signaling, should be adequate to trigger a similar response from the test organism. Since 2-AG is an endogenous agonist for CB1 receptors, we used a CB1/GPR55/μ-opioid receptor antagonist (AM251) alone and in combination with mGluR7 allosteric agonist (AMN082). Stress-induced hyperthermia (SIH) test was performed as a behavioral readout. AM251 has a dual mode on AMN082-mediated effects in SIH in CD-1 mice. Furthermore, the CB1 receptor ligand influenced adaptation to stress in repeated SIH procedures and learning possibilities of mice in the Barnes maze. We also found changes in mGluR7 protein expression levels in the prefrontal cortex (PFC) after mice were exposed to AM251, which showed the potential to attenuate the AMN082-induced decline in mGluR7 levels. The changes induced by AM251 on AMN082-mediated behavioral and biochemical effects were confirmed in electrophysiological experiments in which AM251 abolished AMN082-mediated LTP escalation in PFC. The mGluR7 overexpressed cell line was used to exclude the direct involvement of mGluR7 in AM251 activity. All the above results and the co-localization of CB1 and mGlu7 receptors detected in specific brain regions strongly suggest the specific interaction between CB1 and mGlu7 receptors and their signaling.

SCPL48 regulates the vessel cell programmed cell death during xylem development in Arabidopsis thaliana.

Secondary cell wall (SCW) deposition is tightly coordinated with programmed cell death (PCD) during xylem development and plays a crucial role in plant stress responses. In this study, we characterized a serine carboxypeptidase-like gene, SCPL48, which exhibits xylem cell-specific expression patterns in stem xylem during vascular development. The scpl48 plants exhibited reduced stem xylem cell numbers, particularly vessel cells, accompanied by delayed organelle degradation during PCD and increased secondary wall thickness in xylem vessel cells. In contrast, SCPL48 overexpression resulted in increased vessel cell abundance and accelerated degradation of vessel cell contents, suggesting its critical role in xylem vessel cell differentiation. Notably, SCPL48 expression was significantly up-regulated in response to ABA treatment and drought stress, with SCPL48 overexpression lines demonstrating enhanced drought resistance. Further molecular analyses revealed that SCPL48 was directly targeted and transcriptionally activated by key SCW regulators VND6, and MYB46. Furthermore, the expression of PCD-related protease genes, including XCP1, XSP1, RNS3, MC9, γVPE, and CEP1, showed compensatory changes in both scpl48 mutants and SCPL48 overexpression lines. Collectively, our findings demonstrate that SCPL48 functions as a key regulator in xylem vessel cell differentiation, PCD and drought stress responses.

GhWRKY207 improves drought tolerance through promoting the expression of GhCSD3 and GhFSD2 in Gossypium hirsutum

GhWRKY207 improves drought tolerance through promoting the expression of GhCSD3 and GhFSD2 in Gossypium hirsutum

Comparative transcriptome analysis and heterologous overexpression indicate that the ZjZOG gene may positively regulate the size of jujube fruit

BackgroundFruit size is a crucial economic trait that impacts the quality of jujube (Ziziphus jujuba), however, research in this area remains limited. This study utilized two jujube cultivars with similar genetic backgrounds but differing fruit sizes to investigate the regulatory mechanisms affecting fruit size through cytological observations, transcriptome sequencing, and heterologous overexpression.ResultsThe findings reveal that variations in mesocarp cell numbers during early fruit development significantly influence final fruit size. Comparative transcriptome sequencing identified 16,778 differentially expressed genes across five developmental stages. Co-expression network analysis identified 16 co-expression modules. KEGG enrichment analysis of these modules indicated the significant role of plant hormone-related pathways in fruit development. A detailed analysis of the ‘sky blue’ module revealed candidate genes associated with the regulation of mesocarp cells, leading to the construction of a regulatory network. Heterologous overexpression of the candidate gene ZjZOG in tomato confirmed its positive role in fruit size enhancement. Transcriptomic analysis of these overexpression lines further validated the regulatory network and identified reliable candidate genes for fruit size control.ConclusionThis study provides valuable insights into the regulatory mechanisms of fruit size, which may facilitate the breeding of larger jujube cultivars.

The OsMAPK6-OsWRKY72 module positively regulates rice leaf angle through brassinosteroid signals.

Leaf angle is a major agronomic trait that determines plant architecture, which directly affects rice planting density, photosynthetic efficiency, and yield. The plant phytohormones brassinosteroids (BRs) and the MAPK signaling cascade are known to play crucial roles in regulating the leaf angle, but the underlying molecular mechanisms are not fully understood. Here, we report a rice WRKY family transcription factor gene, OsWRKY72, which positively regulates leaf angle by affecting lamina joint development and BR signaling. Phenotypic analysis showed that oswrky72 mutants had smaller leaf angles and exhibited insensitive to exogenous brassinosteroid, while the OsWRKY72 overexpression lines led to enlarged leaf angles and were hypersensitive to exogenous BR. Histological sections indicated that the change in leaf inclination was due to asymmetric cell proliferation and growth at the lamina joint. Further investigation showed that OsWRKY72 directly bound to the promoter regions of BR receptor kinase (OsBRI1), a key gene in the BR signaling pathway, and activated its expression to positively regulates rice BR signaling. In addition, we discovered that OsWRKY72 can interact with OsMAPK6 and be phosphorylated, and this phosphorylation event enhanced OsWRKY72 activity in promoting OsBRI1 expression. The genetic evidence confirmed that OsMAPK6, OsWRKY72 and OsBRI1 functions in a common pathway to regulate leaf angles. Collectively, our findings elucidate the critical role of the transcription factor OsWRKY72 in regulating rice leaf angle. These results provided valuable insights into the molecular regulatory networks governing plant architecture in rice.

Physiological, Photosynthetic Characteristic and Transcriptome Analysis of PsnWRKY70 Transgenic Populus simonii × Populus nigra Under Salt Stress.

The PsnWRKY70 transcription factor (TF) was reported to play an important role in the salt stress response mechanism of Populus simonii × Populus nigra in our previous research, and we also produced several PsnWRKY70 overexpression (OEXs) and RNAi suppression (REXs) P. simonii × P. nigra lines. In order to further compare the photosynthetic and physiological characteristics of NT (non-transgenic line) and transgenic lines under salt stress, the dynamic phenotypic change, Na+ and K+ content in leaf and root tissues, superoxide dismutase (SOD) and peroxidase (POD) activity, malondialdehyde (MDA) content, chlorophyll content (Chl), photosynthesis parameters (net photosynthetic rate, Pn; stomatal conductance, Gs; intercellular CO2 concentration, Ci; transpiration rate, Tr), chlorophyll fluorescence parameters (electron transport rate, ETR; maximum photochemical efficiency of photosystem II (PSII), Fv/Fm; actual efficiency of PSII, ΦPSII; photochemical quenching coefficient, qP; non-photochemical quenching, NPQ; the photosynthetic light-response curves of ΦPSII and ETR) and RNA-seq of NT, OEX and REX lines were detected and analyzed. The phenotypic observation, MDA content and Chl detection results indicate that the stress damage of REXs was less severe than that of NT and OEX lines under salt stress. Photosynthesis parameter (Pn, Gs, Tr and Ci) and chlorophyll fluorescence parameter (ETR, Fv/Fm, ΦPSII qP and NPQ) detection results indicate that the REX lines exhibited much better photosynthetic adaptability than NT and OEX lines during salt stress. The photosynthetic light-response curves of ΦPSII and ETR of NT, OEX and REX lines indicate that REXs exhibited better ability to activate the photosynthetic protection mechanism and adapt to a certain degree of strong light than NT and OEX lines under salt stress. RNA-seq analysis indicates that the DEGs between OEX1 vs. NT and REX1 vs. NT in different tissues (apical bud and fifth functional leaf) were all different in category and change trend. The expression of PsnWRKY70 was significantly up-regulated in both the apical bud and fifth functional leaf of OEX1, and showed no significant change (namely maintained low expression level) in both the apical bud and fifth functional leaf of REX1, thus indicating the negative regulation role of PsnWRKY70 in P. simonii × P. nigra under salt stress. Additionally, there were a lot of stress response-related TF genes (such as bHLH, WRKY, MYB, NAM and AP2/EREBP) and photosynthesis-related genes among all the DEGs. In REX1, the expression of three Photosystem I P700 chlorophyll a apoprotein A1 genes (Potri.003G065200, Potri.013G141800 and Potri.019G028100) and a Photosystem II protein D1 gene (Potri.013G138300) were significantly up-regulated after 6 days of salt stress. In OEX1, the Heterodimeric geranylgeranyl pyrophosphate synthase small subunit gene (Potri.015G043400) and Phospho-2-dehydro-3-deoxyheptonate aldolase 1 gene (Potri.007G095700) were significantly down-regulated after 6 days of salt stress. These photosynthesis-related genes are probably regulated by PsnWRKY70 TF in response to salt stress. In conclusion, the REX lines suffered less severe salt damage and exhibited better photosynthetic adaptability than NT and OEXs under salt stress. The differences among the DEGs between OEX1 vs. NT and REX1 vs. NT in apical bud and fifth functional leaf, and the significantly differentially expressed photosynthesis-related genes are probably the key clues for discovering the photosynthesis adaptability mechanism of PsnWRKY70 transgenic P. simonii × P. nigra under salt stress.