scholarly journals Exogenous melatonin enhances salt secretion from salt glands by upregulating the expression of ion transporter and vesicle transport genes in Limonium bicolor

2020 ◽  
Author(s):  
Junpeng Li ◽  
Fang Yuan ◽  
Yanlu Liu ◽  
Mingjing Zhang ◽  
Yun Liu ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Plant Growth ◽  
Environmental Stress ◽  
Transport Proteins ◽  
Vesicle Transport ◽  
Ion Transporters ◽  
Salt Glands ◽  
Exogenous Melatonin ◽  
Genes Encoding ◽  
Salt Secretion

Abstract Background: Salt, a common environmental stress factor, inhibits plant growth and reduces yields. Melatonin is a pleiotropic molecule that regulates plant growth and can alleviate environmental stress in plants. All previous research on this topic has focused on the use of melatonin to improve the relatively low salt tolerance of glycophytes by promoting growth and enhancing antioxidant ability. It is unclear whether exogenous melatonin can increase the salt tolerance of halophytes, particularly recretohalophytes, by enhancing salt secretion from the salt glands. Results: To examine the mechanisms of melatonin-mediated salt tolerance, we explored the effects of exogenous applications of melatonin on the secretion of salt from the salt glands of Limonium bicolor (a kind of recretohalophyte) seedlings and on the expression of associated genes. A pretreatment with 5 μM melatonin significantly improved the growth of L. bicolor seedlings under 300 mM NaCl. Furthermore, exogenous melatonin significantly increased the dry weight and endogenous melatonin content of L. bicolor. In addition, this treatment reduced the content of Na+ and Cl– in leaves, but increased the K+ content. Both the salt secretion rate of the salt glands and the expression level of genes encoding ion transporters (LbHTK1, LbSOS1, LbPMA, and LbNHX1) and vesicular transport proteins (LbVAMP721, LbVAP27, and LbVAMP12) were significantly increased by exogenous melatonin treatment. These results indicate that melatonin improves the salt tolerance of the recretohalophyte L. bicolor via the upregulation of salt secretion by the salt glands.Conclusions: Our results showed that melatonin can upregulate the expression of genes encoding ion transporters and vesicle transport proteins to enhance salt secretion from the salt glands. Combining the results of the current study with previous research, we formulated a novel mechanism by which melatonin increases salt secretion in L. bicolor. Ions in mesophyll cells are transported to the salt glands through ion transporters located at the plasma membrane. After the ions enter the salt glands, they are transported to the collecting chamber adjacent to the secretory pore through vesicle transport and ions transporter and then are secreted from the secretory pore of salt glands, which maintain ionic homeostasis in the cells and alleviate NaCl-induced growth inhibition.

scholarly journals Exogenous melatonin enhances salt secretion from salt glands by upregulating the expression of ion transporter and vesicle transport genes in Limonium bicolor

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Junpeng Li ◽  
Fang Yuan ◽  
Yanlu Liu ◽  
Mingjing Zhang ◽  
Yun Liu ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Plant Growth ◽  
Environmental Stress ◽  
Transport Proteins ◽  
Vesicle Transport ◽  
Ion Transporters ◽  
Salt Glands ◽  
Exogenous Melatonin ◽  
Genes Encoding ◽  
Salt Secretion

Abstract Background Salt, a common environmental stress factor, inhibits plant growth and reduces yields. Melatonin is a pleiotropic molecule that regulates plant growth and can alleviate environmental stress in plants. All previous research on this topic has focused on the use of melatonin to improve the relatively low salt tolerance of glycophytes by promoting growth and enhancing antioxidant ability. It is unclear whether exogenous melatonin can increase the salt tolerance of halophytes, particularly recretohalophytes, by enhancing salt secretion from the salt glands. Results To examine the mechanisms of melatonin-mediated salt tolerance, we explored the effects of exogenous applications of melatonin on the secretion of salt from the salt glands of Limonium bicolor (a kind of recretohalophyte) seedlings and on the expression of associated genes. A pretreatment with 5 μM melatonin significantly improved the growth of L. bicolor seedlings under 300 mM NaCl. Furthermore, exogenous melatonin significantly increased the dry weight and endogenous melatonin content of L. bicolor. In addition, this treatment reduced the content of Na+ and Cl− in leaves, but increased the K+ content. Both the salt secretion rate of the salt glands and the expression level of genes encoding ion transporters (LbHTK1, LbSOS1, LbPMA, and LbNHX1) and vesicular transport proteins (LbVAMP721, LbVAP27, and LbVAMP12) were significantly increased by exogenous melatonin treatment. These results indicate that melatonin improves the salt tolerance of the recretohalophyte L. bicolor via the upregulation of salt secretion by the salt glands. Conclusions Our results showed that melatonin can upregulate the expression of genes encoding ion transporters and vesicle transport proteins to enhance salt secretion from the salt glands. Combining the results of the current study with previous research, we formulated a novel mechanism by which melatonin increases salt secretion in L. bicolor. Ions in mesophyll cells are transported to the salt glands through ion transporters located at the plasma membrane. After the ions enter the salt glands, they are transported to the collecting chamber adjacent to the secretory pore through vesicle transport and ions transporter and then are secreted from the secretory pore of salt glands, which maintain ionic homeostasis in the cells and alleviate NaCl-induced growth inhibition.

scholarly journals Exogenous melatonin enhances salt secretion from salt glands by upregulating the expression of ion transporter and vesicle transport genes in Limonium bicolor

2020 ◽  
Author(s):  
Junpeng Li ◽  
Fang Yuan ◽  
Yanlu Liu ◽  
Mingjing Zhang ◽  
Yun Liu ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Plant Growth ◽  
Transport Proteins ◽  
Vesicle Transport ◽  
Ion Transporters ◽  
Salt Glands ◽  
Exogenous Melatonin ◽  
Limonium Bicolor ◽  
Genes Encoding ◽  
Salt Secretion

Abstract Background: Salt stress inhibits plant growth and reduces yields. Melatonin is a pleiotropic molecule and can regulate plant growth and alleviate environmental stress in plants. Previous research has focused on the use of melatonin to improve the relatively low salt tolerance of glycophytes by promoting growth and enhancing antioxidant ability. It is unclear whether exogenous melatonin can increase the salt tolerance of halophytes, particularly recretohalophytes, by enhancing salt secretion from the salt glands. Results: We explored the effects of exogenous applications of melatonin on the secretion of salt from the salt glands of Limonium bicolor (a kind of recretohalophyte) seedlings and on the expression of associated genes. 5 μM exogenous melatonin significantly improved the growth of L. bicolor seedlings under 300 mM NaCl. Furthermore, exogenous melatonin significantly increased the dry weight and endogenous melatonin content of L. bicolor . In addition, this treatment reduced the content of Na + and Cl – in leaves, but increased the K + content. Both the salt secretion rate of the salt glands and the expression level of genes encoding ion transporters and vesicular transport proteins were significantly increased by exogenous melatonin treatment. These results indicate that melatonin improves the salt tolerance of the recretohalophyte L. bicolor via the upregulation of salt secretion by the salt glands. Conclusions: Our results showed that melatonin can upregulate the expression of genes encoding ion transporters and vesicle transport proteins to enhance salt secretion from the salt glands. Combining the results of the current study with previous research, we formulated a novel mechanism by which melatonin increases salt secretion in L. bicolor . Ions in mesophyll cells are transported to the salt glands through ion transporters located at the plasma membrane. After the ions enter the salt glands, they are transported to the collecting chamber adjacent to the secretory pore through vesicle transport and ions transporter and then are secreted from the secretory pore of salt glands, which maintain ionic homeostasis in the cells and alleviate NaCl-induced growth inhibition.

scholarly journals Exogenous melatonin enhances salt secretion from salt glands by upregulating the expression of ion transporter and vesicle transport genes in Limonium bicolor

2020 ◽  
Author(s):  
Junpeng Li ◽  
Fang Yuan ◽  
Yanlu Liu ◽  
Mingjing Zhang ◽  
Yun Liu ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Plant Growth ◽  
Transport Proteins ◽  
Vesicle Transport ◽  
Ion Transporters ◽  
Salt Glands ◽  
Exogenous Melatonin ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Salt Secretion

Abstract Background Salt, a common environmental stress factor, inhibits plant growth and reduces yields. Melatonin is a pleiotropic molecule that regulates plant growth and can alleviate environmental stress in plants. All previous research on this topic has focused on the use of melatonin to improve the relatively low salt tolerance of glycophytes by promoting growth and enhancing antioxidant ability. It is unclear whether exogenous melatonin can increase the salt tolerance of halophytes, particularly recretohalophytes, by enhancing salt secretion from the salt glands. Results To examine the mechanisms of melatonin-mediated salt tolerance, we explored the effects of exogenous applications of melatonin on the secretion of salt from the salt glands of Limonium bicolor (a kind of recretohalophyte) seedlings and on the expression of associated genes. A pretreatment with 5 µM melatonin significantly improved the growth of L. bicolor seedlings under 300 mM NaCl. Furthermore, exogenous melatonin significantly increased the dry weight and endogenous melatonin content of L. bicolor. In addition, this treatment reduced the content of Na+ and Cl− in leaves, but increased the K+ content. Both the salt secretion rate of the salt glands and the expression level of genes encoding ion transporters (LbHTK1, LbSOS1, LbPMA, and LbNHX1) and vesicular transport proteins (LbVAMP721, LbVAP27, and LbVAMP12) were significantly increased by exogenous melatonin treatment. These results indicate that melatonin improves the salt tolerance of the recretohalophyte L. bicolor via the upregulation of salt secretion by the salt glands. Conclusions Our results showed that melatonin can upregulate the expression of genes encoding ion transporters and vesicle transport proteins to enhance salt secretion from the salt glands. Combining the results of the current study with previous research, we formulated a novel mechanism by which melatonin increases salt secretion in L. bicolor. Melatonin binds to an unknown receptor located at the PM, which activates the downstream signaling pathway, and then a NO or ROS signaling pathway. This in turn upregulates the expression of genes encoding ion transporters and vesicle transport proteins. The ion transporters transport ions (mainly Na+) into the salt glands, which are subsequently secreted through the participation of various ion transporters and transport vesicles to maintain ionic homeostasis in the cells and alleviate NaCl-induced growth inhibition.

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

Diversity ◽  
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.

First insights into salt tolerance improvement of Stevia by plant growth-promoting Streptomyces species

2019 ◽  
Vol 201 (9) ◽  
pp. 1295-1306 ◽  
Author(s):  
Sahar T. M. Tolba ◽  
Mohamed Ibrahim ◽  
Essam A. M. Amer ◽  
Doaa A. M. Ahmed
Keyword(s):  
Salt Tolerance ◽  
Plant Growth ◽  
Streptomyces Species ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Tolerance Improvement

scholarly journals A novel gene LbHLH from the halophyte Limonium bicolor enhances salt tolerance via reducing root hair development and enhancing osmotic resistance

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xi Wang ◽  
Yingli Zhou ◽  
Yanyu Xu ◽  
Baoshan Wang ◽  
Fang Yuan
Keyword(s):  
Salt Tolerance ◽  
Root Hair ◽  
Salt Gland ◽  
Nacl Stress ◽  
35S Promoter ◽  
Osmotic Resistance ◽  
Salt Glands ◽  
Limonium Bicolor ◽  
Root Hair Development ◽  
Hair Development

Abstract 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.

scholarly journals Salt-tolerance screening in Limonium sinuatum varieties with different flower colors

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaojing Xu ◽  
Yingli Zhou ◽  
Ping Mi ◽  
Baoshan Wang ◽  
Fang Yuan
Keyword(s):  
Salt Tolerance ◽  
Photosynthetic Rate ◽  
Large Scale ◽  
Soluble Sugars ◽  
Dry Weight ◽  
Salt Gland ◽  
Salt Glands ◽  
Chlorophyll Contents ◽  
Relative Water ◽  
Whole Plants

AbstractLimonium sinuatum, a member of Plumbaginaceae commonly known as sea lavender, is widely used as dried flower. Five L. sinuatum varieties with different flower colors (White, Blue, Pink, Yellow, and Purple) are found in saline regions and are widely cultivated in gardens. In the current study, we evaluated the salt tolerance of these varieties under 250 mmol/L NaCl (salt-tolerance threshold) treatment to identify the optimal variety suitable for planting in saline lands. After the measurement of the fresh weight (FW), dry weight (DW), contents of Na+, K+, Ca2+, Cl−, malondialdehyde (MDA), proline, soluble sugars, hydrogen peroxide (H2O2), relative water content, chlorophyll contents, net photosynthetic rate, and osmotic potential of whole plants, the salt-tolerance ability from strongest to weakest is identified as Pink, Yellow, Purple, White, and Blue. Photosynthetic rate was the most reliable and positive indicator of salt tolerance. The density of salt glands showed the greatest increase in Pink under NaCl treatment, indicating that Pink adapts to high-salt levels by enhancing salt gland formation. These results provide a theoretical basis for the large-scale planting of L. sinuatum in saline soils in the future.

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