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MAIN CONCLUSION: Plant and the soil-associated microbiome is important for imparting bacterial wilt disease tolerance in plants. Plants are versatile organisms that are endowed with the capacity to withstand various biotic and abiotic stresses despite having no locomotory abilities. Being the agent for bacterial wilt (BW) disease, Ralstonia solanacearum (RS) colonizes the xylem vessels and limits the water supply to various plant parts, thereby causing wilting. The havoc caused by RS leads to heavy losses in crop productivity around the world, for which a sustainable mitigation strategy is urgently needed. As several factors can influence plant-microbe interactions, comprehensive understanding of plant and soil-associated microbiome under the influence of RS and various environmental/edaphic conditions is important to control this pathogen. This review mainly focuses on microbiome dynamics associated with BW disease and also provide update on microbial/non-microbial approaches employed to control BW disease in crop plants.
Assuntos
Microbiota , Ralstonia solanacearum , Solo , Doenças das Plantas/microbiologia , Bactérias , PlantasRESUMO
Reactive oxygen species (ROS; free radical form O2 â¢- , superoxide radical; OH⢠, hydroxyl radical; ROO⢠, peroxyl; RO⢠, alkoxyl and non-radical form 1 O2 , singlet oxygen; H2 O2 , hydrogen peroxide) are inevitable companions of aerobic life with crucial role in gut health. But, overwhelming production of ROS can cause serious damage to biomolecules. In this review, we have discussed several sources of ROS production that can be beneficial or dangerous to the human gut. Micro-organisms, organelles and enzymes play crucial role in ROS generation, where NOX1 is the main intestinal enzyme, which produce ROS in the intestine epithelial cells. Previous studies have reported that probiotics play significant role in gut homeostasis by checking the ROS generation, maintaining the antioxidant level, immune system and barrier protection. With current knowledge, we have critically analysed the available literature and presented the outcome in the form of bubble maps to suggest that the probiotics help in controlling the ROS-specific intestinal diseases, such as inflammatory bowel disease (IBD) and colon cancer. Finally, it has been concluded that rebooting of the gut microbiota with probiotics, postbiotics or faecal microbiota transplantation (FMT) can have crucial implications in the structuring of gut communities for the personalized management of the gastrointestinal (GI) diseases.
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Gastroenteropatias , Microbioma Gastrointestinal , Doenças Inflamatórias Intestinais , Probióticos , Disbiose , Transplante de Microbiota Fecal , Humanos , Espécies Reativas de OxigênioRESUMO
RbAp46/RBBP7 and RbAp48/RBBP4 are WD40-repeat histone chaperones and chromatin adaptors that reside in multiple complexes involved in maintenance of chromatin structure. RbAp48 is the essential subunit of the chromatin assembly factor-1 (CAF-1) complex, therefore also named as CAF-1C. A detailed in silico sequence and structure analysis of homologs of RbAp46/48 in Plasmodium falciparum (PF3D7_0110700 and PF3D7_1433300) exhibited conservation of characteristic features in both the protein-seven-bladed WD40 ß-propeller conformation and different binding interfaces. A comparative structural analysis highlighted species-specific features of the parasite, yeast, drosophila, and human RbAp46/48. In the present study, we report cloning, expression, and characterization of P. falciparum PF3D7_0110700, a putative RbAp46/48 (PfRbAp46/48). PfRbAp46/48 was cloned into pTEM11 vector in fusion with 6xHistidine tag and over-expressed in Escherichia coli B834 cells. The protein was purified by Ni-NTA followed by gel permeation chromatography. The protein expressed in all the three asexual blood stages and exhibited nuclear localization. We showed direct interaction of the purified rPfRbAp46/48 with the histone H4. These findings further our understanding of RbAp46/48 proteins and role of these proteins in the parasite biology.
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Chaperonas de Histonas/química , Chaperonas de Histonas/metabolismo , Plasmodium falciparum/química , Proteínas de Protozoários/química , Proteínas de Protozoários/metabolismo , Sequência de Aminoácidos , Núcleo Celular/metabolismo , Cromatina/metabolismo , Expressão Gênica , Chaperonas de Histonas/genética , Histonas/metabolismo , Estágios do Ciclo de Vida/genética , Plasmodium falciparum/genética , Plasmodium falciparum/crescimento & desenvolvimento , Plasmodium falciparum/metabolismo , Ligação Proteica , Conformação Proteica , Proteínas de Protozoários/genética , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/isolamento & purificação , Proteínas Recombinantes de Fusão/metabolismoRESUMO
Arabidopsis amiR:ADC-L2 is a non-lethal line with several developmental defects, it is characterized by a drastic reduction in free polyamine content. Herein, we found that catalase application had growth-promoting effects in amiR:ADC-L2 and parental Ws seedlings. Differences in ROS content between amiR:ADC-L2 and Ws seedlings were detected. Increased H2O2 levels were found in the amiR:ADC-L2, as well as low AtCAT2 gene expression and reduced catalase activity. Estimation of polyamine oxidase activity in amiR:ADC-L2 line indicated that the over-accumulation of H2O2 is independent of polyamine catabolism. However, increments in NADPH oxidase activity and O2â¢- content could be associated to the higher H2O2 levels in the amiR:ADC-L2 line. Our data suggest that low polyamine levels in Arabidopsis seedlings are responsible for the accumulation of ROS, by altering the activities of enzymes involved in ROS production and detoxification.
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Proteínas de Arabidopsis/genética , Arabidopsis/enzimologia , Arabidopsis/genética , Carboxiliases/genética , Regulação para Baixo/genética , Regulação da Expressão Gênica de Plantas , Espécies Reativas de Oxigênio/metabolismo , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/metabolismo , Carboxiliases/metabolismo , Catalase/metabolismo , Peróxido de Hidrogênio/metabolismo , NADPH Oxidases/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/metabolismo , Plantas Geneticamente Modificadas , Plântula/crescimento & desenvolvimento , Superóxidos/metabolismo , Poliamina OxidaseRESUMO
Being sessile, plants are continuously exposed to DNA-damaging agents present in the environment such as ultraviolet (UV) and ionizing radiations (IR). Sunlight acts as an energy source for photosynthetic plants; hence, avoidance of UV radiations (namely, UV-A, 315-400 nm; UV-B, 280-315 nm; and UV-C, <280 nm) is unpreventable. DNA in particular strongly absorbs UV-B; therefore, it is the most important target for UV-B induced damage. On the other hand, IR causes water radiolysis, which generates highly reactive hydroxyl radicals (OH(â¢)) and causes radiogenic damage to important cellular components. However, to maintain genomic integrity under UV/IR exposure, plants make use of several DNA repair mechanisms. In the light of recent breakthrough, the current minireview (a) introduces UV/IR and overviews UV/IR-mediated DNA damage products and (b) critically discusses the biochemistry and genetics of major pathways responsible for the repair of UV/IR-accrued DNA damage. The outcome of the discussion may be helpful in devising future research in the current context.
Assuntos
Dano ao DNA/genética , Reparo do DNA/efeitos da radiação , Redes e Vias Metabólicas/fisiologia , Plantas/efeitos da radiação , Radiação Ionizante , Raios Ultravioleta/efeitos adversos , Desoxirribodipirimidina Fotoliase/metabolismo , Redes e Vias Metabólicas/genética , Dímeros de Pirimidina/efeitos da radiaçãoRESUMO
Jasmonic acid (JA) is a very young candidate of plant growth regulators which is being explored for various antistress properties. Present study deals with the hypothesis that JA can modulate antioxidant mechanism of higher plants with tight regulation of biomembrane peroxidation, making plants tolerant to toxic Ni(2+). 2 mM NiCl2 as a source of Ni(2+) appeared as sub lethal dose for the growth of 15 days old Glycine max seedlings. Exogenous application of 1 µM and 1 nM JA prior to NiCl2 exposure, made seedlings of Glycine max more tolerant to Ni(2+)stress as compared to control untreated seedlings. Regulatory inhibition of MDA and H2O2 production by JA with or without Ni(2+) treatment made plants more resistant to Ni(2+) stress which may be associated with ameliorative activity of antioxidant enzymes system composed of SOD, POD, CAT and APOX. Ascorbate, a secondary metabolite synthesized from D-glucose act as an antioxidant in plant cells. Many fold enhancements in AsA content of Ni(2+) treated seedlings supplemented with different concentrations of JA was observed. Significant improvement in AsA levels by JA with or without Ni(2+) stress may involve two aspects, either denovo synthesis level regulation of AsA or recycling of AsA from an oxidized form. Improvement in total protein content showed the uplift modulation of transcriptional machinery by JA which was also maintained under Ni(2+) stress. Photosynthetic pigments as total chl, chl a and b showed inhibition in presence of Ni(2+) stress which was not found much effective under JA supplementation as compared to control. Present findings revealed that although JA was not helpful for protection of photosynthetic pigments but it modulates the other machinery of plants significantly including various antioxidants positively, while tightly inhibiting stress related processes responsible for lipid peroxidation to make plants tolerant to Ni(2+) stress.
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MAIN CONCLUSION: The present study demonstrates the first direct evidence of the novel role of OsACA6 in providing Cd (2+) stress tolerance in transgenic tobacco by maintaining cellular ion homeostasis and modulating ROS-scavenging pathway. Cadmium, a non-essential toxic heavy metal, interferes with the plant growth and development. It reaches the leaves through xylem and may become part of the food chain, thus causing detrimental effects to human health. Therefore, there is an urgent need to develop strategies for engineering plants for Cd(2+) tolerance and less accumulation. The members of P-type ATPases family transport metal ions including Cd(2+), and thus play important role an ion homeostasis. The present study elucidates the role of P-type 2B Ca(2+) ATPase (OsACA6) in Cd(2+) stress tolerance. The transcript levels of OsACA6 were up-regulated upon Cd(2+), Zn(2+) and Mn(2+) exposure. Transgenic tobacco expressing OsACA6 showed tolerance towards Cd(2+) stress as demonstrated by several physiological indices including root length, biomass, chlorophyll, malondialdehyde and hydrogen peroxide content. The roots of the transgenic lines accumulated more Cd(2+) as compared to shoot. Further, confocal laser scanning microscopy showed that Cd(2+) exposure altered Ca(2+) uptake in OsACA6 transgenic plants. OsACA6 expression in tobacco also protected the transgenic plants from oxidative stress by enhancing the activity of enzymatic (SOD, CAT, APX, GR) and non-enzymatic (GSH and AsA) antioxidant machinery. Transgenic lines also tolerated Zn(2+) and Mn(2+) stress; however, tolerance for these ions was not as significant as observed for Cd(2+) exposure. Thus, overexpression of OsACA6 confers Cd(2+) stress tolerance in transgenic lines by maintaining cellular ion homeostasis and modulating reactive oxygen species (ROS)-scavenging pathway. The results of the present study will help to develop strategies for engineering Cd(2+) stress tolerance in economically important crop plants.
Assuntos
Cádmio/toxicidade , ATPases Transportadoras de Cálcio/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Nicotiana/enzimologia , Antioxidantes/metabolismo , ATPases Transportadoras de Cálcio/genética , Homeostase/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Malondialdeído/metabolismo , Estresse Oxidativo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/enzimologia , Folhas de Planta/genética , Folhas de Planta/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/enzimologia , Raízes de Plantas/genética , Raízes de Plantas/fisiologia , Plantas Geneticamente Modificadas , Espécies Reativas de Oxigênio/metabolismo , Nicotiana/efeitos dos fármacos , Nicotiana/genética , Nicotiana/fisiologia , Xilema/efeitos dos fármacos , Xilema/enzimologia , Xilema/genética , Xilema/fisiologiaRESUMO
Arsenic (As) is an acute toxic metalloid that affects plant growth and development. As is found in the environment in organic and inorganic forms, but arsenite As(III) and arsenate As(V) are the most prevalent forms that negatively impact the plants. Roots exposed to As can easily absorb it mainly through transporters that carry vital mineral nutrients. As reach the food chain via crops irrigated with As-polluted water and exerts a negative impact. Even at low levels, As exposure disrupts the regular functioning of plants by generating a high level of reactive oxygen species (ROS) results into oxidative damage, and disruption of redox system. Plants have built-in defence mechanisms to combat this oxidative damage. The development of a food crop with lower As levels is dependent upon understanding the molecular process of As detoxification in plants, which will help reduce the consumption of As-contaminated food. Numerous genes in plants that may provide tolerance under hazardous conditions have been examined using genetic engineering techniques. The suppression of genes by RNA interference (RNAi) and CRISPR-Cas 9 (CRISPR associated protein 9) technology revealed an intriguing approach for developing a crop that has minimal As levels in consumable portions. This study aims to present current information on the biochemical and molecular networks associated with As uptake, as well as recent advances in the field of As mitigation using exogenous salicylic acid (SA), Serendipita indica and biotechnological tools in terms of generating As-tolerant plants with low As accumulation.
Assuntos
Arsênio , Arsênio/metabolismo , Arsênio/toxicidade , Transporte Biológico , Produtos Agrícolas/metabolismo , Produtos Agrícolas/efeitos dos fármacos , Inativação Metabólica , Plantas/metabolismo , Plantas/efeitos dos fármacosRESUMO
The exact mechanism of helicase-mediated salinity tolerance is not yet understood. We have isolated a DESD-box containing cDNA from Pisum sativum (Pea) and named it as PDH45. It is a unique member of DEAD-box helicase family; containing DESD instead of DEAD/H. PDH45 overexpression driven by constitutive cauliflower mosaic virus-35S promoter in rice transgenic [Oryza sativa L. cv. Pusa Basmati 1 (PB1)] plants confers salinity tolerance by improving the photosynthesis and antioxidant machinery. The Na(+) ion concentration and oxidative stress parameters in leaves of the NaCl (0, 100 or 200 mM) treated PDH45 overexpressing T1 transgenic lines were lower as compared to wild type (WT) rice plants under similar conditions. The 200 mM NaCl significantly reduced the leaf area, plant dry mass, net photosynthetic rate (PN), stomatal conductance (gs), intercellular CO2 (Ci), chlorophyll (Chl) content in WT plants as compared to the transgenics. The T1 transgenics exhibited higher glutathione (GSH) and ascorbate (AsA) contents under salinity stress. The activities of antioxidant enzymes viz. superoxide dismutase (SOD), ascorbate peroxidase (APX), guaiacol peroxidase (GPX) and glutathione reductase (GR) were significantly higher in transgenics; suggesting the existence of an efficient antioxidant defence system to cope with salinity induced-oxidative damage. Yeast two-hybrid assay indicated that the PDH45 protein interacts with Cu/Zn SOD, adenosine-5'-phosphosulfate-kinase, cysteine proteinase and eIF(4G), thus confirming the involvement of ROS scavenging machinery in the transgenic plants to provide salt tolerance. Furthermore, the T2 transgenics were also able to grow, flower, and set viable seeds under continuous salinity stress of 200 mM NaCl. This study provides insights into the mechanism of PDH45 mediated salinity stress tolerance by controlling the generation of stress induced reactive oxygen species (ROS) and also by protecting the photosynthetic machinery through a strengthened antioxidant system.
Assuntos
Antioxidantes/metabolismo , DNA Helicases/metabolismo , Oryza/fisiologia , Fotossíntese/fisiologia , Pisum sativum/enzimologia , Tolerância ao Sal , Estresse Fisiológico , Ácido Ascórbico/metabolismo , Clorofila/metabolismo , Segregação de Cromossomos , Fluorescência , Genes de Plantas/genética , Glutationa/metabolismo , Modelos Biológicos , Oryza/genética , Oryza/crescimento & desenvolvimento , Estresse Oxidativo , Plantas Geneticamente Modificadas , Potássio/metabolismo , Prolina/metabolismo , Ligação Proteica , Espécies Reativas de Oxigênio/metabolismo , Salinidade , Plântula/crescimento & desenvolvimento , Sódio/metabolismo , Técnicas do Sistema de Duplo-HíbridoRESUMO
Aluminium (Al) is the third most abundant element in the Earth's crust. Globally, acidic soil occupies 30-40% of ice-free land areas; Al toxicity is a major threat to crops. The first symptom of Al toxicity is the inhibition of root growth followed by poor root hair development, swollen root apices, necrosis of leaves and reduced yield. Although Rice (Oryza sativa) is an Al toxicity tolerant crop, it shows considerable variations among rice genotypes to Al exposure. Therefore, it is pertinent to understand Al toxicity and underlying mechanisms for Al tolerance in Rice. In the present study, 63 rice genotypes screened under Al stress showed significant variations of root growth. Expression stability of endogenous control genes (ECGs) revealed sulphite reductase (SR) as the most stable ECG that can be used as a reference gene for quantitative real-time PCR (qRT-PCR). Expression patterns of Al-responsive genes suggest genes associated with cytoskeletal dynamics, metabolism, and ion transporter could play significant roles in Al adaptation and tolerance in rice. The results showed Motodhan, Vietnam-1, Yimyu and N-861 as Al-toxicity tolerant, while Lespah, RCPL-13, VL-31329, and UPR2919-141-1 as most Al-sensitive genotypes among the studied rice lines cultivated in North-East India.
Assuntos
Oryza , Alumínio/metabolismo , Raízes de Plantas/metabolismo , Genótipo , Adaptação Fisiológica/genética , Regulação da Expressão Gênica de PlantasRESUMO
Circular RNAs (circRNAs) are important regulators of diverse biological processes of plants. However, the evolution and potential functions of circRNAs during winter dormancy and spring bud flushing of tea plant is largely unknown. Using RNA-seq data, a total of 1184 circRNAs were identified in the winter dormant and spring bud flushing leaf samples of tea plants in two different cultivars exhibiting different duration of winter dormancy. A total of 156 circRNAs are found to be differentially expressed and the weighted gene co-expression network (WGCNA) analysis revealed that 22 and 20 differentially expressed-circRNAs (DE-circRNAs) positively correlated with the flushing and dormant leaf traits, respectively, in both the tea cultivars used. Some transcription factors (TFs) viz. MYB, WRKY, ERF, bHLH and several genes related to secondary metabolite biosynthetic pathways are found to co-express with circRNAs. DE-circRNAs also predicted to interact with miRNAs and can regulate phytohormone biosynthesis and various signalling pathways in tea plant. This study uncovers the potential roles of circRNAs to determine winter dormancy and spring bud flushing conditions in tea plants.
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RuvBL, is a member of SF6 superfamily of helicases and is conserved among the various model systems. Recently, rice (Oryza sativa L.) homolog of RuvBL has been biochemically characterized for its ATPase and DNA helicase activities; however its involvement in stress has not been studied so far. Present investigation reports the detailed functional characterization of OsRuvBL under abiotic stresses through genetic engineering. An efficient Agrobacterium-mediated in planta transformation protocol was developed in indica rice to generate the transgenic lines and study was focused on optimization of factors to achieve maximum transformation efficiency. Overexpressing OsRuvBL1a transgenic lines showed enhanced tolerance under in vivo salinity stress as compared to WT plants. The physiological and biochemical analysis of the OsRuvBL1a transgenic lines showed better performance under salinity and drought stresses. Several stress responsive interacting partners of OsRuvBL1a were identified using Y2H system revealed to its role in stress tolerance. Functional mechanism for boosting stress tolerance by OsRuvBL1a has been proposed in this study. This integration of OsRuvBL1a gene in rice genome using in planta transformation method helped to achieve the abiotic stress resilient smart crop. This study is the first direct evidence to show the novel function of RuvBL in boosting abiotic stress tolerance in plants.
Assuntos
DNA Helicases , Oryza , DNA Helicases/genética , DNA Helicases/metabolismo , Oryza/metabolismo , Resistência à Seca , Salinidade , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Estresse Fisiológico/genética , Secas , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismoRESUMO
Amino acid transporters (AATs), besides, being a crucial component for nutrient partitioning system are also vital for growth and development of the plants and stress resilience. In order to understand the role of AAT genes in seed quality proteins, a comprehensive analysis of AAT gene family was carried out in chickpea leading to identification of 109 AAT genes, representing 10 subfamilies with random distribution across the chickpea genome. Several important stress responsive cis-regulatory elements like Myb, ABRE, ERE were detected in the promoter region of these CaAAT genes. Most of the genes belonging to the same sub-families shared the intron-exon distribution pattern owing to their conserved nature. Random distribution of these CaAAT genes was observed on plasma membrane, vacuolar membrane, Endoplasmic reticulum and Golgi membranes, which may be associated to distinct biochemical pathways. In total 92 out 109 CaAAT genes arise as result of duplication, among which segmental duplication was more prominent over tandem duplication. As expected, the phylogenetic tree was divided into 2 major clades, and further sub-divided into different sub-families. Among the 109 CaAAT genes, 25 were found to be interacting with 25 miRNAs, many miRNAs like miR156, miR159 and miR164 were interacting only with single AAT genes. Tissues specific expression pattern of many CaAAT genes was observed like CaAAP7 and CaAVT18 in nodules, CaAAP17, CaAVT5 and CaCAT9 in vegetative tissues while CaCAT10 and CaAAP23 in seed related tissues as per the expression analysis. Mature seed transcriptome data revealed that genotypes having high protein content (ICC 8397, ICC 13461) showed low CaAATs expression as compared to the genotypes having low protein content (FG 212, BG 3054). Amino acid profiling of these genotypes revealed a significant difference in amount of essential and non-essential amino acids, probably due to differential expression of CaAATs. Thus, the present study provides insights into the biological role of AAT genes in chickpea, which will facilitate their functional characterization and role in various developmental stages, stress responses and involvement in nutritional quality enhancement.
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Cicer , MicroRNAs , Cicer/genética , Cicer/metabolismo , Filogenia , Proteínas de Plantas/química , Sementes , Sistemas de Transporte de Aminoácidos/genética , MicroRNAs/metabolismo , Regulação da Expressão Gênica de PlantasRESUMO
The complexities of a genome are underpinned to the vast expanses of the intergenic region, which constitutes â¼97-98% of the genome. This region is essentially composed of what is colloquially referred to as the "junk DNA" and is composed of various elements like transposons, repeats, pseudogenes, etc. The latter have long been considered as dead elements merely contributing to transcriptional noise in the genome. Many studies now describe the previously unknown regulatory functions of these genes. Recent advances in the Next-generation sequencing (NGS) technologies have allowed unprecedented access to these regions. With the availability of whole genome sequences of more than 788 different plant species in past 20 years, genome annotation has become feasible like never before. Different bioinformatic pipelines are available for the identification of pseudogenes. However, still little is known about their biological functions. The functional validation of these genes remains challenging and research in this area is still in infancy, particularly in plants. CRISPR/Cas-based genome editing could provide solutions to understand the biological roles of these genes by allowing creation of precise edits within these genes. The possibility of pseudogene reactivation or resurrection as has been demonstrated in a few studies might open new avenues of genetic manipulation to yield a desirable phenotype. This review aims at comprehensively summarizing the progress made with regards to the identification of pseudogenes and understanding their biological functions in plants.
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Genoma , Pseudogenes , Pseudogenes/genéticaRESUMO
The tomato is well-known for its anti-oxidative and anti-cancer properties, and with a wide range of health benefits is an important cash crop for human well-being. However, environmental stresses (especially abiotic) are having a deleterious effect on plant growth and productivity, including tomato. In this review, authors describe how salinity stress imposes risk consequences on growth and developmental processes of tomato through toxicity by ethylene (ET) and cyanide (HCN), and ionic, oxidative, and osmotic stresses. Recent research has clarified how salinity stress induced-ACS and - ß-CAS expressions stimulate the accumulation of ET and HCN, wherein the action of salicylic acid (SA),compatible solutes (CSs), polyamines (PAs) and ET inhibitors (ETIs) regulate ET and HCN metabolism. Here we emphasize how ET, SA and PA cooperates with mitochondrial alternating oxidase (AOX), salt overly sensitive (SOS) pathways and the antioxidants (ANTOX) system to better understand the salinity stress resistance mechanism. The current literature evaluated in this paper provides an overview of salinity stress resistance mechanism involving synchronized routes of ET metabolism by SA and PAs, connecting regulated network of central physiological processes governing through the action of AOX, ß-CAS, SOS and ANTOX pathways, which might be crucial for the development of tomato.
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Etilenos , Estresse Salino , Solanum lycopersicum , Etilenos/metabolismo , Solanum lycopersicum/metabolismo , Solanum lycopersicum/fisiologia , Estresse Salino/fisiologiaRESUMO
Mineral nutrients are the integral part of the agricultural systems. Among important plant nutrients, nitrogen (N) and sulphur (S) are known essential elements for growth, development, and various physiological functions in plants. Oleiferous brassicas (rapeseed and mustard) require higher amounts of S in addition to N for optimum growth and yield. Therefore, balancing S-N fertilization, optimization of nutrient replenishment, minimization of nutrient losses to the environment, and the concept of coordination in action between S and N could be a significant strategy for improvement of growth and productivity of oleiferous brassicas. Additionally, positive interaction between S and N has been reported to be beneficial for various aspects of oilseed brassicas. The current paper updates readers on the significance of N and S for the improvement of plant growth, development, and productivity in detail. In addition, S-N nutrition-mediated control of major plant antioxidant defense system components involved in the removal and/or metabolism of stress-induced/generated reactive oxygen species in plants (hence, the control of plant growth, development, and productivity) has been overviewed.
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Brassica/crescimento & desenvolvimento , Brassica/metabolismo , Nitrogênio/farmacocinética , Enxofre/farmacocinética , Agricultura/métodosRESUMO
Helicases function as key enzymes in salinity stress tolerance, and the role and function of PDH45 (pea DNA helicase 45) in stress tolerance have been reported in different crops with selectable markers, raising public and regulatory concerns. In the present study, we developed five lines of marker-free PDH45-overexpressing transgenic lines of rice (Oryza sativa L. cv. IR64). The overexpression of PDH45 driven by CaMV35S promoter in transgenic rice conferred high salinity (200 mM NaCl) tolerance in the T1 generation. Molecular attributes such as PCR, RT-PCR, and Southern and Western blot analyses confirmed stable integration and expression of the PDH45 gene in the PDH45-overexpressing lines. We observed higher endogenous levels of sugars (glucose and fructose) and hormones (GA, zeatin, and IAA) in the transgenic lines in comparison to control plants (empty vector (VC) and wild type (WT)) under salt treatments. Furthermore, photosynthetic characteristics such as net photosynthetic rate (Pn), stomatal conductance (gs), intercellular CO2 (Ci), and chlorophyll (Chl) content were significantly higher in transgenic lines under salinity stress as compared to control plants. However, the maximum primary photochemical efficiency of PSII, as an estimated from variable to maximum chlorophyll a fluorescence (Fv/Fm), was identical in the transgenics to that in the control plants. The activities of antioxidant enzymes, such as catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), and guaiacol peroxidase (GPX), were significantly higher in transgenic lines in comparison to control plants, which helped in keeping the oxidative stress burden (MDA and H2O2) lesser on transgenic lines, thus protecting the growth and photosynthetic efficiency of the plants. Overall, the present research reports the development of marker-free PDH45-overexpressing transgenic lines for salt tolerance that can potentially avoid public and biosafety concerns and facilitate the commercialization of genetically engineered crop plants.
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Polyamines are small organic and basic polycations that perform essential regulatory functions in all living organisms. Fluctuations in polyamine content have been observed to occur during growth, development and under stress conditions, implying that polyamines play pivotal roles in diverse cellular and physiological processes. To achieve polyamine homeostasis, the entire metabolic pathway is subjected to a fine-tuned regulation of its biosynthetic and catabolic genes and enzymes. In this review, we describe and discuss the most important mechanisms implicated in the translational and post-translational regulation of polyamine metabolic enzymes in plants. At the translational level, we emphasize the role of polyamines in the modulation of upstream open reading frame (uORF) activities that control the translation of polyamine biosynthetic and catabolic mRNAs. At the post-translational level, different aspects of the regulation of polyamine metabolic proteins are depicted, such as the proteolytic activation of enzyme precursors, the importance of dimerization in protein stability as well as in protein intracellular localization.
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Plantas , Poliaminas , Biossíntese de Proteínas , Regulação da Expressão Gênica de Plantas , Fases de Leitura Aberta , Plantas/enzimologia , Plantas/genética , Processamento de Proteína Pós-Traducional , RNA MensageiroRESUMO
The eukaryotic pre-replicative complex (Pre-RC), including heterohexameric minichromosome maintenance (MCM2-7) proteins, ensures that the DNA in genome is replicated only once per cell division cycle. The MCMs provide DNA unwinding function during the DNA replication. Since MCM proteins play essential role in cell division and most likely are affected during stress conditions therefore their overexpression in plants may help in stress tolerance. But the role of MCMs in abiotic stress tolerance in plants has not been reported so far. In this study we report that: a) the MCM6 transcript is upregulated in pea plant in response to high salinity and cold stress and not with ABA, drought and heat stress; b) MCM6 overexpression driven by a constitutive cauliflower mosaic virus-35S promoter in tobacco plants confers salinity tolerance. The T(1) transgenics plants were able to grow to maturity and set normal viable seeds under continuous salinity stress, without yield penalty. It was observed that in salt-grown T(1) transgenic plants the Na(+) ions is mostly accumulated in mature leaves and not in seeds of T(1) transgenic lines as compared with the wild-type (WT) plants. T(1) transgenic plants exhibited better growth status under salinity stress conditions in comparison to WT plants. Furthermore, the T(1) transgenic plants maintained significantly higher levels of leaf chlorophyll content, net photosynthetic rate and therefore higher dry matter accumulation and yield with 200 mM NaCl as compared to the WT plants. Tolerance index data showed better salt tolerance potential of T(1) transgenic plants in comparison to WT. These findings provide first direct evidence that overexpression of single subunit MCM6 confers salinity stress tolerance without yield loss. The possible mechanism of salinity tolerance is discussed. These findings suggest that DNA replication machinery can be exploited for promoting stress tolerance in crop plants.
Assuntos
Pisum sativum/crescimento & desenvolvimento , Pisum sativum/genética , Proteínas de Plantas/genética , Tolerância ao Sal/genética , Ácido Abscísico/farmacologia , Sequência de Aminoácidos , Temperatura Baixa , Secas , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Temperatura Alta , Dados de Sequência Molecular , Filogenia , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/classificação , Plantas Geneticamente Modificadas , Subunidades Proteicas/classificação , Subunidades Proteicas/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Plântula/genética , Plântula/crescimento & desenvolvimento , Homologia de Sequência de Aminoácidos , Cloreto de Sódio/farmacologiaRESUMO
MicroRNAs (miRNAs) are an emerging class of small non-coding RNAs that exhibit important role in regulation of gene expression, mostly through the mechanism of cleavage and/or inhibition of translation of target mRNAs during or after transcription. Although much has been unravelled about the role of miRNAs in diverse biological processes like maintenance of functional integrity of genes and genome, growth and development, metabolism, and adaptive responses towards biotic and abiotic stresses in plants, not much is known on their specific roles in majority of cash crops - an area of investigation with potentially significant and gainful economic implications. Tea (Camellia sinensis) is globally the second most consumed beverage after water and its cultivation has major agro-economic and social ramifications. In recent years, global tea production has been greatly challenged by many biotic and abiotic stress factors and a deeper understanding of molecular processes regulating stress adaptation in this largely under investigated crop stands to significantly facilitate potential crop improvement strategies towards durable stress tolerance. This review endeavours to highlight recent advances in our understanding of the role of miRNAs in regulating stress tolerance traits in tea plant with additional focus on their role in determining tea quality attributes.