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1.
Int J Mol Sci ; 22(12)2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34203629

RESUMO

Drought and salinity are major constraints to agriculture. In this review, we present an overview of the global situation and the consequences of drought and salt stress connected to climatic changes. We provide a list of possible genetic resources as sources of resistance or tolerant traits, together with the previous studies that focused on transferring genes from the germplasm to cultivated varieties. We explained the morphological and physiological aspects connected to hydric stresses, described the mechanisms that induce tolerance, and discussed the results of the main studies. Finally, we described more than 100 genes associated with tolerance to hydric stresses in the Triticeae. These were divided in agreement with their main function into osmotic adjustment and ionic and redox homeostasis. The understanding of a given gene function and expression pattern according to hydric stress is particularly important for the efficient selection of new tolerant genotypes in classical breeding. For this reason, the current review provides a crucial reference for future studies on the mechanism involved in hydric stress tolerance and the use of these genes in mark assistance selection (MAS) to select the wheat germplasm to face the climatic changes.


Assuntos
Secas , Estudos de Associação Genética , Tolerância ao Sal/genética , Triticum/genética , Osmose , Salinidade
2.
Int J Mol Sci ; 22(12)2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34203768

RESUMO

Mesembryanthemum crystallinum (common ice plant) is a halophyte species that has adapted to extreme conditions. In this study, we cloned a McHB7 transcription factor gene from the ice plant. The expression of McHB7 was significantly induced by 500 mM NaCl and it reached the peak under salt treatment for 7 days. The McHB7 protein was targeted to the nucleus. McHB7-overexpressing in ice plant leaves through Agrobacterium-mediated transformation led to 25 times more McHB7 transcripts than the non-transformed wild type (WT). After 500 mM NaCl treatment for 7 days, the activities of superoxide dismutase (SOD) and peroxidase (POD) and water content of the transgenic plants were higher than the WT, while malondialdehyde (MDA) was decreased in the transgenic plants. A total of 1082 and 1072 proteins were profiled by proteomics under control and salt treatment, respectively, with 22 and 11 proteins uniquely identified under control and salt stress, respectively. Among the 11 proteins, 7 were increased and 4 were decreased after salt treatment. Most of the proteins whose expression increased in the McHB7 overexpression (OE) ice plants under high salinity were involved in transport regulation, catalytic activities, biosynthesis of secondary metabolites, and response to stimulus. The results demonstrate that the McHB7 transcription factor plays a positive role in improving plant salt tolerance.


Assuntos
Mesembryanthemum/metabolismo , Proteínas de Plantas/metabolismo , Proteômica , Tolerância ao Sal/fisiologia , Sequência de Aminoácidos , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Biologia Computacional , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ontologia Genética , Mesembryanthemum/efeitos dos fármacos , Mesembryanthemum/genética , Filogenia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Transporte Proteico/efeitos dos fármacos , Salinidade , Tolerância ao Sal/efeitos dos fármacos , Tolerância ao Sal/genética , Cloreto de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética , Frações Subcelulares/metabolismo , Fatores de Transcrição/metabolismo
3.
BMC Plant Biol ; 21(1): 328, 2021 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-34238224

RESUMO

BACKGROUND: MYB transcription factors are a kind of DNA binding protein that can specifically interact with the promoter region. Members of MYB TFs are widely involved in plant growth and development, secondary metabolism, stress response, and hormone signal transduction. However, there is no report of comprehensive bioinformatics analysis on the MYB family of Casuarina equisetifolia. RESULTS: In this study, bioinformatics methods were used to screen out 182 MYB transcription factors from the Casuarina equisetifolia genome database, including 69 1R-MYB, 107 R2R3-MYB, 4 R1R2R3-MYB, and 2 4R-MYB. The C. equisetifolia R2R3-MYB genes were divided into 29 groups based on the phylogenetic topology and the classification of the MYB superfamily in Arabidopsis thaliana, while the remaining MYB genes (1R-MYB, R1R2R3-MYB, and 4R-MYB) was divided into 19 groups. Moreover, the conserved motif and gene structure analysis shown that the members of the CeqMYBs were divided into the same subgroups with mostly similar gene structures. In addition, many conserved amino acids in the R2 and R3 domains of CeqMYBs by WebLogo analysis, especially tryptophan residues (W), with 3 conserved W in R2 repeat and 2 conserved W in R3 repeat. Combining promoter and GO annotation analysis, speculated on the various biological functions of CeqMYBs, thus 32 MYB genes were selected to further explore its response to salt stress by using qPCR analysis technique. Most CeqMYB genes were differentially regulated following multiple salt treatments. CONCLUSIONS: Seven genes (CeqMYB164, CeqMYB4, CeqMYB53, CeqMYB32, CeqMYB114, CeqMYB71 and CeqMYB177) were assigned to the "response to salt stress" by GO annotation. Among them, the expression level of CeqMYB4 was up-regulated under various salt treatments, indicating CeqMYB4 might participated in the response to salt stress. Our results provide important information for the biological function of C. equisetifolia, as well as offer candidate genes for further study of salt stress mechanism.


Assuntos
Arabidopsis/genética , Fagales/genética , Genes myb , Estresse Salino/genética , Tolerância ao Sal/genética , Fatores de Transcrição/genética , Mapeamento Cromossômico , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Estudo de Associação Genômica Ampla , Família Multigênica , Filogenia , Proteínas de Plantas/genética
4.
Planta ; 254(2): 25, 2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-34226949

RESUMO

MAIN CONCLUSION: Some salt-stress responsive DEGs, mainly involved in ion transmembrane transport, hormone regulation, antioxidant system, osmotic regulation, and some miRNA jointly regulated the salt response process in allotriploid Populus cathayana. The molecular mechanism of plant polyploid stress resistance has been a hot topic in biological research. In this study, Populus diploids and first division restitution (FDR) and second division restitution (SDR) triploids were selected as research materials. All materials were treated with 70 mM NaCl solutions for 30 days in the same pot environment. We observed the growth state of triploids and diploids and determined the ratio of potassium and sodium ions, peroxidase (POD) activity, proline content, and ABA and jasmonic acid (JA) hormone content in leaves in the same culture environment with the same concentration of NaCl solution treatment. In addition, RNA-seq technology was used to study the differential expression of mRNA and miRNA. The results showed that triploid Populus grew well and the K+ content and the K+/Na+ ratio in the salt treatment were significantly lower than those in the control. The contents of ABA, JA, POD, and proline were increased compared with contents in diploid under salt stress. The salt-stress responsive DEGs were mainly involved in ion transport, cell homeostasis, the MAPK signaling pathway, peroxisome, citric acid cycle, and other salt response and growth pathways. The transcription factors mainly included NAC, MYB, MYB_related and AP2/ERF. Moreover, the differentially expressed miRNAs involved 32 families, including 743 miRNAs related to predicted target genes, among which 22 miRNAs were significantly correlated with salt-stress response genes and related to the regulation of hormones, ion transport, reactive oxygen species (ROS) and other biological processes. Our results provided insights into the physiological and molecular aspects for further research into the response mechanisms of allotriploid Populus cathayana to salt stress. This study provided valuable information for the salt tolerance mechanism of allopolyploids.


Assuntos
MicroRNAs , Populus , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , MicroRNAs/genética , Populus/genética , Tolerância ao Sal/genética , Transcriptoma
5.
BMC Plant Biol ; 21(1): 284, 2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34157974

RESUMO

BACKGROUND: Identifying genes involved in salt tolerance in the recretohalophyte Limonium bicolor could facilitate the breeding of crops with enhanced salt tolerance. Here we cloned the previously uncharacterized gene LbHLH and explored its role in salt tolerance. RESULTS: The 2,067-bp open reading frame of LbHLH encodes a 688-amino-acid protein with a typical helix-loop-helix (HLH) domain. In situ hybridization showed that LbHLH is expressed in salt glands of L. bicolor. LbHLH localizes to the nucleus, and LbHLH is highly expressed during salt gland development and in response to NaCl treatment. To further explore its function, we heterologously expressed LbHLH in Arabidopsis thaliana under the 35S promoter. The overexpression lines showed significantly increased trichome number and reduced root hair number. LbHLH might interact with GLABRA1 to influence trichome and root hair development, as revealed by yeast two-hybrid analysis. The transgenic lines showed higher germination percentages and longer roots than the wild type under NaCl treatment. Analysis of seedlings grown on medium containing sorbitol with the same osmotic pressure as 100 mM NaCl demonstrated that overexpressing LbHLH enhanced osmotic resistance. CONCLUSION: These results indicate that LbHLH enhances salt tolerance by reducing root hair development and enhancing osmotic resistance under NaCl stress.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Genes de Plantas/genética , Proteínas de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Plumbaginaceae/genética , Plantas Tolerantes a Sal/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , Clonagem Molecular , Genes de Plantas/fisiologia , Hibridização In Situ , Pressão Osmótica , Proteínas de Plantas/fisiologia , Plumbaginaceae/metabolismo , Plumbaginaceae/fisiologia , Reação em Cadeia da Polimerase , Estresse Salino , Tolerância ao Sal/genética , Plantas Tolerantes a Sal/metabolismo , Plantas Tolerantes a Sal/fisiologia , Técnicas do Sistema de Duplo-Híbrido
6.
Int J Mol Sci ; 22(9)2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-34068763

RESUMO

Heat shock transcription factors (HSFs) play critical roles in several types of environmental stresses. However, the detailed regulatory mechanisms in response to salt stress are still largely unknown. In this study, we examined the salt-induced transcriptional responses of ThHSFA1-ThWRKY4 in Tamarix hispida and their functions and regulatory mechanisms in salt tolerance. ThHSFA1 protein acts as an upstream regulator that can directly activate ThWRKY4 expression by binding to the heat shock element (HSE) of the ThWRKY4 promoter using yeast one-hybrid (Y1H), chromatin immunoprecipitation (ChIP), and dual-luciferase reporter assays. ThHSFA1 and ThWRKY4 expression was significantly induced by salt stress and abscisic acid (ABA) treatment in the roots and leaves of T. hispida. ThHSFA1 is a nuclear-localized protein with transactivation activity at the C-terminus. Compared to nontransgenic plants, transgenic plants overexpressing ThHSFA1 displayed enhanced salt tolerance and exhibited reduced reactive oxygen species (ROS) levels and increased antioxidant enzyme activity levels under salt stress. Therefore, we further concluded that ThHSFA1 mediated the regulation of ThWRKY4 in response to salt stress in T. hispida.


Assuntos
Proteínas de Arabidopsis/genética , Fatores de Transcrição de Choque Térmico/genética , Estresse Salino/genética , Tamaricaceae/genética , Fatores de Transcrição/genética , Ácido Abscísico/metabolismo , Ácido Abscísico/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Espécies Reativas de Oxigênio/metabolismo , Estresse Salino/efeitos dos fármacos , Tolerância ao Sal/efeitos dos fármacos , Tolerância ao Sal/genética , Sais/toxicidade , Tamaricaceae/efeitos dos fármacos , Tamaricaceae/crescimento & desenvolvimento
7.
Int J Mol Sci ; 22(10)2021 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-34069397

RESUMO

Drought stress is a major constraint in global maize production, causing almost 30-90% of the yield loss depending upon growth stage and the degree and duration of the stress. Here, we report that ectopic expression of Arabidopsis glutaredoxin S17 (AtGRXS17) in field grown maize conferred tolerance to drought stress during the reproductive stage, which is the most drought sensitive stage for seed set and, consequently, grain yield. AtGRXS17-expressing maize lines displayed higher seed set in the field, resulting in 2-fold and 1.5-fold increase in yield in comparison to the non-transgenic plants when challenged with drought stress at the tasseling and silking/pollination stages, respectively. AtGRXS17-expressing lines showed higher relative water content, higher chlorophyll content, and less hydrogen peroxide accumulation than wild-type (WT) control plants under drought conditions. AtGRXS17-expressing lines also exhibited at least 2-fold more pollen germination than WT plants under drought stress. Compared to the transgenic maize, WT controls accumulated higher amount of proline, indicating that WT plants were more stressed over the same period. The results present a robust and simple strategy for meeting rising yield demands in maize under water limiting conditions.


Assuntos
Glutarredoxinas/genética , Glutarredoxinas/metabolismo , Estresse Fisiológico/genética , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Secas , Expressão Ectópica do Gene/genética , Grão Comestível/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Tolerância ao Sal/genética , Estresse Fisiológico/fisiologia , Termotolerância/genética , Zea mays/genética
8.
Plant Cell Rep ; 40(7): 1181-1197, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33945005

RESUMO

KEY MESSAGE: Puccinellia tenuiflora was domesticated for two years by growing it under non-saline conditions, providing epigenetic and biochemical insights into the initial domestication of extreme halophytes. Some halophytes have economic value as crop species. The domestication of halophytes may offer hope in solving the problem of soil salinization. We domesticated a wild halophyte, Puccinellia tenuiflora, for two years by growing it under non-saline conditions in a greenhouse and used re-sequencing, genome-wide DNA methylation, biochemical, and transcriptome analyses to uncover the mechanisms underlying alterations in the halophyte's tolerance to saline following domestication. Our results showed that non-saline domestication altered the methylation status for a number of genes and transposable elements, resulting in a much higher frequency of hypomethylation than hypermethylation. These modifications to DNA methylation were observed in many critical salinity-tolerance genes, particularly their promoter regions or transcriptional start sites. Twenty-nine potassium channel genes were hypomethylated and three were hypermethylated, suggesting that the DNA methylation status of potassium channel genes was influenced by domestication. The accelerated uptake of potassium is a major salinity tolerance characteristic of P. tenuiflora. We propose that modifications to the DNA methylation of potassium channel genes may be associated with the development of salinity tolerance in this species. By assessing whether non-saline domestication could change the salinity tolerance of P. tenuiflora, we demonstrated that non-saline domesticated plants are less tolerant to saline, which may be attributable to altered sucrose metabolism. DNA methylation and transposable elements may, therefore, be integrated into an environment-sensitive molecular engine that promotes the rapid domestication of P. tenuiflora to enable its use as a crop plant.


Assuntos
Metilação de DNA , Poaceae/genética , Tolerância ao Sal/genética , Plantas Tolerantes a Sal/genética , China , Elementos de DNA Transponíveis , Domesticação , Epigênese Genética , Regulação da Expressão Gênica de Plantas , Estudo de Associação Genômica Ampla , Folhas de Planta/anatomia & histologia , Folhas de Planta/genética , Proteínas de Plantas/genética , Poaceae/fisiologia , Polimorfismo de Nucleotídeo Único , Potássio/metabolismo
9.
Plant Cell Rep ; 40(7): 1155-1170, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33950277

RESUMO

KEY MESSAGE: The drought and salt tolerances of wheat were enhanced by ectopic expression of the Arabidopsis ornithine aminotransferase (AtOAT) encoded gene. The OAT was confirmed to play a role in proline biosynthesis in wheat. Proline (Pro) accumulation is a common response to both abiotic and biotic stresses in plants. Ornithine aminotransferase (OAT) is pyridoxal-5-phosphate dependent enzyme involved in plant proline biosynthesis. During stress condition, proline is synthesized via glutamate and ornithine pathways. The OAT is the key enzyme in ornithine pathway. In this study, an OAT gene AtOAT from Arabidopsis was expressed in wheat for its functional characterization under drought, salinity, and heat stress conditions. We found that the expression of AtOAT enhanced the drought and salt stress tolerances of wheat by increasing the proline content and peroxidase activity. In addition, it was confirmed that the expression of AtOAT also played a partial tolerance to heat stress in the transgenic wheat plants. Moreover, quantitative real-time PCR (qRT-PCR) analysis showed that the transformation of AtOAT up-regulated the expression of the proline biosynthesis associated genes TaOAT, TaP5CS, and TaP5CR, and down-regulated that of the proline catabolism related gene TaP5CDH in the transgenic plants under stress conditions. Moreover, the genes involved in ornithine pathway (Orn-OAT-P5C/GSA-P5CR-Pro) were up-regulated along with the up-regulation of those genes involved in glutamate pathway (Glu-P5CS-P5C/GSA-P5CR-Pro). Therefore, we concluded that the expression of AtOAT enhanced wheat abiotic tolerance via modifying the proline biosynthesis by up-regulating the expression of the proline biosynthesis-associated genes and down-regulating that of the proline catabolic gene under stresses condition.


Assuntos
Proteínas de Arabidopsis/genética , Ornitina-Oxo-Ácido Transaminase/genética , Plantas Geneticamente Modificadas/fisiologia , Estresse Fisiológico/genética , Triticum/fisiologia , Secas , Regulação da Expressão Gênica de Plantas , Resposta ao Choque Térmico/genética , Plantas Geneticamente Modificadas/genética , Prolina/genética , Prolina/metabolismo , Tolerância ao Sal/genética , Estresse Fisiológico/fisiologia , Triticum/genética
10.
Plant Sci ; 308: 110903, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34034863

RESUMO

In plants, auxin and ABA play significant roles in conferring tolerance to environmental abiotic stresses. Earlier studies have been shown that some Aux/IAA genes, with important signaling factors in the auxin pathway, were induced in response to drought and other abiotic stresses. However, the mechanistic links between Aux/IAA expression and general drought response remain largely unknown. In this study, OsIAA20, a rice Aux/IAA protein, shown with important roles in abiotic stress. Phenotypic analyses revealed that OsIAA20 RNAi transgenic rice reduced drought and salt tolerance; whereas, OsIAA20 overexpression plants displayed the opposite phenotype. Physiological analyses of OsIAA20 RNAi rice grown under drought or salt stress showed that proline and chlorophyll content significantly decreased, while malondialdehyde content and the ratio of Na+/ K+ significantly increased. In addition, OsIAA20down-regulation reduced stomatal closure and increased the rate of water loss, while transgenic plants overexpressing OsIAA20 exhibited the opposite physiological responses. Furthermore, an ABA-responsive gene, OsRab21, was down-regulated in OsIAA20 RNAi rice lines and upregulated in OsIAA20 overexpression plants. Those results means OsIAA20 played an important role in plant drought and salt stress responses, by an ABA dependent mechanism, and it will be a candidate target gene used to breed abiotic stress tolerance.


Assuntos
Ácido Abscísico/metabolismo , Regulação da Expressão Gênica de Plantas , Oryza/fisiologia , Proteínas de Plantas/genética , Transdução de Sinais/genética , Estresse Fisiológico/genética , Secas , Oryza/genética , Proteínas de Plantas/metabolismo , Tolerância ao Sal/genética
11.
Plant Physiol Biochem ; 165: 1-9, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34029940

RESUMO

Stress associated proteins (SAPs), a class of A20/AN1 zinc finger domain-containing proteins, are involved in a variety of biotic and abiotic stress responses in plants. However, little is known about the SAP gene family and their functions in Tamarix hispida. In this study, we isolated and characterized 11 SAPs from T. hispida. The expression patterns of ThSAPs were analyzed under various stresses (salt and drought) and phytohormone treatment (SA, ABA and MeJA) using real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR). Most ThSAPs exhibited transcriptional responses to abiotic stresses and phytohormones. Among these ThSAPs, ThSAP6 was significantly induced by salt stress. Gain-and loss-of-function analyses revealed that ThSAP6 was a positive regulator of salt stress response. Overexpression of ThSAP6 in T. hispida increased antioxidant enzymes activity and proline content and decreased reactive oxygen species (ROS) accumulation and cell membrane damage under salt stress, while the opposite physiological changes were observed in ThSAP6-RNAi (RNA interference) lines. This study provides a comprehensive description of the SAP gene family in T. hispida, and demonstrates that ThSAP6 is a potential candidate for biotechnological approaches to improve salt tolerance in plants.


Assuntos
Tamaricaceae , Secas , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Tolerância ao Sal/genética , Estresse Fisiológico/genética , Tamaricaceae/genética , Tamaricaceae/metabolismo
12.
Plant Physiol Biochem ; 165: 104-113, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34034156

RESUMO

Calcium-dependent protein kinases (CDPKs) are Ca2+ decoders in plants. AtCPK1 is a positive regulator in the plant response to biotic and abiotic stress. Inactivation of the autoinhibitory domain of AtCPK1 in the mutated form KJM23 provides constitutive activity of the kinase. In the present study, we investigated the effect of overexpressed native and mutant KJM23 forms on salinity tolerance in Nicotiana tabacum. Overexpression of native AtCPK1 provided tobacco resistance to 120 mM NaCl during germination and 180 mM NaCl during long-term growth, while the resistance of plants increased to 240 mM NaCl during both phases of plant development when transformed with KJM23. Mutation in the junction KJM4, which disrupted Ca2+ induced activation, completely nullified the acquired salt tolerance up to levels of normal plants. Analysis by confocal microscopy showed that under high salinity conditions, overexpression of AtCPK1 and KJM23 inhibited reactive oxygen species (ROS) accumulation to levels observed in untreated plants. Quantitative real-time PCR analysis showed that overexpression of AtCPK1 and KJM23 was associated with changes in expression of genes encoding heat shock factors. In all cases, the KJM23 mutation enhanced the effect of AtCPK1, while the KJM4 mutation reduced it to the control level. We suggest that the autoinhibitory domains in CDPKs could be promising targets for manipulation in engineering salt-tolerant plants.


Assuntos
Tolerância ao Sal , Tabaco , Regulação da Expressão Gênica de Plantas , Mutação , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Tolerância ao Sal/genética , Estresse Fisiológico/genética , Tabaco/genética , Tabaco/metabolismo
13.
Int J Mol Sci ; 22(8)2021 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-33919933

RESUMO

Vacuolar sodium/proton (Na+/H+) antiporters (NHXs) can stabilize ion contents to improve the salt tolerance of plants. Here, GhNHX3D was cloned and characterized from upland cotton (Gossypium hirsutum). Phylogenetic and sequence analyses showed that GhNHX3D belongs to the vacuolar-type NHXs. The GhNHX3D-enhanced green fluorescent protein (eGFP) fusion protein localized on the vacuolar membrane when transiently expressed in Arabidopsis protoplasts. The quantitative real-time PCR (qRT-PCR) analysis showed that GhNHX3D was induced rapidly in response to salt stress in cotton leaves, and its transcript levels increased with the aggravation of salt stress. The introduction of GhNHX3D into the salt-sensitive yeast mutant ATX3 improved its salt tolerance. Furthermore, silencing of GhNHX3D in cotton plants by virus-induced gene silencing (VIGS) increased the Na+ levels in the leaves, stems, and roots and decreased the K+ content in the roots, leading to greater salt sensitivity. Our results indicate that GhNHX3D is a member of the vacuolar NHX family and can confer salt tolerance by adjusting the steady-state balance of cellular Na+ and K+ ions.


Assuntos
Antiporters/genética , Gossypium/genética , Estresse Salino/genética , Trocadores de Sódio-Hidrogênio/genética , Antiporters/química , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas/genética , Gossypium/crescimento & desenvolvimento , Gossypium/fisiologia , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/genética , Estresse Salino/fisiologia , Tolerância ao Sal/genética , Trocadores de Sódio-Hidrogênio/química , Vacúolos/enzimologia
14.
Int J Mol Sci ; 22(7)2021 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-33801703

RESUMO

Salt stress is a major increasing threat to global agriculture. Pongamia (Millettia pinnata), a semi-mangrove, is a good model to study the molecular mechanism of plant adaptation to the saline environment. Calcium signaling pathways play critical roles in the model plants such as Arabidopsis in responding to salt stress, but little is known about their function in Pongamia. Here, we have isolated and characterized a salt-responsive MpCML40, a calmodulin-like (CML) gene from Pongamia. MpCML40 protein has 140 amino acids and is homologous with Arabidopsis AtCML40. MpCML40 contains four EF-hand motifs and a bipartite NLS (Nuclear Localization Signal) and localizes both at the plasma membrane and in the nucleus. MpCML40 was highly induced after salt treatment, especially in Pongamia roots. Heterologous expression of MpCML40 in yeast cells improved their salt tolerance. The 35S::MpCML40 transgenic Arabidopsis highly enhanced seed germination rate and root length under salt and osmotic stresses. The transgenic plants had a higher level of proline and a lower level of MDA (malondialdehyde) under normal and stress conditions, which suggested that heterologous expression of MpCML40 contributed to proline accumulation to improve salt tolerance and protect plants from the ROS (reactive oxygen species) destructive effects. Furthermore, we did not observe any measurable discrepancies in the development and growth between the transgenic plants and wild-type plants under normal growth conditions. Our results suggest that MpCML40 is an important positive regulator in response to salt stress and of potential application in producing salt-tolerant crops.


Assuntos
Sinalização do Cálcio , Calmodulina/metabolismo , Millettia/metabolismo , Sinais de Localização Nuclear , Proteínas de Plantas/metabolismo , Motivos de Aminoácidos , Arabidopsis/genética , Arabidopsis/metabolismo , Calmodulina/genética , Regulação da Expressão Gênica de Plantas , Malondialdeído/química , Millettia/genética , Fases de Leitura Aberta , Osmose , Fenótipo , Filogenia , Proteínas de Plantas/genética , Raízes de Plantas , Plantas Geneticamente Modificadas , Prolina/química , Estresse Salino , Tolerância ao Sal/genética , Plantas Tolerantes a Sal/metabolismo , Sementes/metabolismo
15.
Biochem Biophys Res Commun ; 556: 23-30, 2021 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-33836344

RESUMO

The zinc finger transcription factor OXIDATIVE STRESS 2 (OXS2) was previously reported to be involved in oxidative stress tolerance and stress escape. Here we report that an Arabidopsis oxs2-1 mutant is also more sensitive to salt stress. Conversely, the overproduction of a C-terminal fragment of OXS2, the 'AT3' fragment, can enhance salt tolerance in Arabidopsis by upregulating the transcription of at least six salt-induced genes: COR15A, COR47, RD29B, KIN1, ACS2 and ACS6. Mutant analysis showed that the AT3-mediated salt tolerance requires MPK3, MPK6 and 14-3-3Ω. AT3 was shown to interact with MPK3 in planta, with 14-3-3Ω as a likely linker protein. AT3 can be phosphorylated by MPK3 during salt stress, upon which it relocates from the cytoplasm to the nucleus. It appears that the phosphorylation-induced nuclear localization of OXS2 contributes a positive role to the salt stress response.


Assuntos
Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Tolerância ao Sal , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Proteínas 14-3-3/metabolismo , Transporte Ativo do Núcleo Celular , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Núcleo Celular/metabolismo , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica de Plantas , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fragmentos de Peptídeos/genética , Fosforilação , Estresse Salino/genética , Tolerância ao Sal/genética , Fatores de Transcrição/genética
16.
BMC Plant Biol ; 21(1): 176, 2021 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-33845762

RESUMO

BACKGROUND: Salinity is a major threat to the agriculture industry due to the negative impact of salinity stress on crop productivity. In the present study, we isolated rhizobacteria and evaluated their capacities to promote crop growth under salt stress conditions. RESULTS: We isolated rhizospheric bacteria from sand dune flora of Pohang beach, Korea, and screened them for plant growth-promoting (PGP) traits. Among 55 bacterial isolates, 14 produced indole-3-acetic acid (IAA), 10 produced siderophores, and 12 produced extracellular polymeric and phosphate solubilization. Based on these PGP traits, we selected 11 isolates to assess for salinity tolerance. Among them, ALT29 and ALT43 showed the highest tolerance to salinity stress. Next, we tested the culture filtrate of isolates ALT29 and ALT43 for IAA and organic acids to confirm the presence of these PGP products. To investigate the effects of ALT29 and ALT43 on salt tolerance in soybean, we grew seedlings in 0 mM, 80 mM, 160 mM, and 240 mM NaCl treatments, inoculating half with the bacterial isolates. Inoculation with ALT29 and ALT43 significantly increased shoot length (13%), root length (21%), shoot fresh and dry weight (44 and 35%), root fresh and dry weight (9%), chlorophyll content (16-24%), Chl a (8-43%), Chl b (13-46%), and carotenoid (14-39%) content of soybean grown under salt stress. Inoculation with ALT29 and ALT43 also significantly decreased endogenous ABA levels (0.77-fold) and increased endogenous SA contents (6-16%), increased total protein (10-20%) and glutathione contents, and reduced lipid peroxidation (0.8-5-fold), superoxide anion (21-68%), peroxidase (12.14-17.97%), and polyphenol oxidase (11.76-27.06%) contents in soybean under salinity stress. In addition, soybean treated with ALT29 and ALT43 exhibited higher K+ uptake (9.34-67.03%) and reduced Na+ content (2-4.5-fold). Genes involved in salt tolerance, GmFLD19 and GmNARK, were upregulated under NaCl stress; however, significant decreases in GmFLD19 (3-12-fold) and GmNARK (1.8-3.7-fold) expression were observed in bacterial inoculated plants. CONCLUSION: In conclusion, bacterial isolates ALT29 and ALT43 can mitigate salinity stress and increase plant growth, providing an eco-friendly approach for addressing saline conditions in agricultural production systems.


Assuntos
Fenômenos Fisiológicos Bacterianos , Estresse Salino , Tolerância ao Sal , Soja/crescimento & desenvolvimento , Soja/microbiologia , Antioxidantes/metabolismo , Bactérias/isolamento & purificação , Bactérias/metabolismo , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Potássio/metabolismo , Rizosfera , Tolerância ao Sal/genética , Sódio/metabolismo , Soja/genética , Soja/metabolismo
17.
Int J Mol Sci ; 22(9)2021 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-33925342

RESUMO

Canavalia rosea (bay bean), distributing in coastal areas or islands in tropical and subtropical regions, is an extremophile halophyte with good adaptability to seawater and drought. Late embryogenesis abundant (LEA) proteins typically accumulate in response to various abiotic stresses, including dehydration, salinity, high temperature, and cold, or during the late stage of seed development. Abscisic acid-, stress-, and ripening-induced (ASR) genes are stress and developmentally regulated plant-specific genes. In this study, we reported the first comprehensive survey of the LEA and ASR gene superfamily in C. rosea. A total of 84 CrLEAs and three CrASRs were identified in C. rosea and classified into nine groups. All CrLEAs and CrASRs harbored the conserved motif for their family proteins. Our results revealed that the CrLEA genes were widely distributed in different chromosomes, and all of the CrLEA/CrASR genes showed wide expression features in different tissues in C. rosea plants. Additionally, we introduced 10 genes from different groups into yeast to assess the functions of the CrLEAs/CrASRs. These results contribute to our understanding of LEA/ASR genes from halophytes and provide robust candidate genes for functional investigations in plant species adapted to extreme environments.


Assuntos
Canavalia/genética , Canavalia/metabolismo , Proteínas de Plantas/genética , Ácido Abscísico/metabolismo , Adaptação Fisiológica/genética , Canavalia/crescimento & desenvolvimento , China , Secas , Regulação da Expressão Gênica de Plantas/genética , Genoma de Planta/genética , Filogenia , Proteínas de Plantas/metabolismo , Salinidade , Tolerância ao Sal/genética , Plantas Tolerantes a Sal/metabolismo , Sementes/metabolismo , Estresse Fisiológico/genética , Estresse Fisiológico/fisiologia
18.
Int J Mol Sci ; 22(7)2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33915978

RESUMO

The basic/helix-loop-helix (bHLH) transcription factor (TF) plays an important role for plant growth, development, and stress responses. Previously, proteomics of NaCl treated sugar beet leaves revealed that a bHLH TF, BvbHLH93, was significantly increased under salt stress. The BvbHLH93 protein localized in the nucleus and exhibited activation activity. The expression of BvbHLH93 was significantly up-regulated in roots and leaves by salt stress, and the highest expression level in roots and leaves was 24 and 48 h after salt stress, respectively. Furthermore, constitutive expression of BvbHLH93 conferred enhanced salt tolerance in Arabidopsis, as indicated by longer roots and higher content of chlorophyll than wild type. Additionally, the ectopic expression lines accumulated less Na+ and MDA, but more K+ than the WT. Overexpression of the BvBHLH93 enhanced the activities of antioxidant enzymes by positively regulating the expression of antioxidant genes SOD and POD. Compared to WT, the overexpression plants also had low expression levels of RbohD and RbohF, which are involved in reactive oxygen species (ROS) production. These results suggest that BvbHLH93 plays a key role in enhancing salt stress tolerance by enhancing antioxidant enzymes and decreasing ROS generation.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Beta vulgaris/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Tolerância ao Sal/genética , Antioxidantes/metabolismo , Arabidopsis , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Beta vulgaris/genética , Proteínas de Plantas/genética
19.
Gene ; 789: 145670, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33892070

RESUMO

We have functionally characterized the RPL6, a Ribosomal Protein Large subunit gene for salt stress tolerance in rice. The overexpression of RPL6 resulted in tolerance to moderate (150 mM) to high (200 mM) levels of salt (NaCl). The transgenic rice plants expressing RPL6 constitutively showed better phenotypic and physiological responses with high quantum efficiency, accumulation of higher chlorophyll and proline contents, and an overall increase in seed yield compared with the wild type in salt stress treatments. An iTRAQ-based comparative proteomic analysis revealed the high expression of about 333 proteins among the 4378 DAPs in a selected overexpression line of RPL6 treated with 200 mM of NaCl. The functional analysis showed that these highly accumulated proteins (HAPs) are involved in photosynthesis, ribosome and chloroplast biogenesis, ion transportation, transcription and translation regulation, phytohormone and secondary metabolite signal transduction. An in silico network analysis of HAPs predicted that RPL6 binds with translation-related proteins and helicases, which coordinately affect the activities of a comprehensive signaling network, thereby inducing tolerance and promoting growth and productivity in response to salt stress. Our overall findings identified a novel candidate, RPL6, whose characterization contributed to the existing knowledge on the complexity of salt tolerance mechanism in plants.


Assuntos
Oryza/genética , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Proteínas Ribossômicas/genética , Tolerância ao Sal/genética , Clorofila/genética , Cloroplastos/genética , Regulação da Expressão Gênica de Plantas/genética , Fotossíntese/genética , Proteômica/métodos , Estresse Salino/genética , Plântula/genética , Transdução de Sinais/genética
20.
Int J Mol Sci ; 22(7)2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33807153

RESUMO

Soil salinity is an increasing problem facing agriculture in many parts of the world. Climate change and irrigation practices have led to decreased yields of some farmland due to increased salt levels in the soil. Plants that have tolerance to salt are thus needed to feed the world's population. One approach addressing this problem is genetic engineering to introduce genes encoding salinity, but this approach has limitations. Another fairly new approach is the isolation and development of salt-tolerant (halophilic) plant-associated bacteria. These bacteria are used as inoculants to stimulate plant growth. Several reports are now available, demonstrating how the use of halophilic inoculants enhance plant growth in salty soil. However, the mechanisms for this growth stimulation are as yet not clear. Enhanced growth in response to bacterial inoculation is expected to be associated with changes in plant gene expression. In this review, we discuss the current literature and approaches for analyzing altered plant gene expression in response to inoculation with halophilic bacteria. Additionally, challenges and limitations to current approaches are analyzed. A further understanding of the molecular mechanisms involved in enhanced plant growth when inoculated with salt-tolerant bacteria will significantly improve agriculture in areas affected by saline soils.


Assuntos
Halobacteriales/metabolismo , Desenvolvimento Vegetal/genética , Plantas/genética , Plantas/microbiologia , Tolerância ao Sal/genética , Plantas Tolerantes a Sal/metabolismo , Bactérias/metabolismo , Expressão Gênica , Genes de Plantas , Raízes de Plantas/metabolismo , Salinidade , Solo/química , Microbiologia do Solo
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