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1.
Plant Cell ; 36(4): 919-940, 2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38180963

RESUMO

Soil salinity results in oxidative stress and heavy losses to crop production. The S-acylated protein SALT TOLERANCE RECEPTOR-LIKE CYTOPLASMIC KINASE 1 (STRK1) phosphorylates and activates CATALASE C (CatC) to improve rice (Oryza sativa L.) salt tolerance, but the molecular mechanism underlying its S-acylation involved in salt signal transduction awaits elucidation. Here, we show that the DHHC-type zinc finger protein DHHC09 S-acylates STRK1 at Cys5, Cys10, and Cys14 and promotes salt and oxidative stress tolerance by enhancing rice H2O2-scavenging capacity. This modification determines STRK1 targeting to the plasma membrane or lipid nanodomains and is required for its function. DHHC09 promotes salt signaling from STRK1 to CatC via transphosphorylation, and its deficiency impairs salt signal transduction. Our findings demonstrate that DHHC09 S-acylates and anchors STRK1 to the plasma membrane to promote salt signaling from STRK1 to CatC, thereby regulating H2O2 homeostasis and improving salt stress tolerance in rice. Moreover, overexpression of DHHC09 in rice mitigates grain yield loss under salt stress. Together, these results shed light on the mechanism underlying the role of S-acylation in RLK/RLCK-mediated salt signal transduction and provide a strategy for breeding highly salt-tolerant rice.


Assuntos
Oryza , Tolerância ao Sal , Tolerância ao Sal/genética , Oryza/metabolismo , Peróxido de Hidrogênio/metabolismo , Homeostase , Dedos de Zinco , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
2.
Plant Cell ; 35(9): 3604-3625, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37325884

RESUMO

Catalase (CAT) is often phosphorylated and activated by protein kinases to maintain hydrogen peroxide (H2O2) homeostasis and protect cells against stresses, but whether and how CAT is switched off by protein phosphatases remains inconclusive. Here, we identified a manganese (Mn2+)-dependent protein phosphatase, which we named PHOSPHATASE OF CATALASE 1 (PC1), from rice (Oryza sativa L.) that negatively regulates salt and oxidative stress tolerance. PC1 specifically dephosphorylates CatC at Ser-9 to inhibit its tetramerization and thus activity in the peroxisome. PC1 overexpressing lines exhibited hypersensitivity to salt and oxidative stresses with a lower phospho-serine level of CATs. Phosphatase activity and seminal root growth assays indicated that PC1 promotes growth and plays a vital role during the transition from salt stress to normal growth conditions. Our findings demonstrate that PC1 acts as a molecular switch to dephosphorylate and deactivate CatC and negatively regulate H2O2 homeostasis and salt tolerance in rice. Moreover, knockout of PC1 not only improved H2O2-scavenging capacity and salt tolerance but also limited rice grain yield loss under salt stress conditions. Together, these results shed light on the mechanisms that switch off CAT and provide a strategy for breeding highly salt-tolerant rice.


Assuntos
Oryza , Catalase/genética , Catalase/metabolismo , Oryza/metabolismo , Peróxido de Hidrogênio/metabolismo , Proteína Fosfatase 1/metabolismo , Tolerância ao Sal/genética , Homeostase , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
3.
Plant J ; 110(6): 1763-1780, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35411551

RESUMO

S-acylation is an important lipid modification that primarily involves DHHC proteins (DHHCs) and associated S-acylated proteins. No DHHC-S-acylated protein pair has been reported so far in rice (Oryza sativa L.) and the molecular mechanisms underlying S-acylation in plants are largely unknown. We constructed an OsDHHC cDNA library for screening corresponding pairs of DHHCs and S-acylated proteins using bimolecular fluorescence complementation assays. Five DHHC-S-acylated protein pairs (OsDHHC30-OsCBL2, OsDHHC30-OsCBL3, OsDHHC18-OsNOA1, OsDHHC13-OsNAC9, and OsDHHC14-GSD1) were identified in rice. Among the pairs, OsCBL2 and OsCBL3 were S-acylated by OsDHHC30 in yeast and rice. The localization of OsCBL2 and OsCBL3 in the endomembrane depended on S-acylation mediated by OsDHHC30. Meanwhile, all four OsDHHCs screened complemented the thermosensitive phenotype of an akr1 yeast mutant, and their DHHC motifs were required for S-acyltransferase activity. Overexpression of OsDHHC30 in rice plants improved their salt and oxidative tolerance. Together, these results contribute to our understanding of the molecular mechanism underlying S-acylation in plants.


Assuntos
Oryza , Proteínas de Saccharomyces cerevisiae , Aciltransferases/metabolismo , Fluorescência , Biblioteca Gênica , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas/metabolismo , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética
4.
New Phytol ; 237(3): 840-854, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36305219

RESUMO

Light is a particularly important environmental cue that regulates a variety of diverse plant developmental processes, such as photomorphogenesis. Blue light promotes photomorphogenesis mainly through the activation of the photoreceptor cryptochrome 1 (CRY1). However, the mechanism underlying the CRY1-mediated regulation of growth is not fully understood. Here, we found that blue light induced N6 -methyladenosine (m6 A) RNA modification during photomorphogenesis partially via CRY1. Cryptochrome 1 mediates blue light-induced expression of FKBP12-interacting protein 37 (FIP37), which is a component of m6 A writer. Moreover, we showed that CRY1 physically interacted with FIP37 in vitro and in vivo, and mediated blue light activation of FIP37 binding to RNA. Furthermore, CRY1 and FIP37 modulated m6 A on photomorphogenesis-related genes PIF3, PIF4, and PIF5, thereby accelerating the decay of their transcripts. Genetically, FIP37 repressed hypocotyl elongation under blue light, and fip37 mutation could partially rescue the short-hypocotyl phenotype of CRY1-overexpressing plants. Together, our results provide a new insight into CRY1 signal in modulating m6 A methylation and stability of PIFs, and establish an essential molecular link between m6 A modification and determination of photomorphogenesis in plants.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Criptocromos/genética , Criptocromos/metabolismo , Regulação da Expressão Gênica de Plantas , Hipocótilo/metabolismo , Luz , RNA/metabolismo , Proteína 1A de Ligação a Tacrolimo/genética , Proteína 1A de Ligação a Tacrolimo/metabolismo , Fatores de Transcrição/metabolismo
5.
Biotechnol Bioeng ; 119(7): 1949-1964, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35338663

RESUMO

Klebsiella pneumoniae (K. pneumoniae) is a common bacterium whose drug-resistant can cause surgical failures and incurable infections in hospital patients. Thus, how to reverse or delay the resistance induction has become a great challenge for development antiresistant drug. Recently, the combination of nanomaterial-loaded antibiotics with photothermal therapy showed the efficient antibacteria ability under a low dosage of antibiotics. In this study, a nanocomposite of HMPB NPs with inherent photothermal therapy capability was used to eradicate K. pneumoniae after loading with Ofloxacin, an antibiotic against K. pneumoniae in vitro and in vivo. The nanocomplexes named as Ofloxacin@HMPB@HA NPs showed a higher effect against K. pneumoniae by destroying cell integrity and inducing ATP leakage with the assistance of laser irradiation, compared with sole Ofloxacin@HMPB@HA NPs or laser irradiation. Surgical wound infection assay further demonstrated the efficient killing K. pneumoniae and promoting the formation of new tissues, as well, which was reflected by the rapid healing of surgical wound. In summary, these results indicate the great potential of this combinational tactic based on Ofloxacin@HMPB@HA NPs for preventing the failure caused by K. pneumoniae infection.


Assuntos
Infecções por Klebsiella , Ferida Cirúrgica , Antibacterianos/farmacologia , Humanos , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae , Ofloxacino/farmacologia , Ofloxacino/uso terapêutico , Ferida Cirúrgica/tratamento farmacológico
6.
Plant Cell ; 30(5): 1100-1118, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29581216

RESUMO

Salt stress can significantly affect plant growth and agricultural productivity. Receptor-like kinases (RLKs) are believed to play essential roles in plant growth, development, and responses to abiotic stresses. Here, we identify a receptor-like cytoplasmic kinase, salt tolerance receptor-like cytoplasmic kinase 1 (STRK1), from rice (Oryza sativa) that positively regulates salt and oxidative stress tolerance. Our results show that STRK1 anchors and interacts with CatC at the plasma membrane via palmitoylation. CatC is phosphorylated mainly at Tyr-210 and is activated by STRK1. The phosphorylation mimic form CatCY210D exhibits higher catalase activity both in vitro and in planta, and salt stress enhances STRK1-mediated tyrosine phosphorylation on CatC. Compared with wild-type plants, STRK1-overexpressing plants exhibited higher catalase activity and lower accumulation of H2O2 as well as higher tolerance to salt and oxidative stress. Our findings demonstrate that STRK1 improves salt and oxidative tolerance by phosphorylating and activating CatC and thereby regulating H2O2 homeostasis. Moreover, overexpression of STRK1 in rice not only improved growth at the seedling stage but also markedly limited the grain yield loss under salt stress conditions. Together, these results offer an opportunity to improve rice grain yield under salt stress.


Assuntos
Oryza/metabolismo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Regulação da Expressão Gênica de Plantas , Peróxido de Hidrogênio/metabolismo , Oryza/genética , Estresse Oxidativo/genética , Estresse Oxidativo/fisiologia , Fosforilação , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Estresse Fisiológico
7.
Breed Sci ; 69(3): 429-438, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31598075

RESUMO

As glutamate dehydrogenases (GDHs) of microorganisms usually have higher affinity for NH4 + than do those of higher plants, it is expected that ectopic expression of these GDHs can improve nitrogen assimilation in higher plants. Here, a novel NADP(H)-GDH gene (TrGDH) was isolated from the fungus Trichurus and introduced into rice (Oryza sativa L.). Investigation of kinetic properties in vitro showed that, compared with the rice GDH (OsGDH4), TrGDH exhibited higher affinity for NH4 + (K m = 1.48 ± 0.11 mM). Measurements of the NH4 + assimilation rate demonstrated that the NADP(H)-GDH activities of TrGDH transgenic lines were significantly higher than those of the controls. Hydroponic experiments revealed that the fresh weight, dry weight and nitrogen content significantly increased in the TrGDH transgenic lines. Field trials further demonstrated that the number of effective panicles, 1,000-grain weight and grain weight per plant of the transgenic lines were significantly higher than those of the controls, especially under low-nitrogen levels. Moreover, glutelin and prolamine were found to be markedly increased in seeds from the transgenic rice plants. These results sufficiently confirm that overexpression of TrGDH in rice can improve the growth status and grain weight per plant by enhancing nitrogen assimilation. Thus, TrGDH is a promising candidate gene for maintaining yields in crop plants via genetic engineering.

8.
Plant J ; 91(5): 788-801, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28608936

RESUMO

Floral initiation is regulated by various genetic pathways in response to light, temperature, hormones and developmental status; however, the molecular mechanisms underlying the interactions between different genetic pathways are not fully understood. Here, we show that the photoresponsive gene FOF2 (F-box of flowering 2) negatively regulates flowering. FOF2 encodes a putative F-box protein that interacts specifically with ASK14, and its overexpression results in later flowering under both long-day and short-day photoperiods. Conversely, transgenic plants expressing the F-box domain deletion mutant of FOF2 (FOF2ΔF), or double loss of function mutant of FOF2 and FOL1 (FOF2-LIKE 1) present early flowering phenotypes. The late flowering phenotype of the FOF2 overexpression lines is suppressed by the flc-3 loss-of-function mutation. Furthermore, FOF2 mRNA expression is regulated by autonomous pathway gene FCA, and the repressive effect of FOF2 in flowering can be overcome by vernalization. Interestingly, FOF2 expression is regulated by light. The protein level of FOF2 accumulates in response to light, whereas it is degraded under dark conditions via the 26S proteasome pathway. Our findings suggest a possible mechanistic link between light conditions and the autonomous floral promotion pathway in Arabidopsis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Proteínas F-Box/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Proteínas de Domínio MADS/metabolismo , Arabidopsis/citologia , Arabidopsis/fisiologia , Arabidopsis/efeitos da radiação , Proteínas de Arabidopsis/genética , Proteínas F-Box/genética , Flores/citologia , Flores/genética , Flores/fisiologia , Flores/efeitos da radiação , Luz , Proteínas de Domínio MADS/genética , Mutação , Fenótipo , Plantas Geneticamente Modificadas
9.
Biosci Biotechnol Biochem ; 82(11): 1931-1941, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30096253

RESUMO

Gibberellins (GAs) are a family of plant hormones that are important to multiple aspects of plant growth and development, especially stem elongation. A PSRK2 was obtained through screening and identifying RLK dominant negative mutants. Phenotype of the loss-of-function mutants, psrk2-DN and psrk2-RNAi, showed that PSRK2 could influence the length of the uppermost and fourth internodes, indicating that PSRK2 might regulate cell division in the intercalary meristems and/or cell elongation in the internodes. Moreover, the expression pattern showed that PSRK2 was strongly expressed in the joined-nodes after the start-up of reproductive growth, but undetectable in leaves. PSRK2 expression was also found to be induced by GA3, and PSRK2 was involved in GA signaling in cereal aleurone cells, and PSRK2 influence the relative length of the second leaf sheaths in seedling stage. These results indicate PSRK2 is a component of GA signaling pathway that controls stem elongation by negatively regulating GA responses. Abbreviations: Os: Oryza sativa; At: Arabidopsis thaliana; RNAi: RNA interfere; DN: Dominate Negative; SMART: Simple Modular Architecture Research Tool; Uni : Uniconazol; PSRK2: Plant Stature Related receptor-like Kinase 2; RLK: Receptor-like Kinase; GA: Gibberellin; IAA: indole-3-acetic acid; BL: Brassinosteroid.


Assuntos
Giberelinas/fisiologia , Oryza/enzimologia , Caules de Planta/fisiologia , Proteínas Quinases/metabolismo , Indução Enzimática , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Giberelinas/metabolismo , Mutação , Oryza/genética , Filogenia , Caules de Planta/enzimologia , Caules de Planta/crescimento & desenvolvimento , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas , Proteínas Quinases/biossíntese , Proteínas Quinases/genética , Interferência de RNA , Transcrição Reversa , Transdução de Sinais , alfa-Amilases/metabolismo
10.
J Integr Plant Biol ; 60(2): 85-88, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28059483

RESUMO

NADP(H)-dependent glutamate dehydrogenases (GDH) in lower organisms have stronger ammonium affinity than those in higher plants. Here we report that transgenic rice overexpressing the EcGDH from Eurotium cheralieri exhibited significantly enhanced aminating activities. Hydroponic and field tests showed that nitrogen assimilation efficiency and grain yields were markedly increased in these transgenic plants, especially at the low nitrogen conditions. These results suggest that EcGDH may have potential to be used to improve nitrogen assimilation and grain yield in rice.


Assuntos
Expressão Ectópica do Gene , Eurotium/enzimologia , Glutamato Desidrogenase/genética , Nitrogênio/metabolismo , Oryza/metabolismo , Sementes/crescimento & desenvolvimento , Glutamato Desidrogenase/metabolismo , Nitrogênio/farmacologia , Oryza/efeitos dos fármacos , Oryza/genética , Plantas Geneticamente Modificadas , Plântula/efeitos dos fármacos , Plântula/genética , Sementes/efeitos dos fármacos
11.
Planta ; 241(3): 727-40, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25486886

RESUMO

MAIN CONCLUSION: Heterologous expression of a fungal NADP(H)-GDH gene ( MgGDH ) from Magnaporthe grisea can improve dehydration stress tolerance in rice by preventing toxic accumulation of ammonium. Glutamate dehydrogenase (GDH; EC 1.4.1.2 and EC 1.4.1.4) may act as a stress-responsive enzyme in detoxification of high intracellular ammonia and production of glutamate for proline synthesis under stress conditions. In present study, a fungal NADP(H)-GDH gene (MgGDH) from Magnaporthe grisea was over-expressed in rice (Oryza sativa L. cv. 'kitaake'), and the transgenic plants showed the improvement of tolerance to dehydration stress. The kinetic analysis showed that His-TF-MgGDH preferentially utilizes ammonium to produce L-glutamate. Moreover, the affinity of His-TF-MgGDH for ammonium was dramatically higher than that of His-TF-OsGDH for ammonium. Over-expressing MgGDH transgenic rice plants showed lower water-loss rate and higher completely close stomata than the wild-type plants under dehydration stress conditions. In transgenic plants, the NADP(H)-GDH activities were markedly higher than those in wild-type plants and the amination activity was significantly higher than the deamination activity. Compared with wild-type plants, the transgenic plants accumulated much less NH4 (+) but higher amounts of glutamate, proline and soluble sugar under dehydration stress conditions. These results indicate that heterologous expression of MgGDH can prevent toxic accumulation of ammonium and in return improve dehydration stress tolerance in rice.


Assuntos
Desidrogenase de Glutamato (NADP+)/genética , Magnaporthe/genética , Oryza/fisiologia , Estresse Fisiológico , Água/fisiologia , Adaptação Fisiológica , Aminação , Compostos de Amônio/metabolismo , Metabolismo dos Carboidratos , Desidrogenase de Glutamato (NADP+)/metabolismo , Ácido Glutâmico/metabolismo , Cinética , Plantas Geneticamente Modificadas , Prolina/metabolismo , Proteínas Recombinantes/metabolismo
12.
Mol Biol Rep ; 41(6): 3683-93, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24557889

RESUMO

The full-length cDNA encoding a glutamate dehydrogenase (GDH) which catalyzes the reaction of reductive amination of α-oxoglutarate (α-OG) to glutamate (the anabolic activity) and the reverse reaction of oxidative deamination of glutamate (the catabolic activity) was isolated from Sclerotinia sclerotiorum, we designated it as SsGDH. Bioinformatics analysis revealed that SsGDH had a typical GDH spatial structure and extensive homology with other fungal or bacteria GDHs. To evaluate its function in rice, rice (Oryza sativa L. cv. 'kitaake') was transformed with SsGDH in a binary vector construct by Agrobacterium-mediated transformation. Transgenic rice plants showed that transcripts and proteins of SsGDH accumulated at higher levels and GDH enzymatic activity was obviously higher in transgenic rice plants compared with the non-transformant rice plants (CK), though phenotype including plant height, fresh weight and dry weight became slightly weaker compared with CK under 50, 500 and 5,000 µM nitrogen gradient nutrient solution treatment (NH4NO3 as a nitrogen source) after introducing SsGDH into rice. For enzymatic activity assay in vitro, recombinant His6-SsGDH protein was expressed in Escherichia coli BL21 (DE3) and purified by Ni-NTA agarose. Results suggested that recombinant His6-SsGDH protein had GDH activity using ammonium, α-OG, and L-glutamate separately as a substrate at two different concentrations, especially the affinity for ammonium was very high, and its Km value was only 0.28 ± 0.03 mM, indicating that SsGDH can assimilate more ammonium into rice. According to previous reports, transgenic plants expressing fungal or bacteria GDHs might show improved herbicide resistance. Basta resistance test showed that SsGDH expression in rice can significantly enhanced their tolerance to Basta than CK. In conclusion, our results may provide some clues for further investigation on nitrogen utilization via introducing exogenous GDHs from lower organisms into rice.


Assuntos
Glutamato Desidrogenase/biossíntese , Glutamato Desidrogenase/genética , Oryza/genética , Ascomicetos , Clonagem Molecular , Regulação da Expressão Gênica de Plantas , Glutamato Desidrogenase/química , Nitrogênio/metabolismo , Plantas Geneticamente Modificadas/genética , Homologia de Sequência de Aminoácidos
13.
Plant Commun ; 5(7): 100922, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38616490

RESUMO

Proper timing of flowering under different environmental conditions is critical for plant propagation. Light quality is a pivotal environmental cue that plays a critical role in flowering regulation. Plants tend to flower late under light with a high red (R)/far-red (FR) light ratio but early under light with a low R/FR light ratio. However, how plants fine-tune flowering in response to changes in light quality is not well understood. Here, we demonstrate that F-box of Flowering 2 (FOF2), an autonomous pathway-related regulator, physically interacts with VASCULAR PLANT ONE-ZINC FINGER 1 and 2 (VOZ1 and VOZ2), which are direct downstream factors of the R/FR light receptor phytochrome B (PHYB). We show that PHYB physically interacts with FOF2, mediates stabilization of the FOF2 protein under FR light and end-of-day FR light, and enhances FOF2 binding to VOZ2, which leads to degradation of VOZ2 by SCFFOF2 E3 ligase. By contrast, PHYB mediates degradation of FOF2 protein under R light and end-of-day R light. Genetic interaction studies demonstrated that FOF2 functions downstream of PHYB to promote FLC expression and inhibit flowering under both high R/FR light and simulated shade conditions, processes that are partially dependent on VOZ proteins. Taken together, our findings suggest a novel mechanism whereby plants fine-tune flowering time through a PHYB-FOF2-VOZ2 module that modulates FLC expression in response to changes in light quality.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Flores , Regulação da Expressão Gênica de Plantas , Luz , Fitocromo B , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Arabidopsis/efeitos da radiação , Flores/genética , Flores/efeitos da radiação , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Fitocromo B/metabolismo , Fitocromo B/genética , Proteínas de Domínio MADS/genética , Proteínas de Domínio MADS/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
14.
Mol Biol Rep ; 40(3): 2633-44, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23268310

RESUMO

Protein phosphatases type 2C (PP2Cs) from group A, which includes the ABI1/HAB1 and PP2CA branches, are key negative regulators of ABA signaling. HAI-1 gene had been shown to affect both seed and vegetative responses to ABA, which is one of PP2Cs clade A in Arabidopsis thaliana. Transgenic plants containing pHAI-1::GUS (ß-glucuronidase) displayed GUS activity existing in the vascular system of leave veins, stems and petioles. Green fluorescent protein fused HAI-1 (HAI-1-GFP) was found in the nucleus through transient transformation assays with onion epidermal cells. The water-loss assays indicated the loss-of-function mutants did not show symptoms of wilting and they had still turgid green rosette leaves. The assays of seed germination by exogenous ABA and NaCl manifested that the loss-of-function mutants displayed higher insensitivity than wild-type plants. Taken together, the final results suggest that the HAI-1 (AT5G59220) encoded a nuclear protein and it can be highly induced by ABA and wound in Arabidposis, the stress-tolerance phenotype showed a slightly improvement when HAI-1 gene was disrupted.


Assuntos
Adaptação Biológica/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Fosfoproteínas Fosfatases/genética , Fosfoproteínas Fosfatases/metabolismo , Estresse Fisiológico , Núcleo Celular/metabolismo , Secas , Regulação da Expressão Gênica de Plantas , Ordem dos Genes , Vetores Genéticos , Mutação , Fenótipo , Plantas Geneticamente Modificadas , Transporte Proteico , Tolerância ao Sal/genética
15.
Plant Sci ; 329: 111597, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36649757

RESUMO

Catalase (CAT) is a vital antioxidant enzyme, while phosphorylation pivotally regulates its function. Many phosphosites have been identified in CAT, but their functions remained largely elusive. We functionally studied five phosphoserines (Ser-9, -10, -11, -18, and -205) of CatC in rice (Oryza sativa L.). Phospho-Ser-9 and - 11 and dephospho-Ser-18 promoted the enzymatic activity of CatC and enhanced oxidative and salt tolerance in yeast. Phosphorylation status of Ser-18 did not affect CatC peroxisomal targeting and stability, but dephospho-Ser-18 promoted CatC tetramerization to enhance its activity. Moreover, overexpression of dephospho-mimic form CatCS18A in rice significantly improved the tolerance to salt and oxidative stresses by inhibiting the H2O2 accumulation. Together, these results elucidate the mechanism underlying dephosphorylation at Ser-18 promotes CatC activity and salt tolerance in rice. Ser-18 is a promising candidate phosphosite of CatC for breeding highly salt-tolerant rice.


Assuntos
Oryza , Oryza/metabolismo , Peróxido de Hidrogênio , Melhoramento Vegetal , Estresse Oxidativo/fisiologia , Antioxidantes/metabolismo
16.
Mol Biol Rep ; 39(2): 1527-35, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21695426

RESUMO

The homozygous T-DNA mutants of AtCAL1 (Rat1) and AtCAL2 (Rat2) were obtained. The double mutant of Rat2/Rat1RNAi was constructed which showed obvious late-flowering phenotype from others. The expression of various flowering-related genes was studied among mutants and wild-type plants by quantitative RT-PCR. The double mutant plants showed the shortest root length compared with T-DNA insertion mutants and wild type plants under red light, blue light, and white light. The double mutants showed hypersensitivity to NaCl and ABA. However, these mutants had no effect on stomatal closure by ABA.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , DNA Bacteriano/metabolismo , Flores/genética , Regulação da Expressão Gênica de Plantas/genética , Proteínas de Domínio MADS/genética , Mutagênese Insercional/genética , Fenótipo , Primers do DNA/genética , DNA Bacteriano/genética , Flores/fisiologia , Reação em Cadeia da Polimerase em Tempo Real
17.
Planta ; 233(1): 13-23, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20872270

RESUMO

Double B-box 1a (DBB1a) belongs to the zinc-finger family proteins in Arabidopsis thaliana. Transcriptional analysis uncovered that the DBB1a gene expression was blue light-dependently regulated, and the transcript level of DBB1a in cry1cry2 was decreased but not in phyAphyB compared to wild type under blue light conditions. Transgenic plants containing pDBB1a:GUS (ß-glucuronidase) displayed GUS activity in the vascular system of leaves and petioles. Green fluorescent protein (GFP)-fused DDB1a (DBB1a-GFP) protein was found in the nucleus in transient transformation assays with onion epidermal cells as well as in stable transgenic Arabidopsis plants. To investigate the function of DBB1a, we generated DBB1a over-expressing and under-expressing transgenic Arabidopsis plants. Analysis of hypocotyl growth of these lines indicated that DBB1a promoted hypocotyl elongation under blue light condition. The phenotype of transgenic plants with DBB1a over-expression could be impaired by a gibberellin (GA)-biosynthesis inhibitor. Moreover, the expression analysis of GA metabolic and catabolic genes in DBB1a transgenic lines indicated that the DBB1a suppressed GA2-oxidase1 (GA2ox1) and GA2-oxidase8 (GA2ox8) expression, but induced GA3ß-hydroxygenase1 (GA3ox1) and GA20-oxidase1 (GA20ox1) expression under blue light. Taken together, we concluded that DBB1a promotes hypocotyl elongation under blue light condition through an increase in bioactive GA levels in Arabidopsis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/efeitos da radiação , Proteínas de Transporte/metabolismo , Giberelinas/metabolismo , Homeostase/efeitos da radiação , Hipocótilo/crescimento & desenvolvimento , Luz , Arabidopsis/citologia , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Transporte/genética , Núcleo Celular/metabolismo , Núcleo Celular/efeitos da radiação , Criptocromos/metabolismo , Proteínas de Ligação a DNA , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Genes de Plantas/genética , Hipocótilo/efeitos da radiação , Mutação/genética , Folhas de Planta/metabolismo , Folhas de Planta/efeitos da radiação , Raízes de Plantas/citologia , Raízes de Plantas/metabolismo , Raízes de Plantas/efeitos da radiação , Feixe Vascular de Plantas/metabolismo , Feixe Vascular de Plantas/efeitos da radiação , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas/genética , Transporte Proteico/efeitos da radiação , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fatores de Transcrição , Transcrição Gênica/efeitos da radiação
18.
Mol Plant ; 14(8): 1328-1342, 2021 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-33971366

RESUMO

Light is a critical environmental cue that regulates a variety of diverse plant developmental processes. Cryptochrome 1 (CRY1) is the major photoreceptor that mediates blue light-dependent photomorphogenic responses such as the inhibition of hypocotyl elongation. Gibberellin (GA) participates in the repression of photomorphogenesis and promotes hypocotyl elongation. However, the antagonistic interaction between blue light and GA is not well understood. Here, we report that blue light represses GA-induced degradation of the DELLA proteins (DELLAs), which are key negative regulators in the GA signaling pathway, via CRY1, thereby inhibiting the GA response during hypocotyl elongation. Both in vitro and in vivo biochemical analyses demonstrated that CRY1 physically interacts with GA receptors-GA-INSENSITIVE DWARF 1 proteins (GID1s)-and DELLAs in a blue light-dependent manner. Furthermore, we showed that CRY1 inhibits the association between GID1s and DELLAs. Genetically, CRY1 antagonizes the function of GID1s to repress the expression of cell elongation-related genes and thus hypocotyl elongation. Taken together, our findings demonstrate that CRY1 coordinates blue light and GA signaling for plant photomorphogenesis by stabilizing DELLAs through the binding and inactivation of GID1s, providing new insights into the mechanism by which blue light antagonizes the function of GA in photomorphogenesis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Criptocromos/metabolismo , Luz , Receptores de Superfície Celular/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Criptocromos/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Giberelinas/metabolismo , Receptores de Superfície Celular/genética , Transdução de Sinais/fisiologia , Transdução de Sinais/efeitos da radiação
19.
Plant Sci ; 305: 110769, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33691974

RESUMO

Drought stress can significantly affect plant growth and agricultural productivity. Thus, it is essential to explore and identify the optimal genes for the improvement of crop drought tolerance. Here, a fungal NADP(H)-dependent glutamate dehydrogenase gene (AcGDH) was isolated from Aspergillus candidus, and heterologously expressed in rice. AcGDH has a high affinity for NH4+ and increases the ammonium assimilation in rice. AcGDH transgenic plants exhibited a tolerance to drought and alkali stresses, and their photorespiration was significantly suppressed. Our findings demonstrate that AcGDH alleviates ammonium toxicity and suppresses photorespiration by assimilating excess NH4+ and disturbing the delicate balance of carbon and nitrogen metabolism, thereby improving drought tolerance in rice. Moreover, AcGDH not only improved drought tolerance at the seedling stage but also increased the grain yield under drought stress. Thus, AcGDH is a promising candidate gene for maintaining rice grain yield, and offers an opportunity for improving crop yield under drought stress.


Assuntos
Compostos de Amônio/toxicidade , Respiração Celular/fisiologia , Desidratação , Grão Comestível/fisiologia , Proteínas Fúngicas/metabolismo , Oryza/genética , Oryza/fisiologia , Adaptação Fisiológica/genética , Adaptação Fisiológica/fisiologia , Respiração Celular/genética , Secas , Grão Comestível/genética , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Reguladores de Crescimento de Plantas/metabolismo , Estresse Fisiológico/genética , Estresse Fisiológico/fisiologia
20.
Plant Cell Rep ; 28(7): 1065-74, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19455339

RESUMO

Traditional transformation methods are complex and time consuming. It is generally difficult to transform indica rice varieties using traditional transformation methods due to their poor regeneration. In this contribution, a simple method was developed for the transformation of indica rice. In this method, the mature embryos of soaked seeds were pierced by a needle, and then soaked in the Agrobacterium inoculum under vacuum infiltration. The inoculated seeds germinated and grew to maturation (T (0)) under nonsterile conditions. The herbicide or antibiotic analysis and molecular analysis were conducted on T (0) plants. The results showed that although the efficiency of transformation was about 6.0%, it was easier to transform indica rice using the proposed method, and the transformation process was significantly shortened. The success of transformation was further confirmed by the genetic and molecular analyses of T (1) transformants.


Assuntos
Técnicas de Transferência de Genes , Oryza/genética , Rhizobium/genética , Sementes/genética , DNA de Plantas/genética , Regulação da Expressão Gênica de Plantas , Plantas Geneticamente Modificadas/genética , Transformação Genética , Vácuo
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