scholarly journals Arbuscular Mycorrhiza-Mediated Regulation of Polyamines and Aquaporins During Abiotic Stress: Deep Insights on the Recondite Players

2021 ◽  
Vol 12 ◽  
Author(s):  
Karuna Sharma ◽  
Samta Gupta ◽  
Sarda Devi Thokchom ◽  
Pooja Jangir ◽  
Rupam Kapoor

Environmental stresses of (a)biotic origin induce the production of multitudinous compounds (metabolites and proteins) as protective defense mechanisms in plants. On account of the regulation of some of these compounds, arbuscular mycorrhizal fungi (AMF) reinforce the inherent tolerance of plants toward the stress of different origins and kind. This article reviews two specific fundamental mechanisms that are categorically associated with mycorrhiza in alleviating major abiotic stresses, salt, drought, and heavy metal (HM) toxicity. It puts emphasis on aquaporins (AQPs), the conduits of water and stress signals; and polyamines (PAs), the primordial stress molecules, which are regulated by AMF to assure water, nutrient, ion, and redox homeostasis. Under stressful conditions, AMF-mediated host AQP responses register distinct patterns: an upregulation to encourage water and nutrient uptake; a downregulation to restrict water loss and HM uptake; or no alterations. The patterns thereof are apparently an integrative outcome of the duration, intensity, and type of stress, AMF species, the interaction of fungal AQPs with that of plants, and the host type. However, the cellular and molecular bases of mycorrhizal influence on host AQPs are largely unexplored. The roles of PAs in augmenting the antioxidant defense system and improving the tolerance against oxidative stress are well-evident. However, the precise mechanism by which mycorrhiza accords stress tolerance by influencing the PA metabolism per se is abstruse and broadly variable under different stresses and plant species. This review comprehensively analyzes the current state-of-art of the involvement of AMF in “PA and AQP modulation” under abiotic stress and identifies the lesser-explored landscapes, gaps in understanding, and the accompanying challenges. Finally, this review outlines the prospects of AMF in realizing sustainable agriculture and provides insights into potential thrust areas of research on AMF and abiotic stress.

Antioxidants ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 384 ◽  
Author(s):  
Mirza Hasanuzzaman ◽  
M. H. M. Borhannuddin Bhuyan ◽  
Taufika Islam Anee ◽  
Khursheda Parvin ◽  
Kamrun Nahar ◽  
...  

Reactive oxygen species (ROS) generation is a usual phenomenon in a plant both under a normal and stressed condition. However, under unfavorable or adverse conditions, ROS production exceeds the capacity of the antioxidant defense system. Both non-enzymatic and enzymatic components of the antioxidant defense system either detoxify or scavenge ROS and mitigate their deleterious effects. The Ascorbate-Glutathione (AsA-GSH) pathway, also known as Asada–Halliwell pathway comprises of AsA, GSH, and four enzymes viz. ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase, play a vital role in detoxifying ROS. Apart from ROS detoxification, they also interact with other defense systems in plants and protect the plants from various abiotic stress-induced damages. Several plant studies revealed that the upregulation or overexpression of AsA-GSH pathway enzymes and the enhancement of the AsA and GSH levels conferred plants better tolerance to abiotic stresses by reducing the ROS. In this review, we summarize the recent progress of the research on AsA-GSH pathway in terms of oxidative stress tolerance in plants. We also focus on the defense mechanisms as well as molecular interactions.


Author(s):  
Bo Shu ◽  
YaChao Xie ◽  
Fei Zhang ◽  
Dejian Zhang ◽  
Chunyan Liu ◽  
...  

Calmodulin-like (CML) proteins represent a diverse family of protein in plants, and play significant roles in biotic and abiotic stress responses. However, the involvement of citrus CMLs in plant responses to drought stress (abiotic stress) and arbuscular mycorrhizal fungi (AMF) colonization remain relatively unknown. We characterized the citrus CML genes by analyzing the EF-hand domains and a genome-wide search, and identified a total of 38 such genes, distributed across at least nine chromosomes. Six tandem duplication clusters were observed in the CsCMLs, and 12 CsCMLs exhibited syntenic relationships with Arabidopsis thaliana CMLs. Gene expression analysis showed that 29 CsCMLs were expressed in the roots, and exhibited differential expression patterns. The regulation of CsCMLs expression was not consistent with the cis-elements identified in their promoters. CsCML2, 3, and 5 were upregulated in response to drought stress, and AMF colonization repressed the expression of CsCML7, 9, 12, 13,20, 27, 28, and 35,and induced that of CsCML1, 2, 3, 5, 8, 10, 11, 14, 15, 16, 18, 25, 30, 33, and 37. Furthermore, AMF colonization and drought stress exerted a synergistic effect, evident from the enhanced repression of CsCML7, 9, 12, 13, 27, 28, and 35 and enhanced expression of CsCML2, 3, and 5 under AMF colonization and drought stress. The present study provides valuable insights into the CsCML gene family and its responses to AMF colonization and drought stress.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
María Josefina Bompadre ◽  
Mariana Pérgola ◽  
Laura Fernández Bidondo ◽  
Roxana Paula Colombo ◽  
Vanesa Analía Silvani ◽  
...  

The capacity of roots to sense soil physicochemical parameters plays an essential role in maintaining plant nutritional and developmental functions under abiotic stress. These conditions generate reactive oxygen species (ROS) in plant tissues causing oxidation of proteins and lipids among others. Some plants have developed adaptive mechanisms to counteract such adverse conditions such as symbiotic association with arbuscular mycorrhizal fungi (AMF). AMF enhance plant growth and improve transplant survival by protecting host plants against environmental stresses. The aim of this study was to evaluate the alleviation of transplanting stress by two strains ofRhizophagus irregularis(GC2 and GA5) in olive. Our results show that olive plants have an additional energetic expense in growth due to an adaptative response to the growing stage and to the mycorrhizal colonization at the first transplant. However, at the second transplant the coinoculation improves olive plant growth and protects against oxidative stress followed by the GA5-inoculation. In conclusion, a combination of two AMF strains at the beginning of olive propagation produces vigorous plants successfully protected in field cultivation even with an additional cost at the beginning of growth.


2021 ◽  
Vol 7 (4) ◽  
pp. 303
Author(s):  
Murugesan Chandrasekaran ◽  
T. Boopathi ◽  
Paramasivan Manivannan

Population growth and food necessity envisaged the dire need for supplementation to a larger community balance in food production. With the advent of the green revolution, agriculture witnessed the insurrection of horticultural fruit crops and field crops in enormous modes. Nevertheless, chemical fertilizer usage foresees soil pollution and fertility loss. Utilization of biocontrol agents and plant growth promotion by microbial colonization enrooted significant restoration benefits. Constant reliability for healthy foods has been emancipated across the globe stressing high nutritive contents among indigenous field crops like tomato (Solanum lycopersicum). However, stress tolerance mechanisms and efficient abatement require deeper insights. The applicability of arbuscular mycorrhizal fungi (AMF) poses as an ultimate strategy to minimize the deleterious consequences of abiotic stress such as salt, drought, temperature and heavy metal stress sustainably. The rational modality employing the application of AMF is one of significant efforts to lessen cell damages under abiotic stress. The novelty of the compilation can be redressed to cohesive literature for combating stress. The literature review will provide agricultural scientists worldwide in providing a rational approach that can have possible implications in not only tomato but also other vegetable crops.


F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1459
Author(s):  
Shalem Raju Modi ◽  
Tarja Kokkola

GR24 is a synthetic strigolactone analog, demonstrated to regulate the development of plants and arbuscular mycorrhizal fungi. GR24 possesses anti-cancer and anti-apoptotic properties, enhances insulin sensitivity and mitochondrial biogenesis in skeletal myotubes, inhibits adipogenesis, decreases inflammation in adipocytes and macrophages and downregulates the expression of hepatic gluconeogenic enzymes. Transcription factor Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) is a master regulator of antioxidant response, regulating a multitude of genes involved in cellular stress responses and anti-inflammatory pathways, thus maintaining cellular redox homeostasis. Nrf2 activation reduces the deleterious effects of mitochondrial toxins and has multiple roles in promoting mitochondrial function and dynamics. We studied the role of GR24 on gene expression in rat L6 skeletal muscle cells which were differentiated into myotubes. The myotubes were treated with GR24 and analyzed by microarray gene expression profiling. GR24 upregulated the cytoprotective transcription factor Nrf2 and its target genes, activating antioxidant defences, suggesting that GR24 may protect skeletal muscle from the toxic effects of oxidative stress.


2019 ◽  
Author(s):  
Lingzi Xue ◽  
Fangling Jiang ◽  
Mintao Sun ◽  
Zhen Wu ◽  
Lu Yu ◽  
...  

Abstract Background Fruit cracking, occurs easily under unsuitable environmental conditions, is one of the main disorders in fruit production. It is widely accepted that plant have developed a defense mechanisms or regulatory networks in response to abiotic stress. This involves perceiving, integrating and responding to stress signals by modulating the expression of related genes. Fruit cracking is also a kind of physiological disease caused by abiotic stress. Previously reported a single or sevel genes may regulate fruit cracking. However, almost none of these efforts have involved cracking regulatory network. Results Here, 0, 8 and 30 h irrigation treatments resulted in differential expression of 1028 mRNAs and 87 lncRNAs in ‘LA1698’ (cracking resistant, CR) at 8 h_vs_0 h, 468 mRNAs and 15 lncRNAs at CR_30 h_vs_CR_0 h, 321 mRNAs and 19 lncRNAs at CR_30 h_vs_CR_8 h; 531 mRNAs and 75 lncRNAs in ‘LA2683’ (cracking susceptible, CS) at 8 h_vs_0 h, 420 mRNAs and 24 lncRNAs at CS_30 h_vs_CS_0 h, 270 mRNAs and 20 lncRNAs at CS_30 h_vs_CS_8 h; 339 mRNAs and 64 lncRNAs in the two contrasting tomato genotypes at 0 h, 338 mRNAs and 94 lncRNAs at 8 h, and 369 mRNAs and 77 lncRNAs at 30 h. The GO pathway of the differentially expressed mRNAs are mainly enriched in ‘hormone metabolic process’, ‘cell wall organization’, ‘oxidoreductase activity’ and ‘catalytic activity’. In addition, lncRNAs regulated the expression of their neighboring genes and genes related to tomato cracking were selected to construct a lncRNA-mRNA network that influence tomato cracking. Conclutions This study provides insight into the responsive network for water-induced cracking in tomato fruit. specifically lncRNAs regulated hormone-redox-cell wall network, including plant hormone (including auxin, ethylene) and ROS (H 2 O 2 ) signal transduction and many cell wall related mRNAs ( EXP, PG, XTH ), as well as some lncRNAs (XLOC_010878 and XLOC_016662, ect) .


Author(s):  
Nada Milosevic ◽  
Jelena Marinkovic ◽  
Branislava Tintor

Microorganisms could play an important role in adaptation strategies and increase of tolerance to abiotic stresses in agricultural plants. Plant-growth-promoting rhizobacteria (PGPR) mitigate most effectively the impact of abiotic stresses (drought, low temperature, salinity, metal toxicity, and high temperatures) on plants through the production of exopolysaccharates and biofilm formation. PGPR mitigate the impact of drought on plants through a process so-called induced systemic tolerance (IST), which includes: a) bacterial production of cytokinins, b) production of antioxidants and c) degradation of the ethylene precursor ACC by bacterial ACC deaminase. Symbiotic fungi (arbuscular mycorrhizal fungi) and dual symbiotic systems (endophytic rhizospheric bacteria and symbiotic fungi) also tend to mitigate the abiotic stress in plants.


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