NAC (NAM, ATAF, and CUC) transcription factors play important roles in plant biological processes, including phytohormone homeostasis, plant development, and in responses to various environmental ...stresses.
TaNAC29 was introduced into Arabidopsis using the Agrobacterium tumefaciens-mediated floral dipping method. TaNAC29-overexpression plants were subjected to salt and drought stresses for examining gene functions. To investigate tolerant mechanisms involved in the salt and drought responses, expression of related marker genes analyses were conducted, and related physiological indices were also measured. Expressions of genes were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR).
A novel NAC transcription factor gene, designated TaNAC29, was isolated from bread wheat (Triticum aestivum). Sequence alignment suggested that TaNAC29 might be located on chromosome 2BS. TaNAC29 was localized to the nucleus in wheat protoplasts, and proved to have transcriptional activation activities in yeast. TaNAC29 was expressed at a higher level in the leaves, and expression levels were much higher in senescent leaves, indicating that TaNAC29 might be involved in the senescence process. TaNAC29 transcripts were increased following treatments with salt, PEG6000, H2O2, and abscisic acid (ABA). To examine TaNAC29 function, transgenic Arabidopsis plants overexpressing TaNAC29 were generated. Germination and root length assays of transgenic plants demonstrated that TaNAC29 overexpression plants had enhanced tolerances to high salinity and dehydration, and exhibited an ABA-hypersensitive response. When grown in the greenhouse, TaNAC29-overexpression plants showed the same tolerance response to salt and drought stresses at both the vegetative and reproductive period, and had delayed bolting and flowering in the reproductive period. Moreover, TaNAC29 overexpression plants accumulated lesser malondialdehyde (MDA), H2O2, while had higher superoxide dismutase (SOD) and catalase (CAT) activities under high salinity and/or dehydration stress.
Our results demonstrate that TaNAC29 plays important roles in the senescence process and response to salt and drought stresses. ABA signal pathway and antioxidant enzyme systems are involved in TaNAC29-mediated stress tolerance mechanisms.
The trihelix gene family is a plant-specific transcription factor family that plays important roles in plant growth, development, and responses to abiotic stresses. However, to date, no systemic ...characterization of the trihelix genes has yet been conducted in wheat and its close relatives.
We identified a total of 94 trihelix genes in wheat, as well as 22 trihelix genes in Triticum urartu, 29 in Aegilops tauschii, and 31 in Brachypodium distachyon. We analyzed the chromosomal locations and orthology relations of the identified trihelix genes, and no trihelix gene was found to be located on chromosome 7A, 7B, or 7D of wheat, thereby reflecting the uneven distributions of wheat trihelix genes. Phylogenetic analysis indicated that the 186 identified trihelix proteins in wheat, rice, B. distachyon, and Arabidopsis were clustered into five major clades. The trihelix genes belonging to the same clades usually shared similar motif compositions and exon/intron structural patterns. Five pairs of tandem duplication genes and three pairs of segmental duplication genes were identified in the wheat trihelix gene family, thereby validating the supposition that more intrachromosomal gene duplication events occur in the genome of wheat than in that of other grass species. The tissue-specific expression and differential expression profiling of the identified genes under cold and drought stresses were analyzed by using RNA-seq data. qRT-PCR was also used to confirm the expression profiles of ten selected wheat trihelix genes under multiple abiotic stresses, and we found that these genes mainly responded to salt and cold stresses.
In this study, we identified trihelix genes in wheat and its close relatives and found that gene duplication events are the main driving force for trihelix gene evolution in wheat. Our expression profiling analysis demonstrated that wheat trihelix genes responded to multiple abiotic stresses, especially salt and cold stresses. The results of our study built a basis for further investigation of the functions of wheat trihelix genes and provided candidate genes for stress-resistant wheat breeding programs.
•Wheat MYB gene TaMyb1D was cloned.•The expression levels of TaMyb1D was induced under PEG and H2O2 treatments.•TaMyb1D regulated phenylpropanoid metabolism and affected plant development.•TaMyb1D ...enhanced drought and oxidative stress tolerance in transgenic tobacco plants.
MYB transcription factors are involved in the regulation of plant development and response to biotic and abiotic stress. In this study, TaMyb1D, a novel subgroup 4 gene of the R2R3-MYB subfamily, was cloned from wheat (Triticum aestivum L.). TaMyb1D was localized in the nucleus and functioned as a transcriptional repressor. The overexpression of TaMyb1D in tobacco (Nicotiana tabacum) plants repressed the expression of genes related to phenylpropanoid metabolism and down-regulated the accumulation of lignin in stems and flavonoids in leaves. These changes affected plant development under normal conditions. The expression of TaMyb1D was ubiquitous and up-regulated by PEG6000 and H2O2 treatments in wheat. TaMyb1D-overexpressing transgenic tobacco plants exhibited higher relative water content and lower water loss rate during drought stress, as well as higher chlorophyll content in leaves during oxidative stress. The transgenic plants showed a lower leakage of ions as well as reduced malondialdehyde and H2O2 levels during conditions of drought and oxidative stresses. In addition, TaMyb1D up-regulated the expression levels of ROS- and stress-related genes in response to drought stress. Therefore, the overexpression of TaMyb1D enhanced tolerance to drought and oxidative stresses in tobacco plants. Our study demonstrates that TaMyb1D functions as a negative regulator of phenylpropanoid metabolism and a positive regulator of plant tolerance to drought and oxidative stresses.
WD40 domains are abundant in eukaryotes, and they are essential subunits of large multiprotein complexes, which serve as scaffolds. WD40 proteins participate in various cellular processes, such as ...histone modification, transcription regulation, and signal transduction. WD40 proteins are regarded as crucial regulators of plant development processes. However, the systematic identification and analysis of WD40 proteins have yet to be reported in wheat.
In this study, a total of 743 WD40 proteins were identified in wheat, and they were grouped into 5 clusters and 11 subfamilies. Their gene structures, chromosomal locations, and evolutionary relationships were analyzed. Among them, 39 and 46 pairs of TaWD40s were distinguished as tandem duplication and segmental duplication genes. The 123 OsWD40s were identified to exhibit synteny with TaWD40s. TaWD40s showed the specific characteristics at the reproductive developmental stage, and numerous TaWD40s were involved in responses to stresses, including cold, heat, drought, and powdery mildew infection pathogen, based on the result of RNA-seq data analysis. The expression profiles of some TaWD40s in wheat seed development were confirmed through qRT-PCR technique.
In this study, 743 TaWD40s were identified from the wheat genome. As the main driving force of evolution, duplication events were observed, and homologous recombination was another driving force of evolution. The expression profiles of TaWD40s revealed their importance for the growth and development of wheat and their response to biotic and abiotic stresses. Our study also provided important information for further functional characterization of some WD40 proteins in wheat.
Drought is one of the major environmental stresses to plants. The calcium sensor, calcineurin B-like (CBL) proteins, and their interacting protein kinases (CIPK) play important roles in responding to ...abiotic stresses. In this study, we functionally characterized a CIPK gene from Triticum aestivum designated TaCIPK27. The transcriptional levels of TaCIPK27 were increased both in roots and leaves after treatment with polyethylene glycol 8000, abscisic acid and H2O2. Besides, TaCIPK27 interacted with AtCBL1, AtCBL3, AtCBL4, AtCBL5 and AtCBL9 in yeast two-hybrid assays. Ectopic overexpression of TaCIPK27 positively regulates drought tolerance in transgenic Arabidopsis compared with controls, which was demonstrated by seed germination and survival rates experiments, as well as the detection of physiological indices including ion leakage, malonic dialdehyde and H2O2 contents and antioxidant enzyme activities under normal and drought conditions. Moreover, higher concentration of endogenous abscisic acid was detected under drought in TaCIPK27 transgenic plants. In addition, TaCIPK27 transgenic plants were more sensitive to exogenous abscisic acid treatment at seed germination and seedling stage. The expression levels of somedrought stress and abscisic acid related genes were up-regulated in TaCIPK27 transgenic plants. The results suggest that TaCIPK27 functions as a positive regulator under drought partly in an ABA-dependent pathway.
•TaCIPK27 can raise the interests of researchers to focus on the research of resistance mechanism in crops.•TaCIPK27 has a positive regulatory role in drought stress responses through ABA-dependent pathway.•TaCIPK27 shows important multiple roles under stress treatments in Arabidopsis plants.
MYB transcription factors play important roles in plant responses to biotic and abiotic stress. In this study,
, a R2R3-MYB gene, was cloned from wheat (
L.). TaODORANT1 was localized in the nucleus ...and functioned as a transcriptional activator.
was up-regulated in wheat under PEG6000, NaCl, ABA, and H
O
treatments.
-overexpressing transgenic tobacco plants exhibited higher relative water content and lower water loss rate under drought stress, as well as lower Na
accumulation in leaves under salt stress. The transgenic plants showed higher CAT activity but lower ion leakage, H
O
and malondialdehyde contents under drought and salt stresses. Besides, the transgenic plants also exhibited higher SOD activity under drought stress. Our results also revealed that
overexpression up-regulated the expression of several ROS- and stress-related genes in response to both drought and salt stresses, thus enhancing transgenic tobacco plants tolerance. Our studies demonstrate that TaODORANT1 positively regulates plant tolerance to drought and salt stresses.
Hydrogen generation by photocatalytic water-splitting holds great promise for addressing the serious global energy and environmental crises, and has recently received significant attention from ...researchers. In this work, a method of assembling GeC/MXY (M = Zr, Hf; X, Y = S, Se) heterojunctions (HJs) by combining GeC and MXY monolayers (MLs) to construct direct Z-scheme photocatalytic systems is proposed. Based on first-principles calculations, we found that all the GeC/MXY HJs are stable van der Waals (vdW) HJs with indirect bandgaps. These HJs possess small bandgaps and exhibit strong light-absorption ability across a wide range. Furthermore, the built-in electric field (BIEF) around the heterointerface can accelerate photoinduced carrier separation. More interestingly, the suitable band edges of GeC/MXY HJs ensure sufficient kinetic potential to spontaneously accomplish water redox reactions under light irradiation. Overall, the strong light-harvesting ability, wide light-absorption range, small bandgaps, large heterointerfacial BIEFs, suitable band alignments, and carrier migration paths render GeC/MXY HJs highly efficient photocatalysts for overall water decomposition.
Osteosarcoma is the most common primary bone cancer in children and adolescents. In spite of aggressive treatment, osteosarcoma has a high mortality rate with minimal improvements in survival over ...past few decades. Polyphyllin I (PPI), a component in the traditional Chinese medicinal herb Paris polyphylla Smith, has been shown to have anti-tumor properties. However, its mechanism as an anti-osteosarcoma agent has not been well elucidated. In this study, we found that PPI suppressed osteosarcoma cell viability, arrested cell cycle in G
/M phase, induced apoptosis and inhibited invasion and migration of osteosarcoma cells. Moreover, PPI significantly suppressed intratibial primary tumor growth in xenograft orthotopic mouse model without any obvious side effects. These therapeutic efficacies were associated with inactivation of Wnt/β-catenin pathway, as PPI treatment decreased the amount of p-GSK-3β, leading to down-regulated levels of active β-catenin. PPI induced inhibition of osteosarcoma cell viability was abolished upon addition of GSK-3β specific inhibitor, CHIR99021, while PPI induced inhibition of osteosarcoma cell viability and migration were potentiated by β-catenin silencing. These findings suggested that, in vitro and in vivo, PPI treatment inhibited osteosarcoma, at least in part, via the inactivation of Wnt/β-catenin pathway. Thus, PPI could serve a novel therapeutic option for osteosarcoma patients.
Increasing the provitamin A content in staple crops via carotenoid metabolic engineering is one way to address vitamin A deficiency. In this work a combination of methods was applied to specifically ...increase β-carotene content in wheat by metabolic engineering. Endosperm-specific silencing of the carotenoid hydroxylase gene (TaHYD) increased β-carotene content 10.5-fold to 1.76 μg g–1 in wheat endosperm. Overexpression of CrtB introduced an additional flux into wheat, accompanied by a β-carotene increase of 14.6-fold to 2.45 μg g–1. When the “push strategy” (overexpressing CrtB) and “block strategy” (silencing TaHYD) were combined in wheat metabolic engineering, significant levels of β-carotene accumulation were obtained, corresponding to an increase of up to 31-fold to 5.06 μg g–1. This is the first example of successful metabolic engineering to specifically improve β-carotene content in wheat endosperm through a combination of methods and demonstrates the potential of genetic engineering for specific nutritional enhancement of wheat.
Schematic illustration of the function and molecular mechanism of PDT with TPBC-PEG micelles in suppressing primary osteosarcoma growth and pulmonary metastasis. (a) pH-responsive TPBC-PEG micelles ...with photosensitizer absorbing 735-nm visible light were constructed. (b & c) PDT of TPBC-PEG micelles inhibited the growth of primary osteosarcoma and pulmonary metastasis by activating the HIPPO signaling pathway. (b) After intravenous injection into osteosarcoma xenograft mouse models, TPBC-PEG micelles passively targeted and accumulated in osteosarcoma lesions by the enhanced permeability and retention (EPR) effect, and then the photosensitizer TPBC was released into osteosarcoma lesions through an acidic pH response. (c) After PDT at primary osteosarcoma lesions, the expressions of MST1 and LATS1 were downregulated, and nuclear translocation of YAP/TAZ was inhibited, which in turn inactivated TEAD-mediated transcription of the downstream target genes AMOTL2, CTGF, CYR61 and ANKRD1. Finally, this led to the decrease of viability, arrest of cell cycle, inhibition of colony proliferation, migration, and invasion abilities, as well as increase of apoptosis in osteosarcoma cells, thus inhibiting the growth, development and pulmonary metastasis of osteosarcoma to achieve a comprehensive anti-osteosarcoma efficacy.
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•Photodynamic therapy of TPBC-PEG micelles inhibits primary osteosarcoma growth and pulmonary metastasis.•TPBC-PEG nanoplatform activates HIPPO pathway for intratibial osteosarcoma therapy.•Photodynamic therapy of TPBC-PEG micelles had no significant toxicity in the heart, liver, spleen, or kidney.
Cancer is a global leading cause of death, with nearly 10 million people dying from cancer in 2020. Photodynamic therapy (PDT) has emerged as a promising cancer treatment modality; however, the potential molecular mechanisms remain obscure. Herein, we designed a near-infrared (NIR) light-activated nanoplatform (TPBC-PEG) to explore the therapeutic effects and mechanisms of PDT by using a model of intratibial primary and pulmonary metastasis osteosarcoma. Under laser irradiation, TPBC-PEG photosensitizer dose-dependently inhibited proliferative and metastatic capabilities while promoting apoptosis of osteosarcoma cells in vitro, and also effectively suppressed carcinogenesis and pulmonary metastasis in osteosarcoma xenograft mouse model. Moreover, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis after high-throughput mRNA-seq indicated that the HIPPO signaling pathway was one of the 20 most significantly related signaling pathways. And a series of experiments for determining the HIPPO signaling activity were conducted to reconfirm the specificity. Collectively, PDT of TPBC-PEG micelles against carcinogenesis and pulmonary metastasis of deep-seated intratibial osteosarcoma was achieved by activating HIPPO signaling pathway. Our study identified a hitherto uncharacterized molecular mechanism of PDT, which may provide new insights to understand and design promising nanoplatforms for future cancer therapies.
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