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259 result(s) for "Hamayun, Muhammad"
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IAA producing fungal endophyte Penicillium roqueforti Thom., enhances stress tolerance and nutrients uptake in wheat plants grown on heavy metal contaminated soils
Heavy metals contaminated soil is a serious environmental concern that has a negative impact on agriculture and ecosystem. Economical and efficient ways are needed to address this problem worldwide. In this regard, exploration and application of proficient microbial strains that can help the crop plants to thrive in agricultural soils that are greatly contaminated with heavy metals. The present study mainly focused on the effect of IAA producing endophytic fungi Penicillium ruqueforti Thom., on wheat plants cultivated in soil rich in heavy metals (Ni, Cd, Cu, Zn, and Pb). P. ruqueforti has induced great resistance in wheat inoculated plants grown in heavy metal contaminated soil. Application of the isolated strain of P. ruqueforti restricted the transfer of heavy metals from soil to the plants by secreting indole acetic acid (IAA). Furthermore, P. ruqueforti inoculated wheat seedlings watered with waste water had higher plant growth, nutrient uptake and low concentrations of heavy metals in shoot and roots. On the contrary, non-inoculated wheat plants under heavy metal stress had stunted growth with symptoms of chlorosis. From the results, it is concluded that P. ruqueforti inoculation can establish a symbiotic relationship with host plants, which is useful for phytostabilization of heavy metals or in other words helping the host crops to flourish through soil that are highly contaminated with heavy metals.
Heavy metal tolerant endophytic fungiAspergillus welwitschiaeimproves growth, ceasing metal uptake and strengthening antioxidant system inGlycine maxL
In modern agricultural practice, heavy metal (HM) contamination is one of the main abiotic stress threatening sustainable agriculture, crop productivity, and disturb natural soil microbiota. Different reclamation techniques are used to restore the contaminated site; however, they are either costly or unable to remove contaminant when concentration is very low. In such circumstances, bioremediation is used as a novel technique involving microbes for soil restoration. In the current project, Aspergillus welwitschiae (Bk) efficiently endure metal stress (i.e., Cr-VI and As-V in the form of K 2 Cr 2 O 7 and Na 3 AsO 4 ) up to 1200 μg/mL and enhanced the production of phytohormones, i.e., 54.83 μg/mL of indole acetic acid (IAA) compared to control 15.56 μg/mL, solubilized inorganic phosphate, and produced stress-related metabolites. The isolate Bk was able to enhance growth of soybean by showing higher root shoot length and fresh/dry weight under stress ( p <0.05). Besides, the strain strengthened the antioxidant system of the host increasing enzymatic antioxidants, i.e., catalases (CAT) by 1.58 and 1.11 fold, ascorbic acid oxidase (AAO) by 6.75 and 7.94 fold, peroxidase activity (POD) by 1.12 and 1.37 fold, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) by 1.42 and 1.25 fold at 50 μg/mL of chromate and arsenate. Thus, actively scavenging the reactive oxygen species (ROS) produced results in lower ROS accumulation and high ROS scavenging. On the other hand, the isolates cut down Cr and As uptake by approximately 50% at 50 μg/mL from the medium while bio-transforming it, thereby stabilizing it and assisting the host to resume normal growth, thus avoiding phytotoxicity. It is evident from the current study that A. welwitschiae may potentially be used as a bioremediating agent for reclamation of Cr- and As-contaminated soil.
The Recent Advances in the Utility of Microbial Lipases: A Review
Lipases are versatile biocatalysts and are used in different bioconversion reactions. Microbial lipases are currently attracting a great amount of attention due to the rapid advancement of enzyme technology and its practical application in a variety of industrial processes. The current review provides updated information on the different sources of microbial lipases, such as fungi, bacteria, and yeast, their classical and modern purification techniques, including precipitation and chromatographic separation, the immunopurification technique, the reversed micellar system, aqueous two-phase system (ATPS), aqueous two-phase flotation (ATPF), and the use of microbial lipases in different industries, e.g., the food, textile, leather, cosmetics, paper, and detergent industries. Furthermore, the article provides a critical analysis of lipase-producing microbes, distinguished from the previously published reviews, and illustrates the use of lipases in biosensors, biodiesel production, and tea processing, and their role in bioremediation and racemization.
Halotolerant bacteria mitigate the effects of salinity stress on soybean growth by regulating secondary metabolites and molecular responses
Background Salinity is a major threat to the agriculture industry due to the negative impact of salinity stress on crop productivity. In the present study, we isolated rhizobacteria and evaluated their capacities to promote crop growth under salt stress conditions. Results We isolated rhizospheric bacteria from sand dune flora of Pohang beach, Korea, and screened them for plant growth-promoting (PGP) traits. Among 55 bacterial isolates, 14 produced indole-3-acetic acid (IAA), 10 produced siderophores, and 12 produced extracellular polymeric and phosphate solubilization. Based on these PGP traits, we selected 11 isolates to assess for salinity tolerance. Among them, ALT29 and ALT43 showed the highest tolerance to salinity stress. Next, we tested the culture filtrate of isolates ALT29 and ALT43 for IAA and organic acids to confirm the presence of these PGP products. To investigate the effects of ALT29 and ALT43 on salt tolerance in soybean, we grew seedlings in 0 mM, 80 mM, 160 mM, and 240 mM NaCl treatments, inoculating half with the bacterial isolates. Inoculation with ALT29 and ALT43 significantly increased shoot length (13%), root length (21%), shoot fresh and dry weight (44 and 35%), root fresh and dry weight (9%), chlorophyll content (16–24%), Chl a (8–43%), Chl b (13–46%), and carotenoid (14–39%) content of soybean grown under salt stress. Inoculation with ALT29 and ALT43 also significantly decreased endogenous ABA levels (0.77-fold) and increased endogenous SA contents (6–16%), increased total protein (10–20%) and glutathione contents, and reduced lipid peroxidation (0.8–5-fold), superoxide anion (21–68%), peroxidase (12.14–17.97%), and polyphenol oxidase (11.76–27.06%) contents in soybean under salinity stress. In addition, soybean treated with ALT29 and ALT43 exhibited higher K + uptake (9.34–67.03%) and reduced Na + content (2–4.5-fold). Genes involved in salt tolerance, GmFLD19 and GmNARK , were upregulated under NaCl stress; however, significant decreases in GmFLD19 (3–12-fold) and GmNARK (1.8–3.7-fold) expression were observed in bacterial inoculated plants. Conclusion In conclusion, bacterial isolates ALT29 and ALT43 can mitigate salinity stress and increase plant growth, providing an eco-friendly approach for addressing saline conditions in agricultural production systems.
Molecular Mechanisms of the 1-Aminocyclopropane-1-Carboxylic Acid (ACC) Deaminase Producing Trichoderma asperellum MAP1 in Enhancing Wheat Tolerance to Waterlogging Stress
Waterlogging stress (WS) induces ethylene (ET) and polyamine (spermine, putrescine, and spermidine) production in plants, but their reprogramming is a decisive element for determining the fate of the plant upon waterlogging-induced stress. WS can be challenged by exploring symbiotic microbes that improve the plant’s ability to grow better and resist WS. The present study deals with identification and application of 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase-producing fungal endophyte Trichoderma asperellum (strain MAP1), isolated from the roots of Canna indica L., on wheat growth under WS. MAP1 positively affected wheat growth by secreting phytohormones/secondary metabolites, strengthening the plant’s antioxidant system and influencing the physiology through polyamine production and modulating gene expression. MAP1 inoculation promoted yield in comparison to non-endophyte inoculated waterlogged seedlings. Exogenously applied ethephon (ET synthesis inducer) and 1-aminocyclopropane carboxylic acid (ACC; ET precursor) showed a reduction in growth, compared to MAP1-inoculated waterlogged seedlings, while amino-oxyacetic acid (AOA; ET inhibitor) application reversed the negative effect imposed by ET and ACC, upon waterlogging treatment. A significant reduction in plant growth rate, chlorophyll content, and stomatal conductance was noticed, while H 2 O 2 , MDA production, and electrolyte leakage were increased in non-inoculated waterlogged seedlings. Moreover, in comparison to non-inoculated waterlogged wheat seedlings, MAP1-inoculated waterlogged wheat exhibited antioxidant–enzyme activities. In agreement with the physiological results, genes associated with the free polyamine (PA) biosynthesis were highly induced and PA content was abundant in MAP1-inoculated seedlings. Furthermore, ET biosynthesis/signaling gene expression was reduced upon MAP1 inoculation under WS. Briefly, MAP1 mitigated the adverse effect of WS in wheat, by reprogramming the PAs and ET biosynthesis, which leads to optimal stomatal conductance, increased photosynthesis, and membrane stability as well as reduced ET-induced leaf senescence.
In vitro production of IAA by endophytic fungus Aspergillus awamori and its growth promoting activities in Zea mays
Indole-3-acetic acid (IAA) plays an important role in plant microbe interactions. Current study explored the role of indole-3-acetic acid (IAA) as a signalling molecule for chemical dialogue between endophytic fungus and host plant roots. The endophytic fungus was isolated from the leaves of drought stressed Withenia somnifera and was identified as Aspergillus awamori Wl1 through ITS region of 18 S rDNA sequence. The isolated Wl1 strain was capable of producing important secondary metabolites, including IAA, phenols and sugars. Culture filtrate of the strain contained 24.2, 275.4 and 127.4 μg/mL of IAA, phenols and sugars, respectively. The strain has efficiently colonized the maize roots and enhanced the growth of host plant. In order to determine the role of IAA in root colonization by endophyte, we inhibited the biosynthesis of IAA. Inhibition of IAA production by foliar application of yucasin effectively reduced the colonization of endophyte in maize roots by 52%, whereas root application of yucasin has decreased the colonization frequency by 66%. However, the application of IAA restored the ability of Aspergillus awamori to colonize maize roots and significantly improved various growth parameters. From these observations, it is concluded that IAA plays a vital role in initiating a crosstalk between the two partners.
The Antecedents of Willingness to Adopt and Pay for the IoT in the Agricultural Industry: An Application of the UTAUT 2 Theory
This paper aims to examine the factors influencing the willingness of Bangladeshi farmers to adopt and pay for the Internet of Things (IoT) in the agricultural sector by applying the theoretical framework of the Unified Theory of Acceptance and Use of Technology 2 (UTAUT 2). To this end, the study employed a quantitative research methodology and obtained data from 345 farmers from the northern districts of Bangladesh. Using a cross-sectional survey design and convenience sampling method, a study of premium fruit growers was undertaken to assess IoT use in agriculture, and the primary survey data were analyzed using the Structural Equation Modeling (SEM) approach via AMOS 26. The study confirmed that effort expectancy, performance expectancy, facilitating condition, hedonic motivation, government support, price value, personal innovativeness, and trust influence the willingness of Bangladeshi farmers to adopt the IoT. Additionally, predictors such as trust and willingness to adopt were observed to influence the willingness to pay for the IoT, while the construct ‘performance expectancy’ produced no effect. The study also revealed that the willingness to adopt moderates the association between performance expectancy, price value, and willingness to pay for the IoT. This research has novel implications because it investigates the behavior of rural customers with respect to innovation adoption, which in this case is the IoT in agriculture. It outlines precise reasons for the willing adoption of the IoT in agriculture, which will, in turn, assist marketers of IoT technology in the design of appropriate marketing strategies to increase acceptance in rural areas. Using the proposed model that incorporates farmers’ willingness to pay, this empirical study takes the first step in examining whether farmers in a developing economy such as Bangladesh will adopt and pay for the IoT.
Endophytic Fungi Produce Gibberellins and Indoleacetic Acid and Promotes Host-Plant Growth during Stress
We isolated and examined two endophytic fungi for their potential to secrete phytohormones viz. gibberellins (GAs) and indoleacetic acid (IAA) and mitigate abiotic stresses like salinity and drought. The endophytic fungi Phoma glomerata LWL2 and Penicillium sp. LWL3 significantly promoted the shoot and allied growth attributes of GAs-deficient dwarf mutant Waito-C and Dongjin-beyo rice. Analysis of the pure cultures of these endophytic fungi showed biologically active GAs (GA1, GA3, GA4 and GA7) in various quantities. The cultures of P. glomerata and Penicillium sp. also contained IAA. The culture application and endophytic-association with host-cucumber plants significantly increased the plant biomass and related growth parameters under sodium chloride and polyethylene glycol induced salinity and drought stress as compared to control plants. The endophytic symbiosis resulted in significantly higher assimilation of essential nutrients like potassium, calcium and magnesium as compared to control plants during salinity stress. Endophytic-association reduced the sodium toxicity and promoted the host-benefit ratio in cucumber plants as compared to non-inoculated control plants. The symbiotic-association mitigated stress by compromising the activities of reduced glutathione, catalase, peroxidase and polyphenol oxidase. Under stress conditions, the endophyte-infection significantly modulated stress through down-regulated abscisic acid, altered jasmonic acid, and elevated salicylic acid contents as compared to control. In conclusion, the two endophytes significantly reprogrammed the growth of host plants during stress conditions.
Endophytic fungal association via gibberellins and indole acetic acid can improve plant growth under abiotic stress: an example of Paecilomyces formosus LHL10
Background Endophytic fungi are little known for exogenous secretion of phytohormones and mitigation of salinity stress, which is a major limiting factor for agriculture production worldwide. Current study was designed to isolate phytohormone producing endophytic fungus from the roots of cucumber plant and identify its role in plant growth and stress tolerance under saline conditions. Results We isolated nine endophytic fungi from the roots of cucumber plant and screened their culture filtrates (CF) on gibberellins (GAs) deficient mutant rice cultivar Waito-C and normal GAs biosynthesis rice cultivar Dongjin-byeo. The CF of a fungal isolate CSH-6H significantly increased the growth of Waito-C and Dongjin-byeo seedlings as compared to control. Analysis of the CF showed presence of GAs (GA 1 , GA 3 , GA 4 , GA 8 , GA 9 , GA 12 , GA 20 and GA 24 ) and indole acetic acid. The endophyte CSH-6H was identified as a strain of Paecilomyces formosus LHL10 on the basis of phylogenetic analysis of ITS sequence similarity. Under salinity stress, P. formosus inoculation significantly enhanced cucumber shoot length and allied growth characteristics as compared to non-inoculated control plants. The hypha of P. formosus was also observed in the cortical and pericycle regions of the host-plant roots and was successfully re-isolated using PCR techniques. P. formosus association counteracted the adverse effects of salinity by accumulating proline and antioxidants and maintaining plant water potential. Thus the electrolytic leakage and membrane damage to the cucumber plants was reduced in the association of endophyte. Reduced content of stress responsive abscisic acid suggest lesser stress convened to endophyte-associated plants. On contrary, elevated endogenous GAs (GA 3 , GA 4 , GA 12 and GA 20 ) contents in endophyte-associated cucumber plants evidenced salinity stress modulation. Conclusion The results reveal that mutualistic interactions of phytohormones secreting endophytic fungi can ameliorate host plant growth and alleviate adverse effects of salt stress. Such fungal strain could be used for further field trials to improve agricultural productivity under saline conditions.
Silicon Confers Soybean Resistance to Salinity Stress Through Regulation of Reactive Oxygen and Reactive Nitrogen Species
Salt stress is one of the major abiotic stressors that causes huge losses to the agricultural industry worldwide. Different strategies have been adopted over time to mitigate the negative impact of salt stress on plants and reclaim salt-affected lands. In the current study, we used silicon (Si) as a tool for salinity alleviation in soybean and investigated the influence of exogenous Si application on the regulation of reactive oxygen and reactive nitrogen species and other salt stress-related parameters of the treated plants. Our results revealed that the canopy temperature was much higher in sole NaCl-treated plants but declined in Si + NaCl-treated plants. Furthermore, the chlorophyll contents decreased with sole NaCl treatment, whereas Si + NaCl-treated plants showed improved chlorophyll contents. In addition, Si application normalized the photosynthetic responses, such as transpiration rate ( ) and net photosynthesis rate ( ) in salt-treated plants, and reduced the activity of ascorbate peroxidase and glutathione under salt stress. The expression levels of antioxidant-related genes , , and started to decline at 12 h after addition of Si to NaCl-treated plants. Similarly, the -nitrosothiol and nitric oxide (NO)-related genes were upregulated in the salt stress condition but reduced after Si supplementation. Si application downregulated genes associated with reactive oxygen species and reactive nitrogen species and reduced enzymatic and non-enzymatic antioxidants of the treated plants. Results of the current study conclude that Si mitigated the adverse effects of NaCl-induced stress by modulating the crosstalk between antioxidants and NO scavengers. It is suggested that Si may be used in agricultural systems for alleviating salt stress.