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1.
Sameh Sassi Esther M. Gonzalez Samir Aydi Cesar Arrese-Igor Chedly Abdelly 《Plant and Soil》2008,312(1-2):39-48
The response to the osmotic effects of drought may largely vary not only between species but even cultivars of the same species. Gaining knowledge of the reasons underlying these differential responses can be critical in breeding programs to obtain lines with enhanced performance under drought or salinity. In this work, the responses to osmotic stress of two common bean (Phaseolus vulgaris L.) cultivars with contrasting tolerance (Coco blanc, sensitive, and Flamingo, tolerant) have been assessed by analyzing a full array of nodule parameters (enzyme activities, carbohydrate and organic acids content and antioxidant activity). The aim of this work was to study the likely involvement of carbon flux shortage in the decline of N2 fixation under osmotic stress. The maintenance of sucrolytic activities, particularly sucrose synthase, to keep an adequate glycolytic flux, together with isocitrate dehydrogenase, to balance C/N interactions, associated with a suitable antioxidant defense may be relevant for osmotic tolerance in common bean nitrogen fixation. 相似文献
2.
Growth, nitrogen fixation and ammonium assimilation in common bean (Phaseolus vulgaris L) subjected to iron deficiency 总被引:1,自引:0,他引:1
Tarek Slatni Abdelmajid Krouma Samir Aydi Chiraz Chaiffi Houda Gouia Chedly Abdelly 《Plant and Soil》2008,312(1-2):49-57
A greenhouse experiment was carried out aiming to study the effect of iron deficiency on nitrogen fixation and ammonium assimilation in common bean nodules. Host-plant and nodule growth, symbiotic nitrogen fixation, glutamine synthetase (GS) and glutamate dehydrogenase (GDH) were analyzed in two common bean varieties subjected to iron deficiency. Results showed that host-plant and nodules growth, nitrogen fixation and GS activity decreased when under Fe-deficiency against an important increase of ammonium accumulation and GDH activity. Tolerant variety Flamingo is clearly less affected by iron deficiency than the sensitive one, Coco blanc. The allocation of iron to nodules and Fe use-efficiency for nodule growth and symbiotic nitrogen fixation were on the basis of the symbiotic performance of Flamingo under iron deprivation. Under Fe-deficiency, GDH take over GS the ammonium assimilation activity, particularly in the tolerant variety. 相似文献
3.
Phosphorus is one of several factors which affect N2 fixation and along with N, is a principal yield-limiting nutrient in many regions of the world. Since the legume plant is an essential partner in symbiotic N2 fixation, knowledge of host genotype variability for this process at different levels of P availability will be useful when breeding bean cultivars for enhanced N2 fixation. The objective of this study was to obtain common bean (Phaseolus vulgaris L.) lines able with enhanced ability to support biological N2 fixation under different levels of available phosphorus.Experiments were conducted in a growth room using a sand-alumina system to provide different levels of available P and in the field on a low-N soil. In the growth room studies, P availability strongly affected plant growth and traits related to N2 fixation. No significant interaction was detected for P levels × bean lines, indicating that bean lines performed similarly at both high and low P levels.Total shoot N was used as a direct and indirect measure of N2-fixation potential under growth room (N-free media) and field (low-N soil) conditions, respectively. Based on this criterion, two of the 41 and 54 inbred backcross lines of a segregating population evaluated in the growth room and the field, respectively, contained greater shoot N content than the recurrent parent and N shoot contents similar to the donor parent. Variability of N2 fixation under low available P was observed, and high N2 fixing and high yielding progeny lines were detected. 相似文献
4.
Growth and Photosynthetic Characteristics in Pearl Millet under Water Stress and Different Potassium Supply 总被引:1,自引:0,他引:1
Influence of supra-optimal concentrations of K on growth, water relations, and photosynthetic capacity in pearl millet under severe water deficit conditions was assessed in a glasshouse. Nineteen-days-old plants of two lines, ICMV-94133 and WCA-78, of Pennisetum glaucum (L.) R.Br. were subjected for 30 d to 235.0, 352.5, and 470.0 mg(K) kg–1(soil) and two water regimes (100 and 30 % field capacity). Increasing K supply did not alleviate the effect of water deficit on the growth of two lines of pearl millet since additional amount of K in the growth medium had no effect on shoot dry mass, relative growth rate, plant leaf area, net assimilation rate, or leaf area ratio, although there was significant effect of drought stress on these variables. Soil moisture had a significant effect on net photosynthetic rate (P
N), transpiration rate, stomatal conductance, and water use efficiency of both pearl millet lines, but there was no significant effect of varying K supply on these variables. In WCA-78 an ameliorative effect of increasing supply of K on P
N was observed under water deficit. Chlorophyll (Chl) a and b contents increased significantly in both lines with increase in K supply under well watered conditions, but under water deficit they increased only in ICMV-94133. Chl a/b ratios were reduced significantly in WCA-78 with increasing K supply under both watering regimes, but by contrast, in ICMV-94133 this variable was decreased only under water stress. Leaf water potential and osmotic potential of both lines decreased significantly with the imposition of drought. Leaf pressure potential in both lines increased with increase in K supply under water stress. Contents of total free amino acids in the leaves of both pearl millet lines increased significantly with increase in K supply under water stress. Potassium supply had no effect on leaf soluble sugars or soluble proteins. Considerable osmotic adjustment occurred in pearl millet plants experiencing water deficit under high K supply. 相似文献
5.
Marta Susana Dardanelli Paola Solange González Daniela Beatriz Medeot Natalia Soledad Paulucci Miguel Ángel Bueno Mirta Beatriz Garcia 《Symbiosis (Philadelphia, Pa.)》2009,47(3):175-180
The effects of saline and osmotic stress on four peanut rhizobia, plant growth and symbiotic N2-fixation inArachis hypogaea were studied. Abiotic stress was applied by adding either 100 mM NaCl or 20 mM PEG6000. At the rhizobial level,Bradyrhizobium ATCC10317 and TAL1000 showed stronger tolerance to stress than TAL1371 and SEMIA6144. The effect of salinity on the bacterium-plant
association was studied by using the variety Blanco Manfredi M68. In the absence of stresses, all the strains induced a significantly
higher number of nodules on the roots, although TAL1371 and SEMIA6144 were more effective. Both stresses affected the interaction
process, while TALl371 was the best partner. 相似文献
6.
Saber Kouas Julien Louche Ahmed Debez Claude Plassard Jean Jacques Drevon Chedly Abdelly 《Symbiosis (Philadelphia, Pa.)》2009,47(3):141-149
Changes in growth, symbiotic nitrogen fixation (SNF), acid phosphatase (ACP), and phytase activities to phosphorus availability
(15 and 60 μmol KH2PO4 plant−1 week−1) were compared in two recombinant lines (115 and 147) of common bean. Plant growth, nodulation and SNF were genotype and
P level-dependent. 147 was more affected by P shortage (15 μmol P) than 115. Four ACP types were revealed in the nodules of
both lines, ACP1 exhibiting a higher specific activity under P shortage as compared to the 60 μmol P treatment, especially
in 115. A single phytase was revealed for the nodules of both lines and was significantly enhanced by P deficiency. Three
ACP types were found in roots and leaves, showing increasing activity under P deficiency, especially in 115. Regardless of
P supply, leaf ACP specific activity was higher than that of nodules and roots in the both lines. Interestingly, phosphorus
use efficiency for N2 fixation significantly correlated to nodule ACP activity under P shortage in the both lines. The relatively better performance
of 115 as compared to 147 under P deficiency could be partly ascribed to the ability of 115 to maintain higher ACP activity.
This enzyme might be involved in the remobilization of the plant Pi and its utilization for SNF. 相似文献
7.
PREMACHANDRA GNANASIRI S.; SANEOKA HIROHUMI; OGATA SHOITSU 《Journal of experimental botany》1991,42(6):739-745
A field experiment was conducted to investigate the effect ofK nutrition under water stress conditions on cell membrane stabilitymeasured by the polyethylene glycol test, plant growth, internalplant water relations and solute and mineral concentrationsin maize (Zea mays L.). Water-stressed plants showed greateradaptation to water deficits at higher K levels. Cell membranestability increased, leaf water potential and osmotic potentialdecreased, turgor potential increased and stomatal resistancedecreased with increasing K nutrition. Osmotic adjustment wasevident and it may have been influenced by increased K+ concentrationsin leaf tissues with increasing K nutrition. Higher leaf thicknessand higher leaf water content were observed at higher K levels.Results suggested that higher supplies of K nutrition may increaseplant production during periods of water stress. Key words: Zea mays L., cell membrane stability, leaf water potential, osmotic adjustment, osmotic potential, potassium nutrition, water stress 相似文献
8.
Sameh Sassi Samir Aydi Esther M. Gonzalez Cesar Arrese-Igor Chedly Abdelly 《Symbiosis (Philadelphia, Pa.)》2010,52(1):1-10
Drought and salinity are environmental constraints that affect crop yields worldwide. In nature, both stresses are multifaceted
problems that are usually associated with other adverse circumstances which limit plant performance such as water shortage
and nutrient deficits. In order to assess common features of both stresses, the effects of mannitol-induced osmotic stress
were monitored using two Phaseolus vulgaris cultivars, Cv. ‘Flamingo’ (tolerant) and Cv. ‘Coco Blanc’ (sensitive) which differed in their drought and salinity tolerance.
Growth, water relations, organic and inorganic compound accumulation and soluble protein contents were measured in leaves
and nodules of these N2-fixing plants. The aim of the present study was to check whether osmotic stress tolerance is associated with accumulation
of some of these compounds either in leaves, nodules or both organs. At the whole-plant level, Cv. ‘Flamingo’ showed a better
maintenance of plant biomass and shoot water status. At the cell level, this was related to a better osmotic adjustment ability
both in leaves and nodules and also to a better adjustment of the cell wall elasticity. At the metabolic level, the contrasting
accumulation of the different amino acids in nodules of each cultivar suggested that amino acids pathways can be regulated
to different degrees under stress conditions. At the metabolic level, it seems that symbiosis in the sink organ (the nodule)
plays a crucial role in conferring drought and salinity tolerance in the common bean. 相似文献
9.
Thirty-days-old plants of two cultivars of okra (Hibiscus esculentus L.), Sabzpari and Chinese-red, were subjected for 30 d to two water regimes (100 and 60 % field capacity). Leaf water potential and osmotic potential of both lines decreased significantly with the imposition of drought. Both the leaf pressure potential and osmotic adjustment were much lower in Chinese-red than those in Sabzpari. Chlorophyll (Chl) b content increased, whereas Chl a content remained unchanged and thus Chl a/b ratios were reduced in both lines. Drought stress also caused a significant reduction in net photosynthetic rate (P
N), transpiration rate (E), stomatal conductance (g
s), and water use efficiency (WUE) especially in cv. Sabzpari. The lines did not differ in intrinsic WUE (P
Ngs) or intercellular/ambient CO2 ratio. Overall, the growth of two okra cultivars was positively correlated with P
N, but not with g
s or P
N/E, and negatively correlated with osmotic adjustment. 相似文献
10.
Tarek Slatni Abdelmajid Krouma Houda Gouia Chedly Abdelly 《Symbiosis (Philadelphia, Pa.)》2009,47(1):35-42
Iron is an essential nutrient for plants, especially in symbiotic N2-fixing legumes. Although abundant in the soil, iron is generally not available to plants as it is predominantly in an insoluble
form (FeIII) . Mono- and dicotyledonous plants, except Grarnineae, have developed morphological and physiological responses, notably
an increase in rhizosphere acidification (H+-ATPase) and an enhanced plasma membrane ferric chelate reductase activity (Fe-CR) in the roots. However, studies on the physiological
responses of root nodules are lacking. The present study was initiated to investigate the acidification capacity and Fe-CR
activity of nodulated roots, and intact nodules, in two contrasting common bean varieties, Coco blanc sensitive to iron deficiency
and Flamingo tolerant to iron deficiency. The discovery of an induction of H+-ATPase and Fe-CR activities in root nodules of commonbean under iron deficiency, suggests that these organs participate in
improving iron availability for the contained bacteroids. 相似文献
11.
Tarek Slatni Gianpiero ViganiImen Ben Salah Saber KouasMarta Dell’Orto Houda GouiaGraziano Zocchi Chedly Abdelly 《Plant science》2011,181(2):151-158
Iron is an important nutrient in N2-fixing legume nodules. The demand for this micronutrient increases during the symbiosis establishment, where the metal is utilized for the synthesis of various iron-containing proteins in both the plant and the bacteroid. Unfortunately, in spite of its importance, iron is poorly available to plant uptake since its solubility is very low when in its oxidized form Fe(III). In the present study, the effect of iron deficiency on the activity of some proteins involved in Strategy I response, such as Fe-chelate reductase (FC-R), H+-ATPase, and phosphoenolpyruvate carboxylase (PEPC) and the protein level of iron regulated transporter (IRT1) and H+-ATPase proteins has been investigated in both roots and nodules of a tolerant (Flamingo) and a susceptible (Coco blanc) cultivar of common bean plants. The main results of this study show that the symbiotic tolerance of Flamingo can be ascribed to a greater increase in the FC-R and H+-ATPase activities in both roots and nodules, leading to a more efficient Fe supply to nodulating tissues. The strong increase in PEPC activity and organic acid content, in the Flamingo root nodules, suggests that under iron deficiency nodules can modify their metabolism in order to sustain those activities necessary to acquire Fe directly from the soil solution. 相似文献
12.
Elevated CO2 mitigates chilling-induced water stress and photosynthetic reduction during chilling 总被引:1,自引:1,他引:0
Bean, cucumber and corn plants were grown in controlled-environment chambers at 25/18 °C day/night temperature and either ambient (350 μmol mol?1) or elevated (700 μmol mol?1) CO2 concentration, and at 20–30 d after emergence they were exposed to a 24 h chilling treatment (6.5 ± 1.5 °C) at their growth CO2 concentration. Whole-plant transpiration rates (per unit leaf area basis) during the first 3 h of chilling were about 26,28 and 13% lower at elevated than at ambient CO2 for bean, cucumber and corn, respectively. The decline in leaf water potential (ψL) and visible wilting of bean and cucumber during chilling were significantly less at elevated than at ambient CO2. Corn ψL was not significantly affected by chilling, and corn did not exhibit any other symptoms of chilling-induced water stress. Leaf osmotic potentials (measured before chilling only) of bean and cucumber were more negative at elevated than at ambient CO2, and the corresponding calculated leaf turgor potentials were significantly higher at elevated than at ambient CO2. Leaf relative water content (RWC) during chilling at ambient CO2fell to 62 and 48% for bean and cucumber, respectively. RWC during chilling at elevated CO2 was never below 79% for bean or 63% for cucumber. Corn RWC was not measured. After 24 h of chilling at ambient CO2, net photosynthetic rate (PN) reductions were 83, 89 and 24% for bean, cucumber and corn, respectively. PN reductions during chilling were less at elevated CO2: 53, 40 and 4% for bean, cucumber and corn, respectively. At ambient CO2, none of the species fully recovered to pre-chilling PN, but at elevated CO2 both bean and corn recovered fully. The average percentage leaf area with visible leaf damage due to chilling was 20.6 and 9.6% at ambient and elevated CO2, respectively, for bean, and 32.4 and 23.6% at ambient and elevated CO2, respectively, for cucumber. Corn showed no significant permanent leaf damage from chilling at either CO2 concentration. These results indicate that cucumber was most sensitive to chilling as imposed in this study, followed by bean and corn. The results support the hypothesis that, at least in young plants under controlled-environment conditions, elevated CO2 improves plant water relations during chilling and can mitigate photosynthetic depression and chilling damage. The implications for long-term growth and reproductive success in managed and natural ecosystems will require testing of this hypothesis under field conditions. 相似文献
13.
Abdelmajid Krouma 《Phyton》2023,92(7):2133-2150
Iron is an essential element for plants as well as all living organisms, functioning in various physiological and
biochemical processes such as photosynthesis, respiration, DNA synthesis, and N2 fixation. In the soil, Fe bioavailability is extremely low, especially under aerobic conditions and at high pH ranges. In contrast, plants with
nodules on their roots that fix atmospheric nitrogen need much more iron. To highlight the physiological traits
underlying the tolerance of N2-fixing common bean to iron deficiency, two genotypes were hydroponically cultivated in a greenhouse: Coco nain (CN) and Coco blanc (CB). Plants were inoculated with an efficient strain of
Rhizobium tropici, CIAT899, and received a nutrient solution added with 0 µM Fe (severe Fe deficiency, SFeD),
5 µM Fe (moderate Fe deficiency, MFeD) or 45 µM Fe (control, C). Several physiological parameters related to
photosynthesis and symbiotic nitrogen fixation were then analyzed. Iron deficiency significantly reduced whole
plant and nodule growth, chlorophyll biosynthesis, photosynthesis, leghemoglobin (LgHb), nitrogenase (N2ase)
activity, nitrogen, and Fe nutrition, with some genotypic differences. As compared to CB, CN maintained better
Fe allocation to shoots and nodules, allowing it to preserve the integrity of its photosynthetic and symbiotic apparatus, thus maintaining the key functional traits of the plant metabolism (chlorophyll biosynthesis and photosynthesis in shoots, leghemoglobin accumulation, and nitrogenase activity in root nodules). Plant growth
depends on photosynthesis, which needs to be supplied with sufficient iron and nitrogen. Fe deficiency stress
index (FeD-SI) and Fe use efficiency (FeUE) are two physiological traits of tolerance that discriminated the
studied genotypes. 相似文献
14.
The aim of this study was to extent the range of knowledge about water relations and stomatal responses to water stress to
ten Mediterranean plants with different growth forms and leaf habits. Plants were subjected to different levels of water stress
and a treatment of recovery. Stomatal attributes (stomatal density, StoD), stomatal conductance (g
s), stomatal responsiveness to water stress (SR), leaf water relations (pre-dawn and midday leaf water potential and relative
water content), soil to leaf apparent hydraulic conductance (K
L) and bulk modulus of elasticity (ε) were determined. The observed wide range of water relations and stomatal characteristics
was found to be partially depended on the growth form. Maximum g
s was related to StoD and the stomatal area index (SAI), while g
s evolution after water stress and recovery was highly correlated with K
L. Relationships between SR to water deficit and other morphological leaf traits, such as StoD, LMA or ε, provided no general
correlations when including all species. It is concluded that a high variability is present among Mediterranean plants reflecting
a continuum of leaf water relations and stomatal behaviour in response to water stress. 相似文献
15.
Comparative studies of response mechanisms to progressive waterstress were carried out in vegetative faba bean plants. Thesewere grown under controlled environmental conditions and eitherreceived nitrate-N (+ N) or were dependent on N2-fixation (N2).N2-fixing plants reacted faster to water stress by increasedroot growth but were unable to maintain this response. +N plantsshowed a slower response but were able to maintain root andshoot growth throughout the treatment period. Leaf expansionwas similarly affected in +N and N2 plants but there was anincrease of specific leaf weight in the former. In both +N andN2 plants response mechanisms to water stress were aimed atpostponing dehydration: they tolerated stress at high waterpotentials by maintaining water absorption with increased rootgrowth and early stomatal closure. Recovery after watering thestressed plants was faster in +N plants. Stomatal resistancein leaves of N2 plants attained similar values to those of control,non-stressed, plants after 6882 h compared with only20 h in + N plants. Key words: Faba bean, water stress, nitrogen nutrition 相似文献
16.
The role of three-turgor-related cellular parameters, the osmotic potential (
s), the wall yield stress (Y) and the apparent hydraulic conductivity (L'p), in the initiation of ligh-induced expansion of bean (Phaseolus vulgaris L.) leaves has been determined. Although light causes an increase in the total solute content of leaf cells, the water uptake accompanying growth results in a slight increase in
s. Y is about 4 bar; and is unaffected by light. L'p, as calculated from growth rates and isopiestic measurements of leaf water potential, is only slightly greater in rapidly-growing leaves. The turgor pressure of growing cells is lower than that of the controls by about 35%. We conclude that light does not induce cell enlargement in the leaf by altering any of the above parameters, but does so primarily by increasing wall extensibility.Abbreviations and symbols RL
red light
- WL
white light
- L'p
apparent hydraulic conductivity
- OC
osmotic concentration
- Y
wall yield stress
-
s
osmotic potential 相似文献
17.
In order to assess symbiotic activity (the nodules integrity and the iron use efficiency) in common bean (Phaseolus vulgaris L.) under low iron availability, the growth of plants and nodules, the concentration of leghaemoglobin and malondialdehyde,
and activity of nitrogenase, catalase, peroxidase and superoxide dismutase were analysed in two (contrasting) common bean
varieties subjected to iron deficiency. Results show that nitrogen fixation and leghaemoglobin accumulation decreased at limiting
iron availability while malondialdehyde concentration increased under these conditions. The tolerant variety to iron deficiency,
ARA14, was clearly less affected than the sensitive one, Coco blanc. A significant stimulation of peroxidase (POD) activity
was observed in ARA14 under iron deficiency. At the same conditions, SOD and CAT activities in ARA14 plants were maintained
at high level. It was also found that the iron use efficiency for leghaemoglobin accumulation, SOD, CAT and POD activities
were critical for the protection of symbiotic system against oxidative burst and for the maintaining of an optimal functioning
of N2 fixing system. 相似文献
18.
Availabilities of nitrogen (N) and phosphorus (P) have a strong influence on plant growth and the species composition of savannas,
but it is not clear how these availabilities depend on factors such as fire, N2-fixation, and activities of wild herbivores and cattle. We quantified soil N and P availabilities in various ways (extractable
pools, mineralization, resin adsorption) along vegetation gradients within a recently abandoned cattle ranch and a former
game reserve in Tanzania (both areas now part of the Saadani National Park). We also assessed annual N and P balances to evaluate
how long-term availabilities of N and P are affected by large herbivores, symbiotic N2-fixation, and fire. The results show that cattle ranching led to a spatial re-distribution of nutrients, with the local accumulation
of P being stronger and more persistent than that of N. In the former game reserve, intensively grazed patches of short grass
tended to have elevated soil N and P availabilities; however, because quantities of nutrients removed through grazing exceeded
returns in dung and urine, the nutrient balances of these patches were negative. In dense Acacia stands, N2-fixation increased N availability and caused a net annual N input. Fire was the major cause for nutrient losses from tallgrass
savanna, and estimated N inputs from the atmosphere and symbiotic N2-fixation were insufficient to compensate for these losses. Our results call into question the common assumption that N budgets
in annually burned savanna are balanced; rather, these ecosystems are a mosaic of patches with both N enrichment and impoverishment,
which vary according to the vegetation type. 相似文献
19.
In calcareous soils, the yield of grain legumes is often limited by the lower availability of iron (Fe), especially when they depend upon symbiosis with root nodule bacteria for their N nutrition. In order to explore the variability of responses of N(2)-fixing common bean to Fe deficiency the common bean white-seeded lines Striker and Coco blanc, and coloured-seeded lines SVM-29-21 and ARA14 were inoculated with Rhizobium tropici (CIAT 899) and cultivated hydroaeroponically with a N-free nutrient solution supplied or not with 45microM Fe. Differences among lines were observed: Fe-deficiency-induced-chlorosis on young leaves was earlier and more severe in some lines than others. Nodule development and N(2)-fixing capacity was less affected in line ARA14 which preferentially allocated Fe towards nodules. Results suggest that Fe use efficiency for symbiotic nitrogen fixation (FeUE SNF) could be used to screen tolerant bean lines to Fe deficiency in condition of symbiotic nitrogen fixation. 相似文献
20.