scholarly journals The Role of Betacyanins in Plant Salt Tolerance

2021 ◽  
Author(s):  
◽  
Tanja Karl
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
High Light ◽  
Crop Plants ◽  
Ion Flux ◽  
Mesophyll Cells ◽  
Leaf Discs ◽  
Green Leaves ◽  
Flux Response ◽  
Salt Secretion

<p>Soil salinity is a major threat to future food stability. Almost 20% of irrigated land is currently too saline to grow traditional crops. Moreover, rising sea levels, scarcity of fresh water, and more intense and prolonged periods of drought are exacerbating the problem. Saline soils severely reduce yields of most crop plants. By contrast, halophytes, which naturally thrive on saline substrates, have a variety of mechanisms to tolerate both the osmotic and cytotoxic components of salt stress. There has been concerted scientific effort worldwide to understand these mechanisms, and to introduce genes that may increase salinity tolerance in crop plants. Many halophytes in the Caryophyllales are pigmented red owing to a tyrosine-derived alkaloid called betacyanin. Recent studies using Disphyma australe, a succulent halophyte common on coastal dunes and rocky outcrops throughout New Zealand, have indicated a role for betacyanins in salinity tolerance. This thesis focuses on how the mechanism through which betacyanins might affect salt tolerance mechanisms in D. australe and whether the putative benefits of betacyanins on salt tolerance might be transferred to naturally non-betacyanic plants. Effects of betacyanin on Na+ distribution in salt-stressed leaves of red and green morphs of D. australe were studied using fluorescence microscopy, cryo-scanning electron microscopy with energy dispersive X-ray analysis, and atomic absorption spectrometry (AAS). In betacyanic leaves Na+ accumulated in the epidermis, while in green leaves Na+ was distributed more evenly across the epidermis and mesophyll. Both leaf types had similar numbers of salt glands, but salt secretion rates were higher in red than in green leaves. Betacyanic leaves under salt stress were able to maintain relatively high K+/ Na+ ratios, essential for many metabolic processes, while the leaves of green plants were not. Leaf sections stained with fluorescein diacetate and propidium iodide showed that mesophyll viability decreased significantly in green leaves under salt stress, while there was almost no decrease in mesophyll viability in the presence of betacyanins. Thus, betacyanic leaves might protect the photosynthetically active mesophyll from cytotoxic effects of Na+ by accumulating Na+ in the epidermis instead of the mesophyll. This in turn leads to more efficient salt secretion and higher K+/ Na+ ratios in the mesophyll, resulting in increased mesophyll viability under salt stress. Effects of high apoplastic sodium concentrations on ion flux kinetics in mesophyll tissue was studied using the non-invasive microelectrode ion flux estimation technique. Mesophyll cells of both betacyanic and green leaves showed a highly unusual K+ flux response; most crop plants leak K+ out of cells upon salt stress, but D. australe and the native Australian Disphyma crassifolium both showed K+ influx upon salt stress. Actively taking up K+ from the apoplast to maintain a high cytosolic K+/ Na+ ratio during salt stress might be an entirely new mechanism to combat the cytotoxic stress component of salinity stress in these halophytes. The salt induced K+ uptake was dependent on the presence of Cl- and Cl- was also taken up into mesophyll cells upon salt stress. Taking up both cations and anions at the same time could avoid membrane depolarisation. Voltage-gated channels, which are involved in the salt induced K+ efflux in glycophytes, would not be activated and this could be a new mechanism to avoid a K+ leak during salt stress. To test whether the beneficial effect of betacyanin production on salt tolerance could be transferred to naturally non-betacyanic plants, transgenic betacyanin-over-expression (BtOE) mutants of Nicotiana tabacum were generated by our colleagues at Plant & Food Research Ltd. Betacyanins in leaf discs of N. tabacum were associated with decreased chlorophyll degradation upon high light and high salt stress. Additionally, the decline in maximum quantum efficiency of PSII after high light and salt treatment was significantly greater in green than in betacyanic leaves. Placing a polycarbonate filter with a similar absorption spectrum to betacyanin over green N. tabacum leaf discs had a similar effect to the presence of betacyanin. Thus, betacyanins probably have a photoprotective effect in N. tabacum, which is essential as both high light and salinity can impair photosynthesis. To assess if the salt tolerance enhancing effect of betacyanin production observed in the leaf discs also occurs in whole N. tabacum plants, the ability to recover from exposure to saturating light was assessed. Betacyanic plants were able to fully recover quicker after exposure to saturation light than green leaves. This research shows that the presence of betacyanins during salt stress correlates with an altered Na+ distribution in leaf tissues and a higher salt secretion rate, which contributed to higher mesophyll viability. Moreover, a completely new ion flux response to salt stress was observed in D. australe and D. crassifolium. The observed salt induced K+ uptake into the mesophyll cells during salt stress might be an entirely new mechanism, to maintain a high K+/ Na+ ratio in the cytosol and avoid the cytotoxic effects of Na+ in photosynthetically active tissue. The beneficial effects of betacyanins could also be transferred to non-betacyanic species, by introducing betacyanin production. These results strongly suggest that betacyanins play a role in salt tolerance in halophytes and might be a valuable resource in increasing the salt tolerance of naturally non-betacyanic crop plants.</p>

scholarly journals The Role of Betacyanins in Plant Salt Tolerance

2021 ◽  
Author(s):  
◽  
Tanja Karl
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
High Light ◽  
Crop Plants ◽  
Ion Flux ◽  
Mesophyll Cells ◽  
Leaf Discs ◽  
Green Leaves ◽  
Flux Response ◽  
Salt Secretion

<p>Soil salinity is a major threat to future food stability. Almost 20% of irrigated land is currently too saline to grow traditional crops. Moreover, rising sea levels, scarcity of fresh water, and more intense and prolonged periods of drought are exacerbating the problem. Saline soils severely reduce yields of most crop plants. By contrast, halophytes, which naturally thrive on saline substrates, have a variety of mechanisms to tolerate both the osmotic and cytotoxic components of salt stress. There has been concerted scientific effort worldwide to understand these mechanisms, and to introduce genes that may increase salinity tolerance in crop plants. Many halophytes in the Caryophyllales are pigmented red owing to a tyrosine-derived alkaloid called betacyanin. Recent studies using Disphyma australe, a succulent halophyte common on coastal dunes and rocky outcrops throughout New Zealand, have indicated a role for betacyanins in salinity tolerance. This thesis focuses on how the mechanism through which betacyanins might affect salt tolerance mechanisms in D. australe and whether the putative benefits of betacyanins on salt tolerance might be transferred to naturally non-betacyanic plants. Effects of betacyanin on Na+ distribution in salt-stressed leaves of red and green morphs of D. australe were studied using fluorescence microscopy, cryo-scanning electron microscopy with energy dispersive X-ray analysis, and atomic absorption spectrometry (AAS). In betacyanic leaves Na+ accumulated in the epidermis, while in green leaves Na+ was distributed more evenly across the epidermis and mesophyll. Both leaf types had similar numbers of salt glands, but salt secretion rates were higher in red than in green leaves. Betacyanic leaves under salt stress were able to maintain relatively high K+/ Na+ ratios, essential for many metabolic processes, while the leaves of green plants were not. Leaf sections stained with fluorescein diacetate and propidium iodide showed that mesophyll viability decreased significantly in green leaves under salt stress, while there was almost no decrease in mesophyll viability in the presence of betacyanins. Thus, betacyanic leaves might protect the photosynthetically active mesophyll from cytotoxic effects of Na+ by accumulating Na+ in the epidermis instead of the mesophyll. This in turn leads to more efficient salt secretion and higher K+/ Na+ ratios in the mesophyll, resulting in increased mesophyll viability under salt stress. Effects of high apoplastic sodium concentrations on ion flux kinetics in mesophyll tissue was studied using the non-invasive microelectrode ion flux estimation technique. Mesophyll cells of both betacyanic and green leaves showed a highly unusual K+ flux response; most crop plants leak K+ out of cells upon salt stress, but D. australe and the native Australian Disphyma crassifolium both showed K+ influx upon salt stress. Actively taking up K+ from the apoplast to maintain a high cytosolic K+/ Na+ ratio during salt stress might be an entirely new mechanism to combat the cytotoxic stress component of salinity stress in these halophytes. The salt induced K+ uptake was dependent on the presence of Cl- and Cl- was also taken up into mesophyll cells upon salt stress. Taking up both cations and anions at the same time could avoid membrane depolarisation. Voltage-gated channels, which are involved in the salt induced K+ efflux in glycophytes, would not be activated and this could be a new mechanism to avoid a K+ leak during salt stress. To test whether the beneficial effect of betacyanin production on salt tolerance could be transferred to naturally non-betacyanic plants, transgenic betacyanin-over-expression (BtOE) mutants of Nicotiana tabacum were generated by our colleagues at Plant & Food Research Ltd. Betacyanins in leaf discs of N. tabacum were associated with decreased chlorophyll degradation upon high light and high salt stress. Additionally, the decline in maximum quantum efficiency of PSII after high light and salt treatment was significantly greater in green than in betacyanic leaves. Placing a polycarbonate filter with a similar absorption spectrum to betacyanin over green N. tabacum leaf discs had a similar effect to the presence of betacyanin. Thus, betacyanins probably have a photoprotective effect in N. tabacum, which is essential as both high light and salinity can impair photosynthesis. To assess if the salt tolerance enhancing effect of betacyanin production observed in the leaf discs also occurs in whole N. tabacum plants, the ability to recover from exposure to saturating light was assessed. Betacyanic plants were able to fully recover quicker after exposure to saturation light than green leaves. This research shows that the presence of betacyanins during salt stress correlates with an altered Na+ distribution in leaf tissues and a higher salt secretion rate, which contributed to higher mesophyll viability. Moreover, a completely new ion flux response to salt stress was observed in D. australe and D. crassifolium. The observed salt induced K+ uptake into the mesophyll cells during salt stress might be an entirely new mechanism, to maintain a high K+/ Na+ ratio in the cytosol and avoid the cytotoxic effects of Na+ in photosynthetically active tissue. The beneficial effects of betacyanins could also be transferred to non-betacyanic species, by introducing betacyanin production. These results strongly suggest that betacyanins play a role in salt tolerance in halophytes and might be a valuable resource in increasing the salt tolerance of naturally non-betacyanic crop plants.</p>

scholarly journals Functional role of betalains in Disphyma australe under salinty stress

2021 ◽  
Author(s):  
◽  
Gagandeep Jain
Keyword(s):  
Salt Stress ◽  
Salinity Stress ◽  
High Light ◽  
Direct Result ◽  
Quantum Yields ◽  
Salinity Treatment ◽  
Green Leaves ◽  
Mesophyll Tissue ◽  
Abiotic Stressors

<p>Foliar betalainic plants are commonly found in dry and exposed environments such as deserts and sandbanks. This marginal habitat has led many researchers to hypothesise that foliar betalains provide tolerance to abiotic stressors such as strong light, drought, salinity and low temperatures. Among these abiotic stressors, soil salinity is a major problem for agriculture affecting approximately 20% of the irrigated lands worldwide. Betacyanins may provide functional significance to plants under salt stress although this has not been unequivocally demonstrated. The purpose of this thesis is to add knowledge of the various roles of foliar betacyanins in plants under salt stress. For that, a series of experiments were performed on Disphyma australe, which is a betacyanic halophyte with two distinct colour morphs in vegetative shoots.  In chapter two, I aimed to find the effect of salinity stress on betacyanin pigmentation in D. australe and it was hypothesised that betacyanic morphs are physiologically more tolerant to salinity stress than acyanic morphs. Within a coastal population of red and green morphs of D. australe, betacyanin pigmentation in red morphs was a direct result of high salt and high light exposure. Betacyanic morphs were physiologically more tolerant to salt stress as they showed greater maximum CO₂ assimilation rates, water use efficiencies, photochemical quantum yields and photochemical quenching than acyanic morphs. Contrary to this, the green morphs, although possessing the ability to synthesise betalains in flower petals, did not produce betalains in vegetative shoots in response to salt stress. Moreover, green morphs, in terms of leaf photosynthesis, performed poorly under salinity stress.  In chapter three I further investigated the physiological benefit of betacyanin accumulation in D. australe. I postulated that betacyanin in the leaves of D. australe can protect the salt stressed chloroplasts from harmful excessive light by absorbing significant amount of radiation. To test this, a novel experimental approach was used; the key biosynthetic step for betacyanin synthesis was identified, which was deficient in vegetative shoots of the green morphs. By supplying the product of this enzymatic reaction, L-DOPA, betacyanin synthesis could be induced in the leaves of green morphs. This model system was used to compare the photoprotective responses of red vs. green leaves. The L-DOPA induced betacyanic leaves showed similar responses (such as smaller reductions and faster recoveries of PSII and less H₂O₂ production than in the green leaves) to naturally betacyanic leaves when exposed to high light and salinity. The differences in photoinhibition between red and green leaves were attributed to the light absorbing properties of betacyanins. L-DOPA treated and naturally red leaves showed lower photoinactivation than green leaves when exposed to white or green light, although not when exposed to monochromatic (red) light.  In chapter four, I used a similar experimental model to that in the third chapter and showed that other than photoprotection, betacyanins in leaves may be involved in salt tolerance by enhancing toxic ion (such as Na⁺) sequestration in betacyanic epidermal cells, storing Na⁺ away from sensitive mesophyll tissue. The Na⁺ localization between red and green leaves was compared after salinity treatment by using a sodium binding stain (SBFI-AM) and Cryo-SEM analysis. L-DOPA treated and natural red leaves sequestered Na⁺ ions to the epidermal cell layer. In contrast, green leaves retained Na⁺ in the mesophyll tissue, which suggested that red leaves were better equipped to tolerate salt-specific effects. Therefore, betacyanic plants were more tolerant to applied salinity stress and showed relatively higher growth rates than green morphs.  The findings of this thesis provide a significant contribution to our understanding of the role of betacyanins in plants under salinity stress. My data suggest that the multi-faceted properties of betacyanins (such as their photoprotective function, and their involvement in sequestration of toxic ions) clearly provide a benefit to plants under salinity stress.</p>

scholarly journals Insights into the Physiological and Biochemical Impacts of Salt Stress on Plant Growth and Development

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 938 ◽  
Author(s):  
Muhammad Adnan Shahid ◽  
Ali Sarkhosh ◽  
Naeem Khan ◽  
Rashad Mukhtar Balal ◽  
Shahid Ali ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Salinity Tolerance ◽  
Antioxidant Activities ◽  
Soil Salinization ◽  
Crop Plants ◽  
Cellular Damage ◽  
Relative Water ◽  
Ionic Imbalance ◽  
Highly Correlated

Climate change is causing soil salinization, resulting in crop losses throughout the world. The ability of plants to tolerate salt stress is determined by multiple biochemical and molecular pathways. Here we discuss physiological, biochemical, and cellular modulations in plants in response to salt stress. Knowledge of these modulations can assist in assessing salt tolerance potential and the mechanisms underlying salinity tolerance in plants. Salinity-induced cellular damage is highly correlated with generation of reactive oxygen species, ionic imbalance, osmotic damage, and reduced relative water content. Accelerated antioxidant activities and osmotic adjustment by the formation of organic and inorganic osmolytes are significant and effective salinity tolerance mechanisms for crop plants. In addition, polyamines improve salt tolerance by regulating various physiological mechanisms, including rhizogenesis, somatic embryogenesis, maintenance of cell pH, and ionic homeostasis. This research project focuses on three strategies to augment salinity tolerance capacity in agricultural crops: salinity-induced alterations in signaling pathways; signaling of phytohormones, ion channels, and biosensors; and expression of ion transporter genes in crop plants (especially in comparison to halophytes).

scholarly journals Artificial Selection on Microbiomes To Breed Microbiomes That Confer Salt Tolerance to Plants

mSystems ◽  
2021 ◽  
Author(s):  
Ulrich G. Mueller ◽  
Thomas E. Juenger ◽  
Melissa R. Kardish ◽  
Alexis L. Carlson ◽  
Kathleen M. Burns ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Seed Production ◽  
Artificial Selection ◽  
Agricultural Productivity ◽  
Crop Plants ◽  
Experimental Protocol

We developed an experimental protocol that improves earlier methods of artificial selection on microbiomes and then tested the efficacy of our protocol to breed root-associated bacterial microbiomes that confer salt tolerance to a plant. Salt stress limits growth and seed production of crop plants, and artificially selected microbiomes conferring salt tolerance may ultimately help improve agricultural productivity.

scholarly journals Functional role of betalains in Disphyma australe under salinty stress

2021 ◽  
Author(s):  
◽  
Gagandeep Jain
Keyword(s):  
Salt Stress ◽  
Salinity Stress ◽  
High Light ◽  
Direct Result ◽  
Quantum Yields ◽  
Salinity Treatment ◽  
Green Leaves ◽  
Mesophyll Tissue ◽  
Abiotic Stressors

<p>Foliar betalainic plants are commonly found in dry and exposed environments such as deserts and sandbanks. This marginal habitat has led many researchers to hypothesise that foliar betalains provide tolerance to abiotic stressors such as strong light, drought, salinity and low temperatures. Among these abiotic stressors, soil salinity is a major problem for agriculture affecting approximately 20% of the irrigated lands worldwide. Betacyanins may provide functional significance to plants under salt stress although this has not been unequivocally demonstrated. The purpose of this thesis is to add knowledge of the various roles of foliar betacyanins in plants under salt stress. For that, a series of experiments were performed on Disphyma australe, which is a betacyanic halophyte with two distinct colour morphs in vegetative shoots.  In chapter two, I aimed to find the effect of salinity stress on betacyanin pigmentation in D. australe and it was hypothesised that betacyanic morphs are physiologically more tolerant to salinity stress than acyanic morphs. Within a coastal population of red and green morphs of D. australe, betacyanin pigmentation in red morphs was a direct result of high salt and high light exposure. Betacyanic morphs were physiologically more tolerant to salt stress as they showed greater maximum CO₂ assimilation rates, water use efficiencies, photochemical quantum yields and photochemical quenching than acyanic morphs. Contrary to this, the green morphs, although possessing the ability to synthesise betalains in flower petals, did not produce betalains in vegetative shoots in response to salt stress. Moreover, green morphs, in terms of leaf photosynthesis, performed poorly under salinity stress.  In chapter three I further investigated the physiological benefit of betacyanin accumulation in D. australe. I postulated that betacyanin in the leaves of D. australe can protect the salt stressed chloroplasts from harmful excessive light by absorbing significant amount of radiation. To test this, a novel experimental approach was used; the key biosynthetic step for betacyanin synthesis was identified, which was deficient in vegetative shoots of the green morphs. By supplying the product of this enzymatic reaction, L-DOPA, betacyanin synthesis could be induced in the leaves of green morphs. This model system was used to compare the photoprotective responses of red vs. green leaves. The L-DOPA induced betacyanic leaves showed similar responses (such as smaller reductions and faster recoveries of PSII and less H₂O₂ production than in the green leaves) to naturally betacyanic leaves when exposed to high light and salinity. The differences in photoinhibition between red and green leaves were attributed to the light absorbing properties of betacyanins. L-DOPA treated and naturally red leaves showed lower photoinactivation than green leaves when exposed to white or green light, although not when exposed to monochromatic (red) light.  In chapter four, I used a similar experimental model to that in the third chapter and showed that other than photoprotection, betacyanins in leaves may be involved in salt tolerance by enhancing toxic ion (such as Na⁺) sequestration in betacyanic epidermal cells, storing Na⁺ away from sensitive mesophyll tissue. The Na⁺ localization between red and green leaves was compared after salinity treatment by using a sodium binding stain (SBFI-AM) and Cryo-SEM analysis. L-DOPA treated and natural red leaves sequestered Na⁺ ions to the epidermal cell layer. In contrast, green leaves retained Na⁺ in the mesophyll tissue, which suggested that red leaves were better equipped to tolerate salt-specific effects. Therefore, betacyanic plants were more tolerant to applied salinity stress and showed relatively higher growth rates than green morphs.  The findings of this thesis provide a significant contribution to our understanding of the role of betacyanins in plants under salinity stress. My data suggest that the multi-faceted properties of betacyanins (such as their photoprotective function, and their involvement in sequestration of toxic ions) clearly provide a benefit to plants under salinity stress.</p>

Salt tolerance of Glycyrrhiza inflata seedlings in Xinjiang and its ion response to salt stress

2014 ◽  
Vol 37 (9) ◽  
pp. 839-850 ◽  
Author(s):  
Jia-Hui LU ◽  
Xin LÜ ◽  
Yong-Chao LIANG ◽  
Hai-Rong LIN
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Glycyrrhiza Inflata

Genetic Potential for Salt Tolerance During Germination in Lycopersicon Species

HortScience ◽  
1997 ◽  
Vol 32 (2) ◽  
pp. 296-300 ◽  
Author(s):  
M.R. Foolad ◽  
G.Y. Lin
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Genotypic Variation ◽  
Control Treatment ◽  
Molar Ratio ◽  
Wild Accession ◽  
Salt Tolerant ◽  
Plant Introductions ◽  
Genetic Potential ◽  
Stress Levels

Seed of 42 wild accessions (Plant Introductions) of Lycopersicon pimpinellifolium Jusl., 11 cultigens (cultivated accessions) of L. esculentum Mill., and three control genotypes [LA716 (a salt-tolerant wild accession of L. pennellii Corr.), PI 174263 (a salt-tolerant cultigen), and UCT5 (a salt-sensitive breeding line)] were evaluated for germination in either 0 mm (control) or 100 mm synthetic sea salt (SSS, Na+/Ca2+ molar ratio equal to 5). Germination time increased in response to salt-stress in all genotypes, however, genotypic variation was observed. One accession of L. pimpinellifolium, LA1578, germinated as rapidly as LA716, and both germinated more rapidly than any other genotype under salt-stress. Ten accessions of L. pimpinellifolium germinated more rapidly than PI 174263 and 35 accessions germinated more rapidly than UCT5 under salt-stress. The results indicate a strong genetic potential for salt tolerance during germination within L. pimpinellifolium. Across genotypes, germination under salt-stress was positively correlated (r = 0.62, P < 0.01) with germination in the control treatment. The stability of germination response at diverse salt-stress levels was determined by evaluating germination of a subset of wild, cultivated accessions and the three control genotypes at 75, 150, and 200 mm SSS. Seeds that germinated rapidly at 75 mm also germinated rapidly at 150 mm salt. A strong correlation (r = 0.90, P < 0.01) existed between the speed of germination at these two salt-stress levels. At 200 mm salt, most accessions (76%) did not reach 50% germination by 38 days, demonstrating limited genetic potential within Lycopersicon for salt tolerance during germination at this high salinity.

scholarly journals Characterization of Interactions between the Soybean Salt-Stress Responsive Membrane-Intrinsic Proteins GmPIP1 and GmPIP2

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1312
Author(s):  
Jia Liu ◽  
Weicong Qi ◽  
Haiying Lu ◽  
Hongbo Shao ◽  
Dayong Zhang
Keyword(s):  
Plasma Membrane ◽  
Salt Stress ◽  
Salt Tolerance ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Gene Expression Profiles ◽  
Early Gene ◽  
Plant Responses ◽  
Constitutive Overexpression ◽  
Important Trait

Salt tolerance is an important trait in soybean cultivation and breeding. Plant responses to salt stress include physiological and biochemical changes that affect the movement of water across the plasma membrane. Plasma membrane intrinsic proteins (PIPs) localize to the plasma membrane and regulate the water and solutes flow. In this study, quantitative real-time PCR and yeast two-hybridization were engaged to analyze the early gene expression profiles and interactions of a set of soybean PIPs (GmPIPs) in response to salt stress. A total of 20 GmPIPs-encoding genes had varied expression profiles after salt stress. Among them, 13 genes exhibited a downregulated expression pattern, including GmPIP1;6, the constitutive overexpression of which could improve soybean salt tolerance, and its close homologs GmPIP1;7 and 1;5. Three genes showed upregulated patterns, including the GmPIP1;6 close homolog GmPIP1;4, when four genes with earlier increased and then decreased expression patterns. GmPIP1;5 and GmPIP1;6 could both physically interact strongly with GmPIP2;2, GmPIP2;4, GmPIP2;6, GmPIP2;8, GmPIP2;9, GmPIP2;11, and GmPIP2;13. Definite interactions between GmPIP1;6 and GmPIP1;7 were detected and GmPIP2;9 performed homo-interaction. The interactions of GmPIP1;5 with GmPIP2;11 and 2;13, GmPIP1;6 with GmPIP2;9, 2;11 and GmPIP2;13, and GmPIP2;9 with itself were strengthened upon salt stress rather than osmotic stress. Taken together, we inferred that GmPIP1 type and GmPIP2 type could associate with each other to synergistically function in the plant cell; a salt-stress environment could promote part of their interactions. This result provided new clues to further understand the soybean PIP–isoform interactions, which lead to potentially functional homo- and heterotetramers for salt tolerance.

scholarly journals Comprehensive transcriptome and metabolome profiling reveal metabolic mechanisms of Nitraria sibirica Pall. to salt stress

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Huanyong Li ◽  
Xiaoqian Tang ◽  
Xiuyan Yang ◽  
Huaxin Zhang
Keyword(s):  
Salt Stress ◽  
Amino Acid ◽  
Salt Tolerance ◽  
Metabolic Pathways ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Sulfur Metabolism ◽  
Enrichment Analysis ◽  
Extracellular Region ◽  
Nitraria Sibirica

AbstractNitraria sibirica Pall., a typical halophyte that can survive under extreme drought conditions and in saline-alkali environments, exhibits strong salt tolerance and environmental adaptability. Understanding the mechanism of molecular and physiological metabolic response to salt stress of plant will better promote the cultivation and use of halophytes. To explore the mechanism of molecular and physiological metabolic of N. sibirica response to salt stress, two-month-old seedlings were treated with 0, 100, and 400 mM NaCl. The results showed that the differentially expressed genes between 100 and 400 mmol L−1 NaCl and unsalted treatment showed significant enrichment in GO terms such as binding, cell wall, extemal encapsulating structure, extracellular region and nucleotide binding. KEGG enrichment analysis found that NaCl treatment had a significant effect on the metabolic pathways in N. sibirica leaves, which mainly including plant-pathogen interaction, amino acid metabolism of the beta alanine, arginine, proline and glycine metabolism, carbon metabolism of glycolysis, gluconeogenesis, galactose, starch and sucrose metabolism, plant hormone signal transduction and spliceosome. Metabolomics analysis found that the differential metabolites between the unsalted treatment and the NaCl treatment are mainly amino acids (proline, aspartic acid, methionine, etc.), organic acids (oxaloacetic acid, fumaric acid, nicotinic acid, etc.) and polyhydric alcohols (inositol, ribitol, etc.), etc. KEGG annotation and enrichment analysis showed that 100 mmol L−1 NaCl treatment had a greater effect on the sulfur metabolism, cysteine and methionine metabolism in N. sibirica leaves, while various amino acid metabolism, TCA cycle, photosynthetic carbon fixation and sulfur metabolism and other metabolic pathways have been significantly affected by 400 mmol L−1 NaCl treatment. Correlation analysis of differential genes in transcriptome and differential metabolites in metabolome have found that the genes of AMY2, BAM1, GPAT3, ASP1, CML38 and RPL4 and the metabolites of L-cysteine, proline, 4-aminobutyric acid and oxaloacetate played an important role in N. sibirica salt tolerance control. This is a further improvement of the salt tolerance mechanism of N. sibirica, and it will provide a theoretical basis and technical support for treatment of saline-alkali soil and the cultivation of halophytes.

scholarly journals OsNAC45 is Involved in ABA Response and Salt Tolerance in Rice

Rice ◽  
2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Xiang Zhang ◽  
Yan Long ◽  
Jingjing Huang ◽  
Jixing Xia
Keyword(s):  
Transcription Factors ◽  
Salt Stress ◽  
Salt Tolerance ◽  
Stress Responses ◽  
Crop Yields ◽  
Plant Stress ◽  
Root Cells ◽  
Nac Transcription Factors ◽  
Rice Plants ◽  
Plant Stress Responses

Abstract Background Salt stress threatens crop yields all over the world. Many NAC transcription factors have been reported to be involved in different abiotic stress responses, but it remains unclear how loss of these transcription factors alters the transcriptomes of plants. Previous reports have demonstrated that overexpression of OsNAC45 enhances salt and drought tolerance in rice, and that OsNAC45 may regulate the expression of two specific genes, OsPM1 and OsLEA3–1. Results Here, we found that ABA repressed, and NaCl promoted, the expression of OsNAC45 in roots. Immunostaining showed that OsNAC45 was localized in all root cells and was mainly expressed in the stele. Loss of OsNAC45 decreased the sensitivity of rice plants to ABA and over-expressing this gene had the opposite effect, which demonstrated that OsNAC45 played an important role during ABA signal responses. Knockout of OsNAC45 also resulted in more ROS accumulation in roots and increased sensitivity of rice to salt stress. Transcriptome sequencing assay found that thousands of genes were differently expressed in OsNAC45-knockout plants. Most of the down-regulated genes participated in plant stress responses. Quantitative real time RT-PCR suggested that seven genes may be regulated by OsNAC45 including OsCYP89G1, OsDREB1F, OsEREBP2, OsERF104, OsPM1, OsSAMDC2, and OsSIK1. Conclusions These results indicate that OsNAC45 plays vital roles in ABA signal responses and salt tolerance in rice. Further characterization of this gene may help us understand ABA signal pathway and breed rice plants that are more tolerant to salt stress.

Sign in / Sign up

Export Citation Format

Share Document