Mechanisms of salt tolerance and interactive effects of Azospirillum brasilense inoculation on maize cultivars grown under salt stress conditions

2004 ◽  
Vol 44 (2) ◽  
pp. 165-174 ◽  
Author(s):  
M. Abd El-Samad Hamdia ◽  
M.A.K. Shaddad ◽  
M.M. Doaa
2018 ◽  
Vol 48 (3) ◽  
Author(s):  
Yongzhe Ren ◽  
Yanhua Xu ◽  
Wan Teng ◽  
Bin Li ◽  
Tongbao Lin

ABSTRACT: Soil salinity limits agricultural production and is a major obstacle for increasing crop yield. Common wheat is one of the most important crops with allohexaploid characteristic and a highly complex genome. QTL mapping is a useful way to identify genes for quantitative traits such as salinity tolerance in hexaploid wheat. In the present study, a hydroponic trial was carried out to identify quantitative trait loci (QTLs) associated with salinity tolerance of wheat under 150mM NaCl concentration using a recombinant inbred line population (Xiaoyan 54×Jing 411). Values of wheat seedling traits including maximum root length (MRL), root dry weight (RDW), shoot dry weight (SDW), total dry weight (TDW) and the ratio of TDW of wheat plants between salt stress and control (TDWR) were evaluated or calculated. A total of 19QTLs for five traits were detected through composite interval mapping method by using QTL Cartographer version 2.5 under normal and salt stress conditions. These QTLs distributed on 12 chromosomes explained the percentage of phenotypic variation by individual QTL varying from 7.9% to 19.0%. Among them, 11 and six QTLs were detected under normal and salt stress conditions, respectively and two QTLs were detected for TDWR. Some salt tolerance related loci may be pleiotropic. Chromosome 1A, 3A and 7A may harbor crucial candidate genes associated with wheat salt tolerance. Our results would be helpful for the marker assisted selection to breed wheat varieties with improved salt tolerance.


2020 ◽  
Vol 44 ◽  
Author(s):  
André Dias de Azevedo Neto ◽  
Katia Núbia Azevedo Barros Mota ◽  
Petterson Costa Conceição Silva ◽  
Alide Mitsue Watanabe Cova ◽  
Rogério Ferreira Ribas ◽  
...  

ABSTRACT Salinity is one of the main limiting factors for crop growth. The metabolic responses to salt stress are variable and depend on species characteristics. This study aimed to select sunflower genotypes tolerant to salt stress and evaluate some mechanisms of salt tolerance in two contrasting (salt-tolerant and salt-sensitive) genotypes. In the first assay, the biomass production and the accumulation of Na+ and K+ in 26 sunflower genotypes were evaluated. Genotypes AG963, AG967, AG972, BRS321, BRS324, H251, H360 and H863 showed lower biomass production and were characterized as salt-sensitive and the genotypes BRS323, Catisol, EXP11-26, EXP44-49, EXP60050, EXP887, HLA860HO and Olisun 5 showed higher biomass production and were considered salt-tolerant. The high K+ content and the low Na+ content in the leaves were the ion traits related to salt tolerance and can be used in sunflower breeding programs for this purpose. In the second assay, the plants of salt-tolerant BRS323 had lower Na+ and Cl- contents and higher levels of K+ than plants of salt-sensitive AG967. A better homeostasis in the mechanisms of transport, distribution and accumulation of inorganic solutes in conjunction with a more efficient osmoregulation mechanism through the synthesis of organic solutes may, at least in part, explain the greater salt-tolerance of BRS323 genotype in comparison to AG967.


2021 ◽  
Vol 12 ◽  
Author(s):  
Pu-Sheng Li ◽  
Wei-Liang Kong ◽  
Xiao-Qin Wu ◽  
Yu Zhang

Salt stress is one of the major abiotic stresses that affects plant growth and development. The use of plant growth-promoting rhizobacteria to mitigcate salt stress damage in plants is an important way to promote crop growth under salt stress conditions. Rahnella aquatilis JZ-GX1 is a plant growth-promoting rhizobacterial strain, but it is not clear whether it can improve the salt tolerance of plants, and in particular, the role of volatile substances in plant salt tolerance is unknown. We investigated the effects of volatile organic compounds (VOCs) from JZ-GX1 on the growth performance, osmotic substances, ionic balance and antioxidant enzyme activities of acacia seedlings treated with 0 and 100mm NaCl and explored the VOCs associated with the JZ-GX1 strain. The results showed that compared to untreated seedlings, seedlings exposed to plant growth-promoting rhizobacterium JZ-GX1 via direct contact with plant roots under salt stress conditions exhibited increases in fresh weight, lateral root number and primary root length equal to approximately 155.1, 95.4, and 71.3%, respectively. Robinia pseudoacacia seedlings exposed to VOCs of the JZ-GX1 strain showed increases in biomass, soil and plant analyser development values and lateral root numbers equal to 132.1, 101.6, and 166.7%, respectively. Additionally, decreases in malondialdehyde, superoxide anion (O2−) and hydrogen peroxide (H2O2) contents and increases in proline contents and superoxide dismutase, peroxidase and glutathione reductase activities were observed in acacia leaves. Importantly, the sodium-potassium ratios in the roots, stems, and leaves of acacia exposed to VOCs of the JZ-GX1 strain were significantly lower than those in the control samples, and this change in ion homeostasis was consistent with the upregulated expression of the (Na+, K+)/H+ reverse cotransporter RpNHX1 in plant roots. Through GC-MS and creatine chromatography, we also found that 2,3-butanediol in the volatile gases of the JZ-GX1 strain was one of the important signaling substances for improving the salt tolerance of plants. The results showed that R. aquatilis JZ-GX1 can promote the growth and yield of R. pseudoacacia under normal and salt stress conditions. JZ-GX1 VOCs have good potential as protectants for improving the salt tolerance of plants, opening a window of opportunity for their application in salinized soils.


Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2549
Author(s):  
Md Al Samsul Huqe ◽  
Md Sabibul Haque ◽  
Ashaduzzaman Sagar ◽  
Md Nesar Uddin ◽  
Md Alamgir Hossain ◽  
...  

Increasing soil salinity due to global warming severely restricts crop growth and yield. To select and recommend salt-tolerant cultivars, extensive genotypic screening and examination of plants’ morpho-physiological responses to salt stress are required. In this study, 18 prescreened maize hybrid cultivars were examined at the early growth stage under a hydroponic system using multivariate analysis to demonstrate the genotypic and phenotypic variations of the selected cultivars under salt stress. The seedlings of all maize cultivars were evaluated with two salt levels: control (without NaCl) and salt stress (12 dS m−1 simulated with NaCl) for 28 d. A total of 18 morpho-physiological and ion accumulation traits were dissected using multivariate analysis, and salt tolerance index (STI) values of the examined traits were evaluated for grouping of cultivars into salt-tolerant and -sensitive groups. Salt stress significantly declined all measured traits except root–shoot ratio (RSR), while the cultivars responded differently. The cultivars were grouped into three clusters and the cultivars in Cluster-1 such as Prabhat, UniGreen NK41, Bisco 51, UniGreen UB100, Bharati 981 and Star Beej 7Star exhibited salt tolerance to a greater extent, accounting for higher STI in comparison to other cultivars grouped in Cluster-2 and Cluster-3. The high heritability (h2bs, >60%) and genetic advance (GAM, >20%) were recorded in 13 measured traits, indicating considerable genetic variations present in these traits. Therefore, using multivariate analysis based on the measured traits, six hybrid maize cultivars were selected as salt-tolerant and some traits such as Total Fresh Weight (TFW), Total Dry Weight (TDW), Total Na+, Total K+ contents and K+–Na+ Ratio could be effectively used for the selection criteria evaluating salt-tolerant maize genotypes at the early seedling stage.


2021 ◽  
Vol 22 (22) ◽  
pp. 12238
Author(s):  
Zhongyu Wang ◽  
Ning Li ◽  
Qinghui Yu ◽  
Huan Wang

Soil salinization is a major environmental stress that causes crop yield reductions worldwide. Therefore, the cultivation of salt-tolerant crops is an effective way to sustain crop yield. Tomatoes are one of the vegetable crops that are moderately sensitive to salt stress. Global market demand for tomatoes is huge and growing. In recent years, the mechanisms of salt tolerance in tomatoes have been extensively investigated; however, the molecular mechanism through which non-coding RNAs (ncRNAs) respond to salt stress is not well understood. In this study, we utilized small RNA sequencing and whole transcriptome sequencing technology to identify salt-responsive microRNAs (miRNAs), messenger RNAs (mRNAs), and circular RNAs (circRNAs) in roots of M82 cultivated tomato and Solanum pennellii (S. pennellii) wild tomato under salt stress. Based on the theory of competitive endogenous RNA (ceRNA), we also established several salt-responsive ceRNA networks. The results showed that circRNAs could act as miRNA sponges in the regulation of target mRNAs of miRNAs, thus participating in the response to salt stress. This study provides insights into the mechanisms of salt tolerance in tomatoes and serves as an effective reference for improving the salt tolerance of salt-sensitive cultivars.


2015 ◽  
Vol 43 (2) ◽  
pp. 501-506
Author(s):  
Mohamad Al HASSAN ◽  
Gholamreza GOHARI ◽  
Monica BOSCAIU ◽  
Oscar VICENTE ◽  
Marius N. GRIGORE

The anatomic structure of roots and culms of two Juncus species with different degrees of salt tolerance was analysed in plants grown for two months under salt stress (NaCl treatments) and in control, non-treated plants. The aim of the study was not only to compare the anatomical structures of a halophyte (J. acutus) and a related glycophyte (J. articulatus), but mostly to assess whether salt stress induced anatomical modifications, by identifying differences between control and treated plants. Several slight differences have been indeed detected, in terms of endodermis type, development of aerenchyma and extent of sclerenchyma in perivascular sheaths. The role of Casparian endodermis was here discussed in relation to its complex implications in controlling salt influx at the root level that is an efficient mechanism involved in halophytes. Aerenchyma is a common feature found in marshy halophytes, allowing them to survive naturally under flooding conditions; however, when occurring in non-waterlogged plants, as is the case of this study, it should be regarded as a genetically, constitutive adaptation rather than an inducible one. Nevertheless, such anatomic modifications should be regarded as mere alterations due to stress – that is, as stress responses – and not as truly adaptations to salinity. In this context, the nature of these modifications – either considered as adaptations or damage indicators of salt stress – should be further reconsidered.


2021 ◽  
Vol 26 (3) ◽  
pp. 151
Author(s):  
Galang Rizki Ramadhan ◽  
Sholeh Avivi ◽  
Bambang Sugiharto ◽  
Wahyu Indra Duwi Fanata

Plants activate the unfolded protein response as part of cellular adaptation, thereby maintaining the endoplasmic reticulum homeostasis during external stresses exposure. In this study, we examined the relationship between the degree of salt tolerance and unfolded protein response-related gene expression in India salt-tolerant Pokkali and INPARI 35 varieties compared to the Indica salt-sensitive counterpart IR64 and INPARI 4 varieties.  Our result showed that the salt tolerance of Pokkali and INPARI 35 had been confirmed by their higher survival rate, higher chlorophyll content, lower electrolyte leakage, and lower H2O2 and malondialdehyde content under salt stress conditions. Furthermore, the expression of unfolded protein response genes was highest in INPARI 35, whereas IR64 and INPARI 4 exhibited low gene induction during endoplasmic reticulum stress conditions. Among the four examined varieties the salt tolerant Pokkali surprisingly showed the lowest induction of all examined unfolded protein response-related genes. These results indicated the possibility that unfolded protein response supports the rice plant for adapting to the saline environment.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12683
Author(s):  
Rui Yang ◽  
Zhifen Yang ◽  
Ze Peng ◽  
Fang He ◽  
Luxi Shi ◽  
...  

Background Soil salinity is a major environmental stress that restricts crop growth and yield. Methods Here, crucial proteins and biological pathways were investigated under salt-stress and recovery conditions in Tritipyrum ‘Y1805’ using the data-independent acquisition proteomics techniques to explore its salt-tolerance mechanism. Results In total, 44 and 102 differentially expressed proteins (DEPs) were identified in ‘Y1805’ under salt-stress and recovery conditions, respectively. A proteome-transcriptome-associated analysis revealed that the expression patterns of 13 and 25 DEPs were the same under salt-stress and recovery conditions, respectively. ‘Response to stimulus’, ‘antioxidant activity’, ‘carbohydrate metabolism’, ‘amino acid metabolism’, ‘signal transduction’, ‘transport and catabolism’ and ‘biosynthesis of other secondary metabolites’ were present under both conditions in ‘Y1805’. In addition, ‘energy metabolism’ and ‘lipid metabolism’ were recovery-specific pathways, while ‘antioxidant activity’, and ‘molecular function regulator’ under salt-stress conditions, and ‘virion’ and ‘virion part’ during recovery, were ‘Y1805’-specific compared with the salt-sensitive wheat ‘Chinese Spring’. ‘Y1805’ contained eight specific DEPs related to salt-stress responses. The strong salt tolerance of ‘Y1805’ could be attributed to the strengthened cell walls, reactive oxygen species scavenging, osmoregulation, phytohormone regulation, transient growth arrest, enhanced respiration, transcriptional regulation and error information processing. These data will facilitate an understanding of the molecular mechanisms of salt tolerance and aid in the breeding of salt-tolerant wheat.


2018 ◽  
Vol 19 (9) ◽  
pp. 2609 ◽  
Author(s):  
Ping Li ◽  
Hong Yang ◽  
Gaojing Liu ◽  
Wenzhang Ma ◽  
Chuanhong Li ◽  
...  

Senescence-associated receptor-like kinase (SARK) family members in Arabidopsis, soybean, and rice are known to be positive regulators of leaf senescence. In the meantime, SARKs are extensively involved in stress response. However, their function and underlying molecular mechanism in stress responses in moss are not well known. Here, we investigated functional roles of SARK isolated from Physcomitrella patens (PpSARK) in salt stress response and senescence. PpSARK transcripts significantly accumulated under NaCl and abscisic acid (ABA) treatments, with higher expression in the moss gametophyte stage. Insertional gain-of-function mutants of PpSARK (PpSARKg) were more tolerant to salt stress and ABA than wild type (WT), whereas senescence of mutants was delayed during the protonema stage. Expression of stress-responsive genes in the ABA related pathway, such as PpABI3, PpABI5, PpPP2C, and PpLEA were significantly higher in PpSARKg and WT under salt stress conditions, suggesting that PpSARK might positively regulate salt tolerance via an ABA-related pathway. Endogenous ABA contents also increased 3-fold under salt stress conditions. These results indicate that PpSARK functions as a positive regulator in salt stress responses, while possibly functioning as a negative regulator in senescence in moss.


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