Combined Application of Microbial Inoculation and Biochar to Mitigate Drought Stress in Wheat

Abstract Drought stress adversely influences the crop plants. Herein, present research was designed to elucidate the role of plant growth promoting microbes for amelioration of water stress in wheat. A pot experiment was conducted for screening the microorganisms on the basis of plant growth, chlorophyll and proline content under water stress. Bacillus sp. BT3 and Klebsiella sp. HA9 were found more promising strains that positively influenced the plant growth, chlorophyll and proline status of seedlings under water stress condition. Further, Bacillus sp. BT-3 and Klebsiella sp. HA9 along with check strain (BioNPK) were used for elucidating their detailed effect on morphological, biochemical, physiological and molecular traits to mitigate drought stress in wheat. Microbial inoculation significantly enhanced plant growth, biomass, relative water content, chlorophyll content and root morphological parameters over the uninoculated water stressed (30% FC) control. Likewise, sugar content, protein content and antioxidant enzymes were also significantly enhanced due to microbial inoculation under water stress (30% FC). Microbial inoculation significantly decreased proline, glycine betaine, lipid peroxidation, peroxide and superoxide radicals in wheat over the uninoculated water stressed (30%FC) control. Quantitative real-time (qRT)- PCR analysis revealed that Bacillus sp. BT-3, Klebsiella sp. HA9 and BioNPK inoculation significantly upregulated stress responsive genes (DHN, DREB, L15 and TaABA-8OH) over the uninoculated water stressed (30% F.C.) control. The study reports the potential of Bacillus sp. BT3 and Klebsiella sp. HA9 along with BioNPK in water stress alleviation in wheat which could be recommended as effective biofertilizers.

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Combined application of zinc and silicon alleviates terminal drought stress in wheat by triggering morpho-physiological and antioxidants defense mechanisms

PLoS ONE ◽

10.1371/journal.pone.0256984 ◽

2021 ◽

Vol 16 (10) ◽

pp. e0256984

Author(s):

Abdul Sattar ◽

Xiukang Wang ◽

Tahira Abbas ◽

Ahmad Sher ◽

Muhammad Ijaz ◽

...

Keyword(s):

Drought Stress ◽

Defense Mechanisms ◽

Antioxidant Defense ◽

Defense Mechanism ◽

Foliar Application ◽

Soluble Proteins ◽

Regulatory Pathways ◽

Combined Application ◽

Terminal Drought ◽

Terminal Drought Stress

Wheat is an important global staple food crop; however, its productivity is severely hampered by changing climate. Erratic rain patterns cause terminal drought stress, which affect reproductive development and crop yield. This study investigates the potential and zinc (Zn) and silicon (Si) to ameliorate terminal drought stress in wheat and associated mechanisms. Two different drought stress levels, i.e., control [80% water holding capacity (WHC) was maintained] and terminal drought stress (40% WHC maintained from BBCH growth stage 49 to 83) combined with five foliar-applied Zn-Si combinations (i.e., control, water spray, 4 mM Zn, 40 mM Si, 4 mM Zn + 40 mM Si applied 7 days after the initiation of drought stress). Results revealed that application of Zn and Si improved chlorophyll and relative water contents under well-watered conditions and terminal drought stress. Foliar application of Si and Zn had significant effect on antioxidant defense mechanism, proline and soluble protein, which showed that application of Si and Zn ameliorated the effects of terminal drought stress mainly by regulating antioxidant defense mechanism, and production of proline and soluble proteins. Combined application of Zn and Si resulted in the highest improvement in growth and antioxidant defense. The application of Zn and Si improved yield and related traits, both under well-watered conditions and terminal drought stress. The highest yield and related traits were recorded for combined application of Zn and Si. For grain and biological yield differences among sole and combined Zn-Si application were statistically non-significant (p>0.05). In conclusion, combined application of Zn-Si ameliorated the adverse effects of terminal drought stress by improving yield through regulating antioxidant mechanism and production of proline and soluble proteins. Results provide valuable insights for further cross talk between Zn-Si regulatory pathways to enhance grain biofortification.

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Combined Application of Arbuscular Mycorrhizal Fungi and Exogenous Melatonin Alleviates Drought Stress and Improves Plant Growth in Tobacco Seedlings

Journal of Plant Growth Regulation ◽

10.1007/s00344-020-10165-6 ◽

2020 ◽

Cited By ~ 1

Author(s):

Ling Liu ◽

Dong Li ◽

Yilin Ma ◽

Hongtao Shen ◽

Shimin Zhao ◽

...

Keyword(s):

Drought Stress ◽

Plant Growth ◽

Arbuscular Mycorrhizal Fungi ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Exogenous Melatonin ◽

Combined Application ◽

Tobacco Seedlings

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Application of Trehalose and Salicylic Acid Mitigates Drought Stress in Sweet Basil and Improves Plant Growth

Plants ◽

10.3390/plants10061078 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1078

Author(s):

Faisal Zulfiqar ◽

Jianjun Chen ◽

Patrick M. Finnegan ◽

Adnan Younis ◽

Muhammad Nafees ◽

...

Keyword(s):

Oxidative Stress ◽

Salicylic Acid ◽

Drought Stress ◽

Plant Growth ◽

Defense Mechanisms ◽

Negative Impact ◽

Field Capacity ◽

Antioxidant Responses ◽

Sweet Basil ◽

Combined Application

Trehalose (Tre) and salicylic acid (SA) are increasingly used to mitigate drought stress in crop plants. In this study, a pot experiment was performed to study the influence of Tre and SA applied individually or in combination on the growth, photosynthesis, and antioxidant responses of sweet basil (Ocimum basilicum L.) exposed to drought stress. Basil plants were watered to 60% or 100% field capacity with or without treatment with 30 mM Tre and/or 1 mM SA. Drought negatively affected growth, physiological parameters, and antioxidant responses. Application of Tre and/or SA resulted in growth recovery, increased photosynthesis, and reduced oxidative stress. Application of Tre mitigated the detrimental effects of drought more than SA. Furthermore, co-application of Tre and SA largely eliminated the negative impact of drought by reducing oxidative stress through increased activities of antioxidant enzymes superoxide dismutase, peroxidase, and catalase, as well as the accumulation of the protective osmolytes proline and glycine betaine. Combined Tre and SA application improved water use efficiency and reduced the amount of malondialdehyde in drought-stressed plants. Our results suggested that combined application of Tre and SA may trigger defense mechanisms of sweet basil to better mitigate oxidative stress induced by drought stress, thereby improving plant growth.

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Zinc and iron-mediated alleviation water deficiency of maize by modulating antioxidant metabolism

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha48211923 ◽

2020 ◽

Vol 48 (2) ◽

pp. 989-1004

Author(s):

Mojtaba AFSHARI ◽

Ahmad NADERI ◽

Mani MOJADAM ◽

Shahram LACK ◽

Mojtaba ALAVIFAZEL

Keyword(s):

Superoxide Dismutase ◽

Drought Stress ◽

Grain Yield ◽

Growth Stage ◽

Foliar Application ◽

Inorganic Compounds ◽

Biologically Active ◽

Combined Application ◽

Seed Growth ◽

Maize Plants

Microelements are inorganic compounds involved in the synthesis of enzymes and biologically active substances. To evaluate the physiological responses of maize to ZnSO4 and FeSO4 under drought stress, a field experiment was conducted on maize plants grown under different soil moistures and treated with foliar ZnSO4 and FeSO4 applications. Drought stress especially at early seed growth stage significantly reduced grain yield and Fv/Fm ratio; however, the activity of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and glutathione reductase (GR) was enhanced under drought stress. Foliar applied ZnSO4 and FeSO4 boosted the grain yield under non irrigation at vegetative growth stage and at early seed growth stage, respectively. Between grain yield and MDA concentration (r= -0.73), superoxide dismutase (r= -0.57), peroxidase (r= -0.49), H2O2 (r= -0.67) and catalase enzyme (r= -0.42) significant and negative correlation were observed. Combined application of ZnSO4 and FeSO4 resulted in alleviation of maize plant drought stress by Zn and Fe-mediated improvement in photosynthetic attributes. In addition, the foliar application of ZnSO4 and FeSO4 regulated physiological processes in maize plants and alleviated the adverse effects of water stress. According to the results, ZnSO4 and FeSO4 could be used for improving maize growth under drought stress.

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Rhizobacteria Inoculation and Caffeic Acid Alleviated Drought Stress in Lentil Plants

Sustainability ◽

10.3390/su13179603 ◽

2021 ◽

Vol 13 (17) ◽

pp. 9603

Author(s):

Muhammad Zafar-ul-Hye ◽

Muhammad Naeem Akbar ◽

Yasir Iftikhar ◽

Mazhar Abbas ◽

Atiqa Zahid ◽

...

Keyword(s):

Drought Stress ◽

Plant Growth ◽

Caffeic Acid ◽

Nitrogen Concentration ◽

Turgor Pressure ◽

Acc Deaminase ◽

Growth And Yield ◽

Phosphorus Concentration ◽

Cell Membrane Stability ◽

Combined Application

Lentil (Lens culinaris Medik) is an important component of the human diet due to its high mineral and protein contents. Abiotic stresses, i.e., drought, decreases plant growth and yield. Drought causes the synthesis of reactive oxygen species, which decrease a plant’s starch contents and growth. However, ACC-deaminase (1-aminocyclopropane-1-carboxylate deaminase) producing rhizobacteria can alleviate drought stress by decreasing ethylene levels. On the other hand, caffeic acid (CA) can also positively affect cell expansion and turgor pressure maintenance under drought stress. Therefore, the current study was planned with an aim to assess the effect of CA (0, 20, 50 and 100 ppm) and ACC-deaminase rhizobacteria (Lysinibacillus fusiform, Bacillus amyloliquefaciens) on lentils under drought stress. The combined application of CA and ACC-deaminase containing rhizobacteria significantly improved plant height (55%), number of pods per plant (51%), 1000-grain weight (45%), nitrogen concentration (56%), phosphorus concentration (19%), potassium concentration (21%), chlorophyll (54%), relative water contents RWC (60%) and protein contents (55%). A significant decrease in electrolyte leakage (30%), proline contents (44%), and hydrogen peroxide contents (54%), along with an improvement in cell membrane stability (34% over control) validated the combined use of CA and rhizobacteria. In conclusion, co-application of CA (20 ppm) and ACC-deaminase producing rhizobacteria can significantly improve plant growth and yield for farmers under drought stress. More investigations are suggested at the field level to select the best rhizobacteria and CA level for lentils under drought.

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