Omeprazole Promotes Chloride Exclusion and Induces Salt Tolerance in Greenhouse Basil

The role of small bioactive molecules (<500 Da) in mechanisms improving resource use efficiency in plants under stress conditions draws increasing interest. One such molecule is omeprazole (OMP), a benzimidazole derivative and inhibitor of animal proton pumps shown to improve nitrate uptake and exclusion of toxic ions, especially of chloride from the cytosol of salt-stressed leaves. Currently, OMP was applied as substrate drench at two rates (0 or 10 μM) on hydroponic basil (Ocimum basilicum L. cv. Genovese) grown under decreasing NO3−:Cl− ratio (80:20, 60:40, 40:60, or 20:80). Chloride concentration and stomatal resistance increased while transpiration, net CO2 assimilation rate and beneficial ions (NO3−, PO43−, and SO42−) decreased with reduced NO3−:Cl− ratio under the 0 μM OMP treatment. The negative effects of chloride were not only mitigated by the 10 μM OMP application in all treatments, with the exception of 20:80 NO3−:Cl−, but plant growth at 80:20, 60:40, and 40:60 NO3−:Cl− ratios receiving OMP application showed maximum fresh yield (+13%, 24%, and 22%, respectively), shoot (+10%, 25%, and 21%, respectively) and root (+32%, 76%, and 75%, respectively) biomass compared to the corresponding untreated treatments. OMP was not directly involved in ion homeostasis and compartmentalization of vacuolar or apoplastic chloride. However, it was active in limiting chloride loading into the shoot, as manifested by the lower chloride concentration in the 80:20, 60:40, and 40:60 NO3−:Cl− treatments compared to the respective controls (−41%, −37%, and −24%), favoring instead that of nitrate and potassium while also boosting photosynthetic activity. Despite its unequivocally beneficial effect on plants, the large-scale application of OMP is currently limited by the molecule’s high cost. However, further studies are warranted to unravel the molecular mechanisms of OMP-induced reduction of chloride loading to shoot and improved salt tolerance.

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Potassium and sodium relations in salinised barley tissues as a basis of differential salt tolerance

Functional Plant Biology ◽

10.1071/fp06237 ◽

2007 ◽

Vol 34 (2) ◽

pp. 150 ◽

Cited By ~ 190

Author(s):

Zhonghua Chen ◽

Meixue Zhou ◽

Ian A. Newman ◽

Neville J. Mendham ◽

Guoping Zhang ◽

...

Keyword(s):

Salt Tolerance ◽

Grain Yield ◽

Large Scale ◽

Germination Rate ◽

Co2 Assimilation ◽

Shoot Biomass ◽

Salinity Treatment ◽

Root Cells ◽

Barley Cultivars ◽

Plant Salt Tolerance

A large-scale glasshouse trial, including nearly 70 barley cultivars (5300 plants in total), was conducted over 2 consecutive years to investigate plant physiological responses to salinity. In a parallel set of experiments, plant salt tolerance was assessed by non-invasive microelectrode measurements of net K+ flux from roots of 3-day-old seedlings of each cultivar after 1 h treatment in 80 mm NaCl as described in our previous publication (Chen et al. 2005). K+ flux from the root in response to NaCl treatment was highly (P < 0.001) inversely correlated with relative grain yield, shoot biomass, plant height, net CO2 assimilation, survival rate and thousand-seed weight measured in glasshouse experiments after 4–5 months of salinity treatment. No significant correlation with relative germination rate or tillering was found. In general, 62 out of 69 cultivars followed an inverse relationship between K+ efflux and salt tolerance. In a few cultivars, however, high salt tolerance (measured as grain yield at harvest) was observed for plants showing only modest ability to retain K+ in the root cells. Tissue elemental analysis showed that these plants had a much better ability to prevent Na+ accumulation in plant leaves and, thus, to maintain a higher K+/Na+ ratio. Taken together, our results show that a plant’s ability to maintain high K+/Na+ ratio (either retention of K+ or preventing Na+ from accumulating in leaves) is a key feature for salt tolerance in barley.

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Advances in Sensing, Response and Regulation Mechanism of Salt Tolerance in Rice

International Journal of Molecular Sciences ◽

10.3390/ijms22052254 ◽

2021 ◽

Vol 22 (5) ◽

pp. 2254

Author(s):

Kimberly S. Ponce ◽

Lijun Meng ◽

Longbiao Guo ◽

Yujia Leng ◽

Guoyou Ye

Keyword(s):

Salt Tolerance ◽

Molecular Mechanisms ◽

Current Knowledge ◽

Ion Homeostasis ◽

Regulation Mechanism ◽

Global Food Security ◽

Adaptive Mechanisms ◽

Mechanisms Of Salt Tolerance ◽

Key Genes ◽

Salt Tolerant Cultivars

Soil salinity is a serious menace in rice production threatening global food security. Rice responses to salt stress involve a series of biological processes, including antioxidation, osmoregulation or osmoprotection, and ion homeostasis, which are regulated by different genes. Understanding these adaptive mechanisms and the key genes involved are crucial in developing highly salt-tolerant cultivars. In this review, we discuss the molecular mechanisms of salt tolerance in rice—from sensing to transcriptional regulation of key genes—based on the current knowledge. Furthermore, we highlight the functionally validated salt-responsive genes in rice.

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Comparative Transcriptome Analysis of Halophyte Zoysia macrostachya in Response to Salinity Stress

Plants ◽

10.3390/plants9040458 ◽

2020 ◽

Vol 9 (4) ◽

pp. 458 ◽

Cited By ~ 2

Author(s):

Rong Wang ◽

Xi Wang ◽

Kuan Liu ◽

Xue-Jie Zhang ◽

Luo-Yan Zhang ◽

...

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Molecular Mechanisms ◽

Plant Hormone ◽

Ion Homeostasis ◽

Oxygen Species ◽

Molecular Processes ◽

Salt Tolerant ◽

Salt Glands ◽

Differently Expressed Genes

As one of the most severe environmental stresses, salt stress can cause a series of changes in plants. In salt tolerant plant Zoysia macrostachya, germination, physiology, and genetic variation under salinity have been studied previously, and the morphology and distribution of salt glands have been clarified. However, no study has investigated the transcriptome of such species under salt stress. In the present study, we compared transcriptome of Z. macrostachya under normal conditions and salt stress (300 mmol/L NaCl, 24 h) aimed to identify transcriptome responses and molecular mechanisms under salt stress in Z. macrostachya. A total of 8703 differently expressed genes (DEGs) were identified, including 4903 up-regulated and 3800 down-regulated ones. Moreover, a series of molecular processes were identified by Gene Ontology (GO) analysis, and these processes were suggested to be closely related to salt tolerance in Z. macrostachya. The identified DEGs concentrated on regulating plant growth via plant hormone signal transduction, maintaining ion homeostasis via salt secretion and osmoregulatory substance accumulation and preventing oxidative damage via increasing the activity of ROS (reactive oxygen species) scavenging system. These changes may be the most important responses of Z. macrostachya under salt stress. Some key genes related to salt stress were identified meanwhile. Collectively, our findings provided valuable insights into the molecular mechanisms and genetic underpinnings of salt tolerance in Z. macrostachya.

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Low Mannitol Concentrations in Arabidopsis thaliana Expressing Ectocarpus Genes Improve Salt Tolerance

Plants ◽

10.3390/plants9111508 ◽

2020 ◽

Vol 9 (11) ◽

pp. 1508

Author(s):

Pramod Rathor ◽

Tudor Borza ◽

Yanhui Liu ◽

Yuan Qin ◽

Sophia Stone ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Salt Tolerance ◽

Transgenic Plants ◽

Salinity Stress ◽

Stress Responses ◽

Molecular Mechanisms ◽

Ion Homeostasis ◽

Biotic And Abiotic Stress ◽

Expression Of Genes ◽

Wide Range

Mannitol is abundant in a wide range of organisms, playing important roles in biotic and abiotic stress responses. Nonetheless, mannitol is not produced by a vast majority of plants, including many important crop plants. Mannitol-producing transgenic plants displayed improved tolerance to salt stresses though mannitol production was rather low, in the µM range, compared to mM range found in plants that innately produce mannitol. Little is known about the molecular mechanisms underlying salt tolerance triggered by low concentrations of mannitol. Reported here is the production of mannitol in Arabidopsis thaliana, by expressing two mannitol biosynthesis genes from the brown alga Ectocarpus sp. strain Ec32. To date, no brown algal genes have been successfully expressed in land plants. Expression of mannitol-1-phosphate dehydrogenase and mannitol-1-phosphatase genes was associated with the production of 42.3–52.7 nmol g−1 fresh weight of mannitol, which was sufficient to impart salinity and temperature stress tolerance. Transcriptomics revealed significant differences in the expression of numerous genes, in standard and salinity stress conditions, including genes involved in K+ homeostasis, ROS signaling, plant development, photosynthesis, ABA signaling and secondary metabolism. These results suggest that the improved tolerance to salinity stress observed in transgenic plants producing mannitol in µM range is achieved by the activation of a significant number of genes, many of which are involved in priming and modulating the expression of genes involved in a variety of functions including hormone signaling, osmotic and oxidative stress, and ion homeostasis.

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Arabidopsis heat shock transcription factor HSFA7b positively mediates salt stress tolerance by binding to an E-box-like motif to regulate gene expression

Journal of Experimental Botany ◽

10.1093/jxb/erz261 ◽

2019 ◽

Vol 70 (19) ◽

pp. 5355-5374 ◽

Cited By ~ 11

Author(s):

Dandan Zang ◽

Jingxin Wang ◽

Xin Zhang ◽

Zhujun Liu ◽

Yucheng Wang

Keyword(s):

Gene Expression ◽

Transcription Factors ◽

Heat Shock ◽

Salt Tolerance ◽

Stress Responses ◽

Ion Homeostasis ◽

Cellulose Synthase ◽

Regulate Gene Expression ◽

E Box ◽

Regulate Gene

Abstract Plant heat shock transcription factors (HSFs) are involved in heat and other abiotic stress responses. However, their functions in salt tolerance are little known. In this study, we characterized the function of a HSF from Arabidopsis, AtHSFA7b, in salt tolerance. AtHSFA7b is a nuclear protein with transactivation activity. ChIP-seq combined with an RNA-seq assay indicated that AtHSFA7b preferentially binds to a novel cis-acting element, termed the E-box-like motif, to regulate gene expression; it also binds to the heat shock element motif. Under salt conditions, AtHSFA7b regulates its target genes to mediate serial physiological changes, including maintaining cellular ion homeostasis, reducing water loss rate, decreasing reactive oxygen species accumulation, and adjusting osmotic potential, which ultimately leads to improved salt tolerance. Additionally, most cellulose synthase-like (CSL) and cellulose synthase (CESA) family genes were inhibited by AtHSFA7b; some of them were randomly selected for salt tolerance characterization, and they were mainly found to negatively modulate salt tolerance. By contrast, some transcription factors (TFs) were induced by AtHSFA7b; among them, we randomly identified six TFs that positively regulate salt tolerance. Thus, AtHSFA7b serves as a transactivator that positively mediates salinity tolerance mainly through binding to the E-box-like motif to regulate gene expression.

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Salinity Effects on Gene Expression, Morphological, and Physio-Biochemical Responses of Stevia rebaudiana Bertoni In Vitro

Plants ◽

10.3390/plants10040820 ◽

2021 ◽

Vol 10 (4) ◽

pp. 820

Author(s):

Clara Azzam ◽

Sudad Al-Taweel ◽

Ranya Abdel-Aziz ◽

Karim Rabea ◽

Alaa Abou-Sreea ◽

...

Keyword(s):

Salt Tolerance ◽

Biochemical Parameters ◽

Large Scale ◽

Stevia Rebaudiana ◽

Multiple Shoots ◽

High Salt ◽

Stress Factors ◽

Stevia Rebaudiana Bertoni ◽

Nacl Concentration

Stevia rebaudiana Bertoni is a little bush, which is cultivated on a large scale in many countries for medicinal purposes and used as a natural sweetener in food products. The present work aims to conduct a protocol for stevia propagation in vitro to produce and introduce Stevia rebaudiana plants as a new sweetener crop to Egyptian agriculture. To efficiently maximize its propagation, it is important to study the influence of stress factors on the growth and development of Stevia rebaudiana grown in vitro. Two stevia varieties were investigated (Sugar High A3 and Spanti) against salt stress. Leaves were used as the source of explants for callus initiation, regeneration, multiplication and rooting. Some stress-related traits, i.e., photosynthetic pigments, proline contents, and enzyme activity for peroxidase (POD), polyphenol oxidase (PPO), and malate dehydrogenase (MDH) were studied. Murashig and Skoog (MS) medium was supplemented with four NaCl concentrations: 500, 1000, 2000, and 3000 mgL−1, while a salt-free medium was used as the control. The data revealed that salinity negatively affected all studied characters: the number of surviving calli, regeneration%, shoot length, the number of multiple shoots, number of leaf plantlets−1, number of root plantlets−1, and root length. The data also revealed that Sugar High A3 is more tolerant than Spanti. The total chlorophyll content decreased gradually with increasing NaCl concentration. However, the opposite was true for proline content. Isozyme’s fractionation exhibited high levels of variability among the two varieties. Various biochemical parameters associated with salt tolerance were detected in POD. Namely, POD4, POD6, POD 9 at an Rf of 0.34, 0.57, and 0.91 in the Sugar High A3 variety under high salt concentration conditions, as well as POD 10 at an Rf of 0.98 in both varieties under high salt concentrations. In addition, the overexpression of POD 5 and POD 10 at Rf 0.52 and 0.83 was found in both varieties at high NaCl concentrations. Biochemical parameters associated with salt tolerance were detected in PPO (PPO1, PPO2 and PPO4 at an Rf of 0.38, 0.42 and 0.62 in the Sugar High A3 variety under high salt concentrations) and MDH (MDH 3 at an Rf of 0.40 in both varieties at high salt concentrations). Therefore, these could be considered as important biochemical markers associated with salt tolerance and could be applied in stevia breeding programs (marker-assisted selection). This investigation recommends stevia variety Sugar High A3 to be cultivated under salt conditions.

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EGCG binds intrinsically disordered N-terminal domain of p53 and disrupts p53-MDM2 interaction

Nature Communications ◽

10.1038/s41467-021-21258-5 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Jing Zhao ◽

Alan Blayney ◽

Xiaorong Liu ◽

Lauren Gandy ◽

Weihua Jin ◽

...

Keyword(s):

Large Scale ◽

Molecular Mechanisms ◽

Epigallocatechin Gallate ◽

Cancer Drug ◽

Dynamic Interactions ◽

Cancer Drug Discovery ◽

Intrinsically Disordered ◽

Terminal Domain ◽

Cancerous Cells

AbstractEpigallocatechin gallate (EGCG) from green tea can induce apoptosis in cancerous cells, but the underlying molecular mechanisms remain poorly understood. Using SPR and NMR, here we report a direct, μM interaction between EGCG and the tumor suppressor p53 (KD = 1.6 ± 1.4 μM), with the disordered N-terminal domain (NTD) identified as the major binding site (KD = 4 ± 2 μM). Large scale atomistic simulations (>100 μs), SAXS and AUC demonstrate that EGCG-NTD interaction is dynamic and EGCG causes the emergence of a subpopulation of compact bound conformations. The EGCG-p53 interaction disrupts p53 interaction with its regulatory E3 ligase MDM2 and inhibits ubiquitination of p53 by MDM2 in an in vitro ubiquitination assay, likely stabilizing p53 for anti-tumor activity. Our work provides insights into the mechanisms for EGCG’s anticancer activity and identifies p53 NTD as a target for cancer drug discovery through dynamic interactions with small molecules.

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Molecular mechanisms of local adaptation for salt‐tolerance in a treefrog

Molecular Ecology ◽

10.1111/mec.15867 ◽

2021 ◽

Author(s):

Molly A. Albecker ◽

Adam M.M. Stuckert ◽

Christopher N. Balakrishnan ◽

Michael W. McCoy

Keyword(s):

Salt Tolerance ◽

Local Adaptation ◽

Molecular Mechanisms

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Multigram synthesis of an orthogonally protected pentasaccharide for use as glycan precursor in a Shigella flexneri 3a conjugate vaccine: application to a ready-for-conjugation decasaccharide

Organic Chemistry Frontiers ◽

10.1039/d1qo00761k ◽

2021 ◽

Author(s):

Johan Cornil ◽

Zhaoyu Hu ◽

Marion Bouchet ◽

Laurence A. MULARD

Keyword(s):

Conjugate Vaccine ◽

Large Scale ◽

Shigella Flexneri ◽

Bioactive Molecules

The rapidly growing interest for carbohydrate-based bioactive molecules calls for strategies enabling appropriate design and large scale delivery of the glycan moiety. Here, we described a robust and high-yielding chemical...

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Successive Harvests Modulate the Productive and Physiological Behavior of Three Genovese Pesto Basil Cultivars

Agronomy ◽

10.3390/agronomy11030560 ◽

2021 ◽

Vol 11 (3) ◽

pp. 560

Author(s):

Luigi Formisano ◽

Michele Ciriello ◽

Christophe El-Nakhel ◽

Marios C. Kyriacou ◽

Youssef Rouphael

Keyword(s):

Dry Matter ◽

Co2 Assimilation ◽

Stomatal Resistance ◽

Matter Content ◽

Dry Matter Content ◽

Technological Parameters ◽

Net Co2 Assimilation ◽

Dry Biomass ◽

Crop Cycle ◽

The Impact

In the Italian culinary tradition, young and tender leaves of Genovese basil (Ocimum basilicum L.) are used to prepare pesto sauce, a tasty condiment that attracts the interest of the food processing industry. Like other leafy or aromatic vegetables, basil is harvested more than once during the crop cycle to maximize yield. However, the mechanical stress induced by successive cuts can affect crucial parameters associated with pesto processing (leaf/stem ratio, stem diameter, and dry matter). Our research accordingly aimed to evaluate the impact of successive harvests on three field-grown Genovese basil cultivars (“Aroma 2”, “Eleonora” and “Italiano Classico”) in terms of production, physiological behavior, and technological parameters. Between the first and second harvest, marketable fresh yield and shoot dry biomass increased by 148.4% and 172.9%, respectively; by contrast, the leaf-to-stem ratio decreased by 22.5%, while the dry matter content was unchanged. The increased fresh yield and shoot dry biomass at the second harvest derived from improved photosynthetic efficiency, which enabled higher net CO2 assimilation, Fv/Fm and transpiration as well as reduced stomatal resistance. Our findings suggest that, under the Mediterranean environment, “Italiano Classico” carries superior productive performance and optimal technological characteristics in line with industrial requirements. These promising results warrant further investigation of the impact successive harvests may have on the qualitative components of high-yielding basil genotypes with respect to consumer expectations of the final product.

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