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1.
This study aimed to determine the effects of exogenous application of salicylic acid (SA) on the toxic effects of salt in relation to ethylene and polyamine synthesis, and to correlate these traits with the expression of genes involved in ethylene and polyamine metabolism in two tomato species differing in their sensitivity to salt stress, Solanum lycopersicum cv Ailsa Craig and its wild salt‐resistant relative Solanum chilense. In S. chilense, treatment with 125 m M NaCl improved plant growth, increased production of ethylene, endogenous salicylic acid and spermine. The production was related to a modification of expression of genes involved in ethylene and polyamine metabolism. In contrast, salinity decreased plant growth in S. lycopersicum without affecting endogenous ethylene, salicylic or polyamine concentrations. Exogenous application of salicylic acid at 0.01 m M enhanced shoot growth in both species and affected ethylene and polyamine production in S. chilense. Concomitant application of NaCl and salicylic acid improved osmotic adjustment, thus suggesting that salt and SA may act in synergy on osmolyte synthesis. However, the beneficial impact of exogenous application of salicylic acid was mitigated by salt stress since NaCl impaired endogenous SA accumulation in the shoot and salicylic acid did not improve plant growth in salt‐treated plants. Our results thus revealed that both species respond differently to salinity and that salicylic acid, ethylene and polyamine metabolisms are involved in salt resistance in S. chilense. 相似文献
2.
Salinity is a major environmental stress that limits plant production and portraits a critical challenge to food security in the world. In this research, the impacts of plant growth–promoting bacteria (Pseudomonas RS-198 and Azospirillum brasilense RS-SP7) and foliar application of plant hormones (salicylic acid 1 mM and jasmonic acid 0.5 mM) on alleviating the harmful effects of salt stress in rapeseed plants (Brassica napus cv. okapi) were examined under greenhouse condition. Salt stress diminished rapeseed biomass, leaf area, water content, nitrogen, phosphorus, potassium, calcium, magnesium, and chlorophyll content, while it increased sodium content, endogenous salicylic and jasmonic acids, osmolyte production, H2O2 and O2•− generations, TBARS content, and antioxidant enzyme activities. Plant growth, nutrient content, leaf expansion, osmolyte production, and antioxidant enzyme activities were increased, but oxidative and osmotic stress indicators were decreased by bacteria inoculation + salicylic acid under salt stress. Antioxidant enzyme activities were amplified by jasmonic acid treatments under salt stress, although rapeseed growth was not generally affected by jasmonic acid. Bacterial + hormonal treatments were superior to individual treatments in reducing detrimental effects of salt stress. The best treatment in rectifying rapeseed growth under salt stress was combination of Pseudomonas and salicylic acid. This combination attenuated destructive salinity properties and subsequently amended rapeseed growth via enhancing endogenous salicylic acid content and some essential nutrients such as potassium, phosphorus, and magnesium. 相似文献
3.
In order to examine the influence of microsymbionts on plants, arbuscular mycorrhizal (AM) fungi and rhizobia were used to
examine the growth of Lathyrus sativus under sulphate salt stress. Seedlings of L. sativus were inoculated with a combination of selected microsymbionts. Plants were grown under greenhouse conditions with five Na 2SO 4 concentrations (0, 1%, 2%, 3% and 4% (weight : weight)). The inoculations combinations used were the AM fungus, Glomus mosseae and/or the rhizobium, Mesorhizobium mediterraneum. The results showed that sulphate salinity inhibited plant growth and biomass production. However, compared with the control
treatments, dual-inoculation of G. mosseae and M. mediterraneum reduced the harmful influence of sulphate salinity. Parmeters including plant height, the extent of AM colonization, total
biomass, nodules biomass, P concentration, N concentration and proline concentration confirmed that dual inoculation plays
a vital role in promoting the growth of L. sativus under sulphate salt stress. The results suggested that the use of this dual inoculation could be exploited in grassland plantation
establishment and in pastoral ecosystem reclamation programmes in arid and semi-arid areas subject to moderate salt contamination. 相似文献
4.
- Involvement of nitric oxide (NO) in plant metabolism and its connection with phytohormones has not been fully described, thus information about the role of this molecule in signalling pathways remains fragmented. In this study, the effects of NO on calmodulin (CAM), calcium protein kinase (CPK), content of phytohormones and secondary metabolites in canola plants under salinity stress were investigated.
- We applied 100 μM sodium nitroprusside as an NO source to canola plants grown under saline (100 mM NaCl) and non-saline conditions at the vegetative stage.
- Plant growth was negatively affected by salinity, but exogenous NO treatment improved growth. NO caused a significant increase in activity of CAT, SOD and POX through their enhanced gene expression in stressed canola. Salinity-responsive genes, namely CAM and CPK, were induced by NO in plants grown under salinity. NO application enhanced phenolic compounds, such as gallic acid and coumaric acid and flavonoid compound,s catechin, diadzein and kaempferol, in plants subjected to salinity. NO treatment enhanced abscisic acid and brassinosteroids but decreased auxin and gibberellin in stressed canola plants.
- The impacts of NO in improving stress tolerance in canola required CAM and CPK. Also, NO signalling re-established the phytohormone balance and resulted in enhanced tolerance to salt stress. Furthermore, NO improved salinity tolerance in canola by increasing enzymatic and non-enzymatic antioxidant content.
相似文献
5.
Salinity stress is one of the most significant global issues that negatively affect plant growth and development. Modern agricultural practices have expanded the destructive effects of salinity stress, affecting plants through immediate osmotic stress, followed by a slow onset of ionic or hyper-osmotic stress. Plants alteration and resistance to salinity stress involve complex physiological, biochemical, and molecular systems to maintain homeostasis. As of late, the investigation of gaseous molecules in plants has attained much consideration, particularly for abiotic stress. Abiotic stresses generally initiate gasotransmitter (GT) generation in plants. In the interim, these GTs enhance the accumulation and activities of few antioxidant molecules, check the destructiveness of reactive oxygen species (ROS), and improve plant resilience under different stress conditions. The current review presented the role of gaseous molecules in plants under salinity stress, which include nitric oxide (·NO), hydrogen sulfide (H2S), hydrogen gas (H2), carbon monoxide (CO), methane (CH4), and the only gaseous phytohormone ethylene. Further, we highlighted the underlying molecular mechanisms of the gasotransmitter signaling and cross-talks in salinity stress. Also, we presented a general update on the inclusion of GT in salt stress response, including the research gaps and its applications in the advancement of salinity-resistant plants. 相似文献
6.
The objective of this work was to search out the probable molecule behind the activation of broad spectrum resistance during abiotic elicitors such as arachidonic acid, cupric chloride, chitosan, isonicotinic acid and salicylic acid mediated induced systemic resistance (ISR) in Raphanus sativus L. The elicitor compounds were sprayed on the radish leaves of healthy plant and after 24 h incubation a significant increase of β-1,3 glucanase, peroxidase, polyphenol oxidase and phenolics as well as a remarkable increase of nitric oxide (NO), a probable potent defense-signaling molecule in plant, was observed. Furthermore, treatment of the host with NO donor, sodium nitroprusside, also induced the same defense molecules. The results suggests that NO might be the signaling molecule during abiotic elicitor mediated ISR induction in the host system. 相似文献
7.
In the present study, four endophytic fungi (GM-1, GM-2, GM-3, and GM-4) were tested for their ability to improve soybean plant growth under salinity stress conditions. The seed germination and plant growth were higher in seeds pretreated with endophytic fungal cultures than their controls. The positive influence of fungi on plant growth was supported by gibberellins analysis of culture filtrate (CF), which showed wide diversity and various concentrations of GAs. Specifically, GA 4, GA 7, GA 8, GA 9, GA 12, and GA 20 were found in fungal CFs. Under salinity stress conditions, GM-1 significantly enhanced the length and fresh weight of soybean plants relative to other fungal treatments. GM-1 effectively mitigated the adverse effects of salinity by limiting lipid peroxidation and accumulating protein content. GM-2, GM-3, and GM-4 also counteracted the salinity induced oxidative stress in soybean plants through reduction of lipid peroxidation and enhancement of protein content, maintaining the length and fresh weight of shoots. The activities of the antioxidant enzymes catalase, superoxide dismutase and peroxidase were inhibited in salinity exposed plants, while GM-1 significantly enhanced these antioxidant enzyme activities in plants under salt stress. GM-1 treatment also showed lower levels of abscisic acid and elevated levels of salicylic acid in plants under salinity stress. Hence, GM-1 was identified as Fusarium verticillioides (teleomorph Gibberella moniliformis) isolate RK01 based on its DNA sequence homology. These results suggest that endophytic fungal ( F. verticillioides) pre-treatment of soybean seeds would be an effective method to promote soybean plant growth under salinity stress conditions. 相似文献
8.
Effects of salicylic acid on some physiological and biochemical characteristics of maize (
Zea mays L.) seedlings under NaCl stress were studied. Pre-soaking treatments of NaCl (0, 50, 100 and 200 mM) were given to maize
seeds in the presence as well as in the absence of 0.5 mM salicylic acid. Two-week-old maize seedlings exhibited significant
decrease in dry weight, root length, shoot length and leaf area on 6 h exposure of 100 and 200 mM NaCl stress. Photosynthetic
pigments and NR activity in leaves decreased sharply with increasing stress levels. Both proline content and lipid peroxidation
(measured in terms of MDA) levels increased significantly under saline conditions. However, seedlings pretreated with 0.5 mM
salicylic acid along with the salinity levels showed enhancement in growth parameters, photosynthetic pigments, NR activity
while, free proline and MDA levels decreased. The results showed that salt-induced deleterious effects in maize seedlings
were significantly encountered by the pretreatment of salicylic acid. It is concluded that 0.5 mM salicylic acid improves
the adaptabilities of maize plants to NaCl stress. 相似文献
9.
Endophytic fungi are potential sources of secondary metabolites; however, they are little known for phytohormones secretion and amelioration of plant growth under abiotic stresses. We isolated a novel endophyte from the roots of Cucumis sativus and identified it as a strain of Exophiala sp. by sequencing internal transcribed spacer/large subunit rDNA and phylogenetic analysis. Prior to identification, culture filtrate (CF) of Exophiala sp. has shown significant growth promotion of Waito‐C [a gibberellins (GAs)‐deficient mutant cultivar] and Dongjin‐byeo (normal GAs biosynthesis cultivar) rice seedlings. CF analysis of Exophiala sp. showed the presence of physiologically active GAs (GA 1, GA 3, GA 4 and GA 7) and inactive GAs (GA 5, GA 8, GA 9, GA 12 and GA 20). Exophiala sp. had higher GAs in its CF than wild‐type strain of Gibberella fujikuroi except GA 3. Influence of Exophiala sp. was assessed on cucumber plant's growth and endogenous abscisic acid (ABA), salicylic acid (SA) and bioactive GAs under salinity and drought stresses. Exophiala sp.‐treated plants have shown significantly higher growth and rescued the host plants from stress promulgated water deficit, osmotic and cellular damage. The altered levels of stress‐responsive ABA showed low level of stress confined to endophyte‐applied plants than control. Elevated levels of SA and bioactive GAs (GA 3 and GA 4) in endophyte‐associated plants suggest stress‐modulating response toward salinity and drought. In conclusion, symbiotic relations between Exophiala and cucumber have reprogrammed the host plant growth under abiotic stresses, thus indicating a possible threshold role of endophytic fungi in stress alleviation. This study could be extended for improving agricultural productivity under extreme environmental conditions. 相似文献
10.
We assessed the role of plant growth-promoting rhizobacteria (PGPR) strains viz. Burkholdera cepacia SE4, Promicromonospora sp. SE188 and Acinetobacter calcoaceticus SE370 in counteracting salinity and drought stress to cucumber plants. The control plants had stunted growth, while PGPR-treated plants had significantly higher biomass and chlorophyll contents under salinity and drought stress. The ameliorative effects of PGPR-application were also evidenced by the increased water potential and decreased electrolytic leakage. The PGPR-applied plants had reduced sodium ion concentration, while the potassium and phosphorus were abundantly present as compared to control under stress. Oxidative stress was mitigated by PGPR through reduced activities of catalase, peroxidase, polyphenol oxidase, and total polyphenol as compared to control. The control plants showed up-regulation of stress-responsive abscisic acid as compared to PGPR application, while salicylic acid and gibberellin 4 were significantly higher in PGPR. In conclusion, the PGPR application might be used in marginalized agricultural lands to increase crop productivity. 相似文献
11.
Abstract Pollen of Saffron ( Crocus sativus L.), a sterile autotriploid plant was studied using scanning and transmission electron microscopy. The pollen of mature anthers had grains not containing pores or furrows, a discontinuous thin exine and a very thick intine crossed by tubules containing granular electron-dense material. Electron transparent material and lipid bodies were abundant in the cytoplasm which also contained a large number of vesicles. A high percentage of pollen grains showed anomalies. 相似文献
12.
Soil salinity is one of the most severe factors limiting growth and physiological response in Raphanus sativus. In this study, the possible role of plant growth promoting bacteria (PGPB) in alleviating soil salinity stress during plant growth under greenhouse conditions was investigated. Increasing salinity in the soil decreased plant growth, photosynthetic pigments content, phytohormones contents (indole-3-acetic acid, IAA and gibberellic acid, GA 3) and mineral uptake compared to soil without salinity. Seeds inoculated with Bacillus subtilis and Pseudomonas fluorescens caused significantly increase in fresh and dry masses of roots and leaves, photosynthetic pigments, proline, total free amino acids and crude protein contents compared to noninoculated ones under salinity. The bacteria also increased phytohormones contents (IAA and GA 3) and the contents of N, P, K +, Ca 2+, and Mg 2+ but decreased ABA contents and Na + and Cl ? content which may contribute in part to activation of processes involved in the alleviation of the effect of salt. 相似文献
13.
Abscisic acid (ABA) regulates plant adaptive responses to various environmental stresses. 9- cis-epoxycarotenoid dioxygenase (NCED) is the key enzyme of ABA biosynthesis in higher plants. A NCED gene, SgNCED1, was overexpressed in transgenic tobacco plants which resulted in 51–77% more accumulation of ABA in leaves. Transgenic tobacco
plants decreased stomatal conductance, transpiration rate, and photosynthetic rate but induced activities of superoxide dismutase
(SOD), catalase (CAT), and ascorbate-peroxidase (APX). Hydrogen peroxide (H 2O 2) and nitric oxide (NO) in leaves were also induced in the transgenic plants. Compared to the wild-type control, the transgenic
plants improved growth under 0.1 M mannitol-induced drought stress and 0.1 M NaCl-induced salinity stress. It is suggested
that the ABA-induced H 2O 2 and NO generation upregulates the stomatal closure and antioxidant enzymes, and therefore increases drought and salinity
tolerance in the transgenic plants. 相似文献
15.
Silicon (Si) application shows beneficial effects on plant growth; however, its effects on the phytohormone and enzymatic antioxidant regulation have not been fully understood. We studied the effects of short-term (6, 12, and 24 h) silicon (0.5, 1.0, and 2.0 mM) application on salinity (NaCl)-induced phytohormonal [abscisic acid (ABA), jasmonic acid (JA), and salicylic acid (SA)] and antioxidant regulation in Oryza sativa. The results showed that Si treatments significantly increased rice plant growth compared to controls under salinity stress. Si treatments reduced the sodium accumulation resulting in low electrolytic leakage and lipid peroxidation compared to control plants under salinity stress. Enzymatic antioxidant (catalase, peroxidase and polyphenol oxidase) responses were more pronounced in control plants than in Si-treated plants under salinity stress. Stress- and defense-related phytohormones like JA were significantly downregulated and SA was irregular after short-term Si applications under salinity stress compared to control. Conversely, ABA was significantly higher after 6 and 12 h but insignificant after 24 h in Si-treated plants under salinity stress. After 6 and 12 h, Si and salinity stress resulted in upregulation of zeaxanthin epoxidase and 9- cis-epoxycarotenoid dioxygenase 1 and 4 ( NCED1 and 4), whereas 24-h treatments significantly downregulated the expressions of these genes compared to those in the control. NCED3 expression increased after 6 and 24 h but it was insignificant after 12 h of Si application compared to control. The current findings indicate that increasing the Si concentrations for longer periods of time can regulate the salinity-induced stress by modulating phytohormonal and enzymatic antioxidants’ responses. 相似文献
16.
Abstract Viability and germinability tests were carried out on the pollen of Crocus sativus L., a sterile triploid commonly known as saffron. Pollen taken from dehiscent anthers was examined by means of vital staining and cytochemical techniques in order to detect its viability; germination in vitro was evaluated. From the results obtained it is evident that saffron pollen is viable at a high percentage (65%) but germinates at a very low percentage. Moreover in vitro germination is very slow, and is accompained by numerous morphological anomalies. The low germination of the pollen is due to the triploidy of C. sativus. 相似文献
17.
Crocus sativus corms were grown in Perlite and watered by half-strength modified Hoagland nutrient solution containing 0, 50, 100, 150, 200 mM NaCl. Growth parameters
and contents of proteins, proline, polyphenols, minerals and saccharides were studied in fibrous roots, contractile roots,
corms and leaves. All plants remained alive and did not display any sign of foliar damage even at 200 mM NaCl. However, the
salinity decreased growth, relative water content and increased contents of proline and Na + in all organs. Total protein content was increased in corms and contractile roots but decreased in fibrous roots. Changes
in protein pattern were also observed. Polyphenol content was increased by salinity in all organs except the leaves. As salinity
increased, content of soluble saccharides decreased except in the contractile roots. 相似文献
18.
Little is known about the physiological adaptation mechanisms of the desert halophyte Nitraria tangutorum Bobr. to the environment. In this study, callus from Nitraria tangutorum Bobr. was used to investigate physiological responses to salinity and the regulatory function of nitric oxide (NO) on catalase
(CAT) activity. Increased dry weight and soluble proteins were observed in the callus exposed to lower salinity (50 and 100 mM
NaCl), whereas 200 mM NaCl led to significant decreases of these two growth parameters, and the levels of proline and soluble
carbohydrates also were enhanced under NaCl treatment. In addition, short-term stress from 50 mM NaCl and the application
of lower sodium nitroprusside (SNP, a NO donor) concentration resulted in decreased levels of malondialdehyde (MDA). In contrast,
higher concentrations of NaCl and SNP induced significant oxidative damage in Nitraria tangutorum Bobr. callus. Analysis based on the fluorescent probe DAF-FM DA revealed that NaCl and SNP treatment led to enhanced levels
of NO in the callus cells. Moreover, the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO)
reduced endogenous NO concentrations and abolished the enhancement in dry weight and the decrease in MDA level under 50-mM-NaCl
treatment. CAT activity increased under salt stress, and the 50-mM-NaCl effect was alleviated by treatment with c-PTIO or
the nitric oxide synthase inhibitor N ω-nitro- l-arginine. We suggest that Nitraria tangutorum Bobr. callus exhibited tolerance to lower-salinity stress. We also showed that increased NO generation in response to salinity
might be associated with regulation of growth, protection against oxidative damage, and excitation of CAT activity in Nitraria tangutorum Bobr. callus under salt stress. 相似文献
19.
AbstractCrocus sativus L. is known in herbal medicine for the various pharmacological effects of its components, but no data are found in literature about its biological properties toward Helicobacter pylori, Plasmodium spp . and Leishmania spp. In this work, the potential anti-bacterial and anti-parasitic effects of crocin and safranal, two important bioactive components in C. sativus, were explored, and also some semi-synthetic derivatives of safranal were tested in order to establish which modifications in the chemical structure could improve the biological activity. According to our promising results, we virtually screened our compounds by means of molecular modeling studies against the main H. pylori enzymes in order to unravel their putative mechanism of action. 相似文献
20.
The genome size and base composition of the triploid Crocus sativus and its two diploid most probable ancestors, C. cartwrightianus and C. thomasii, was investigated and compared inter- and intra-specifically by means of flow cytometry. There was little variation in C. sativus and little difference from C. cartwrightianus. Crocus thomasii was significantly different from the others. Crocus cartwrightianus is the most probable diploid ancestor of C. sativus. 相似文献
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