Free proline, soluble sugars and soluble proteins concentration as affected by salt stress in two sugarcane (Saccharum sp.) cultivars differing in their salt tolerance

The objective of this study was to investigate whether the application of silicon (Si) ameliorates the detrimental effects of salinity stress on sainfoin (Onobrychis viciaefolia). Three-week-old seedlings were exposed to 0 and 100 mmol/L NaCl with or without 1 mmol/L Si for 7 days. The results showed that salinity stress significantly reduced plant growth, shoot chlorophyll content and root K+ concentration, but increased shoot malondialdehyde (MDA) concentration, relative membrane permeability (RMP) and Na+ concentrations of shoot and root in sainfoin compared to the control (no added Si and NaCl). However, the addition of Si significantly enhanced growth, chlorophyll content of shoot, K+ and soluble sugars accumulation in root, while it reduced shoot MDA concentration, RMP and Na+ accumulation of shoot and root in plants under salt stress. It is clear that silicon ameliorates the adverse effects of salt stress on sainfoin by limiting Na+ uptake and enhancing selectivity for K+, and by adjusting the levels of organic solutes. The present study provides physiological insights into understanding the roles of silicon in salt tolerance in sainfoin.

Download Full-text

Transcriptome Profiling of the Salt Stress Response in the Leaves and Roots of Halophytic Eutrema salsugineum

Frontiers in Genetics ◽

10.3389/fgene.2021.770742 ◽

2021 ◽

Vol 12 ◽

Author(s):

Chuanshun Li ◽

Yuting Qi ◽

Chuanzhi Zhao ◽

Xingjun Wang ◽

Quan Zhang

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Soluble Sugars ◽

Lignin Biosynthesis ◽

Sugar Metabolism ◽

Transcriptome Profiling ◽

Salt Stress Response ◽

Salt Shock ◽

Eutrema Salsugineum ◽

Leaves And Roots

Eutrema salsugineum can grow in natural harsh environments; however, the underlying mechanisms for salt tolerance of Eutrema need to be further understood. Herein, the transcriptome profiling of Eutrema leaves and roots exposed to 300 mM NaCl is investigated, and the result emphasized the role of genes involved in lignin biosynthesis, autophagy, peroxisome, and sugar metabolism upon salt stress. Furthermore, the expression of the lignin biosynthesis and autophagy-related genes, as well as 16 random selected genes, was validated by qRT-PCR. Notably, the transcript abundance of a large number of lignin biosynthesis genes such as CCoAOMT, C4H, CCR, CAD, POD, and C3′H in leaves was markedly elevated by salt shock. And the examined lignin content in leaves and roots demonstrated salt stress led to lignin accumulation, which indicated the enhanced lignin level could be an important mechanism for Eutrema responding to salt stress. Additionally, the differentially expressed genes (DEGs) assigned in the autophagy pathway including Vac8, Atg8, and Atg4, as well as DEGs enriched in the peroxisome pathway such as EsPEX7, EsCAT, and EsSOD2, were markedly induced in leaves and/or roots. In sugar metabolism pathways, the transcript levels of most DEGs associated with the synthesis of sucrose, trehalose, raffinose, and xylose were significantly enhanced. Furthermore, the expression of various stress-related transcription factor genes including WRKY, AP2/ERF-ERF, NAC, bZIP, MYB, C2H2, and HSF was strikingly improved. Collectively, the increased expression of biosynthesis genes of lignin and soluble sugars, as well as the genes in the autophagy and peroxisome pathways, suggested that Eutrema encountering salt shock possibly possess a higher capacity to adjust osmotically and facilitate water transport and scavenge reactive oxidative species and oxidative proteins to cope with the salt environment. Thus, this study provides a new insight for exploring the salt tolerance mechanism of halophytic Eutrema and discovering new gene targets for the genetic improvement of crops.

Download Full-text

Exogenous melatonin improves salt stress adaptation of cotton seedlings by regulating active oxygen metabolism

PeerJ ◽

10.7717/peerj.10486 ◽

2020 ◽

Vol 8 ◽

pp. e10486

Author(s):

Dan Jiang ◽

Bin Lu ◽

Liantao Liu ◽

Wenjing Duan ◽

Li Chen ◽

...

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Seedling Growth ◽

Lipid Membrane ◽

Soluble Sugars ◽

Oxygen Metabolism ◽

Membrane Lipid ◽

Biotic And Abiotic Stress ◽

Exogenous Melatonin ◽

Cotton Seedling

Melatonin is a small-molecule indole hormone that plays an important role in participating in biotic and abiotic stress resistance. Melatonin has been confirmed to promote the normal development of plants under adversity stress by mediating physiological regulation mechanisms. However, the mechanisms by which exogenous melatonin mediates salt tolerance via regulation of antioxidant activity and osmosis in cotton seedlings remain largely unknown. In this study, the regulatory effects of melatonin on reactive oxygen species (ROS), the antioxidant system, and osmotic modulators of cotton seedlings were determined under 0–500 µM melatonin treatments with salt stress induced by 150 mM NaCl treatment. Cotton seedlings under salt stress exhibited an inhibition of growth, excessive hydrogen peroxide (H2O2), superoxide anion (O2−), and malondialdehyde (MDA) accumulations in leaves, increased activity levels of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and elevated ascorbic acid (AsA) and glutathione (GSH) content in leaves. However, the content of osmotic regulators (i.e., soluble sugars and proteins) in leaves was reduced under salt stress. This indicates high levels of ROS were produced, and the cell membrane was damaged. Additionally, osmotic regulatory substance content was reduced, resulting in osmotic stress, which seriously affected cotton seedling growth under salt stress. However, exogenous melatonin at different concentrations reduced the contents of H2O2, O2−, and MDA in cotton leaves, increased the activity of antioxidant enzymes and the content of reductive substances (i.e., AsA and GSH), and promoted the accumulation of osmotic regulatory substances in leaves under salt stress. These results suggest that melatonin can inhibit ROS production in cotton seedlings, improve the activity of the antioxidant enzyme system, raise the content of osmotic regulation substances, reduce the level of membrane lipid peroxidation, and protect the integrity of the lipid membrane under salt stress, which reduces damage caused by salt stress to seedlings and effectively enhances inhibition of salt stress on cotton seedling growth. These results indicate that 200 µM melatonin treatment has the best effect on the growth and salt tolerance of cotton seedlings.

Download Full-text

Indole-3-butyric acid application mitigates sodium chloride stress in two cotton cultivars differing in salt tolerance

Acta Agronomica Hungarica ◽

10.1556/aagr.57.2009.4.9 ◽

2009 ◽

Vol 57 (4) ◽

pp. 471-488

Author(s):

A. Tammam

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Food Production ◽

Soluble Sugars ◽

Inhibitory Effect ◽

Total Soluble Sugars ◽

Electrophoretic Patterns ◽

Major Constraint ◽

Sodium Chloride Stress ◽

Tolerance To Salinity

Soil salinity is a major constraint to food production because it limits crop yield and restricts the use of land previously uncultivated. Breeding for tolerance to salinity in crops has usually been limited by the lack of reliable traits for selection. The mechanism of salt tolerance in two cotton ( Gossypium barbadens L.) cultivars (Giza 70 and Giza 88) and their responses to shoot spraying with 200 ppm m −3 IBA were studied.Treatment with IBA not only improved the growth of salt-affected Giza 70, but also increased the growth of this cultivar up to −2.7 MPa and reduced the inhibitory effect of salinity on photosynthetic pigments.This was accompanied by differences in the accumulation of sucrose and total soluble sugars and in the total available carbohydrate and protein contents. IBA ameliorated the inhibitory effect of salinity on growth, increased the carbohydrate and protein contents of both cotton cultivars and markedly retarded the accumulation of proline and glycine betaine. It resulted in the reduction of Na + accumulation in Giza 70, while in Giza 88 it enhanced the absorption and translocation of K + , resulting in higher K + /Na + ratios in the shoots. There were pronounced differences in the electrophoretic patterns of the proteins in both cultivars under salt stress and IBA treatment.

Download Full-text

Changes in the Physiological Parameters ofSbPIP1-Transformed Wheat Plants under Salt Stress

International Journal of Genomics ◽

10.1155/2015/384356 ◽

2015 ◽

Vol 2015 ◽

pp. 1-6 ◽

Cited By ~ 6

Author(s):

G. H. Yu ◽

X. Zhang ◽

H. X. Ma

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Protein Biosynthesis ◽

Soluble Sugar ◽

Soluble Sugars ◽

Early Period ◽

Normal Growth ◽

Physiological Parameters ◽

Salt Stress Response ◽

Mda Content

The SbPIP1 gene is a new member of the plasma membrane major intrinsic gene family cloned from the euhalophyteSalicornia bigeloviiTorr. In order to understand the physiological responses in plants that are mediated by the SbPIP1 gene, SbPIP1-overexpressing wheat lines and WT plants of the wheat cv. Ningmai 13 were treated with salt stress. Several physiological parameters, such as the proline content, the malondialdehyde (MDA) content, and the content of soluble sugars and proteins, were compared between SbPIP1-transformed lines and WT plants under normal growth or salt stress conditions. The results indicate that overexpression of the SbPIP1 gene can increase the accumulation of the osmolyte proline, decrease the MDA content, and enhance the soluble sugar biosynthesis in the early period but has no influence on the regulation of soluble protein biosynthesis in wheat. The results suggest that SbPIP1 contributes to salt tolerance by facilitating the accumulation of the osmolyte proline, increasing the antioxidant response, and increasing the biosynthesis of soluble sugar in the early period. These results indicate SbPIP1 plays an important role in the salt stress response. Overexpression of SbPIP1 might be used to improve the salt tolerance of important crop plants.

Download Full-text

Identification and Characterization of Wheat Germplasm for Salt Tolerance

Plants ◽

10.3390/plants10020268 ◽

2021 ◽

Vol 10 (2) ◽

pp. 268

Author(s):

Xiaoyan Quan ◽

Xiaoli Liang ◽

Hongmei Li ◽

Chunjuan Xie ◽

Wenxing He ◽

...

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Redox Homeostasis ◽

Soluble Sugars ◽

Dry Weight ◽

Limiting Factors ◽

Salt Tolerant ◽

Fresh Weight ◽

Shoot Height ◽

Wheat Genotypes

Salinity is one of the limiting factors of wheat production worldwide. A total of 334 internationally derived wheat genotypes were employed to identify new germplasm resources for salt tolerance breeding. Salt stress caused 39, 49, 58, 55, 21 and 39% reductions in shoot dry weight (SDW), root dry weight (RDW), shoot fresh weight (SFW), root fresh weight (RFW), shoot height (SH) and root length (RL) of wheat, respectively, compared with the control condition at the seedling stage. The wheat genotypes showed a wide genetic and tissue diversity for the determined characteristics in response to salt stress. Finally, 12 wheat genotypes were identified as salt-tolerant through a combination of one-factor (more emphasis on the biomass yield) and multifactor analysis. In general, greater accumulation of osmotic substances, efficient use of soluble sugars, lower Na+/K+ and a higher-efficiency antioxidative system contribute to better growth in the tolerant genotypes under salt stress. In other words, the tolerant genotypes are capable of maintaining stable osmotic potential and ion and redox homeostasis and providing more energy and materials for root growth. The identified genotypes with higher salt tolerance could be useful for developing new salt-tolerant wheat cultivars as well as in further studies to underline the genetic mechanisms of salt tolerance in wheat.

Download Full-text

Comparative Analysis of Physiological, Enzymatic, and Transcriptomic Responses Revealed Mechanisms of Salt Tolerance and Recovery in Tritipyrum

Frontiers in Plant Science ◽

10.3389/fpls.2021.800081 ◽

2022 ◽

Vol 12 ◽

Author(s):

Ze Peng ◽

Yiqin Wang ◽

Guangdong Geng ◽

Rui Yang ◽

Zhifen Yang ◽

...

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Regulatory Networks ◽

Soluble Sugars ◽

Inhibitory Effect ◽

Salt Tolerant ◽

Transcriptional Regulatory Networks ◽

Transcriptional Regulatory ◽

Transcriptomic Responses ◽

Thinopyrum Elongatum

Salt stress results in the severe decline of yield and quality in wheat. In the present study, salt-tolerant Tritipyrum (“Y1805”) and salt-sensitive wheat “Chinese Spring” (“CS”) were selected from 121 wheat germplasms to test their physiological, antioxidant enzyme, and transcriptomic responses and mechanisms against salt stress and recovery. 56 chromosomes were identified in “Y1805” that comprised A, B, and D chromosomes from wheat parent and E chromosomes from Thinopyrum elongatum, adding to salt-tolerant trait. Salt stress had a greater inhibitory effect on roots than on shoots, and “Y1805” demonstrated stronger salt tolerance than “CS.” Compared with “CS,” the activities of superoxide dismutase and catalase in “Y1805” significantly increased under salt stress. “Y1805” could synthesize more proline and soluble sugars than “CS.” Both the net photosynthetic rate and chlorophyll a/b were affected by salt stress, though the level of damage in “Y1805” was significantly less than in “CS.” Transcriptome analysis showed that the differences in the transcriptional regulatory networks of “Y1805” were not only in response to salt stress but also in recovery. The functions of many salt-responsive differentially expressed genes were correlated closely with the pathways “peroxisome,” “arginine and proline metabolism,” “starch and sucrose metabolism,” “chlorophyll and porphyrin metabolism,” and “photosynthesis.”

Download Full-text

Ectopic Expression of a Thellungiella salsuginea Aquaporin Gene, TsPIP1;1, Increased the Salt Tolerance of Rice

International Journal of Molecular Sciences ◽

10.3390/ijms19082229 ◽

2018 ◽

Vol 19 (8) ◽

pp. 2229 ◽

Cited By ~ 8

Author(s):

Wei Li ◽

Xiao-Jing Qiang ◽

Xiao-Ri Han ◽

Lin-Lin Jiang ◽

Shu-Hui Zhang ◽

...

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Small Molecules ◽

Differentially Expressed Genes ◽

Osmotic Potential ◽

Soluble Sugars ◽

Ectopic Expression ◽

Differentially Expressed ◽

Thellungiella Salsuginea ◽

Transgenic Lines

Aquaporins play important regulatory roles in the transport of water and small molecules in plants. In this study, a Thellungiella salsuginea TsPIP1;1 aquaporin was transformed into Kitaake rice, and three transgenic lines were evaluated by profiling the changes of the physiological metabolism, osmotic potential, and differentially expressed genes under salt stress. The TsPIP1;1 protein contains six transmembrane domains and is localized in the cytoplasm membrane. Overexpression of the TsPIP1;1 gene not only increased the accumulation of prolines, soluble sugars and chlorophyll, but also lowered the osmotic potential and malondialdehyde content in rice under salt stress, and alleviated the amount of salt damage done to rice organs by regulating the distribution of Na/K ions, thereby promoting photosynthetic rates. Transcriptome sequencing confirmed that the differentially expressed genes that are up-regulated in rice positively respond to salt stimulus, the photosynthetic metabolic process, and the accumulation profiles of small molecules and Na/K ions. The co-expressed Rubisco and LHCA4 genes in rice were remarkably up-regulated under salt stress. This data suggests that overexpression of the TsPIP1;1 gene is involved in the regulation of water transport, the accumulation of Na/K ions, and the translocation of photosynthetic metabolites, thus conferring enhanced salt tolerance to rice.

Download Full-text

Changes in physiological indicators associated with salt tolerance in two contrasting cashew rootstocks

Brazilian Journal of Plant Physiology ◽

10.1590/s1677-04202008000100006 ◽

2008 ◽

Vol 20 (1) ◽

pp. 51-59 ◽

Cited By ~ 22

Author(s):

Sérgio L. Ferreira-Silva ◽

Joaquim A.G. Silveira ◽

Eduardo L. Voigt ◽

Lucilene S.P. Soares ◽

Ricardo A. Viégas

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Soluble Sugar ◽

Soluble Sugars ◽

Membrane Damage ◽

Significant Drop ◽

Nacl Salinity ◽

Physiological Indicators ◽

Physiological Variables ◽

Leaf Osmotic Potential

In order to identify salt tolerance indicators, several physiological variables were evaluated in two contrasting cashew (Anacardium occidentale L.) rootstocks in response to salt stress. The tolerant CCP 09 genotype showed better growth performance after two weeks under a large range of NaCl salinity (50, 100, 150 and 200 mM). The NaCl treatments induced a significant drop in transpiration as a consequence of an increased stomatal resistance in both genotypes. No significant differences in Na+, Cl, and K+ concentrations were found in both roots and leaves regardless of rootstocks. The tolerant genotype exhibited lower relative water content and less negative leaf osmotic potential as compared with the sensitive genotype and, therefore, these variables could not be related to salt tolerance. Salt stress caused more significant changes in protein and amino acid concentrations in roots than in leaves. Among the physiological indicators, leaf membrane damage was closely associated with the differences in salt tolerance between the two cashew genotypes. Furthermore, under NaCl salinity the tolerant rootstock showed greater ability to accumulate compatible organic solutes (amino acids, proline and soluble sugars) in leaves in addition to maintaining the soluble sugar concentration in roots as compared with the sensitive rootstock.

Download Full-text

Morpho-Physiological, Biochemical, and Genetic Responses to Salinity in Medicago truncatula

Plants ◽

10.3390/plants10040808 ◽

2021 ◽

Vol 10 (4) ◽

pp. 808

Author(s):

Sabrine Hdira ◽

Loua Haddoudi ◽

Mohsen Hanana ◽

Irene Romero ◽

Asma Mahjoub ◽

...

Keyword(s):

Salt Stress ◽

Medicago Truncatula ◽

Plant Biomass ◽

Soluble Sugars ◽

Functional Characterization ◽

Soluble Proteins ◽

Pcr Analysis ◽

Plant Weight ◽

Erf Family ◽

Genetic Responses

We used an integrated morpho-physiological, biochemical, and genetic approach to investigate the salt responses of four lines (TN1.11, TN6.18, JA17, and A10) of Medicago truncatula. Results showed that TN1.11 exhibited a high tolerance to salinity, compared with the other lines, recording a salinity induced an increase in soluble sugars and soluble proteins, a slight decrease in malondialdehyde (MDA) accumulation, and less reduction in plant biomass. TN6.18 was the most susceptible to salinity as it showed less plant weight, had elevated levels of MDA, and lower levels of soluble sugars and soluble proteins under salt stress. As transcription factors of the APETALA2/ethylene responsive factor (AP2/ERF) family play important roles in plant growth, development, and responses to biotic and abiotic stresses, we performed a functional characterization of MtERF1 gene. Real-time PCR analysis revealed that MtERF1 is mainly expressed in roots and is inducible by NaCl and low temperature. Additionally, under salt stress, a greater increase in the expression of MtERF1 was found in TN1.11 plants than that in TN6.18. Therefore, the MtERF1 pattern of expression may provide a useful marker for discriminating among lines of M. truncatula and can be used as a tool in breeding programs aiming at obtaining Medicago lines with improved salt tolerance.

Download Full-text