scholarly journals Increased Ascorbate Biosynthesis Does Not Improve Nitrogen Fixation Nor Alleviate the Effect of Drought Stress in Nodulated Medicago truncatula Plants

2021 ◽  
Vol 12 ◽  
Author(s):  
Libertad Cobos-Porras ◽  
María Isabel Rubia ◽  
Raúl Huertas ◽  
David Kum ◽  
David A. Dalton ◽  
...  
Keyword(s):  
Drought Stress ◽  
Plant Growth ◽  
Medicago Truncatula ◽  
Cellular Damage ◽  
Antioxidant Compounds ◽  
Biosynthesis Pathway ◽  
Promising Strategy ◽  
Gene Coding ◽  
Abiotic Constraints ◽  
Ascorbate Biosynthesis

Legume plants are able to establish nitrogen-fixing symbiotic relations with Rhizobium bacteria. This symbiosis is, however, affected by a number of abiotic constraints, particularly drought. One of the consequences of drought stress is the overproduction of reactive oxygen (ROS) and nitrogen species (RNS), leading to cellular damage and, ultimately, cell death. Ascorbic acid (AsA), also known as vitamin C, is one of the antioxidant compounds that plants synthesize to counteract this oxidative damage. One promising strategy for the improvement of plant growth and symbiotic performance under drought stress is the overproduction of AsA via the overexpression of enzymes in the Smirnoff-Wheeler biosynthesis pathway. In the current work, we generated Medicago truncatula plants with increased AsA biosynthesis by overexpressing MtVTC2, a gene coding for GDP-L-galactose phosphorylase. We characterized the growth and physiological responses of symbiotic plants both under well-watered conditions and during a progressive water deficit. Results show that increased AsA availability did not provide an advantage in terms of plant growth or symbiotic performance either under well-watered conditions or in response to drought.

scholarly journals Copper Nanoparticle Application Enhances Plant Growth and Grain Yield in Maize Under Drought Stress Conditions

2021 ◽  
Author(s):  
Dong Van Nguyen ◽  
Huong Mai Nguyen ◽  
Nga Thanh Le ◽  
Kien Huu Nguyen ◽  
Hoa Thi Nguyen ◽  
...  
Keyword(s):  
Drought Stress ◽  
Plant Growth ◽  
Grain Yield ◽  
Stress Conditions ◽  
Copper Nanoparticle

Plant growth promotion by Azospirillum sp. in sugarcane is influenced by genotype and drought stress

2010 ◽  
Vol 337 (1-2) ◽  
pp. 233-242 ◽  
Author(s):  
Jean-Francois Yvan Moutia ◽  
Salem Saumtally ◽  
Stijn Spaepen ◽  
Jos Vanderleyden
Keyword(s):  
Drought Stress ◽  
Plant Growth ◽  
Plant Growth Promotion ◽  
Growth Promotion

scholarly journals Characterization of the Role of para-Aminobenzoic Acid Biosynthesis in Folate Production by Lactococcus lactis

2007 ◽  
Vol 73 (8) ◽  
pp. 2673-2681 ◽  
Author(s):  
Arno Wegkamp ◽  
Wietske van Oorschot ◽  
Willem M. de Vos ◽  
Eddy J. Smid
Keyword(s):  
Gene Cluster ◽  
Lactococcus Lactis ◽  
Gene Clusters ◽  
Defined Medium ◽  
Biosynthesis Pathway ◽  
Chemically Defined Medium ◽  
Aminobenzoic Acid ◽  
Biosynthesis Gene Cluster ◽  
Gene Coding ◽  
Aba Biosynthesis

ABSTRACT The pab genes for para-aminobenzoic acid (pABA) biosynthesis in Lactococcus lactis were identified and characterized. In L. lactis NZ9000, only two of the three genes needed for pABA production were initially found. No gene coding for 4-amino-4-deoxychorismate lyase (pabC) was initially annotated, but detailed analysis revealed that pabC was fused with the 3′ end of the gene coding for chorismate synthetase component II (pabB). Therefore, we hypothesize that all three enzyme activities needed for pABA production are present in L. lactis, allowing for the production of pABA. Indeed, the overexpression of the pABA gene cluster in L. lactis resulted in elevated pABA pools, demonstrating that the genes are involved in the biosynthesis of pABA. Moreover, a pABA knockout (KO) strain lacking pabA and pabB C was constructed and shown to be unable to produce folate when cultivated in the absence of pABA. This KO strain was unable to grow in chemically defined medium lacking glycine, serine, nucleobases/nucleosides, and pABA. The addition of the purine guanine, adenine, xanthine, or inosine restored growth but not the production of folate. This suggests that, in the presence of purines, folate is not essential for the growth of L. lactis. It also shows that folate is not strictly required for the pyrimidine biosynthesis pathway. L. lactis strain NZ7024, overexpressing both the folate and pABA gene clusters, was found to produce 2.7 mg of folate/liter per optical density unit at 600 nm when the strain was grown on chemically defined medium without pABA. This is in sharp contrast to L. lactis strains overexpressing only one of the two gene clusters. Therefore, we conclude that elevated folate levels can be obtained only by the overexpression of folate combined with the overexpression of the pABA biosynthesis gene cluster, suggesting the need for a balanced carbon flux through the folate and pABA biosynthesis pathway in the wild-type strain.

Effects of Nitric Oxide Application on Antioxidant Enzyme Activities of Pepper Plants under Drought Stress

2021 ◽  
Vol 5 (4) ◽  
pp. 846-853
Author(s):  
Fikret YAŞAR ◽  
Özlem ÜZAL
Keyword(s):  
Nitric Oxide ◽  
Drought Stress ◽  
Plant Growth ◽  
Nutrient Solution ◽  
Enzyme Activities ◽  
Growth Parameters ◽  
Antioxidative Enzyme ◽  
High Dose ◽  
Antioxidant Enzyme Activities ◽  
Hoagland Nutrient Solution

The purpose of the study was to determine the relationship between the messenger molecule Nitric oxide (NO) and antioxidative enzyme (SOD: Superoxide Dismutase; CAT: Catalase; APX: Ascorbate Peroxidase) activities in some metabolic changes that occur under the effect of drought stress in plants, to determine the possible roles of Nitric Oxide and to obtain complementary information. The experiment conducted in a controlled environment, and plant were cultured in containers containing Hoagland nutrient solution. For drought stress application, 10% Polyethylene Glycol (PEG 6000) was added to the nutrient solution, which is equivalent to -0.40 MPa osmotic potential. Before the drought stress is applied, pepper seedlings of Demre cv were pre-treated with different doses of Sodium Nitroprusside (SNP) and Carboxy-PTIO (potassium salt) (cPTIO) (SNP 0.01, SNP 1, SNP 100 and SNP 0.01 + cPTIO, SNP + cPTIO, SNP 100+ cPTIO). On the 10th day of the drought application, the growth parameters of the plants; the plant fresh weights and their Antioxidative Enzyme Activities (SOD, CAT, APX) were determined. In terms of plant growth parameters, both plant growth and antioxidant anzyme activities of plants pretreated with 0.01 and 1 doses of SNP were lower than the high dose of SNP and the PEG application without pretreatment. The reason for the low enzyme activities in these applications can be attributed to factors such as the excess accumulation of organic acids such as proline in the cells of the plants and the decrease in H2O2 and O-2 levels in the presence of SNP.

scholarly journals AtMybL-O modulates abscisic acid biosynthesis to optimize plant growth and ABA signaling in response to drought stress

2018 ◽  
Vol 61 (4) ◽  
pp. 473-477 ◽  
Author(s):  
Chan Young Jeong ◽  
Won Je Lee ◽  
Hai An Truong ◽  
Cao Sơn Trịnh ◽  
Suk-Whan Hong ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Drought Stress ◽  
Plant Growth ◽  
Aba Signaling ◽  
Acid Biosynthesis ◽  
Abscisic Acid Biosynthesis

scholarly journals Genome-wide analysis of autophagy-related genes in Medicago truncatula highlights their roles in seed development and response to drought stress

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mingkang Yang ◽  
Liping Wang ◽  
Chumin Chen ◽  
Xu Guo ◽  
Chuanglie Lin ◽  
...  
Keyword(s):  
Drought Stress ◽  
Seed Development ◽  
Medicago Truncatula ◽  
Interaction Network ◽  
Abiotic Stress Response ◽  
Biotic And Abiotic Stress ◽  
Comprehensive Overview ◽  
Network Analyses ◽  
Atg Genes ◽  
Gene Structures

AbstractAutophagy is a highly conserved process of degradation of cytoplasmic constituents in eukaryotes. It is involved in the growth and development of plants, as well as in biotic and abiotic stress response. Although autophagy-related (ATG) genes have been identified and characterized in many plant species, little is known about this process in Medicago truncatula. In this study, 39 ATGs were identified, and their gene structures and conserved domains were systematically characterized in M. truncatula. Many cis-elements, related to hormone and stress responsiveness, were identified in the promoters of MtATGs. Phylogenetic and interaction network analyses suggested that the function of MtATGs is evolutionarily conserved in Arabidopsis and M. truncatula. The expression of MtATGs, at varied levels, was detected in all examined tissues. In addition, most of the MtATGs were highly induced during seed development and drought stress, which indicates that autophagy plays an important role in seed development and responses to drought stress in M. truncatula. In conclusion, this study gives a comprehensive overview of MtATGs and provides important clues for further functional analysis of autophagy in M. truncatula.

scholarly journals Exploration of physiological and biochemical processes of canola with exogenously applied fertilizers and plant growth regulators under drought stress

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260960
Author(s):  
Muhammad Mahran Aslam ◽  
Fozia Farhat ◽  
Mohammad Aquil Siddiqui ◽  
Shafquat Yasmeen ◽  
Muhammad Tahir Khan ◽  
...  
Keyword(s):  
Water Stress ◽  
Drought Stress ◽  
Stomatal Conductance ◽  
Plant Growth ◽  
Stability Index ◽  
Leaf Temperature ◽  
Membrane Stability Index ◽  
Chemical Fertilizers ◽  
Chlorophyll Contents ◽  
Water Contents

Environmental stresses may alter the nutritional profile and economic value of crops. Chemical fertilizers and phytohormones are major sources which can enhance the canola production under stressful conditions. Physio-biochemical responses of canola altered remarkably with the use of nitrogen/phosphorus/potassium (N/P/K) fertilizers and plant growth regulators (PGRs) under drought stress. The major aim of current study was to evaluate nutritional quality and physio-biochemical modulation in canola (Brassica napus L.) from early growth to seed stage with NPK and PGRs in different water regimes. To monitor biochemical and physiological processes in canola, two season field experiment was conducted as spilt plot under randomized complete block design (RCBD) with four treatments (Control, Chemical fertilizers [N (90 kg/ha), P and K (45 kg ha-1)], PGRs; indole acetic acid (IAA) 15g ha-1, gibberellic acid (GA3) 15g ha-1 and the combination of NPK and PGRs] under different irrigations regimes (60, 100, 120, 150 mm evaporations). Water stress enhanced peroxidase (POD), catalase (CAT), superoxide dismutase (SOD), polyphenol oxidase (PPO), soluble sugar, malondialdehyde (MDA), proline contents as well as leaf temperature while substantially reduced leaf water contents (21%), stomatal conductance (50%), chlorophyll contents (10–67%), membrane stability index (24%) and grain yield (30%) of canola. However, the combined application of NPK and PGR further increased the enzymatic antioxidant pool, soluble sugars, along with recovery of leaf water contents, chlorophyll contents, stomatal conductance and membrane stability index but decreased the proline contents and leaf temperature at different rate of evaporation. There is positive interaction of applied elicitors to the water stress in canola except leaf area. The outcomes depicted that the combination of NPK with PGRs improved the various morpho-physiological as well as biochemical parameters and reduced the pressure of chemical fertilizers cost about 60%. It had also reduced the deleterious effect of water limitation on the physiology and grain yield and oil contents of canola in field experiments.

scholarly journals Enhancement of drought tolerance in diverse Vicia faba cultivars by inoculation with plant growth-promoting rhizobacteria under newly reclaimed soil conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Elsayed Mansour ◽  
Hany A. M. Mahgoub ◽  
Samir A. Mahgoub ◽  
El-Sayed E. A. El-Sobky ◽  
Mohamed I. Abdul-Hamid ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Plant Growth ◽  
Plant Growth Promoting Rhizobacteria ◽  
Severe Drought ◽  
Drought Conditions ◽  
Moderate Drought ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Effects Of Drought

AbstractWater deficit has devastating impacts on legume production, particularly with the current abrupt climate changes in arid environments. The application of plant growth-promoting rhizobacteria (PGPR) is an effective approach for producing natural nitrogen and attenuating the detrimental effects of drought stress. This study investigated the influence of inoculation with the PGPR Rhizobium leguminosarum biovar viciae (USDA 2435) and Pseudomonas putida (RA MTCC5279) solely or in combination on the physio-biochemical and agronomic traits of five diverse Vicia faba cultivars under well-watered (100% crop evapotranspiration [ETc]), moderate drought (75% ETc), and severe drought (50% ETc) conditions in newly reclaimed poor-fertility sandy soil. Drought stress substantially reduced the expression of photosynthetic pigments and water relation parameters. In contrast, antioxidant enzyme activities and osmoprotectants were considerably increased in plants under drought stress compared with those in well-watered plants. These adverse effects of drought stress reduced crop water productivity (CWP) and seed yield‐related traits. However, the application of PGPR, particularly a consortium of both strains, improved these parameters and increased seed yield and CWP. The evaluated cultivars displayed varied tolerance to drought stress: Giza-843 and Giza-716 had the highest tolerance under well-watered and moderate drought conditions, whereas Giza-843 and Sakha-4 were more tolerant under severe drought conditions. Thus, co-inoculation of drought-tolerant cultivars with R. leguminosarum and P. putida enhanced their tolerance and increased their yield and CWP under water-deficit stress conditions. This study showed for the first time that the combined use of R. leguminosarum and P. putida is a promising and ecofriendly strategy for increasing drought tolerance in legume crops.

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