Halopriming Imparts Salt Tolerance by Reducing Oxidative, Osmotic Stress and DNA Damage in Five Different Legume Varieties

Background: Salinity challenges legume production worldwide. To maintain the overall legume production, seed halopriming has been adopted as a cost-effective, farmer friendly technique, minimizing noxious effects of NaCl on plant growth. Methods: Nonprimed and haloprimed seeds were grown under different NaCl concentrations and harvested after 21 days. NaCl-induced alterations on physio-biochemical attributes and DNA damage were studied. Result: NaCl exposure in nonprimed seedlings exhibited growth inhibition, depletion in water contents, increased accumulation of H2O2, MDA and proline causing DNA damage. Conversely, in primed seedlings, these toxic effects were altered and extent of DNA damage reduced. Decreased catalase activity in nonprimed seedlings failed to detoxify the ROS generated under salinity inducing DNA damage whereas in NaCl-treated haloprimed seedlings, improved catalase activity helped to overcome such adversities favouring improved growth of all tested legume varieties.

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Overview of the Role of Rhizobacteria in Plant Salt Stress Tolerance

Agronomy ◽

10.3390/agronomy11091759 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1759

Author(s):

Miguel Ayuso-Calles ◽

José David Flores-Félix ◽

Raúl Rivas

Keyword(s):

Salt Stress ◽

Plant Growth ◽

Osmotic Stress ◽

Nutrient Deficiency ◽

Cost Effective ◽

Growth And Yield ◽

Soil Conditions ◽

Saline Stress ◽

Plant Growth Promoting Bacteria ◽

Plant Tolerance

Salinity is one of the main causes of abiotic stress in plants, resulting in negative effects on crop growth and yield, especially in arid and semi-arid regions. The effects of salinity on plant growth mainly generate osmotic stress, ion toxicity, nutrient deficiency, and oxidative stress. Traditional approaches for the development of salt-tolerant crops are expensive and time-consuming, as well as not always being easy to implement. Thus, the use of plant growth-promoting bacteria (PGPB) has been reported as a sustainable and cost-effective alternative to enhance plant tolerance to salt stress. In this sense, this review aims to understand the mechanisms by which PGPB help plants to alleviate saline stress, including: (i) changes in the plant hormonal balance; (ii) release of extracellular compounds acting as chemical signals for the plant or enhancing soil conditions for plant development; (iii) regulation of the internal ionic content of the plant; or iv) aiding in the synthesis of osmoprotectant compounds (which reduce osmotic stress). The potential provided by PGPB is therefore an invaluable resource for improving plant tolerance to salinity, thereby facilitating an increase in global food production and unravelling prospects for sustainable agricultural productivity.

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Silicon Stimulates Plant Growth and Metabolism in Rice Plants under Conventional and Osmotic Stress Conditions

Plants ◽

10.3390/plants10040777 ◽

2021 ◽

Vol 10 (4) ◽

pp. 777

Author(s):

Sara Monzerrat Ramírez-Olvera ◽

Libia Iris Trejo-Téllez ◽

Fernando Carlos Gómez-Merino ◽

Lucero del Mar Ruíz-Posadas ◽

Ernesto Gabriel Alcántar-González ◽

...

Keyword(s):

Plant Growth ◽

Osmotic Stress ◽

Abiotic Factors ◽

Stress Conditions ◽

Chlorophyll B ◽

Rice Seedlings ◽

Root Volume ◽

Total Sugars ◽

Dry Biomass ◽

Peg 8000

Exogenous silicon (Si) can enhance plant resistance to various abiotic factors causing osmotic stress. The objective of this research was to evaluate the application of 1 and 2 mM Si to plants under normal conditions and under osmotic stress. Morelos A-98 rice seedlings, were treated with 1 and 2 mM SiO2 for 28 d. Subsequently, half of the plants were subjected to osmotic stress with the addition of 10% polyethylene glycol (PEG) 8000; and continued with the addition of Si (0, 1 and 2 mM SiO2) for both conditions. The application of Si under both conditions increased chlorophyll b in leaves, root volume, as well as fresh and dry biomass of roots. Interestingly, the number of tillers, shoot fresh and dry biomass, shoot water content, concentration of total chlorophyll, chlorophyll a/b ratio, and the concentration of total sugars and proline in shoot increased with the addition of Si under osmotic stress conditions. The addition of Si under normal conditions decreased the concentration of sugars in the roots, K and Mn in roots, and increased the concentration of Fe and Zn in shoots. Therefore, Si can be used as a potent inorganic biostimulant in rice Morelos A-98 since it stimulates plant growth and modulates the concentration of vital biomolecules and essential nutrients.

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Growth Promotion or Osmotic Stress Response: How SNF1-Related Protein Kinase 2 (SnRK2) Kinases Are Activated and Manage Intracellular Signaling in Plants

Plants ◽

10.3390/plants10071443 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1443

Author(s):

Yoshiaki Kamiyama ◽

Sotaro Katagiri ◽

Taishi Umezawa

Keyword(s):

Protein Kinase ◽

Plant Growth ◽

Osmotic Stress ◽

Protein Function ◽

Intracellular Signaling ◽

Growth Promotion ◽

Research Field ◽

Dependent Manner ◽

Related Protein ◽

Wide Range

Reversible phosphorylation is a major mechanism for regulating protein function and controls a wide range of cellular functions including responses to external stimuli. The plant-specific SNF1-related protein kinase 2s (SnRK2s) function as central regulators of plant growth and development, as well as tolerance to multiple abiotic stresses. Although the activity of SnRK2s is tightly regulated in a phytohormone abscisic acid (ABA)-dependent manner, recent investigations have revealed that SnRK2s can be activated by group B Raf-like protein kinases independently of ABA. Furthermore, evidence is accumulating that SnRK2s modulate plant growth through regulation of target of rapamycin (TOR) signaling. Here, we summarize recent advances in knowledge of how SnRK2s mediate plant growth and osmotic stress signaling and discuss future challenges in this research field.

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SYNERGISM BETWEEN INDOLEACETIC AND NICOTINIC ACIDS IN A PLANT GROWTH INHIBITION

Journal of Biological Chemistry ◽

10.1016/s0021-9258(17)35053-6 ◽

1947 ◽

Vol 169 (2) ◽

pp. 465-466

Author(s):

Arthur W. Galston

Keyword(s):

Plant Growth ◽

Growth Inhibition ◽

Plant Growth Inhibition

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Genome Insights into the Novel Species Jejubacter calystegiae, a Plant Growth-Promoting Bacterium in Saline Conditions

Diversity ◽

10.3390/d13010024 ◽

2021 ◽

Vol 13 (1) ◽

pp. 24

Author(s):

Ling Min Jiang ◽

Yong Jae Lee ◽

Ho Le Han ◽

Myoung Hui Lee ◽

Jae Cheol Jeong ◽

...

Keyword(s):

Salt Tolerance ◽

Plant Growth ◽

Novel Species ◽

Endophytic Bacterium ◽

Morning Glory ◽

Plant Growth Promoting Bacteria ◽

Illumina Hiseq ◽

Plant Growth Promoting ◽

Growth Promoting ◽

Sequencing Platforms

Jejubacter calystegiae KSNA2T, a moderately halophilic, endophytic bacterium isolated from beach morning glory (Calystegia soldanella), was determined to be a novel species in a new genus in the family Enterobacteriaceae. To gain insights into the genetic basis of the salinity stress response of strain KSNA2T, we sequenced its genome using two complementary sequencing platforms (Illumina HiSeq and PacBio RSII). The genome contains a repertoire of metabolic pathways, such as those for nitrogen, phosphorus, and some amino acid metabolism pathways. Functional annotation of the KSNA2T genome revealed several genes involved in salt tolerance pathways, such as those encoding sodium transporters, potassium transporters, and osmoprotectant enzymes. Plant growth-promoting bacteria-based experiments indicated that strain KSNA2T promotes the germination of vegetable seeds in saline conditions. Overall, the genetic and biological analyses of strain KSNA2T provide valuable insights into bacteria-mediated salt tolerance in agriculture.

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