Pretreatment with a Low Concentration of Methyl Viologen Decreases the Effects of Salt Stress on Chloroplast Ultrastructure in Rice Leaves (Oryza sativaL.)

Abstract Background Inoculation of arbuscular mycorrhizal (AM) fungi has the potential to alleviate salt stress in host plants through the mitigation of ionic imbalance. However, inoculation effects vary, and the underlying mechanisms remain unclear. Two maize genotypes (JD52, salt-tolerant with large root system, and FSY1, salt-sensitive with small root system) inoculated with or without AM fungus Funneliformis mosseae were grown in pots containing soil amended with 0 or 100 mM NaCl (incrementally added 32 days after sowing, DAS) in a greenhouse. Plants were assessed 59 DAS for plant growth, tissue Na+ and K+ contents, the expression of plant transporter genes responsible for Na+ and/or K+ uptake, translocation or compartmentation, and chloroplast ultrastructure alterations. Results Under 100 mM NaCl, AM plants of both genotypes grew better with denser root systems than non-AM plants. Relative to non-AM plants, the accumulation of Na+ and K+ was decreased in AM plant shoots but increased in AM roots with a decrease in the shoot: root Na+ ratio particularly in FSY1, accompanied by differential regulation of ion transporter genes (i.e., ZmSOS1, ZmHKT1, and ZmNHX). This induced a relatively higher Na+ efflux (recirculating) rate than K+ in AM shoots while the converse outcoming (higher Na+ influx rate than K+) in AM roots. The higher K+: Na+ ratio in AM shoots contributed to the maintenance of structural and functional integrity of chloroplasts in mesophyll cells. Conclusion AM symbiosis improved maize salt tolerance by accelerating Na+ shoot-to-root translocation rate and mediating Na+/K+ distribution between shoots and roots.

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Effects of long-term salt stress on antioxidant defence systems, leaf water relations and chloroplast ultrastructure of potato plants

Annals of Applied Biology ◽

10.1111/j.1744-7348.2004.tb00374.x ◽

2004 ◽

Vol 145 (2) ◽

pp. 185-192 ◽

Cited By ~ 62

Author(s):

FERNANDA FIDALGO ◽

ARLETE SANTOS ◽

ISABEL SANTOS ◽

R SALEMA

Keyword(s):

Salt Stress ◽

Water Relations ◽

Chloroplast Ultrastructure ◽

Leaf Water ◽

Leaf Water Relations ◽

Antioxidant Defence ◽

Potato Plants

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Changes in crassulacean acid metabolism expression, chloroplast ultrastructure, photochemical and antioxidant activity in the Aloe vera during acclimation to combined drought and salt stress

Functional Plant Biology ◽

10.1071/fp21008 ◽

2021 ◽

Author(s):

Ghader Habibi

Keyword(s):

Antioxidant Activity ◽

Salt Stress ◽

Crassulacean Acid Metabolism ◽

Acid Metabolism ◽

Aloe Vera ◽

Chloroplast Ultrastructure ◽

Drought And Salt Stress

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Reducing the Halotolerance Gap between Sensitive and Resistant Tomato by Spraying Melatonin

Agronomy ◽

10.3390/agronomy12010084 ◽

2021 ◽

Vol 12 (1) ◽

pp. 84

Author(s):

Rong Zhou ◽

Benjian Cen ◽

Fangling Jiang ◽

Mintao Sun ◽

Junqin Wen ◽

...

Keyword(s):

Salt Stress ◽

Electrolyte Leakage ◽

Crop Improvement ◽

Chloroplast Ultrastructure ◽

Stem Diameter ◽

Pigment Content ◽

Photosynthetic Parameters ◽

H2o2 Content ◽

Antioxidant Mechanism ◽

Antioxidant Parameters

Salt stress is one of the primary abiotic stresses that negatively affects agricultural production. Melatonin, as a useful hormone in plants, has been shown to play positive roles in crop improvement to abiotic stress conditions. However, it remains unclear whether spraying melatonin could reduce the halotolerance gap between tomato genotypes with different salt sensitivities. Here, plant growth, H2O2 content, electrolyte leakage, antioxidant system, gas exchange, pigment content, and chloroplast ultrastructure of salt sensitive genotype (SG) and resistant genotype (RG) at CK (control), M (spraying melatonin), S (salt), and SM (spraying melatonin under salt stress) were investigated. The results showed that the weight, height, and stem diameter of the plant at SM from both genotypes significantly increased compared with S. The plant undergoing SM from both genotypes showed significantly decreased H2O2 but increased activity of SOD, APX, GR, and GSH, as well as net photosynthetic rate and Fv/Fm, as compared with S. The ratio between SM and S (SM/S) of SG was significantly higher than that of RG in terms of plant height and stem diameter, whereas antioxidant parameters, H2O2 content, and electrolyte leakage showed no difference between RG and SG in SM/S. The SM/S of SG in terms of photosynthetic parameters and pigment content were significantly higher than that of RG. Chloroplast ultrastructure showed remarkable changes under salt stress, whereas spraying melatonin reduced the destruction of chloroplasts, especially for SG. We concluded that spraying melatonin reduces the halotolerance gap between SG and RG by photosynthesis regulation instead of the antioxidant mechanism. This indicated that the positive roles of melatonin on tomato plants at salt stress depend on the genotype sensitivity.

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Alleviation of Salt-Induced Adverse Effects on Gas Exchange, Photosynthetic Pigments Content and Chloroplast Ultrastructure in Gerbera Jamesonii L. by Exogenous Salicylic Acid Application

Asian Journal of Research in Agriculture and Forestry ◽

10.9734/ajraf/2021/v7i230123 ◽

2021 ◽

pp. 1-13

Author(s):

Kapila Kumara ◽

A. D. Ampitiyawatta ◽

Adithya Padmaperuma ◽

Chalinda Beneragama ◽

Xia Yi Ping

Keyword(s):

Salicylic Acid ◽

Salt Stress ◽

Gas Exchange ◽

Photosynthetic Pigments ◽

Photosynthetic Pigment ◽

Chloroplast Ultrastructure ◽

Flower Initiation ◽

Photosynthetic System ◽

Pigment Contents ◽

Gas Exchange Characteristics

Aims: The effects of exogenously applied salicylic acid (SA) on gas exchange characteristics, photosynthetic pigments and chloroplast ultrastructure were investigated in gerbera at their reproductive stage under salt-stressed conditions. Methodology: A pot experiment was conducted under glasshouse conditions at the Zhejiang University, Hangzhou, China, (30° N/120° E) between February 2008 and March 2009.Plants, pretreated with foliar applications of 0, 0.5, and 1.0 mmoldm-3 SA at the onset of flower initiation were irrigated with 100 mmoldm-3NaCl(aq) for two weeks, starting after three days from the SA pretreatment. Control did not receive either NaCl or SA.Photosynthetic rate, gas exchange, photosynthetic pigments content and chloroplast ultrastructure were investigated against treatments. All data were subjected to analysis of variance (ANOVA) and Generalized Linear Model (GLM) using SAS statistical software. Pearson’s correlation test was carried out to study the relationships among the parameters. The means were compared using Duncan’s multiple range test (DMRT). For all the tests, P< .05 was considered statistically significant. Results: Salt stress adversely affected the gas exchange characteristics, photosynthetic pigment contents and chloroplast ultrastructure. SA application significantly increased the net photosynthesis, stomatal conductivity, intra-cellular CO2 content and transpiration rate but decreased the stomatal limitation, compared to those of untreated salt-stressed plants. Further, the enhanced photosynthetic pigment contents and notably undamaged chloroplast ultrastructure were evident of the ameliorative effects of SA on photosynthetic system under salt stress. Of the two concentrations tested, 0.5 mmoldm-3 SA concentration seemed to have greater effect throughout the experiment showing no significant variation from control in some attributes (chlorophyll contents and chloroplast ultrastructure). Conclusion: Responses of plants pretreated with SA spraying and significant correlation among them plausibly suggest SA-induced enhancement of photosynthetic system as another target for conferring salt tolerance in crop plants.

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Comparative analysis of salt stress, duration and intensity, on the chloroplast ultrastructure and photosynthetic apparatus in Thellungiella salsuginea

Journal of Photochemistry and Photobiology B Biology ◽

10.1016/j.jphotobiol.2018.04.047 ◽

2018 ◽

Vol 183 ◽

pp. 275-287 ◽

Cited By ~ 20

Author(s):

Rahma Goussi ◽

Arafet Manaa ◽

Walid Derbali ◽

Simone Cantamessa ◽

Chedly Abdelly ◽

...

Keyword(s):

Salt Stress ◽

Comparative Analysis ◽

Photosynthetic Apparatus ◽

Chloroplast Ultrastructure ◽

Thellungiella Salsuginea

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A thermoluminescence study of Photosystem II back electron transfer reactions in rice leaves – effects of salt stress

Photosynthesis Research ◽

10.1007/s11120-004-6427-z ◽

2005 ◽

Vol 84 (1-3) ◽

pp. 131-137 ◽

Cited By ~ 14

Author(s):

Jorge L. Zurita ◽

Mercedes Roncel ◽

Manuel Aguilar ◽

José M. Ortega

Keyword(s):

Electron Transfer ◽

Salt Stress ◽

Photosystem Ii ◽

Transfer Reactions ◽

Electron Transfer Reactions ◽

Thermoluminescence Study ◽

Back Electron Transfer ◽

Rice Leaves

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Salt stress-induced expression of rice AOX1a is mediated through an accumulation of hydrogen peroxide

Biologia ◽

10.2478/s11756-010-0100-0 ◽

2010 ◽

Vol 65 (5) ◽

Cited By ~ 6

Author(s):

Hanqing Feng ◽

Yifeng Wang ◽

Hongyu Li ◽

Rongfang Wang ◽

Kun Sun ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Salt Stress ◽

Alternative Oxidase ◽

Oryza Sativa L ◽

Transcript Level ◽

Nacl Stress ◽

H2o2 Production ◽

Respiratory Pathway ◽

Alternative Respiratory Pathway ◽

Rice Leaves

AbstractTreatment with 300 mM NaCl increased the capacity of the alternative respiratory pathway and induced the expression of AOX1a of the leaves of rice (Oryza sativa L.) seedlings. A significant increase in the content of hydrogen peroxide (H2O2) was observed in rice leaves treated with 300 mM NaCl. However, NaCl at 150 mM did not significantly affect the capacity of the alternative respiratory pathway, the content of H2O2, and the transcript level of AOX1a. Exogenous application of H2O2 enhanced the levels of the capacity of the alternative respiratory pathway and AOX1a expression. The accumulation of H2O2 in rice leaves in response to 300 mM NaCl was inhibited by the pretreatment with dimethylthiourea (DMTU, scavenger of H2O2). This treatment also suppressed the induction of AOX1a expression and the increase in the capacity of the alternative respiratory pathway under 300 mM NaCl stress. Moreover, the salt-stressed (300 mM NaCl) seedlings pretreated with 1 mM salicylhydroxamic acid (SHAM, a special inhibitor of alternative oxidase) had higher level of H2O2 production than the seedlings either subjected to 300 mM NaCl stress or SHAM treatment alone did. These observations suggest that the expression of AOX1a in response to higher salt stress is mediated through an accumulation of H2O2 and alternative oxidase could play a role in antioxidant protection under the condition of higher salt stress.

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