Effect of salinity on root-nodule conductance to the oxygen diffusion in the Cicer arietinum Mesorhizobium ciceri symbiosis

Department of Biology, Faculté des Sciences de Tunis, Tunis-Ville, Tūnis, Tunisia
Journal of Plant Physiology (Impact Factor: 2.56). 09/2007; 164(8):1028-36. DOI: 10.1016/j.jplph.2006.05.016
Source: PubMed


Nodule conductance to O2 diffusion has been involved as a major factor of the inhibition of N2 fixation by soil salinity that severely reduces the production of grain legumes. In order to determine the effect of this constraint on the nodule conductance, oxygen uptake by the nodulated roots of Cicer arietinum was measured by recording the concentration of O2 as a function of pO2 in a gas-tight incubator. After germination and inoculation with the strain Mesorhizobium ciceri UPMCa7, the varieties Amdoun 1 and INRAT 93-1 were hydroponically grown in a glasshouse on 1L glass bottles filled with nutrient solution containing 25 mM NaCl. Salinity induced a marked decrease in shoot (30% versus 14%), root (43% versus 20%), and nodule biomass (100% versus 43%) for Amdoun 1 relative to INRAT 93-1. Although salinity completely prevented nodule formation in the sensitive variety Amdoun 1, nodule number and biomass were higher in the first than in the second variety in the absence of salt. This effect was associated with a significantly higher O2 uptake by nodulated root (510 versus 255 micromol O2 plant(-1)h(-1)) and nodule conductance (20 versus 5 microm s(-1)) in Amdoun 1 than in INRAT 93-1. Salinity did not significantly change the nodule conductance and nodule permeability for INRAT 93-1. Thus, the salt tolerance of this variety appears to be associated with stability in nodule conductance and the capacity to form nodules under salt constraint.

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Available from: Mainassara Zaman-Allah, Oct 10, 2015
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    • "Pre-sowing sodium chloride treatment significantly affected the seedlings as well as reduced the nodule number, their biomass and the nitrogenase activity at mature stage (Table 1). In this study, decline in nodule number and nodule fresh/dry biomass under salt stress is in confirmation with the reported findings (Ashraf and Bashir, 2003; Ltaief et al., 2007). Nodules of pea are noted to be differentially affected as compared with other vegetative parts as a consequence of salt stress (Cordovilla et al., 1999; Salah et al., 2009). "
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    ABSTRACT: The response of pea (Pisum sativum L.) cv. Climax seeds imbibed with 24-epibrassinolide (EBL) and sodium chloride (NaCl) prior to sowing was evaluated. Soaking of seeds in two different concentrations of EBL (5 and 10 μM) for 4 hours, caused an increase in germination, embryo axis length and most of the aspects of shoot and root growth at seedling stage, maturity stage (90 DAS) along with seed yield at the time of harvest. Both the EBL treatments (5 and 10 μM) improved the above mentioned attributes but maximum improvement was observed in response to EBL concentration of 10 μM with respect to the control. At seedling stage, EBL (10 μM) significantly enhanced the fresh and dry biomass, seedling height (shoot + root), photosynthesis rate (Pn), stomatal conductance (gs), total chlorophyll contents (Chl), proline contents, superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), nitrate reductase activity (NRA) and nitrite reductase activity (NiRA) as compared to control (water soaked alone). Similarly, at maturity stage the plants grown from seeds pre-imbibed in EBL (10 μM) also exhibited the augmentation in dry biomass, physiological aspects (Pn, gs and Chl), enzymatic activities (NRA, NiRA, SOD, POD, CAT), leaf proline contents, nodule number and nodule dry biomass in comparison to water imbibed control. Seed attributes like seed yield, seed number and seed protein contents also showed the improvement in response to EBL (10 μM) at the time of harvest. Although, plants subjected to saline stress exhibited a reduction in all the morpho-physiological and enzymatic attributes (NRA and NiRA) but proline contents and enzymatic activities of antioxidants were enhanced in response to NaCl stress. However, deleterious effects induced by salinity were reduced if seeds were treated with EBL before or after NaCl imbibitions.
    Australian Journal of Crop Science 05/2011; 5(5). · 1.63 Impact Factor
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    • "Buckets were placed alternating I-93 and Amdoum positions in a greenhouse portion showing homogeneity in light and temperature. Inter-Bucket effects were previously tested [89]. "
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    ABSTRACT: The combination of high-throughput transcript profiling and next-generation sequencing technologies is a prerequisite for genome-wide comprehensive transcriptome analysis. Our recent innovation of deepSuperSAGE is based on an advanced SuperSAGE protocol and its combination with massively parallel pyrosequencing on Roche's 454 sequencing platform. As a demonstration of the power of this combination, we have chosen the salt stress transcriptomes of roots and nodules of the third most important legume crop chickpea (Cicer arietinum L.). While our report is more technology-oriented, it nevertheless addresses a major world-wide problem for crops generally: high salinity. Together with low temperatures and water stress, high salinity is responsible for crop losses of millions of tons of various legume (and other) crops. Continuously deteriorating environmental conditions will combine with salinity stress to further compromise crop yields. As a good example for such stress-exposed crop plants, we started to characterize salt stress responses of chickpeas on the transcriptome level. We used deepSuperSAGE to detect early global transcriptome changes in salt-stressed chickpea. The salt stress responses of 86,919 transcripts representing 17,918 unique 26 bp deepSuperSAGE tags (UniTags) from roots of the salt-tolerant variety INRAT-93 two hours after treatment with 25 mM NaCl were characterized. Additionally, the expression of 57,281 transcripts representing 13,115 UniTags was monitored in nodules of the same plants. From a total of 144,200 analyzed 26 bp tags in roots and nodules together, 21,401 unique transcripts were identified. Of these, only 363 and 106 specific transcripts, respectively, were commonly up- or down-regulated (>3.0-fold) under salt stress in both organs, witnessing a differential organ-specific response to stress.Profiting from recent pioneer works on massive cDNA sequencing in chickpea, more than 9,400 UniTags were able to be linked to UniProt entries. Additionally, gene ontology (GO) categories over-representation analysis enabled to filter out enriched biological processes among the differentially expressed UniTags. Subsequently, the gathered information was further cross-checked with stress-related pathways. From several filtered pathways, here we focus exemplarily on transcripts associated with the generation and scavenging of reactive oxygen species (ROS), as well as on transcripts involved in Na+ homeostasis. Although both processes are already very well characterized in other plants, the information generated in the present work is of high value. Information on expression profiles and sequence similarity for several hundreds of transcripts of potential interest is now available. This report demonstrates, that the combination of the high-throughput transcriptome profiling technology SuperSAGE with one of the next-generation sequencing platforms allows deep insights into the first molecular reactions of a plant exposed to salinity. Cross validation with recent reports enriched the information about the salt stress dynamics of more than 9,000 chickpea ESTs, and enlarged their pool of alternative transcripts isoforms. As an example for the high resolution of the employed technology that we coin deepSuperSAGE, we demonstrate that ROS-scavenging and -generating pathways undergo strong global transcriptome changes in chickpea roots and nodules already 2 hours after onset of moderate salt stress (25 mM NaCl). Additionally, a set of more than 15 candidate transcripts are proposed to be potential components of the salt overly sensitive (SOS) pathway in chickpea. Newly identified transcript isoforms are potential targets for breeding novel cultivars with high salinity tolerance. We demonstrate that these targets can be integrated into breeding schemes by micro-arrays and RT-PCR assays downstream of the generation of 26 bp tags by SuperSAGE.
    BMC Plant Biology 02/2011; 11(1):31. DOI:10.1186/1471-2229-11-31 · 3.81 Impact Factor
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    • "Maximum salinity tolerance was achieved in Pusa-329 through mycorrhizal inoculation at 4 dS m -1 in the rooting medium, where complete amelioration of negative eff ects of salinity was observed and the shoot and root biomass were even greater than in the untreated controls. Th e results from this study agree with previous data (Rabie and Almadini 2005; Sannazzaro et al. 2006; Tufenkci et al. 2006; Sharifi et al. 2007). "
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    ABSTRACT: Most legumes in natural conditions form a symbiosis with arbuscular mycorrhizal (AM) fungi. AM fungi in saline soils have been reported to improve salinity tolerance and growth in plants. In the present study, interaction between mycorrhizal fungus, Glomus mosseae, and salinity stress in relation to plant growth, nitrogen fixation, and nutrient accumulation was evaluated in Cicer arietinum (L.) (chickpea). Two genotypes of chickpea (Pusa-329, salt tolerant, and Pusa-240, salt sensitive) were compared under different levels of salinity with and without mycorrhizal inoculations. Salt stress resulted in a noticeable decline in shoot and root dry matter accumulation, resulting in a decline in the shoot-to-root ratio (SRR) in all plants. However, Pusa-329 was found to be more tolerant to salinity than Pusa- 240. AM plants exhibited better growth and biomass accumulation under stressed as well as unstressed conditions. Mycorrhizal infection (MI) was reduced with increasing salinity levels, but the mycorrhizal dependency (MD) increased, which was more evident in Pusa-240. Salinity resulted in a marked decline in the nodule dry weights, whereas a surge in the nodule number was recorded. Nitrogenase activity was reduced with increasing salt concentrations. AM plants had considerably higher nodule numbers, dry weights, and nitrogenase activity under both saline and nonsaline environments. Pusa-329 had a comparatively lower Na+ concentration and higher K+ and Ca2+ concentrations than Pusa- 240. Although nitrogen (N) and phosphorus (P) contents declined with increasing salinity, Pusa-329 had higher levels of N and P as compared with Pusa-240. Plants inoculated with Glomus mosseae had better plant growth and nitrogen fi xation under salt stress.
    Turkish Journal of Agriculture and Forestry 01/2011; 35:205-214. DOI:10.3906/tar-0908-12 · 0.93 Impact Factor
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