Divergences in morphological changes and antioxidant responses in salt-tolerant and salt-sensitive rice seedlings after salt stress

Saline soil is a critical environmental problem affecting crop yield worldwide. Tibetan wild barley is distinguished for its vast genetic diversity and high degree of tolerance to abiotic stress, including salinity. The present study compared the response of antioxidant defense system in the XZ16 wild and CM72 cultivated barleys to salt stress. Wild barley was relatively more tolerant than cultivated CM72, salt-tolerant cultivar, with less Na+ uptake and more K+, Ca2+, and Mg2+ retention in plant tissues. The results of diaminobenzidine (DAB) and nitroblue tetrazolium (NBT) staining showed that XZ16 had significantly lower H2O2 and O2− concentrations than a salt-sensitive cultivar Gairdner, suggesting that the salt-tolerant genotype suffer from less oxidative damage. Moreover, XZ16 and Gairdner had the highest and lowest anti-oxidative enzyme activities and proline content in plant tissues. In addition, the microscopic examination revealed that DNA damage in cv. Gairdner was closely correlated to oxidative stress, representing that more reactive oxygen species accumulation in plants tissues leads to subsequent DNA damage. The present results show that higher salt tolerance of wild barley XZ16 is attributed to less Na+ accumulation and stronger anti-oxidative capacity.

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Effects of exogenous proline and trehalose on physiological responses in rice seedlings during salt-stress and after recovery

Plant Soil and Environment ◽

10.17221/762/2011-pse ◽

2012 ◽

Vol 58 (No. 7) ◽

pp. 309-315 ◽

Cited By ~ 32

Author(s):

N. Nounjan ◽

P. Theerakulpisut

Keyword(s):

Antioxidant Enzymes ◽

Salt Stress ◽

Physiological Responses ◽

Recovery Period ◽

Growth Enhancement ◽

Salt Tolerant ◽

Rice Seedlings ◽

Growth Recovery ◽

Growth Increase ◽

High Level

Two osmoprotectants (proline – Pro; trehalose – Tre) were exogenously supplied to seedlings of rice cvs. Pokkali (PK – salt-tolerant) and Khao Dawk Mali 105 (KDML105 – salt-sensitive) to investigate their effects on plants exposed to 200 mmol/L NaCl for 6 days and 5 days after recovery from stress. The reduction of growth, increase in Na+ to K+ ratio, high level of hydrogen peroxide (H2O2) content, enhanced activity of antioxidant enzymes (superoxide dismutase – SOD, peroxidase – POX, catalase – CAT and ascorbate peroxidase – APX) were observed in both rice cultivars under NaCl treatments. Exogenous Pro and Tre supplement to NaCl-stressed plants did not mitigate the reduction of growth during salt-stress. Nevertheless, during recovery plants previously supplied with Tre showed markedly higher percentage of growth recovery than those treated with NaCl alone or supplied with Pro. The beneficial effect of Tre on growth recovery was clearly demonstrated in KDML105 in which growth enhancement was related to reduction in Na+ to K+ ratio. Exogenous Pro was able to reduce H2O2 in both cultivars during salt stress whereas Tre could reduce it only in KDML105. Exogenous Tre did not enhance any antioxidant enzymes during stress but enhanced APX activity in KDML105 during recovery. Exogenous Pro enhanced the activity of APX in PK, and POX, CAT and APX in KDML105 during both stress and recovery period.

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Exogenous Sorbitol and Trehalose Mitigated Salt Stress Damage in Salt-sensitive but not Salt-tolerant Rice Seedlings

Asian Journal of Crop Science ◽

10.3923/ajcs.2012.165.170 ◽

2012 ◽

Vol 4 (4) ◽

pp. 165-170 ◽

Cited By ~ 19

Author(s):

P. Theerakulp ◽

W. Gunnula

Keyword(s):

Salt Stress ◽

Salt Tolerant ◽

Rice Seedlings ◽

Stress Damage

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Genetic Potential for Salt Tolerance During Germination in Lycopersicon Species

HortScience ◽

10.21273/hortsci.32.2.296 ◽

1997 ◽

Vol 32 (2) ◽

pp. 296-300 ◽

Cited By ~ 46

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.

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Exogenous Melatonin Improves the Growth of Rice Seedlings by Regulating Redox Balance and Ion Homeostasis Under Salt Stress

Journal of Plant Growth Regulation ◽

10.1007/s00344-021-10417-z ◽

2021 ◽

Author(s):

Long Wei ◽

Haiyan Zhao ◽

Baoxiang Wang ◽

Xinyi Wu ◽

Rujia Lan ◽

...

Keyword(s):

Salt Stress ◽

Ion Homeostasis ◽

Redox Balance ◽

Rice Seedlings ◽

Exogenous Melatonin

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Melatonin Regulates Antioxidant Strategy in Response to Continuous Salt Stress in Rice Seedlings

Plant Physiology and Biochemistry ◽

10.1016/j.plaphy.2021.05.003 ◽

2021 ◽

Author(s):

Feiyu Yan ◽

Haimin Wei ◽

Yanfeng Ding ◽

Weiwei Li ◽

Zhenghui Liu ◽

...

Keyword(s):

Salt Stress ◽

Rice Seedlings

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Endophytic halotolerant Bacillus velezensis FMH2 alleviates salt stress on tomato plants by improving plant growth and altering physiological and antioxidant responses.

Plant Physiology and Biochemistry ◽

10.1016/j.plaphy.2021.05.025 ◽

2021 ◽

Author(s):

Fatma MASMOUDI ◽

Slim TOUNSI ◽

Christopher A. DUNLAP ◽

Mohamed TRIGUI

Keyword(s):

Salt Stress ◽

Plant Growth ◽

Bacillus Velezensis ◽

Tomato Plants ◽

Antioxidant Responses

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Antioxidative and Metabolic Contribution to Salinity Stress Responses in Two Rapeseed Cultivars during the Early Seedling Stage

Antioxidants ◽

10.3390/antiox10081227 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1227

Author(s):

Ali Mahmoud El-Badri ◽

Maria Batool ◽

Ibrahim A. A. Mohamed ◽

Zongkai Wang ◽

Ahmed Khatab ◽

...

Keyword(s):

Salt Stress ◽

Salinity Stress ◽

Stress Responses ◽

Antioxidant Activities ◽

Tricarboxylic Acid Cycle ◽

Seedling Stage ◽

Plant Performance ◽

Salt Tolerant ◽

Brassica Napus L ◽

Early Seedling

Measuring metabolite patterns and antioxidant ability is vital to understanding the physiological and molecular responses of plants under salinity. A morphological analysis of five rapeseed cultivars showed that Yangyou 9 and Zhongshuang 11 were the most salt-tolerant and -sensitive, respectively. In Yangyou 9, the reactive oxygen species (ROS) level and malondialdehyde (MDA) content were minimized by the activation of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) for scavenging of over-accumulated ROS under salinity stress. Furthermore, Yangyou 9 showed a significantly higher positive correlation with photosynthetic pigments, osmolyte accumulation, and an adjusted Na+/K+ ratio to improve salt tolerance compared to Zhongshuang 11. Out of 332 compounds identified in the metabolic profile, 225 metabolites were filtrated according to p < 0.05, and 47 metabolites responded to salt stress within tolerant and sensitive cultivars during the studied time, whereas 16 and 9 metabolic compounds accumulated during 12 and 24 h, respectively, in Yangyou 9 after being sown in salt treatment, including fatty acids, amino acids, and flavonoids. These metabolites are relevant to metabolic pathways (amino acid, sucrose, flavonoid metabolism, and tricarboxylic acid cycle (TCA), which accumulated as a response to salinity stress. Thus, Yangyou 9, as a tolerant cultivar, showed improved antioxidant enzyme activity and higher metabolite accumulation, which enhances its tolerance against salinity. This work aids in elucidating the essential cellular metabolic changes in response to salt stress in rapeseed cultivars during seed germination. Meanwhile, the identified metabolites can act as biomarkers to characterize plant performance in breeding programs under salt stress. This comprehensive study of the metabolomics and antioxidant activities of Brassica napus L. during the early seedling stage is of great reference value for plant breeders to develop salt-tolerant rapeseed cultivars.

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