scholarly journals The Protective Effect of Exogenous Putrescine in the Response of Tea Plants (Camellia sinensis) to Salt Stress

HortScience ◽  
2018 ◽  
Vol 53 (11) ◽  
pp. 1640-1646 ◽  
Author(s):  
Fei Xiong ◽  
Jieren Liao ◽  
Yuanchun Ma ◽  
Yuhua Wang ◽  
Wanping Fang ◽  
...  
Keyword(s):  
Salt Stress ◽  
Camellia Sinensis ◽  
Effective Means ◽  
Plant Performance ◽  
Photosynthetic Parameters ◽  
Activity Levels ◽  
Salinity Treatment ◽  
Ros Scavenging ◽  
Stress Levels ◽  
Tea Plants

Camellia sinensis cultivars were treated with 5 mm putrescine (Put) under a range of sodium chloride (NaCl) concentrations. Plant performance, as indicated by various indicators associated with plant growing condition such as photosynthetic parameters and polyamine (PA) contents, especially the content of Put, was improved by the treatment. The extent of both Na+ accumulation and K+ loss increased. The activity levels of the antioxidant enzymes related to salt stress, such as superoxide dismutase (SOD), peroxidase (POD), and catalase, were significantly altered with different salt stress levels and showed a decrease in the general trend. Besides, tea polyphenols, the tea quality indicator, increased during the salinity treatment but decreased when we applied Put. These findings suggest that treatment with Put might constitute an effective means for alleviating salinity stress–induced injury through its positive effect on photosynthetic efficiency and for controlling reactive oxygen species (ROS) scavenging ability under appropriate salt stress levels.

scholarly journals Developing Salinity Tolerate Trees for Challenging Sites and Urban Forests Based on the Inferences of Physiological Responses: Using Ulmus Pumila as an Example

2021 ◽  
Author(s):  
Deyu Mu ◽  
Chen Ding
Keyword(s):  
Salt Stress ◽  
Salinity Stress ◽  
Physiological Responses ◽  
Urban Forests ◽  
Antioxidant Enzyme Activities ◽  
Protein Accumulation ◽  
Salinity Treatment ◽  
Ex Vitro ◽  
Ros Scavenging ◽  
Ulmus Pumila

Elevated salinity is one of the major environmental limitation factors of plant growth and development and salinity stress compromises the production and survival of plantation and urban forests and agricultural crops in the arid, semi-arid, and intertidal zones. Ulmus pumila, a salt- indigenous tree species in Asia and is widely deployed in salt-affected areas in China, and U.pumila is promising for multi-varietal forestry in plantation and urban forests. The comprehensive mechanism of the intraspecific salt tolerance is still not clear yet. Here, we investigated the physiological responses of the salinity stress based on the antioxidant enzyme activities, osmotic adjustments, and gas exchange among salt-tolerant U. pumila genotypes for 100 days under five different NaCl levels (0%, 0.3%, 0.5%, 0.7%, and 0.9% w/v) with natural surroundings and rain shade at age-2. Salt stress decreased height (HR), ground diameter (DR), and dry weight (biomass) were significantly different among genotypes. HR and performance indices were positively correlated with photosynthesis rate (Pn), apparent mesophyll conductance (AMC), and chlorophyll (CHLL) with (r= 0.7 - 0.8 ***), but were negatively related to the free proline, sugar, and protein accumulation (r=-0.5 ~ -0.7***). We found that high accumulation of sugars and more activities of SOD enzyme in leaf tissue contribute to the osmotic adjustment and ROS scavenging system under salinity treatment; the sugar content and SOD activity play key roles in U. pumila’s tolerance to salt stress, and are promising indicators for U. pumila species ex vitro selections. The ex vitro selection results align with the previous in vitro studies [37] and is promising for the MVF development.

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 Biochemical characterization of specific Alanine Decarboxylase (AlaDC) and its ancestral enzyme Serine Decarboxylase (SDC) in tea plants (Camellia sinensis)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Peixian Bai ◽  
Liyuan Wang ◽  
Kang Wei ◽  
Li Ruan ◽  
Liyun Wu ◽  
...  
Keyword(s):  
Gene Duplication ◽  
Camellia Sinensis ◽  
Biochemical Characterization ◽  
Specific Activity ◽  
Protein Sequences ◽  
Biochemical Properties ◽  
High Similarity ◽  
New Gene ◽  
Tea Plants

Abstract Background Alanine decarboxylase (AlaDC), specifically present in tea plants, is crucial for theanine biosynthesis. Serine decarboxylase (SDC), found in many plants, is a protein most closely related to AlaDC. To investigate whether the new gene AlaDC originate from gene SDC and to determine the biochemical properties of the two proteins from Camellia sinensis, the sequences of CsAlaDC and CsSDC were analyzed and the two proteins were over-expressed, purified, and characterized. Results The results showed that exon-intron structures of AlaDC and SDC were quite similar and the protein sequences, encoded by the two genes, shared a high similarity of 85.1%, revealing that new gene AlaDC originated from SDC by gene duplication. CsAlaDC and CsSDC catalyzed the decarboxylation of alanine and serine, respectively. CsAlaDC and CsSDC exhibited the optimal activities at 45 °C (pH 8.0) and 40 °C (pH 7.0), respectively. CsAlaDC was stable under 30 °C (pH 7.0) and CsSDC was stable under 40 °C (pH 6.0–8.0). The activities of the two enzymes were greatly enhanced by the presence of pyridoxal-5′-phosphate. The specific activity of CsSDC (30,488 IU/mg) was 8.8-fold higher than that of CsAlaDC (3467 IU/mg). Conclusions Comparing to CsAlaDC, its ancestral enzyme CsSDC exhibited a higher specific activity and a better thermal and pH stability, indicating that CsSDC acquired the optimized function after a longer evolutionary period. The biochemical properties of CsAlaDC might offer reference for theanine industrial production.

scholarly journals Down-Regulation of SlGRAS10 in Tomato Confers Abiotic Stress Tolerance

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 623
Author(s):  
Sidra Habib ◽  
Yee Yee Lwin ◽  
Ning Li
Keyword(s):  
Salt Stress ◽  
Abiotic Stress ◽  
Plant Growth ◽  
Stress Tolerance ◽  
Abiotic Stresses ◽  
Abiotic Stress Tolerance ◽  
Functional Characterization ◽  
Flavonoid Biosynthesis ◽  
Ros Scavenging ◽  
Down Regulation

Adverse environmental factors like salt stress, drought, and extreme temperatures, cause damage to plant growth, development, and crop yield. GRAS transcription factors (TFs) have numerous functions in biological processes. Some studies have reported that the GRAS protein family plays significant functions in plant growth and development under abiotic stresses. In this study, we demonstrated the functional characterization of a tomato SlGRAS10 gene under abiotic stresses such as salt stress and drought. Down-regulation of SlGRAS10 by RNA interference (RNAi) produced dwarf plants with smaller leaves, internode lengths, and enhanced flavonoid accumulation. We studied the effects of abiotic stresses on RNAi and wild-type (WT) plants. Moreover, SlGRAS10-RNAi plants were more tolerant to abiotic stresses (salt, drought, and Abscisic acid) than the WT plants. Down-regulation of SlGRAS10 significantly enhanced the expressions of catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) to reduce the effects of reactive oxygen species (ROS) such as O2− and H2O2. Malondialdehyde (MDA) and proline contents were remarkably high in SlGRAS10-RNAi plants. Furthermore, the expression levels of chlorophyll biosynthesis, flavonoid biosynthesis, and stress-related genes were also enhanced under abiotic stress conditions. Collectively, our conclusions emphasized the significant function of SlGRAS10 as a stress tolerate transcription factor in a certain variety of abiotic stress tolerance by enhancing osmotic potential, flavonoid biosynthesis, and ROS scavenging system in the tomato plant.

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

Antioxidants ◽  
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.

Methyl jasmonate improves tolerance to high salt stress in the recretohalophyte Limonium bicolor

2019 ◽  
Vol 46 (1) ◽  
pp. 82 ◽  
Author(s):  
Fang Yuan ◽  
Xue Liang ◽  
Ying Li ◽  
Shanshan Yin ◽  
Baoshan Wang
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Methyl Jasmonate ◽  
Salt Gland ◽  
Underlying Mechanism ◽  
Photosynthetic Parameters ◽  
Salt Glands ◽  
Plasma Membrane Permeability ◽  
Limonium Bicolor ◽  
Relative Electrical Conductivity

Limonium bicolor is a typical recretohalophyte with salt glands in the epidermis, which shows maximal growth at moderate salt concentrations (100mM NaCl) but reduced growth in the presence of excess salt (more than 200mM). Jasmonic acid (JA) alleviates the reduced growth of L. bicolor under salt stress; however, the underlying mechanism is unknown. In this study we investigated the effects of exogenous methyl jasmonate (MeJA) application on L. bicolor growth at high NaCl concentrations. We found that treatment with 300mM NaCl led to dramatic inhibition of seedling growth that was significantly alleviated by the application of 0.03mM MeJA, resulting in a biomass close to that of plants not subjected to salt stress. To determine the parameters that correlate with MeJA-induced salt tolerance (assessed as the biomass production in saline and control conditions), we measured 14 physiological parameters relating to ion contents, plasma membrane permeability, photosynthetic parameters, salt gland density, and salt secretion. We identified a correlation between individual indicators and salt tolerance: the most positively correlated indicator was net photosynthetic rate, and the most negatively correlated one was relative electrical conductivity. These findings provide insights into a possible mechanism underlying MeJA-mediated salt stress alleviation.

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