Changes in chloroplast lipid contents and chloroplast ultrastructure in Sulla carnosa and Sulla coronaria leaves under salt stress

2016 ◽  
Vol 198 ◽  
pp. 32-38 ◽  
Author(s):  
Fatma Bejaoui ◽  
Joaquín J. Salas ◽  
Issam Nouairi ◽  
Abderrazak Smaoui ◽  
Chedly Abdelly ◽  
...  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Hao Wang ◽  
Tingting An ◽  
Di Huang ◽  
Runjin Liu ◽  
Bingcheng Xu ◽  
...  

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.


2004 ◽  
Vol 7 (4) ◽  
pp. 435-441 ◽  
Author(s):  
Koji Yamane ◽  
Shahidur Rahman ◽  
Michio Kawasaki ◽  
Mitsutaka Taniguchi ◽  
Hiroshi Miyake

Agronomy ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 84
Author(s):  
Rong Zhou ◽  
Benjian Cen ◽  
Fangling Jiang ◽  
Mintao Sun ◽  
Junqin Wen ◽  
...  

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.


Author(s):  
Kapila Kumara ◽  
A. D. Ampitiyawatta ◽  
Adithya Padmaperuma ◽  
Chalinda Beneragama ◽  
Xia Yi Ping

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.


2004 ◽  
Vol 7 (3) ◽  
pp. 292-300 ◽  
Author(s):  
Koji Yamane ◽  
Shahidur Rahman ◽  
Michio Kawasaki ◽  
Mitsutaka Taniguchi ◽  
Hiroshi Miyake

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