scholarly journals Conjugated Polyamines in Root Plasma Membrane Enhanced the Tolerance of Plum Seedling to Osmotic Stress by Stabilizing Membrane Structure and Therefore Elevating H+-ATPase Activity

2022 ◽  
Vol 12 ◽  
Author(s):  
Hongyang Du ◽  
Benxue Chen ◽  
Qiang Li ◽  
Huaipan Liu ◽  
Ronald Kurtenbach
Keyword(s):  
Plasma Membrane ◽  
Drought Stress ◽  
Osmotic Stress ◽  
Atpase Activity ◽  
Membrane Structure ◽  
Membrane Damage ◽  
Cellular Level ◽  
Water Retention Capacity ◽  
Retention Capacity ◽  
Conjugated Polyamines

Polyamines are small positively charged molecules in plants and play important functions in many biological processes under various environmental stresses. One of the most confounding problems relating to polyamines (PAs) in stresses is the lack of understanding of the mechanisms underlying their function(s). Furthermore, a limited number of studies have addressed this issue at the sub-cellular level, especially in tree plants under drought stress. Therefore, in this research, by simulating natural drought stress with polyethylene glycol (PEG) osmotic stress, the relationship between the levels of conjugated polyamines and the activity of H+-ATPase in the plasma membrane was elucidated with the roots of two plum (Prunus salicina L.) cultivars, which were different in drought tolerance, as experimental materials. Furthermore, free PA levels and the activities of S-adenosylmethionine decarboxylase (SAMDC) and transglutaminase (TGase), which were closely associated with the levels of free and conjugated PAs, were also detected. Results showed that under osmotic stress, the increases of the levels of non-covalently conjugated (non-CC) spermidine (Spd) and spermine (Spm), covalently conjugated (CC) putrescine (Put) and Spd in the plasma membrane of drought-tolerant Ganli No. 5 were more significant than those of drought-sensitive Suli No. 3, indicating that these conjugated PAs might be involved in the tolerance of plum seedlings to stress. Furthermore, the conjugated PAs were closely correlated with plum seedling growth, water retention capacity, plasma membrane damage degree, and hydrogen (H+)-ATPase activity in the plasma membrane. To get more complementary pieces of evidence, we subjected plum seedlings to combined treatments of PEG and exogenous PA (Spd and Spm), and an inhibitor of SAMDC [methylglyoxal-bis (guanylhydrazone), (MGBG)] or TGase (o-phenanthroline). These results collectively suggested that non-CC Spd and Spm, CC Put and Spd in plasma membrane might function in enhancing the tolerance of plum seedlings to osmotic stress by stabilizing membrane structure and therefore elevating H+-ATPase activity.

scholarly journals Screening of Mungbean Genotypes under Polyethylene Glycol (PEG) Induced Drought Stress Condition

2020 ◽  
pp. 1-12
Author(s):  
Abdullah All Imtiaz ◽  
Saleh Ahmed Shahriar ◽  
Md. Abdullahil Baque ◽  
Most. Nurjahan Khatun Eaty ◽  
Maliha Rahman Falguni
Keyword(s):  
Drought Stress ◽  
Water Retention ◽  
Stress Condition ◽  
Dry Weight ◽  
Water Retention Capacity ◽  
Retention Capacity ◽  
Shoot Dry Weight ◽  
Root Shoot Ratio ◽  
Relative Water ◽  
Drought Stress Condition

Sixteen advance genotypes of mungbeans under 5 different concentrations of Polyethylene Glycol (PEG) were studied to find out the better cultivar against drought stress condition. The experiment results revealed that germination, seedling production and water-related behavior of mungbean genotypes differed significantly under different PEG (drought inducer) concentrations. The mungbean genotype BINA Mung-6 (V8) is proved as highly tolerant against drought stress condition among all other tested genotypes. The results of the investigation revealed that BINA Mung-6 (V8) genotype consistently scored the highest value for all parameters except for the root shoot ratio and water retention capacity that was statistically comparable to genotypes BARI Mung-4 (V2) and BINA Mung-5 (V7). Consistently poor performance were recorded from IPM-02-03 (V16) genotype which is statistically similar as genotypes BMXK1-09015-2 (V13) and BMXK1-09015-6 (V10). The maximum percentage of germination (98.12%), shoot length (139.40 mm), root length (99.07 mm), shoot dry weight (22.32 mg), root dry weight (6.88 mg), relative water content (94.78), water retention capacity (24.98), germination co-efficient (22.27) and vigor index (233.90) were reported from BINA Mung-6 (V8) at a concentration of 0 percent PEG. The minimum percentage of germination (28.22 percent), shoot length (31.17 mm), root length (16.50 mm), shoot dry weight (2.21 mg), root dry weight (0.97 mg), relative water content (25.55), water retention capacity (3.08), germination co-efficient (6.06) and vigor index (13.45) were reported from IPM-02-03 (V16) mungbean advance lines at 0 percent PEG. Maximum (0.92) root shoot ratio was recorded from both BARI Mung-8 (V6) and BMX-08011-2 (V11) mungbean genotypes at 20 percent PEG concentration and minimum (0.22) at 0 percent PEG concentration from BARI Mung-5 (V3) genotype. Maximum water retention capacity (74.45) was recorded at 20 per cent PEG concentration from IPM-02-03 (V16) genotype and minimum (5.22) was at 0 per cent PEG concentration from BINA Mung-6 (V8) genotype.

scholarly journals Geldanamycin disrupts platelet-membrane structure, leading to membrane permeabilization and inhibition of platelet aggregation

2000 ◽  
Vol 345 (2) ◽  
pp. 307-314 ◽  
Author(s):  
Sudawadee SUTTITANAMONGKOL ◽  
Adrian R. L. GEAR ◽  
Renata POLANOWSKA-GRABOWSKA
Keyword(s):  
Plasma Membrane ◽  
Platelet Aggregation ◽  
Membrane Structure ◽  
Kinase Inhibitor ◽  
Adenine Nucleotides ◽  
Membrane Damage ◽  
Heat Shock Protein 90 ◽  
Human Platelets ◽  
Membrane Permeabilization ◽  
Plasma Membrane Damage

Geldanamycin (GA), a benzoquinoid ansamycin antibiotic, has been used as a tyrosine kinase inhibitor and an anti-tumour agent and is known to bind to heat-shock protein 90. In the present study on human platelets we have found that GA inhibited platelet aggregation induced by ADP, thrombin and the thrombin-receptor-activating peptide and caused platelet plasma-membrane damage, detected by leakage of adenine nucleotides as well as serotonin. Scanning electron microscopy (SEM) revealed that platelet exposure to GA led to the formation of holes or fenestrations in the platelet plasma membrane, confirming GA's ability to initiate membrane damage. In addition, GA itself caused both the dephosphorylation and phosphorylation of proteins in resting platelets and prevented agonist-induced phosphorylation of pleckstrin, the 20-kDa myosin light chain and other proteins. Another ansamycin, herbimycin A, also inhibited platelet aggregation, but caused minimal membrane permeabilization, as detected by 3H release from platelets labelled previously with [3H]adenine, and much less membrane damage, revealed by SEM. Overall, GA is able to disrupt membrane structure and inhibit platelet aggregation, an ability which may be linked to alterations in the activity of protein kinases and phosphatases.

scholarly journals Enzymatic activity and gene expression related to drought stress tolerance in maize seeds and seedlings

2021 ◽  
Vol 37 ◽  
pp. e37079
Author(s):  
Milena Christy Santos ◽  
Édila Vilela de Resende Von Pinho ◽  
Heloisa Oliveira dos Santos ◽  
Danielle Rezende Vilela ◽  
Izabel Costa Silva Neta ◽  
...  
Keyword(s):  
Drought Stress ◽  
Water Deficit ◽  
Selection Process ◽  
Limiting Factor ◽  
Water Retention Capacity ◽  
Maize Seedlings ◽  
Retention Capacity ◽  
Maize Seeds ◽  
Expression Of Genes ◽  
Different Tissues

Drought stress is a major limiting factor for the development of maize, and the identification of the expression of genes related to this stress in seeds and seedlings can be an important tool to accelerate the selection process. The expression of genes related to tolerance to water deficit in seeds and in different tissues of maize seedlings were evaluated. Four tolerant genotypes (91-T, 32-T, 91x75-T, 32x75-T) and four non-tolerant genotypes (37-NT, 57-NT, 37x57-NT and 31x37-NT) were seeded in a substrate with 10% (stress) and 70% (control) water retention capacity. The expression of 4 enzymes were evaluated: catalase (CAT), peroxidase (PO), esterase (EST), and heat-resistant protein (HRP), as well as the relative expression of 6 genes: ZmLEA3, ZmPP2C, ZmCPK11, ZmDREB2A/2.1s, ZmDBP3 and ZmAN13 were evaluated in seed, shoots and roots of seedlings submitted or not to stress. There was variation in the expression of CAT, PO, SOD, EST and HRP enzymes among the evaluated genotypes and also in the different tissues evaluated. Higher expression of the CAT and PO was observed in the shoots. There was a greater expression of the EST in the genotypes non-tolerant to water deficit. HRP was expressed only in seeds. In the aerial part of maize seedlings, classified as tolerant, higher expression of genes ZmLEA3 and ZmCPK11 was observed. There was a higher expression of the ZmAN13 and ZmDREB2A/2.1S genes in roots developed under stress conditions and a higher expression of the ZmPP2C gene in seeds of line 91-T, which is classified as tolerant to drought stress.

scholarly journals Comparative Proteomics Analysis of the Seedling Root Response of Drought-sensitive and Drought-tolerant Maize Varieties to Drought Stress

2019 ◽  
Vol 20 (11) ◽  
pp. 2793 ◽  
Author(s):  
Wenjing Zeng ◽  
Yunling Peng ◽  
Xiaoqiang Zhao ◽  
Boyang Wu ◽  
Fenqi Chen ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Molecular Mechanisms ◽  
Mrna Level ◽  
Differentially Expressed ◽  
Water Retention Capacity ◽  
Coding Region ◽  
Retention Capacity ◽  
Drought Tolerant ◽  
Maize Varieties

The growth and development of maize roots are closely related to drought tolerance. In order to clarify the molecular mechanisms of drought tolerance between different maize (Zea mays L.) varieties at the protein level, the isobaric tags for relative and absolute quantitation (iTRAQ) quantitative proteomics were used for the comparative analysis of protein expression in the seedling roots of the drought-tolerant Chang 7-2 and drought-sensitive TS141 maize varieties under 20% polyethylene glycol 6000 (PEG 6000)-simulated drought stress. We identified a total of 7723 differentially expressed proteins (DEPs), 1243 were significantly differentially expressed in Chang 7-2 following drought stress, 572 of which were up-regulated and 671 were down-regulated; 419 DEPs were identified in TS141, 172 of which were up-regulated and 247 were down-regulated. In Chang 7-2, the DEPs were associated with ribosome pathway, glycolysis/gluconeogenesis pathway, and amino sugar and nucleotide sugar metabolism. In TS141, the DEPs were associated with metabolic pathway, phenylpropanoid biosynthesis pathway, and starch and sucrose metabolism. Compared with TS141, the higher drought tolerance of Chang 7-2 root system was attributed to a stronger water retention capacity; the synergistic effect of antioxidant enzymes; the strengthen cell wall; the osmotic stabilization of plasma membrane proteins; the effectiveness of recycling amino acid; and an improvement in the degree of lignification. The common mechanisms of the drought stress response between the two varieties included: The promotion of enzymes in the glycolysis/gluconeogenesis pathway; cross-protection against the toxicity of aldehydes and ammonia; maintenance of the cell membrane stability. Based on the proteome sequencing information, the coding region sequences of eight DEP-related genes were analyzed at the mRNA level by quantitative real-time PCR (qRT-PCR). The findings of this study can inform the future breeding of drought-tolerant maize varieties.

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