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1.
Environ Microbiol ; 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34435423

RESUMO

Plant growth promotion by microbes is a cumulative phenomenon involving multiple traits, many of which are not explored yet. Hence, to unravel microbial mechanisms underlying growth promotion, we have analysed the genomes of two potential growth-promoting microbes, viz., Pseudomonas sp. CK-NBRI-02 (P2) and Bacillus marisflavi CK-NBRI-03 (P3) for the presence of plant-beneficial traits. Besides known traits, we found that microbes differ in their ability to metabolize methylglyoxal (MG), a ubiquitous cytotoxin regarded as general consequence of stress in plants. P2 exhibited greater tolerance to MG and possessed better ability to sustain plant growth under dicarbonyl stress. However, under salinity, only P3 showed a dose-dependent induction in MG detoxification activity in accordance with concomitant increase in MG levels, contributing to enhanced salt tolerance. Furthermore, salt-stressed transcriptomes of both the strains showed differences with respect to MG, ion and osmolyte homeostasis, with P3 being more responsive to stress. Importantly, application of either strain altered MG levels and subsequently MG detoxification machinery in Arabidopsis, probably to strengthen plant defence response and growth. We therefore, suggest a crucial role of microbial MG resistance in plant growth promotion and that it should be considered as a beneficial trait while screening microbes for stress mitigation in plants.

2.
Int J Mol Sci ; 22(11)2021 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-34204152

RESUMO

In nature, plants are exposed to an ever-changing environment with increasing frequencies of multiple abiotic stresses. These abiotic stresses act either in combination or sequentially, thereby driving vegetation dynamics and limiting plant growth and productivity worldwide. Plants' responses against these combined and sequential stresses clearly differ from that triggered by an individual stress. Until now, experimental studies were mainly focused on plant responses to individual stress, but have overlooked the complex stress response generated in plants against combined or sequential abiotic stresses, as well as their interaction with each other. However, recent studies have demonstrated that the combined and sequential abiotic stresses overlap with respect to the central nodes of their interacting signaling pathways, and their impact cannot be modelled by swimming in an individual extreme event. Taken together, deciphering the regulatory networks operative between various abiotic stresses in agronomically important crops will contribute towards designing strategies for the development of plants with tolerance to multiple stress combinations. This review provides a brief overview of the recent developments in the interactive effects of combined and sequentially occurring stresses on crop plants. We believe that this study may improve our understanding of the molecular and physiological mechanisms in untangling the combined stress tolerance in plants, and may also provide a promising venue for agronomists, physiologists, as well as molecular biologists.


Assuntos
Produtos Agrícolas/fisiologia , Estresse Fisiológico/fisiologia , Produtos Agrícolas/crescimento & desenvolvimento , Homeostase , Fotossíntese/fisiologia , Espécies Reativas de Oxigênio/metabolismo
3.
Plant Physiol Biochem ; 166: 593-604, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34186283

RESUMO

In rice (Oryza sativa), Si nutrition is known to improve salinity tolerance; however, limited efforts have been made to elucidate the underlying mechanism. Salt-Overly Sensitive (SOS) pathway contributes to salinity tolerance in plants in a major way which works primarily through Na+ exclusion from the cytosol. SOS1, a vital component of SOS pathway is a Na+/H+ antiporter that maintains ion homeostasis. In this study, we evaluated the effect of overexpression of Oryza sativa SOS1 (OsSOS1) in tobacco (cv. Petit Havana) and rice (cv. IR64) for modulating its response towards salinity further exploring its correlation with Si nutrition. OsSOS1 transgenic tobacco plants showed enhanced tolerance to salinity as evident by its high chlorophyll content and maintaining favorable ion homeostasis under salinity stress. Similarly, transgenic rice overexpressing OsSOS1 also showed improved salinity stress tolerance as shown by higher seed germination percentage, seedling survival and low Na+ accumulation under salinity stress. At their mature stage, compared with the non-transgenic plants, the transgenic rice plants showed better growth and maintained better photosynthetic efficiency with reduced chlorophyll loss under stress. Also, roots of transgenic rice plants showed reduced accumulation of Na+ leading to reduced oxidative damage and cell death under salinity stress which ultimately resulted in improved agronomic traits such as higher number of panicles and fertile spikelets per panicle. Si nutrition was found to improve the growth of salinity stressed OsSOS1 rice by upregulating the expression of Si transporters (Lsi1 and Lsi2) that leads to more uptake and accumulation of Si in the rice shoots. Metabolite profiling showed better stress regulatory machinery in the transgenic rice, since they maintained higher abundance of most of the osmolytes and free amino acids.


Assuntos
Oryza , Oryza/genética , Proteínas de Plantas/genética , Salinidade , Estresse Salino , Tolerância ao Sal , Silício/farmacologia , Estresse Fisiológico
4.
Trends Plant Sci ; 26(6): 575-587, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33893048

RESUMO

Ensuring the sustainability of agriculture under climate change has led to a surge in alternative strategies for crop improvement. Advances in integrated crop breeding, social acceptance, and farm-level adoption are crucial to address future challenges to food security. Societal acceptance can be slow when consumers do not see the need for innovation or immediate benefits. We consider how best to address the issue of social licence and harmonised governance for novel gene technologies in plant breeding. In addition, we highlight optimised breeding strategies that will enable long-term genetic gains to be achieved. Promoted by harmonised global policy change, innovative plant breeding can realise high and sustainable productivity together with enhanced nutritional traits.


Assuntos
Agricultura , Melhoramento Vegetal , Mudança Climática , Plantas , Tecnologia
5.
Plant Physiol Biochem ; 163: 15-25, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33799014

RESUMO

Silicon (Si) is a beneficial macronutrient for plants. The Si supplementation to growth media mitigates abiotic and biotic stresses by regulating several physiological, biochemical and molecular mechanisms. The uptake of Si from the soil by root cells and subsequent transport are facilitated by Lsi1 (Low silicon1) belonging to nodulin 26-like major intrinsic protein (NIP) subfamily of aquaporin protein family, and Lsi2 (Low silicon 2) belonging to putative anion transporters, respectively. The soluble Si in the cytosol enhances the production of jasmonic acid, enzymatic and non-enzymatic antioxidants, secondary metabolites and induces expression of genes in plants under stress conditions. Silicon has been found beneficial in conferring tolerance against biotic and abiotic stresses by scavenging the reactive oxygen species (ROS) and regulation of different metabolic pathways. In the present review, Si transporters identified in various plant species and mechanisms of Si-mediated abiotic and biotic stress tolerance have been presented. In addition, role of Si in regulating gene expression under various abiotic and biotic stresses as revealed by transcriptome level studies has been discussed. This provides a deeper understanding of various mechanisms of Si-mediated stress tolerance in plants and may help in devising strategies for stress resilient agriculture.


Assuntos
Plantas , Silício , Agricultura , Transporte Biológico , Silício/farmacologia , Estresse Fisiológico
6.
Physiol Plant ; 171(4): 653-676, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32949408

RESUMO

The plasma membrane (PM) is possibly the most diverse biological membrane of plant cells; it separates and guards the cell against its external environment. It has an extremely complex structure comprising a mosaic of lipids and proteins. The PM lipids are responsible for maintaining fluidity, permeability and integrity of the membrane and also influence the functioning of membrane proteins. However, the PM is the primary target of environmental stress, which affects its composition, conformation and properties, thereby disturbing the cellular homeostasis. Maintenance of integrity and fluidity of the PM is a prerequisite for ensuring the survival of plants during adverse environmental conditions. The ability of plants to remodel membrane lipid and protein composition plays a crucial role in adaptation towards varying abiotic environmental cues, including high or low temperature, drought, salinity and heavy metals stress. The dynamic changes in lipid composition affect the functioning of membrane transporters and ultimately regulate the physical properties of the membrane. Plant membrane-transport systems play a significant role in stress adaptation by cooperating with the membrane lipidome to maintain the membrane integrity under stressful conditions. The present review provides a holistic view of stress responses and adaptations in plants, especially the changes in the lipidome and proteome of PM under individual or combined abiotic stresses, which cause alterations in the activity of membrane transporters and modifies the fluidity of the PM. The tools to study the varying lipidome and proteome of the PM are also discussed.


Assuntos
Plantas , Estresse Fisiológico , Adaptação Fisiológica , Secas , Salinidade
7.
Physiol Plant ; 171(4): 688-702, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33034380

RESUMO

Chloride channels (CLCs), member of anion transporting proteins, are present ubiquitously in all life forms. Diverging from its name, the CLC family includes both channel and exchanger (proton-coupled) proteins; nevertheless, they share conserved structural organization. They are engaged in diverse indispensable functions such as acid and fluoride tolerance in prokaryotes to muscle stabilization, transepithelial transport, and neuronal development in mammals. Mutations in genes encoding CLCs lead to several physiological disorders in different organisms, including severe diseases in humans. Even in plants, loss of CLC protein function severely impairs various cellular processes critical for normal growth and development. These proteins sequester Cl- into the vacuole, thus, making them an attractive target for improving salinity tolerance in plants caused by high abundance of salts, primarily NaCl. Besides, some CLCs are involved in NO3 - transport and storage function in plants, thus, influencing their nitrogen use efficiency. However, despite their high significance, not many studies have been carried out in plants. Here, we have attempted to concisely highlight the basic structure of CLC proteins and critical residues essential for their function and classification. We also present the diverse functions of CLCs in plants from their first cloning back in 1996 to the knowledge acquired as of now. We stress the need for carrying out more in-depth studies on CLCs in plants, for they may have future applications towards crop improvement.


Assuntos
Canais de Cloreto , Tolerância ao Sal , Transporte Biológico , Canais de Cloreto/genética , Canais de Cloreto/metabolismo , Prótons , Vacúolos/metabolismo
8.
Front Microbiol ; 11: 509919, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33042042

RESUMO

Drought is a critical factor limiting the productivity of legumes worldwide. Legumes can enter into a unique tripartite symbiotic relationship with root-nodulating bacteria of genera Rhizobium, Bradyrhizobium, or Sinorhizobium and colonization by arbuscular mycorrhizal fungi (AMF). Rhizobial symbiosis provides nitrogen necessary for growth. AMF symbiosis enhances uptake of diffusion-limited nutrients such as P, Zn, Cu, etc., and also water from the soil via plant-associated fungal hyphae. Rhizobial and AMF symbioses can act synergistically in promoting plant growth and fitness, resulting in overall yield benefits under drought stress. One of the approaches that rhizobia use to survive under stress is the accumulation of compatible solutes, or osmolytes, such as trehalose. Trehalose is a non-reducing disaccharide and an osmolyte reported to accumulate in a range of organisms. High accumulation of trehalose in bacteroids during nodulation protects cells and proteins from osmotic shock, desiccation, and heat under drought stress. Manipulation of trehalose cell concentrations has been directly correlated with stress response in plants and other organisms, including AMF. However, the role of this compound in the tripartite symbiotic relationship is not fully explored. This review describes the biological importance and the role of trehalose in the tripartite symbiosis between plants, rhizobia, and AMF. In particular, we review the physiological functions and the molecular investigations of trehalose carried out using omics-based approaches. This review will pave the way for future studies investigating possible metabolic engineering of this biomolecule for enhancing abiotic stress tolerance in plants.

9.
New Phytol ; 227(3): 714-721, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32249440

RESUMO

Methylglyoxal (MG), a reactive carbonyl compound, is generated during metabolism in living systems. However, under stress, its levels increase rapidly leading to cellular toxicity. Although the generation of MG is spontaneous in a cell, its detoxification is essentially catalyzed by the glyoxalase enzymes. In plants, modulation of MG content via glyoxalases influences diverse physiological functions ranging from regulating growth and development to conferring stress tolerance. Interestingly, there has been a preferred expansion in the number of isoforms of these enzymes in plants, giving them high plasticity in their actions for accomplishing diverse roles. Future studies need to focus on unraveling the interplay of these multiple isoforms of glyoxalases possibly contributing towards the unique adaptability of plants to diverse environments.


Assuntos
Lactoilglutationa Liase , Plantas , Aldeído Pirúvico
10.
Microbiol Resour Announc ; 9(7)2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32054702

RESUMO

Here, we report the 4.34-Mb draft genome assembly of Bacillus marisflavi CK-NBRI-03 (or P3), a Gram-positive bacterium, with an average G+C content of 48.66%. P3 was isolated from agricultural soil from the Badaun (midwestern plain zone) region of Uttar Pradesh, India.

11.
BMC Genomics ; 21(1): 145, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32041545

RESUMO

BACKGROUND: The glyoxalase pathway is evolutionarily conserved and involved in the glutathione-dependent detoxification of methylglyoxal (MG), a cytotoxic by-product of glycolysis. It acts via two metallo-enzymes, glyoxalase I (GLYI) and glyoxalase II (GLYII), to convert MG into D-lactate, which is further metabolized to pyruvate by D-lactate dehydrogenases (D-LDH). Since D-lactate formation occurs solely by the action of glyoxalase enzymes, its metabolism may be considered as the ultimate step of MG detoxification. By maintaining steady state levels of MG and other reactive dicarbonyl compounds, the glyoxalase pathway serves as an important line of defence against glycation and oxidative stress in living organisms. Therefore, considering the general role of glyoxalases in stress adaptation and the ability of Sorghum bicolor to withstand prolonged drought, the sorghum glyoxalase pathway warrants an in-depth investigation with regard to the presence, regulation and distribution of glyoxalase and D-LDH genes. RESULT: Through this study, we have identified 15 GLYI and 6 GLYII genes in sorghum. In addition, 4 D-LDH genes were also identified, forming the first ever report on genome-wide identification of any plant D-LDH family. Our in silico analysis indicates homology of putatively active SbGLYI, SbGLYII and SbDLDH proteins to several functionally characterised glyoxalases and D-LDHs from Arabidopsis and rice. Further, these three gene families exhibit development and tissue-specific variations in their expression patterns. Importantly, we could predict the distribution of putatively active SbGLYI, SbGLYII and SbDLDH proteins in at least four different sub-cellular compartments namely, cytoplasm, chloroplast, nucleus and mitochondria. Most of the members of the sorghum glyoxalase and D-LDH gene families are indeed found to be highly stress responsive. CONCLUSION: This study emphasizes the role of glyoxalases as well as that of D-LDH in the complete detoxification of MG in sorghum. In particular, we propose that D-LDH which metabolizes the specific end product of glyoxalases pathway is essential for complete MG detoxification. By proposing a cellular model for detoxification of MG via glyoxalase pathway in sorghum, we suggest that different sub-cellular organelles are actively involved in MG metabolism in plants.


Assuntos
Lactato Desidrogenases/genética , Lactoilglutationa Liase/genética , Proteínas de Plantas/genética , Aldeído Pirúvico/metabolismo , Ácido Pirúvico/metabolismo , Sorghum/enzimologia , Tioléster Hidrolases/genética , Estudo de Associação Genômica Ampla , Lactato Desidrogenases/classificação , Lactoilglutationa Liase/classificação , Filogenia , Proteínas de Plantas/classificação , Sorghum/genética , Estresse Fisiológico/genética , Tioléster Hidrolases/classificação
13.
J Exp Bot ; 71(2): 684-698, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31613368

RESUMO

GATA represents a highly conserved family of transcription factors reported in organisms ranging from fungi to angiosperms. A member of this family, OsGATA8, localized within the Saltol QTL in rice, has been reported to be induced by salinity, drought, and ABA. However, its precise role in stress tolerance has not yet been elucidated. Using genetic, molecular, and physiological analyses, in this study we show that OsGATA8 increases seed size and tolerance to abiotic stresses in both Arabidopsis and rice. Transgenic lines of rice were generated with 3-fold overexpression of OsGATA8 compared to the wild-type together with knockdown lines with 2-fold lower expression. The overexpressing lines showed higher biomass accumulation and higher photosynthetic efficiency in seedlings compared to the wild-type and knockdown lines under both normal and salinity-stress conditions. OsGATA8 appeared to be an integrator of diverse cellular processes, including K+/Na+ content, photosynthetic efficiency, relative water content, Fv/Fm ratio, and the stability to sub-cellular organelles. It also contributed to maintaining yield under stress, which was ~46% higher in overexpression plants compared with the wild-type. OsGATA8 produced these effects by regulating the expression of critical genes involved in stress tolerance, scavenging of reactive oxygen species, and chlorophyll biosynthesis.


Assuntos
Arabidopsis/fisiologia , Fatores de Transcrição GATA/genética , Oryza/fisiologia , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/fisiologia , Sementes/crescimento & desenvolvimento , Estresse Fisiológico/genética , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Fatores de Transcrição GATA/metabolismo , Oryza/genética , Oryza/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Locos de Características Quantitativas , Sementes/genética
15.
Microbiol Resour Announc ; 8(43)2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31649082

RESUMO

Pseudomonas sp. strain CK-NBRI-02 is a potential plant growth-promoting Gram-negative rhizobacterium isolated from the rhizosphere of maize plants growing in fields in Srinagar, Jammu, and Kashmir, India. Here, we report a 5.25-Mb draft assembly of the genome sequence of Pseudomonas sp. strain CK-NBRI-02 with an average G+C content of 62.47%.

16.
Sci Rep ; 9(1): 11015, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31337776

RESUMO

 A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

17.
Photosynth Res ; 142(2): 211-227, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31317383

RESUMO

Although only 2-4% of absorbed light is emitted as chlorophyll (Chl) a fluorescence, its measurement provides valuable information on photosynthesis of the plant, particularly of Photosystem II (PSII) and Photosystem I (PSI). In this paper, we have examined photosynthetic parameters of Suaeda fruticosa L. (family: Amaranthaceae), surviving under extreme xerohalophytic conditions, as influenced by diurnal rhythm or continuous dark condition. We report here CO2 gas exchange and the kinetics of Chl a fluorescence of S. fruticosa, made every 3 hours (hrs) for 3 days, using a portable infra-red gas analyzer and a Handy PEA fluorimeter. Our measurements on CO2 gas exchange show the maximum rate of photosynthesis to be at 08:00 hrs under diurnal condition and at 05:00 hrs under continuous dark. From the OJIP phase of Chl a fluorescence transient, we have inferred that the maximum quantum yield of PSII photochemistry must have increased during the night under diurnal rhythm, and between 11:00 and 17:00 hrs under constant dark. Overall, our study has revealed novel insights into how photosynthetic reactions are affected by the photoperiodic cycles in S. fruticosa under high salinity. This study has further revealed a unique strategy operating in this xero-halophyte where the repair mechanism for damaged PSII operates during the dark, which, we suggest, contributes to its ecological adaptation and ability to survive and reproduce under extreme saline, high light, and drought conditions. We expect these investigations to help in identifying key genes and pathways for raising crops for saline and dry areas.


Assuntos
Dióxido de Carbono/metabolismo , Chenopodiaceae/crescimento & desenvolvimento , Chenopodiaceae/metabolismo , Clorofila A/metabolismo , Ritmo Circadiano , Escuridão , Fluorescência , Fotossíntese , Folhas de Planta/metabolismo
18.
Sci Rep ; 8(1): 7621, 2018 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-29752473

RESUMO

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

19.
Sci Rep ; 8(1): 4072, 2018 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-29511223

RESUMO

Cytoskeleton plays a vital role in stress tolerance; however, involvement of intermediate filaments (IFs) in such a response remains elusive in crop plants. This study provides clear evidence about the unique involvement of IFs in cellular protection against abiotic stress in rice. Transcript abundance of Oryza sativa intermediate filament (OsIF) encoding gene showed 2-10 fold up-regulation under different abiotic stress. Overexpression of OsIF in transgenic rice enhanced tolerance to salinity and heat stress, while its knock-down (KD) rendered plants more sensitive thereby indicating the role of IFs in promoting survival under stress. Seeds of OsIF overexpression rice germinated normally in the presence of high salt, showed better growth, maintained chloroplast ultrastructure and favourable K+/Na+ ratio than the wild type (WT) and KD plants. Analysis of photosynthesis and chlorophyll a fluorescence data suggested better performance of both photosystem I and II in the OsIF overexpression rice under salinity stress as compared to the WT and KD. Under salinity and high temperature stress, OsIF overexpressing plants could maintain significantly high yield, while the WT and KD plants could not. Further, metabolite profiling revealed a 2-4 fold higher accumulation of proline and trehalose in OsIF overexpressing rice than WT, under salinity stress.


Assuntos
Resposta ao Choque Térmico , Filamentos Intermediários/metabolismo , Oryza/fisiologia , Fotossíntese , Salinidade , Estresse Fisiológico , Expressão Gênica , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Técnicas de Silenciamento de Genes , Filamentos Intermediários/genética , Metabolômica , Oryza/efeitos dos fármacos , Oryza/genética , Oryza/efeitos da radiação , Prolina/análise , RNA Mensageiro/análise , Trealose/análise
20.
Curr Genomics ; 19(1): 50-59, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29491732

RESUMO

Cystathionine ß-synthase (CBS) domains have been identified in a wide range of proteins of unrelated functions such as, metabolic enzymes, kinases and channels, and usually occur as tandem re-peats, often in combination with other domains. In plants, CBS Domain-Containing Proteins (CDCPs) form a multi-gene family and only a few are so far been reported to have a role in development via regu-lation of thioredoxin system as well as in abiotic and biotic stress response. However, the function of majority of CDCPs still remains to be elucidated in plants. Here, we report the cloning, characterization and functional validation of a CBS domain containing protein, OsCBSCBSPB4 from rice, which pos-sesses two CBS domains and one PB1 domain. We show that OsCBSCBSPB4 encodes a nucleo-cytoplasmic protein whose expression is induced in response to various abiotic stress conditions in salt-sensitive IR64 and salt-tolerant Pokkali rice cultivars. Further, heterologous expression of OsCBSCB-SPB4 in E. coli and tobacco confers marked tolerance against various abiotic stresses. Transgenic tobac-co seedlings over-expressing OsCBSCBSPB4 were found to exhibit better growth in terms of delayed leaf senescence, profuse root growth and increased biomass in contrast to the wild-type seedlings when subjected to salinity, dehydration, oxidative and extreme temperature treatments. Yeast-two hybrid stud-ies revealed that OsCBSCBSPB4 interacts with various proteins. Of these, some are known to be in-volved in abiotic stress tolerance. Our results suggest that OsCBSCBSPB4 is involved in abiotic stress response and is a potential candidate for raising multiple abiotic stress tolerant plants.

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