scholarly journals Interactions between hydrogen sulfide and rhizobia modulate the physiology and metabolism during water deficiency-induced oxidative defense in soybean

2021 ◽  
Author(s):  
Xueyuan Lin ◽  
Nina Zhang ◽  
Yamei Zhang ◽  
Yiwen Zhao ◽  
Wuyu Liu ◽  
...  
Keyword(s):  
Nitrogenase Activity ◽  
Combined Effect ◽  
Marker Genes ◽  
Water Deficiency ◽  
Signal Molecule ◽  
Adaptation Mechanism ◽  
Leaf Chlorophyll ◽  
Relative Water ◽  
Early Nodulin ◽  
Soybean Nodulation

Hydrogen sulphide (H2S), as a new gas signal molecule, participates in the regulation of a variety of abiotic stresses in plants. However, it was unclear how H2S and rhizobia can together to affect the adaptation of soybean to water deficiency. Here, the adaptation mechanism of H2S and rhizobia in soybean to water deficiency was studied. Our results showed that H2S and rhizobia jointly enhanced leaf chlorophyll content, the relative water content (RWC) and caused an increase biomass in soybean under water deficiency. Besides, under water deficiency, H2S enhanced biomass by affecting nodule numbers and nitrogenase activity during the growth of soybean. The expression of soybean nodulation marker genes including early nodulin 40 (GmENOD40), ERF required for nodulation (GmERN), and nodulation inception genes were up-regulated by H2S and rhizobia in nodules. Moreover, the combined effect of H2S and rhizobia were proved to affect the enzyme activities and gene expression level of antioxidant, as well as osmotic protective substance under water deficiency. In addition, the metabolomics results provided that the changes of lipids and lipid-like molecules were remarkably promoted by the combined effect of H2S and rhizobia. Thus, H2S and rhizobia synergistically subsided the oxidative damage by increasing the accumulation of metabolites and strengthening the antioxidant capacity under water deficiency.

scholarly journals Improved tolerance of wheat plants (Triticum aestivum L.) to drought stress and rewatering by the arbuscular mycorrhizal fungus Glomus claroideum: effect on growth and cell membrane stability

2008 ◽  
Vol 20 (1) ◽  
pp. 29-37 ◽  
Author(s):  
José Beltrano ◽  
Marta G. Ronco
Keyword(s):  
Water Stress ◽  
Drought Stress ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Dry Weight ◽  
Leaf Chlorophyll ◽  
Severe Water Stress ◽  
Relative Water ◽  
Mycorrhizal Plants ◽  
Total Dry Weight

The aim of this paper was to investigate the contribution of the arbuscular mycorrhizal fungus Glomus claroideum to drought stress tolerance in wheat plants grown under controlled conditions in a growth chamber, and subjected to moderate or severe water stress and rewatering. Water stress tolerance was determined through total dry weight, leaf relative water content, leakage of solutes and leaf chlorophyll and protein concentrations in mycorrhizal and non-mycorrhizal wheat plants. Total dry weight and leaf chlorophyll concentrations were significantly higher in mycorrhizal plants after moderate or severe water stress treatments compared with non-mycorrhizal ones. Electrolyte leakage was significantly lower in water-stressed inoculated plants. Compared to non-inoculated plants, leaf relative water content and total protein concentration of inoculated individuals increased only under severe water stress. When irrigation was re-established, mycorrhizal plants increased their total dry weight and leaf chlorophyll concentration, and recovered cell membrane permeability in leaves compared with non-mycorrhizal plants. In conclusion, root colonization by G. claroideum could be an adequate strategy to alleviate the deleterious effects of drought stress and retard the senescence syndrome in wheat.

scholarly journals Shading as a means of mitigating water deficit in seedlings of Campomanesia xanthocarpa (Mart.) O. Berg

2020 ◽  
Vol 48 (1) ◽  
pp. 234-244
Author(s):  
Edinéia M.M. BARTIERES ◽  
Silvana P.Q. SCALON ◽  
Daiane M. DRESCH ◽  
Edvânia A.S. CARDOSO ◽  
Mailson V. JESUS ◽  
...  
Keyword(s):  
Water Content ◽  
Water Deficit ◽  
Relative Water Content ◽  
Growth Characteristics ◽  
Water Deficiency ◽  
Cultivation Conditions ◽  
Continuous Irrigation ◽  
Intermittent Irrigation ◽  
Relative Water ◽  
Number Of Leaves

In this research it was hypothesized that Campomanesia xanthocarpa can overcome some level of water deficiency by adjusting physiological parameters and that shading minimizes the water deficit effects while maintaining elevated photosynthetic rates and relative water content of the leaves and makes a resumption of metabolism and growth when the water supply is normalized. The seedlings were submitted to two water regimes (continuous irrigation - CI and intermittent irrigation - II), three shading percentages (0, 30 and 70%) and six evaluation times (Start - T0, 1st Photosynthesis Zero - 1st P0, 1st Recovery - 1st REC, 2nd Photosynthesis Zero - 2nd P0, 2nd Recovery - 2nd REC and END). Plants under water deficit at 0% shading led to a reduction in photosynthetic metabolism, relative water content (RWC), leaf area, number of leaves, and height, especially during the stress periods 1st and 2nd P0. The 30 and 70% shading mitigated the stressful effect of water deficit on C. xanthocarpa seedlings. The results did not confirm the hypothesis that C. xanthocarpa seedlings are intolerant to water deficit since, although sensitive, they presented a potential for recovery of photosynthetic and growth characteristics under all cultivation conditions. It was concluded that that shading minimizes the stressful effects of water deficit.

scholarly journals Effect of Water Deficiency and Potassium Application on Plant Growth, Osmolytes and Grain Yield of Brassica Napus Cultivars

2014 ◽  
Vol 73 (2) ◽  
pp. 299-314 ◽  
Author(s):  
Murad Ali ◽  
Jehan Bakht ◽  
Gul Daraz Khan
Keyword(s):  
Brassica Napus ◽  
Grain Yield ◽  
Water Content ◽  
Relative Water Content ◽  
Field Experiments ◽  
Dependent Manner ◽  
Water Deficiency ◽  
Brassica Crop ◽  
Relative Water ◽  
Potassium Application

Abstract One of the major issues with brassica oil seed production is the water requirement of the brassica crop. To address the problem, field experiments were conducted to evaluate the effect of potassium (K) and water deficiency levels on canola (Brassica napus L.). Analysis of the data revealed that application of K, irrigation and interactions between irrigation and cultivar (I x C), irrigation and potassium (I x K), potassium and cultivar (K x C), and irrigation and cultivar and potassium (I x C x K) had a significant (p < 0.05) effect on shoot proline content, relative water content, plant fresh weight and grain yield. Potassium application, irrigation and interaction between I x C, K x C, and I x C x K had a significant (p < 0.05) effect on shoot sugar content. Water deficiency increased shoot proline and sugar contents and decreased relative water content. Potassium application increased shoot proline level in a dose dependent manner. Minimum proline and sugar contents and maximum relative water content, plant fresh and dry weight and yield were obtained when 100% irrigation was applied. Maximum grain yield was obtained upon application of 100% irrigation in combination with 120 kg ha−1 K.

scholarly journals Excess nitrate induces nodule greening and reduces transcript and protein expression levels of soybean leghaemoglobins

2020 ◽  
Vol 126 (1) ◽  
pp. 61-72
Author(s):  
Mengke Du ◽  
Zhi Gao ◽  
Xinxin Li ◽  
Hong Liao
Keyword(s):  
Nitrogenase Activity ◽  
Expression Patterns ◽  
Bioinformatic Analysis ◽  
Nodule Development ◽  
Nodule Formation ◽  
N Availability ◽  
Soybean Plants ◽  
Systematic Identification ◽  
Biological Nitrogen ◽  
Soybean Nodulation

Abstract Background and Aims Efficient biological nitrogen fixation (BNF) requires leghaemoglobin (Lb) to modulate oxygen pressure in nodules. Excess N supply severely inhibits BNF through effects on Lb during nodulation. As yet, a systematic identification and characterization of Lb-encoding genes in soybean has not been reported. Methods The effects of N on BNF were studied in soybean plants inoculated with rhizobia and exposed to excess or low N availability in hydroponic cultures. To identify soybean Lb proteins, BLAST searches were performed on the Phytozome website. Bioinformatic analysis of identified GmLbs was then carried out to investigate gene structure, protein homology and phylogenetic relationships. Finally, quantitative real-time PCR was employed to analyse the expression patterns of soybean Lb genes in various tissues and in response to high N availability. Key Results Excess N significantly accelerated nodule senescence and the production of green Lb in nodules. In total, seven haemoglobin (Hb) genes were identified from the soybean genome, with these Hb genes readily split into two distinct clades containing predominantly symbiosis-associated or non-symbiotic Hb members. Expression analysis revealed that all of the symbiosis-associated Lbs except GmLb5 were specifically expressed in nodules, while the non-symbiotic GmHbs, GmHb1 and GmHb2, were predominantly expressed in leaves and roots, respectively. Among identified GmLbs, GmLb1–4 are the major Lb genes acting in soybean nodulation, and each one is also significantly suppressed by exposure to excess N. Conclusions Taken together, the results show that excess N inhibits BNF by reducing nodule formation, Lb concentration and nitrogenase activity. The characteristics of the entire Hb family were analysed, and we found that GmLb1–4 are closely associated with nodule development and N2 fixation. This works forms the basis for further investigations of the role of Lbs in soybean nodulation.

Responses of Rhizobium-inoculated and nitrogen-supplied Phaseolus vulgaris and Vigna unguiculata plants to root volume restriction

1999 ◽  
Vol 26 (6) ◽  
pp. 613 ◽  
Author(s):  
María Luisa Izaguirre-Mayoral ◽  
Margarita Sicardi de Mallorca
Keyword(s):  
Phaseolus Vulgaris ◽  
Vigna Unguiculata ◽  
Chlorophyll Concentration ◽  
Dry Weight ◽  
Root Volume ◽  
Leaf Chlorophyll ◽  
Fold Reduction ◽  
Relative Water ◽  
Leaf Relative Water Content ◽  
Total Reducing Sugars

Present investigation was undertaken to analyse the effect of root volume restriction on the physiological performance of Rhizobium-inoculated (R+ ) and nitrogen-supplied (N+) cowpea (Vigna unguiculata (L.) Walp. var. Tuy.) and bean (Phaseolus vulgaris L. var. Montalbán.) plants. Restriction of root volume (RRV) was imposed via an 8-fold reduction in the rooting space. Plants were grown under controlled conditions and an unlimited availability of water and nutrients. For both plant species, RRV reduced the dry weight of roots, shoots and nodules, retarded the rate of leaf initiation and development, and increased the leaf chlorophyll concentration, regardless of the source of nitrogen. In contrast, RRV did not alter the shoot/root, leaf/root and nodule/root ratios, the concentration of total reducing sugars in shoots, roots and nodules, the leaf relative water content or the concentration of Rubisco in mature leaves of R+ and N+ bean and cowpea plants. Concentration of ureide and α-amino-N in shoots and nodules of R+ plants as well as of α-amino-N in shoots of N+ plants were also not affected by RRV, and abscission of trifoliolated leaves was not recorded in any of the treatment combinations. We conclude that dwarfism of RRV plants was not due to water stress, decreased rates of assimilation, increased abscisic acid, sink/source alterations, or to a reduction on the effectiveness of the symbiotic process or of nitrogen uptake in R+ and N+ plants, respectively.

Effect of Seed Hardening and Pelleting on Growth, Yield, Physiology and Resultant Seed Quality of Cowpea under Natural Saline Conditions

2020 ◽  
Author(s):  
G. Sathiyanarayanan ◽  
S. Maamallan ◽  
M. Prakash ◽  
S. Rameshkumar
Keyword(s):  
Gas Exchange ◽  
Chlorophyll Content ◽  
Seed Quality ◽  
Growth Yield ◽  
Combined Effect ◽  
Gas Exchange Parameters ◽  
Leaf Chlorophyll ◽  
Leaf Powder ◽  
Exchange Parameters

Background: Cowpea (Vigna unguiculata) is one of the most important legume crops cultivated throughout the world. Cowpea is used as food, feed, forage, fodder, green manuring and vegetable. It’s seed is a nutritious component in the human diet, as well as for livestock. Seed hardening and pelleting are seed enhancement techniques used to improve seed germination and seedling vigour and growth by altering the physiological state of the seed. This alteration may improve the vigor or the physiology of the seed by enhancing uniformity of germination. Seed enhancement techniques like hardening and priming include use of chemicals that trigger systemic acquired resistance or improve stress tolerance whereas the pelleting treatments improve seed handling and planting. They also enhance nutrient availability or provide inoculates by delivering materials needed during sowing, germination and seedling establishment. Hence in order to study the combined effect of seed hardening and pelleting on growth, yield and resultant seed quality of cowpea under natural saline conditions, the present study was taken up. Methods: The present field and laboratory investigations were carried out to study the effect of seed hardening, seed pelleting and their combined effect on growth, physiology, yield and resultant seed quality of cowpea under natural saline conditions. The fresh seeds of cowpea seeds cv. CO (CP) 7 were hardened with KCl @ 1%, CaCl2 @ 1% and both KCl and CaCl2 @ 1% and then the hardened seeds were further pelleted with pungam leaf powder @ 100, 150 and 200 g kg-1 of seed. Then the treated seeds were evaluated for their seed productivity and resultant seed qualities using untreated seeds as control. Observations on growth, leaf chlorophyll content, gas exchange parameters, yield and resultant seed quality parameters were recorded. Result: The experimental results revealed that among the treatments, seeds hardened with KCl @ 1 % + CaCl2 @ 1 % and pelleted with pungam leaf powder @ 200 g per kg recorded higher growth, yield parameters, leaf chlorophyll content, gas exchange parameters and resultant seed quality when compared to control and other treatments.

scholarly journals Use of physiological parameters as fast tools to screen for drought tolerance in sugarcane

2007 ◽  
Vol 19 (3) ◽  
pp. 193-201 ◽  
Author(s):  
Marcelo de A. Silva ◽  
John L. Jifon ◽  
Jorge A.G. da Silva ◽  
Vivek Sharma
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Crop Improvement ◽  
Relative Increase ◽  
Physiological Parameters ◽  
Screening Tools ◽  
Leaf Chlorophyll ◽  
Drought Tolerant ◽  
Relative Water ◽  
Leaf Relative Water Content

Drought is one of the major limitations to plant productivity worldwide. Identifying suitable screening tools and quantifiable traits would facilitate the crop improvement process for drought tolerance. In the present study, we evaluated the ability of four relatively physiological parameters (variable-to-maximum chlorophyll a fluorescence ratio, F v/F m; estimated leaf chlorophyll content via SPAD index; leaf temperature, LT; and, leaf relative water content, RWC) to distinguish between drought tolerant and susceptible sugarcane genotypes subjected to a 90-d drought cycle. Eight field-grown genotypes were studied. By 45 d after the onset of treatments, the F v/F m, SPAD index and RWC of drought-stressed plants had declined significantly in all genotypes compared to values at the onset of well-watered treatments. However, the reductions were more severe in leaves of susceptible genotypes. Under drought stress, the tolerant genotypes as a group, maintained higher F v/F m (8%), SPAD index (15%), and RWC (16%) than susceptible genotypes. In general, LT of drought-stressed plants was higher (~4ºC) than that of well-watered plants but the relative increase was greater among drought susceptible genotypes. Under drought stress, LT of tolerant genotypes was on average 2.2ºC lower than that of susceptible genotypes. The results are consistent with the tolerant-susceptible classification of these genotypes and indicate that these tools can be reliable in screening for drought tolerance, with F v/F m, SPAD index and LT having the added advantage of being nondestructive and easily and quickly assessed.

scholarly journals Growth, photosynthesis, nodule nitrogen and carbon fixation in the chickpea cultivars under salt stress

2004 ◽  
Vol 16 (3) ◽  
pp. 137-146 ◽  
Author(s):  
Neera Garg ◽  
Ranju Singla
Keyword(s):  
Nitrogen Fixation ◽  
Salt Stress ◽  
Carbon Fixation ◽  
Symbiotic Nitrogen Fixation ◽  
Nitrogenase Activity ◽  
Saline Stress ◽  
Negative Effects ◽  
Leaf Chlorophyll ◽  
Mediterranean Origin ◽  
Salt Affected Soils

Four cultivars of chickpea, two of them of Mediterranean origin (kabuli), CSG 9651, BG 267 and two Indian (desi) types, CSG 8962, DCP 92-3, differing in their salt sensitivities were identified after screening ten genotypes in saline soils. The cultivars CSG 9651 and CSG 8962 were salt tolerant while BG 267 and DCP 92-3 were salt sensitive, respectively. The seeds of different cultivars were inoculated with Mesorhizobium ciceri, strain F: 75 and the plants were grown in the greenhouse. After the establishment of symbiosis, 15-day-old seedlings were administered doses of saline at varying concentrations (0, 4, 6, 8 dSm-1 NaCl, Na2SO4, CaCl2). Plants were harvested at 40, 70 and 100 days after sowing, for analyses. The main aim was to compare the relative salt tolerance of both desi and kabuli cultivars in terms of nitrogen fixation and carbon metabolism, as well as to ascertain whether the negative effects of saline stress on nitrogen fixation were due to a limitation of photosynthate supply to the nodule or to a limitation on the nodular metabolism that sustains nitrogenase activity. Plant growth, nodulation and nitrogenase activity was more severely affected in BG 267 and DCP 92-3 under salinity treatments (6 and 8 dSm-1) compared with CSG 9651 and CSG 8962. Nodule number as well as nodule mass increased under salt stress in CSG 9651 and CSG 8962 which might be responsible for their higher nitrogen fixation. Salinity reduced leaf chlorophyll and Rubisco activities in all cultivars. However, tolerant cultivars CSG 9651 and CSG 8962 showed smaller declines than the sensitive ones. Phosphoenolpyruvate carboxylase (PEPCase) activity increased significantly in the nodules of tolerant cultivars under salt stress at all harvests, and this was clearly related to salt concentrations. Our results suggest that in salt-affected soils tolerant cultivars have more efficient nodulation and support higher rates of symbiotic nitrogen fixation than the sensitive cultivars.

scholarly journals Enhanced Drought Tolerance of Arabica Coffee (Coffea arabica L.) by Grafting Method

2021 ◽  
Vol 50 (11) ◽  
pp. 3219-3229
Author(s):  
Ngoc-Thang Vu ◽  
Jong-Man Park ◽  
Ngoc-Quat Nguyen ◽  
Trong-Truong-Son Nguyen ◽  
Il-Soep Kim ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Water Deficit ◽  
Coffea Arabica ◽  
Growth Parameters ◽  
Dry Weight ◽  
Leaf Length ◽  
Ion Leakage ◽  
Leaf Chlorophyll ◽  
Relative Water ◽  
Coffee Plants

The objective of this study was to evaluate grafting method to improve the drought tolerance of Coffea arabica. Using C. arabica species as scions, and C. robusta as rootstock, the grafted plant was compared with the non-grafted plant (C. arabica) under water deficit condition. The result shown that growth parameters such as plant height, leaf length, and leaf width of the grafted coffee plants were higher than those of the non-grafted. The leaf area, fresh and dry weight of plants were highly reduced in non-grafted coffee plants. The leaf chlorophyll content (SPAD) and chlorophyll fluorescence (Fv/Fm) values of the grafted and non-grafted coffee plants decreased significantly with increasing duration under water deficit condition. The SPAD and Fv/Fm values of the two coffee types were also increased significantly with increasing duration after re-watering. Compared to the non-grafted plants, higher values of SPAD, Fv/Fm and relative water content in the leaf were observed in the grafted coffee plants. Moreover, lower values of relative ion leakage were observed in the grafted coffee plants after three days of water withholding and one month after re-watering. On the other hand, the grafted coffee plants showed enhanced drought tolerance by reducing the percentages of wilting plant under water deficit condition, and increasing the recovery percentages after re-watering.

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