RESUMEN
Accumulation of cadmium (Cd) in rice is not only harmful to the growth of plants but also poses a threat to human health. Exposure to Cd triggers unfolded protein response (UPR) within cells, a process that is still not completely understood. The study demonstrated that the lack of OsbZIP39, an essential endoplasmic reticulum (ER)-resident regulator of the UPR, resulted in decreased Cd intake and reduced Cd levels in the roots, stems, and grains of rice. Upon exposure to Cd stress, GFP-OsbZIP39 translocated from ER to nucleus, initiating UPR. Further investigation revealed that Cd treatment caused changes in sphingolipid levels in the membrane, influencing the localization and activation of OsbZIP39. Yeast one-hybrid and dual-LUC assays were conducted to validate the interaction between activated OsbZIP39 and the promoter of the defensin-like gene OsCAL2, resulting in an increase in its expression. Different variations were identified in the coding region of OsbZIP39, which may explain the varying levels of Cd accumulation observed in the indica and japonica subspecies. Under Cd treatment, OsbZIP39ind exhibited a more significant enhancement in the transcription of OsCAL2 compared to OsbZIP39jap. Our data suggest that OsbZIP39 positively regulates Cd uptake in rice, offering an encouraging objective for the cultivation of low-Cd rice.
Asunto(s)
Cadmio , Estrés del Retículo Endoplásmico , Regulación de la Expresión Génica de las Plantas , Oryza , Proteínas de Plantas , Oryza/metabolismo , Oryza/genética , Oryza/efectos de los fármacos , Cadmio/toxicidad , Cadmio/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estrés del Retículo Endoplásmico/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Defensinas/genética , Defensinas/metabolismo , Respuesta de Proteína Desplegada/efectos de los fármacos , Raíces de Plantas/metabolismo , Raíces de Plantas/efectos de los fármacosRESUMEN
Patchoulol, a valuable compound belonging to the sesquiterpenoid family, is the primary component of patchouli oil produced by Pogostemon cablin (P. cablin). It has a variety of pharmacological and biological activities and is widely used in the medical and cosmetic industries. However, despite its significance, there is a lack of research on the transcriptional modulation of patchoulol biosynthesis.Salicylic acid (SA), is a vital plant hormone that serves as a critical signal molecule and plays an essential role in plant growth and defense. However, to date, no studies have explored the modulation of patchoulol biosynthesis by SA. In our study, we discovered that the application of SA can enhance the production of patchoulol. Utilizing transcriptome analysis of SA-treated P. cablin, we identified a crucial downstream transcription factor, PatWRKY71. The transcription level of PatWRKY71 was significantly increased with the use of SA. Furthermore, our research has revealed that PatWRKY71 was capable of binding to the promoter of PatPTS, ultimately leading to an increase in its expression. When PatWRKY71 was silenced by a virus, the expression of both PatWRKY71 and PatPTS was reduced, resulting in the down-regulation of patchoulol production. Through our studies, we discovered that heterologous expression of PatWRKY71 leads to an increase in the sensitivity of Arabidopsis to salt and Cd, as well as an outbreak of reactive oxygen species (ROS). Additionally, we uncovered the regulatory role of PatWRKY71 in both patchoulol biosynthesis and plant defense response. This discovery provided a theoretical basis for the improvement of the content of patchoulol and the resistance of P. cablin through genetic engineering.
Asunto(s)
Arabidopsis , Pogostemon , Sesquiterpenos , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Plantas/metabolismo , Pogostemon/genética , Sesquiterpenos/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismoRESUMEN
Ipomoea pes-caprae is a seashore halophytic plant and is therefore a good model for studying the molecular mechanisms underlying salt and stress tolerance in plant research. Here, we performed Full-length cDNA Over-eXpressor (FOX) gene hunting with a functional screening of a cDNA library using a salt-sensitive yeast mutant strain to isolate the salt-stress-related genes of I. pes-caprae (IpSR genes). The library was screened for genes that complemented the salt defect of yeast mutant AXT3 and could grow in the presence of 75 mM NaCl. We obtained 38 candidate salt-stress-related full-length cDNA clones from the I. pes-caprae cDNA library. The genes are predicted to encode proteins involved in water deficit, reactive oxygen species (ROS) scavenging, cellular vesicle trafficking, metabolic enzymes, and signal transduction factors. When combined with the quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analyses, several potential functional salt-tolerance-related genes were emphasized. This approach provides a rapid assay system for the large-scale screening of I. pes-caprae genes involved in the salt stress response and supports the identification of genes responsible for the molecular mechanisms of salt tolerance.
Asunto(s)
Genes de Plantas , Técnicas Genéticas , Ipomoea/genética , Ipomoea/fisiología , Estrés Salino/genética , ADN Complementario/genética , Ecosistema , Regulación de la Expresión Génica de las Plantas , Biblioteca de Genes , Estudios de Asociación Genética , Peróxido de Hidrógeno/toxicidad , Anotación de Secuencia Molecular , Presión Osmótica , Potasio/metabolismo , Saccharomyces cerevisiae/metabolismo , Tolerancia a la Sal/genética , Sodio/metabolismoRESUMEN
Ipomoea pes-caprae L. is an extremophile halophyte with strong adaptability to seawater and drought. It is widely used in the ecological restoration of coastal areas or degraded islands in tropical and subtropical regions. In this study, a new abscisic acid, stressandripening (ASR) gene, IpASR, was reported, and is mainly associated with biological functions involved in salt and drought tolerance. Sequence analysis of IpASR showed that this protein contains an ABA/WDS (abscisic acid/water deficit stress) domain, which is a common feature of all plant ASR members. Overexpression of IpASR improved Escherichia coli growth performance compared with the control under abiotic stress treatment. The transgenic overexpressing IpASR Arabidopsis showed higher tolerance to salt and drought stress than the wild type and lower accumulation of hydrogen peroxide (H2O2) and superoxide (O2-) accompanied by increased antioxidant enzyme activity in vivo. IpASR exhibits transcription factor's activity. Therefore, the overexpression of IpASR in Arabidopsis is supposed to influence the expression of some genes involved in anti-oxidative and abiotic stresses. The results indicate that IpASR is involved in the plant response to salt and drought and probably acts as a reactive oxygen species scavenger or transcription factor, and therefore influences physiological processes associated with various abiotic stresses in plants.
Asunto(s)
Arabidopsis , Escherichia coli , Ipomoea/genética , Microorganismos Modificados Genéticamente , Proteínas de Plantas , Plantas Modificadas Genéticamente , Salinidad , Plantas Tolerantes a la Sal , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Deshidratación/genética , Deshidratación/metabolismo , Escherichia coli/genética , Escherichia coli/crecimiento & desarrollo , Microorganismos Modificados Genéticamente/genética , Microorganismos Modificados Genéticamente/crecimiento & desarrollo , Proteínas de Plantas/biosíntesis , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/crecimiento & desarrollo , Plantas Tolerantes a la Sal/genética , Plantas Tolerantes a la Sal/crecimiento & desarrolloRESUMEN
In this study we produced transgenic tobacco plants by overexpressing a serine proteinase inhibitor gene, SaPIN2a, from the American black nightshade Solanum americanum under the control of the CaMV 35S promoter using Agrobacterium tumefaciens-mediated transformation. SaPIN2a was properly transcribed and translated as indicated by Northern blot and Western blot analyses. Functional integrity of SaPIN2a in transgenic plants was confirmed by proteinase inhibitory activity assay. Bioassays for insect resistance showed that SaPIN2a-overexpressing transgenic tobacco plants were more resistant to cotton bollworm (Helicoverpa armigera) and tobacco cutworm (Spodoptera litura) larvae, two devastating pests of important crop plants, than the control plants. Interestingly, overexpression of SaPIN2a in transgenic tobacco plants resulted in a significant increase in glandular trichome density and a promotion of trichome branching, which could also provide an additional resistance mechanism in transgenic plants against insect pests. Therefore, SaPIN2a could be used as an alternative proteinase inhibitor for the production of insect-resistant transgenic plants.
Asunto(s)
Lepidópteros/crecimiento & desarrollo , Nicotiana/genética , Proteínas de Plantas/metabolismo , Inhibidores de Proteasas/metabolismo , Solanum/metabolismo , Spodoptera/crecimiento & desarrollo , Tricomas/metabolismo , Animales , Larva/metabolismo , Hojas de la Planta/metabolismo , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente/metabolismo , Nicotiana/metabolismoRESUMEN
SaPIN2a, a plant proteinase inhibitor from nightshade (Solanum americanum), was located to the enucleate sieve elements (SEs) of phloem. The expressed SaPIN2a in transgenic lettuce showed inhibition of plant endogenous trypsin- and chymotrypsin-like activities, suggesting that SaPIN2a can regulate proteolysis in plant cells. To further investigate the physiological role of SaPIN2a, we produced transgenic nightshade and lettuce plants overexpressing SaPIN2a from the cauliflower mosaic virus (CaMV) 35S promoter using Agrobacterium-mediated transformation. Overexpression of SaPIN2a in transgenic plants was demonstrated by northern blot and western blot analysis. SaPIN2a-overexpressing transgenic nightshade plants showed significantly lower height than wild-type plants. Transmission electron microscopy analysis showed that chloroplast-like organelles with thylakoids, which are not present in enucleate SEs of wild-type plants, were present in the enucleate SEs of SaPIN2a-overexpressing transgenic plants. This finding is discussed in terms of the possible role played by SaPIN2a in the regulation of proteolysis in SEs.
Asunto(s)
Cloroplastos/ultraestructura , Lactuca/genética , Lactuca/ultraestructura , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/ultraestructura , Inhibidores de Serina Proteinasa/fisiología , Caulimovirus/genética , Microscopía Electrónica de Transmisión , Orgánulos/ultraestructura , Floema/química , Floema/ultraestructura , Regiones Promotoras Genéticas , Rhizobium/genética , Inhibidores de Serina Proteinasa/análisis , Inhibidores de Serina Proteinasa/genética , Solanum/genética , Tilacoides/ultraestructuraRESUMEN
OBJECTIVE: Chilling tolerance of salicylic acid (SA) in banana seedlings (Musa acuminata cv., Williams 8818) was investigated by changes in ultrastructure in this study. METHODS: Light and electron microscope observation. RESULTS: Pretreatment with 0.5 mmol/L SA under normal growth conditions (30/22 degrees C) by foliar spray and root irrigation resulted in many changes in ultrastructure of banana cells, such as cells separation from palisade parenchymas, the appearance of crevices in cell walls, the swelling of grana and stromal thylakoids, and a reduction in the number of starch granules. These results implied that SA treatment at 30/22 degrees C could be a type of stress. During 3 d of exposure to 7 degrees C chilling stress under low light, however, cell ultrastructure of SA-pretreated banana seedlings showed less deterioration than those of control seedlings (distilled water-pretreated). CONCLUSION: SA could provide some protection for cell structure of chilling-stressed banana seedling.
Asunto(s)
Musa/ultraestructura , Ácido Salicílico , Adaptación Fisiológica , Frío , Microscopía Electrónica , Musa/fisiología , Hojas de la Planta/ultraestructura , Transpiración de PlantasRESUMEN
The best known property of plant proteinase inhibitor II (PIN2) genes is their wound-inducible expression in leaves and constitutive expression in flowers. Here we show by promoter analysis in transgenic plants and in situ reverse transcription-PCR (RT-PCR) analysis that SaPIN2b, a member of the PIN2 gene family of nightshade (Solanum americanum), is also constitutively expressed in glandular trichomes. SaPIN2b promoter and its deletions were cloned and fused upstream of beta-glucuronidase (GUS) to transform the nightshade and tobacco (Nicotiana tabacum) plants. Histochemical staining assays indicated that SaPIN2b:GUS was expressed constitutively in glandular trichomes, predominantly in the gland cells, of both transgenic nightshade and tobacco plants. Constitutive expression of SaPIN2b in glandular trichomes was further confirmed by liquid phase in situ RT-PCR analysis of nightshade leaves. Deletion analysis from the 5' end of the SaPIN2b promoter revealed that separate regulatory elements control SaPIN2b expression in gland cells and stalk cells of glandular trichomes. Fluorometric GUS assays showed that SaPIN2b:GUS expression was significantly increased in transgenic plant leaves after mechanical wounding or methyl jasmonate treatment. The SaPIN2b promoter sequence contains six MYB-binding motifs and an L1 box that are involved in trichome differentiation and development. Overexpression of SaPIN2b in tobacco resulted in a significant increase in glandular trichome density and promotion of trichome branching. These results suggest that, as well as being an induced defensive protein of the well-known PIN2 family, SaPIN2b could also play roles in trichome-based defense by functioning as a constitutive component of trichome chemical defense and/or by regulating the development of glandular trichomes.