Browsing by Author "Waquar Akhter Ansari"

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Biotechnological Interventions in Tomato (Solanum lycopersicum) for Drought Stress Tolerance: Achievements and Future Prospects
(MDPI, 2022) Ram Krishna; Waquar Akhter Ansari; P.S. Soumia; Akhilesh Yadav; Durgesh Kumar Jaiswal; Sudhir Kumar; Achuit Kumar Singh; Major Singh; Jay Prakash Verma
Tomato production is severely affected by abiotic stresses (drought, flood, heat, and salt) and causes approximately 70% loss in yield depending on severity and duration of the stress. Drought is the most destructive abiotic stress and tomato is very sensitive to the drought stress, as cultivated tomato lack novel gene(s) for drought stress tolerance. Only 20% of agricultural land worldwide is irrigated, and only 14.51% of that is well-irrigated, while the rest is rain fed. This scenario makes drought very frequent, which restricts the genetically predetermined yield. Primarily, drought disturbs tomato plant physiology by altering plant–water relation and reactive oxygen species (ROS) generation. Many wild tomato species have drought tolerance gene(s); however, their exploitation is very difficult because of high genetic distance and pre- and post-transcriptional barriers for embryo development. To overcome these issues, biotechnological methods, including transgenic technology and CRISPR-Cas, are used to enhance drought tolerance in tomato. Transgenic technology permitted the exploitation of non-host gene/s. On the other hand, CRISPR-Cas9 technology facilitated the editing of host tomato gene(s) for drought stress tolerance. The present review provides updated information on biotechnological intervention in tomato for drought stress management and sustainable agriculture. © 2022 by the authors.
Co-overexpression of AtDREB1A and BcZAT12 increases drought tolerance and fruit production in double transgenic tomato (Solanum lycopersicum) plants
(Elsevier B.V., 2021) Ram Krishna; Waquar Akhter Ansari; Durgesh Kumar Jaiswal; Achuit Kumar Singh; Jay Prakash Verma; Major Singh
Drought is the major problem in agricultural production due to loss of moisture content in soil as well as climate variations. Our main aim is to enhance drought tolerance and yield potential in the present study pyramided Arabidopsis thaliana Dehydration Responsive Element Binding1A (AtDREB1A) and Brasica caranata Zinc finger proteins (BcZAT12) transcription factor genes driven by ectopic promoter rd29 A of Arabidopsis thaliana and Brassica carinata lea1, respectively. Co-overexpression of both the genes provides tolerance to multiple abiotic stresses but the AtDREB1A overexpression has been reported to cause retarded growth and dwarf phenotype; however BcZAT12 overexpressing transgenic plants does not show retarded growth and dwarf phenotype. Co-overexpressing of AtDREB1A and BcZAT12 in five (DZ1-DZ5) double transgenic (DT) tomato lines has been observed under 0, 07, 14 and 21 Days of Water Deficit (DWD). The DT plants showed enhanced drought tolerance and yield potential than single transgenic (ST) and non transgenic (NT) plants. Furthermore, AtDREB1A and BcZAT12 co-overexpressed plants showed reduced level of electrolyte leakage (EL), hydrogen peroxide and membrane lipid peroxidation and elevated level of relative water content (RWC), proline, chlorophyll color index (CCI) and photosynthetic efficiency as compared to ST and NT. The plant growth and yield attributes were improved by the co-overexpression of AtDREB1A and BcZAT12 in DT plants. The transcript analysis showed the increased level of DREB1A, ZAT12 and P5CS genes expression which were higher in DT tomato plants, and indicate that both the genes induce together in the DT plants. The present study which is first report of co-overexpressing AtDREB1A and BcZAT12 in tomato will provide a base for genetic engineering in plants through the multigenic transgenic approach to cope against various biotic and abiotic stresses. © 2021 Elsevier B.V.
Drought mediated physiological and molecular changes in muskmelon (Cucumis melo L.)
(Public Library of Science, 2019) Waquar Akhter Ansari; Neelam Atri; Javed Ahmad; Mohammad Irfan Qureshi; Bijendra Singh; Ram Kumar; Vandna Rai; Sudhakar Pandey
Water deficiency up to a certain level and duration leads to a stress condition called drought. It is a multi-dimensional stress causing alteration in the physiological, morphological, biochemical, and molecular traits in plants resulting in improper plant growth and development. Drought is one of the major abiotic stresses responsible for loss of crops including muskmelon (Cucumis melo. L). Muskmelon genotype SC-15, which exhibits high drought resistance as reported in our earlier reports, was exposed to deficient water condition and studied for alteration in physiological, molecular and proteomic profile changes in the leaves. Drought stress results in reduced net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration (E) rate. With expanded severity of drought, declination recorded in content of total chlorophyll and carotenoid while enhancement observed in phenol content indicating generation of oxidative stress. In contrary, activities of catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX), and guaiacol (POD) were increased under drought stress. Peptide mass fingerprinting (PMF) showed that drought increased the relative abundance of 38 spots while decreases10 spots of protein. The identified proteins belong to protein synthesis, photosynthesis, nucleotide biosynthesis, stress response, transcription regulation, metabolism, energy and DNA binding. A drought-induced MADSbox transcription factor was identified. The present findings indicate that under drought muskmelon elevates the abundance of defense proteins and suppresses catabolic proteins. The data obtained exhibits possible mechanisms adopted by muskmelon to counter the impacts of drought induced stress. © 2019 Ansari et al.
Fabrication of an ultra-sensitive hydrazine sensor based on nano-chips shaped nickel hydroxide modified electrodes
(Springer Science and Business Media Deutschland GmbH, 2022) Marya Khan; Rafiq Ahmad; Nirmalya Tripathy; Ajit Khosla; M. Iqbal R. Khan; Prabhash Mishra; Mansoor Ali Syed; Waquar Akhter Ansari
To exploit the possibilities provided by the nanostructure morphology of nano-materials in sensing applications, we synthesized nano-chips shaped nickel hydroxide (Ni(OH)2) nanostructures using hydrothermal method. The nano-chips shaped Ni(OH)2 nanostructure were further utilized to modify the gold working electrode (gold sputtered on glass substrate) to fabricate the hydrazine sensor. The fabricated hydrazine sensor was used for the highly sensitive detection of hydrazine in a water solution. The hydrazine sensor displayed ultra-high sensitivity (1861.25 µA/µM/cm2), a linear response in the concentration range of 0–120 nM, and a lower detection limit (10 nM) during hydrazine sensing. The obtained sensitivity is comparatively higher than any previously reported values. Other features of fabricated hydrazine sensor include a highly reproducible fabrication process, stability, and selectivity. Conceivably, these nano-chips shaped Ni(OH)2 nanostructure hold significant potential for the future applications in nano-material-based chemical/biological sensors. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.
Genetic diversity in Indian cucumber based on microsatellite and morphological markers
(2013) Sudhakar Pandey; Waquar Akhter Ansari; Vinay Kumar Mishra; Asheesh Kumar Singh; Major Singh
Genetic variation among 44 cucumber accessions was assessed using morphological and SSR markers. High genetic variability was observed for days to 50% female flowering (37-46 days from sowing), number of fruits per plant (1.4-6.0), individual fruit weight (0.04-0.552kg) and root length (14.25-32.8cm). The pair-wise Jaccard similarity coefficient ranged between 0.25 and 0.85 indicating that the accessions represent genetically diverse populations. The allelic diversity of polymorphic markers ranged from 0.001 to 0.9396 with an average of 0.31 based on polymorphic information content. The clustering pattern of SSR markers was not in consonance with the groupings based on quantitative traits. The accession of Indian state i.e.; Madhya Pradesh and Uttar Pradesh were diverged from the accessions of other parts of India. The study provides information for future exploration and collection of cucumber germplasm in India and utilization of diverse germplasm for developing cultivars/hybrids for specific traits. © 2013 Elsevier Ltd.
Genetic diversity in muskmelon based on SSR markers and morphological traits under well-watered and water-deficit condition
(Elsevier Ltd, 2020) Waquar Akhter Ansari; Neelam Atri; Luming Yang; Bijendra Singh; Sudhakar Pandey
In the present study genetic diversity among 48 muskmelon accessions was analyzed employing various morphological traits under well-watered and water-deficit condition and SSR markers. Maximum values for horticultural traits were, 44 cm for fruit polar circumference, 33.2 cm for fruit equatorial circumference, 21 for number of fruits, 41.5 for days to first male flowering, 44 for days to 50% male flowering, 44 days to first female flowering, 45 days to 50% female flowering and 5.66 for number of shoot branching under well-watered condition. While under water-deficit condition maximum values of same parameters were 28.8 cm, 26 cm, 18, 37.2, 39, 47, 46.2 and 4.4, respectively. Based on morphological traits genotypes were clustered in three major clusters under well-watered condition, while grouped in five major clusters under water-deficit condition. Out of the 52 SSR markers, 35 produced polymorphic patterns, a total of 125 amplification products were obtained, the mean number of alleles per locus was 3.57, and the size of amplified products ranged from 120 bp to 605 bp. The average PIC value was estimated to be 0.492. Jaccard similarity coefficients calculated from SSR data varied from 0.03 to 0.89 with a mean value of 0.46. The clustering pattern of muskmelon accessions based on SSR markers was random but not in consonance with the groupings based on quantitative traits under well-watered and water-deficit condition. High genetic variability was observed based on various morphological traits, under both well-watered and water-deficit condition and SSR markers, indicating genetically diverse accessions. © 2020
Genetically Modified Cereal Crops Regulation Policies
(Springer Singapore, 2023) Ram Krishna; P.S. Soumia; Waquar Akhter Ansari; Kiran Khandagale; Major Singh
The history of crop genetic manipulation through conventional breeding (artificial selection and selective breeding) dates back to more than 10, 000 years. To feed the intense growing population, conventional breeding is unsuitable due to time, money consumption, and lack of desirable traits in plant genetic pool. The introduction of biotechnology in the late twentieth century and the start of the twenty-first century revolutionized modern agriculture by introducing the unavailable desired traits from other sources. The adaptation of genetically modified (GM) crops may create many socio-economic, food, and sustainability opportunities for both farmer ecosystem and farmers. In the last two decades GM crop adaptation increased due to its ability to multiply the quality agricultural productivity. Worldwide during 2017, 30% of canola, 80% of cotton, 32% of maize, and 77% of GM soybean were cultivated. Globally, 26 countries (21 developing and 5 industrialized countries) planted 191.7 million hectares of biotech crops. Furthermore, 43 other countries have formally cultivated GM crops to measure the utilization of GM crops. Despite the above facts a huge gap exists in both rapid acceptance of GM crops by farmers in many countries and for food, feeds, and limited acceptance by consumers in global market. These facts also characterized the various opinions of consumers. The significant factors influencing consumer’s attitudes are the awareness of benefit and risk, knowledge and trust, and personal values. GM crops have sparked tremendous public outrage, particularly on the rising concerns over GM food labelling, prompting the government to withdraw Bt brinjal from India. The increasing GM crop cultivation has augmented a wide range of distresses with respect to environmental, socio-economic, and food safety issues. In this chapter, we explained the present status of GM crops research, regulatory framework, and challenges involved in GM research globally. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023.
Heavy metals toxicity to food crops and application of microorganisms in bioremediation
(Elsevier, 2020) Mohammad Tarique Zeyad; Waquar Akhter Ansari; Mohd Aamir; Ram Krishna; Sushil Kumar Singh; Neelam Atri; Abdul Malik
In recent times, industrialization and urbanization has increased alarmingly over the year that resulted an upsurge in contamination of heavy metals (HMs) in soil systems. The indiscriminate application of HMs in different industries causes the discharge of HMs in superfluous amount that ultimately causes the losses in soil fertility, microbial diversity, as well as crop productivity. Food crops (vegetables, cereals, and legumes) are one of the important dietary human food components worldwide. After their discharge, HMs reaches to soil system and taken up by plants and ultimately causes the toxicity to plants. The toxicity of HMs in plant organs can be seen in the form of cytotoxicity, oxidative stress, and DNA damage. Furthermore, when HM contaminated foods are consumed by humans, they cause severe disease symptoms and some childhood malignancies. To overcome the problem of HMs contamination, several physicochemical strategies have been applied by scientific workers in many ways. But these chemical strategies of HM removal from contaminated sites have certain limitations and most of the time causes failure. So, now a days, a group of beneficial soil bacteria often termed plant growth promoting rhizobacteria (PGPR) having biological properties of growth promotion and HM removal are being applied to clean up the HM contaminated sites. These PGPR have the unique ability of metal chelation, biosorption, metal reduction, and bioremediation. Present chapter describes about the toxicity of HM to various food crops and their biomanagement efficacy by using the soil bacteria, that is, PGPR. © 2021 Elsevier Inc.
Impact of Plant Growth-Promoting Microorganism (PGPM) Consortium on Biochemical Properties and Yields of Tomato Under Drought Stress
(Multidisciplinary Digital Publishing Institute (MDPI), 2024) Ram Krishna; Waquar Akhter Ansari; Mohammad Altaf; Durgesh Kumar Jaiswal; Sudhakar Pandey; Achuit Kumar Singh; Sudhir Kumar; Jay Prakash Verma
Drought is the most important abiotic stress that restricts the genetically predetermined yield potential of the crops. In the present study, four tomato varieties: Kashi Vishesh, Kashi Aman, Kashi Abhiman, and Kashi Amrit, were used to study the effect of PGPMs (plant growth-promoting microorganisms). PGPM strains, Bacillus megaterium BHUPSB14, Pseudomonas fluorescens BHUPSB06, Pseudomonas aeruginosa BHUPSB01, Pseudomonas putida BHUPSB0, Paenibacillus polymixa BHUPSB17, and Trichoderma horzianum, were used as the consortium. The control group was irrigated up to 80% of field capacity, while 7-, 14-, and 21-day water-deficit-exposed (DWD) plants’ pot soil moisture was maintained to 40, 25, and 15% of the field capacity, both with and without the PGPM inoculation condition. The physiological parameters, such as electrolyte leakage, relative water content, photosynthetic efficiency, and chlorophyll color index, were significantly improved by PGPM application under progressive drought stress, compared to the control. PGPM application enhanced the proline accumulation and reduced the formation of hydrogen peroxide and lipid peroxidation under drought stress. The plant growth attributes were significantly increased by PGPM application. The Kashi Amrit variety showed the highest fruit yield among the four varieties under all the treatments. The PGPM consortium application also improved the soil physico-biological properties and nutrient availability in the soil. The PGPM consortium used in this study can potentially mitigate drought stress on tomato in drought-prone regions and act as a biofertilizer. The present study will open a new avenue of drought stress management in tomato. © 2024 by the authors.
Importance and utilization of plant-beneficial rhizobacteria in agriculture
(Springer Singapore, 2019) Bansh Narayan Singh; Mahendra Vikram Singh Rajawat; Akash Hidangmayum; Waquar Akhter Ansari; Devendra Singh; Mohammad Tarique Zeyad; Shiv Charan Kumar; Manish Roy; Murugan Kumar
Due to the use of a large amount of chemical fertilizers, continuous loss of soil fertility puts pressure on farmers toward more crop production in a sustainable manner. This problem creates a big challenge for farmers to fulfill the demand for the next generation. If an adequate amount of fertilizers is not supplied to crops, it raises major issue related to global food production and food security. Therefore, it requires adapting an eco-friendly, sustainable, and cost-effective approach for agricultural practices without arising environmental issues. Several natural rhizobacteria inhabiting the rhizospheric soil exist, which are used for plant growth promotion. They have tremendous capacity to provide directly or indirectly nutrient availability to the plants, stimulate plant hormones, and secrete certain compounds that help in the association of several other beneficial microbes with plant roots. In addition to restoring soil fertility, they have the capability to protect plants against soil-borne pathogens, thereby promoting plant growth. Further, application of plant growth-promoting rhizobacteria reduces the utilization of chemical fertilizers, pesticides, and other artificial growth regulators that cause severe health and environmental issues, soil infertility, water pollution, and biodiversity losses. In this context, sustainable use of rhizobacteria has been suggested to be an eco-friendly and cost-effective approach which increases crop yields and directly or indirectly protects plant from soil-borne pathogens for a long time. © Springer Nature Singapore Pte Ltd. 2019.
Insight in the transcriptome data of hairy root disease-causing bacterium-Agrobacterium rhizogenes
(Elsevier Inc., 2020) Akhilesh Yadav; Hariom Verma; Waquar Akhter Ansari; Asha Lata Singh; Major Singh
Agrobacterium rhizogenes induce the production of the hairy root through the transformation of plant genomes. In this article, we executed the transcriptome of A. rhizogenes through RNA-sequencing. RNA-sequencing of A. rhizogenes generated a total of 2.6 Gb raw data with a 75 bp paired-end sequence. The raw data has been submitted to the SRA database of NCBI with accession number SRR5641651. Reads were generated 2946 unigenes and all unigenes were annotated in the database. The length of transcripts ranged from 90 to 6369 bp, with a median transcript length of 968. The transcripts were annotated through the number of databases to obtain information about SSRs, SNPs, Gene Ontology, Transcription factors, and pathways analysis. © 2020 The Author(s)
Modern molecular and omics tools for understanding the plant growth-promoting rhizobacteria
(Elsevier, 2019) Ram Krishna; Waquar Akhter Ansari; Jay Prakash Verma; Major Singh
Current agricultural practices have become threats to the environment and to human health because of extensive use of chemical fertilizers, pesticides, and herbicides to improve crop yields. The plant growth-promoting rhizobacteria (PGPR) is a root-associated bacteria that produces that improve crop yield. While it is known that a PGPR is needed, due to the large number and types of PGPRs and soil types, it is difficult to determine the best PGPR for specific applications. Conventional techniques like morphological, staining, and biochemical are not precise enough, as many bacteria may be similar in morphology and produce the same biochemical reaction, but differ in genetic content. Even small genetic variations make a big difference in the performance of PGPRs and thus it is important to study PGPR with molecular techniques with the capability to discriminate very closely-related microbial samples within a community. © 2019 Elsevier Inc. All rights reserved.
Molecular Approaches for Biofortification of Cereal Crops
(Springer Singapore, 2023) Heresh Puren; Bodeddulla Jayasankar Reddy; Akashi Sarma; Sushil Kumar Singh; Waquar Akhter Ansari
Cereals are edible grains and the primary staple food crops globally. They are the major source of energy, nutrients, and bioactive substances, which provide potential health benefits in humans and livestock animals. The green revolution enhanced the crop yield potential but did not enhance the nutritional requirements, which can now be overcome by genetic revolution. There is a colossal shortage of micronutrient consumption by a preponderance of the population globally for hidden hunger. Biofortification is a new paradigm, an instrumental intervention for providing nutrients to the people deprived of access to micronutrients while keeping the promise of least cost and sustainability. It can provide enough calories and essential nutrients to meet the requirement for the sound health of the target population. Meanwhile, there is a continuous increase in population in developing nations, and climate change is a serious challenge to fulfill the food and nutritional requirements. Thus, a more rapid and efficient strategy for biofortification is the need of the hour. Molecular breeding approaches are proven suitable for biofortification by transferring mapped QTLs/genes into nutrient-deficient crops such as QPM maize, high Fe, and Zn-rich rice lines, golden rice enriched with vitamin A, etc. However, molecular breeding advises for limited employment, citing insufficient genetic variation among crops. Furthermore, genetic engineering technologies go beyond the agricultural gene pool to increase the concentration of micronutrients. Similarly, recent genome sequencing technologies have paved the way for identifying new regulatory genes and miRNA within the crops, which can be further modified by genome editing approaches using CRISPR-Cas technology. This chapter highlights the strategies of molecular methods for the biofortification of crops substantiated to be precise and effective strategies for potential economic enrichment of nutritional status to overcome the hidden hunger worldwide. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023.
Molecular chaperones: A key player for combating the effect of abiotic stresses
(Elsevier, 2021) Sushil Kumar Singh; Pompi Das; Rahul Chandrakant Kaldate; Swapnilkumar Meshram; Waquar Akhter Ansari; Heresh Puren
Undesirable environmental situations, namely, drought, extreme salinity, and temperature, are the most common abiotic stresses constantly challenge in various agricultural regions. These types of stress(s) ultimately result in yield loss to different crop species. Under the influence of abiotic stresses, most horticultural crop species (tomato, banana, soybean, etc.) induce activation of genes for stress physiology. Boosting up the level of heat shock proteins (HSPs)/chaperones in a diverse range of stresses signifies its importance in metabolic stress response. In plants it belonges to divergent classes and are homologous to prokaryotes and other eukaryotes. Chaperones are the essential mechanism under adverse conditions to maintain homeostasis at the cellular level. Interaction of molecular chaperones with misfolded or newly synthesized proteins assists proper folding of proteins. However, molecular chaperones like protein disulfide isomerase, cyclophilin, and calnexin/calreticulin, have also been found to activate defence response against abiotic stresses in various crop species. This activity specifies the importance of HSPs as stress-responsive cascade and therefore, considering its vital role in genome-wide studies in several crop species. The chaperone network’s sensitive tuning and its reciprocal relationship with other cellular components are still yet to be researched to know the appropriate character and function of chaperones. In the present chapter, the emphasis has been given to describe the structure and characteristics of diverse HSP and plant-cell chaperones in the endoplasmic reticulum of various horticulture crops. We also describe the mechanism of molecular chaperon under adverse climatic conditions and during the accumulation of seed storage protein at the development phase of seeds. © 2021 Elsevier Inc.
Overexpression of AtDREB1 and BcZAT12 genes confers drought tolerance by reducing oxidative stress in double transgenic tomato (Solanum lycopersicum L.)
(Springer Science and Business Media Deutschland GmbH, 2021) Ram Krishna; Waquar Akhter Ansari; Durgesh Kumar Jaiswal; Achuit Kumar Singh; Ram Prasad; Jay Prakash Verma; Major Singh
Key message: Double transgenic tomato developed byAtDREB1AandBcZAT12genes pyramiding showed significant drought tolerance by reducing oxidative stress with enhanced yield. Abstract: Although a large number of efforts have been made by different researchers to develop abiotic stress tolerance tomato for improving yield using single gene, however, no reports are available which targets AtDREB1 and BcZAT12 genes together. Hence, in the present study, double transgenic plants were developed using AtDREB1 and BcZAT12 genes to improve yield potential with better drought tolerance. Double transgenic (DZ1–DZ5) tomato lines showed enhanced drought tolerance than their counterpart non-transgenic and single transgenic plants at 0, 07, 14, and 21 days of water deficit, respectively. Double transgenic plants showed increased activity of antioxidant enzymes, like catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR) and guaiacol peroxidase (POD), and accumulation of non-enzymatic antioxidants like ascorbic acid, glutathione as compared to non-transgenic and single transgenic. Additionally, the transcript analysis of antioxidant enzymes revealed the increased level of gene expression in double transgenic tomato lines. Developed double-transgenic tomato plants co-over-expressing both genes exhibited more enzymatic and non-enzymatic anti-oxidative activities as compared to the non-transgenic and single transgenic control, respectively. This is the preliminary report in tomato, which forms the basis for a multigene transgenic approach to cope with drought stress. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
Potential Microbial Consortium Mitigates Drought Stress in Tomato (Solanum lycopersicum L.) Plant by Up-regulating Stress-Responsive Genes and Improving Fruit Yield and Soil Properties
(Springer Science and Business Media Deutschland GmbH, 2022) Ram Krishna; Durgesh Kumar Jaiswal; Waquar Akhter Ansari; Saurabh Singh; P.S. Soumia; Achuit Kumar Singh; Babita Kumari; Major Singh; Jay Prakash Verma
The present study is conducted for the growth and yield improvement of tomato plants under drought stress by inoculation of hexa plant growth-promoting microorganisms (PGPM). Hexa-PGPM consortium (Bacillus megaterium, Pseudomonas fluorescens, P. aeruginosa, P. putida, Paenibacillus polymyxa, and Trichoderma harzianum) is inoculated to the tomato plant, and growth attributes, membrane integrity, water status, accumulation of osmolyte, reactive oxygen species (ROS) scavenging capability, and the qRT-PCR analysis were performed for expression of stress-responsive DREB, APX, CAT, SOD, and P5CS under 80% and 40% moisture content of the field capacity. Soil physico-chemical and microbial properties were also evaluated. Our results revealed that under drought, hexa-PGPM consortium-inoculated plants exhibited lower cellular damage and better plant growth and yield than non-inoculated plants. Antioxidant enzyme catalase (CAT), superoxide dismutase (SOD), and ascorbate peroxidase (APX) activity decreases under drought stress condition and it increases in hexa-PGPM-inoculated plants. Simultaneously, the gene expression analysis showed up-regulation of a transcriptional activator (DREB1), osmolyte accumulators (P5CS), and ROS scavengers (CAT, SOD, APX) gene by application of hexa-PGPM consortium. Overall, the results showed that the hexa-PGPM application confers drought mitigation in tomatoes by altering different physico-biochemical and molecular parameters. In addition, the PGPM application also improved the soil’s physical, chemico-chemical, and biological properties under drought stress conditions. The present study supports the application of hexa- PGPM consortium to elevate drought tolerance, yield, and soil fertility enhancement under drought stress as a low-cost agro-biotechnology tool and environment-friendly drought management techniques in tomato crops. © 2022, The Author(s) under exclusive licence to Sociedad Chilena de la Ciencia del Suelo.
Relevance of plant growth-promoting bacteria in reducing the severity of tomato wilt caused by Fusarium oxysporum f. sp. lycopersici by altering metabolites and related genes
(Frontiers Media SA, 2024) Waquar Akhter Ansari; Ram Krishna; Sarvesh Pratap Kashyap; Khalid Mashay Al-Anazi; Mohammad Abul Farah; Durgesh Kumar Jaiswal; Akhilesh Yadav; Mohammad Tarique Zeyad; Jay Prakash Verma
Among the biotic stresses, wilt disease severely affects tomato quality and productivity globally. The causal organism of this disease is Fusarium oxysporum f. sp. lycopersici (Fol), which is very well known and has a significant impact on the productivity of other crops as well. Efforts have been made to investigate the effect of plant growth-promoting bacteria (PGPB) on alleviating tomato wilt disease. Four PGPB strains, such as Pseudomonas aeruginosa BHUPSB01 (T1), Pseudomonas putida BHUPSB04 (T2), Paenibacillus polymyxa BHUPSB16 (T3), and Bacillus cereus IESDJP-V4 (T4), were used as inocula to treat Fol-challenged plants. The results revealed that PGPB treatments T1, T2, T3, and T4 were able to decrease the severity of Fusarium wilt in the tomato plants at different levels. Among the treatments, T3 displayed the strongest protective effect, with the lowest disease frequency, which was 15.25%. There were no significant differences observed in parameters such as fruit yield and relative water content in the PGPB-inoculated plants, although T3 and T4 showed minimal electrolyte leakage. Significant changes in chlorophyll fluorescence were also recorded. A lower level of H2O2 and malondialdehyde (MDA) was observed in the T3 and T4 treatments. In addition, proline accumulation was highest in the T3-treated plants. Antioxidative enzyme activities, such as catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD), significantly increased in the PGPB-treated plants. Furthermore, the highest phenylalanine ammonia-lyase (PAL) and polyphenol oxidase (PPO) activity was reported in the T3 and T4 plants, respectively. The PGPB-treated plants showed elevated expression of the PAL, PPO, PR3, PR2, SOD, CAT, and PO genes. This study’s results reveal that PGPB strains can be utilized as biocontrol agents (BCAs) to enhance tomato resistance against Fusarium wilt. Copyright © 2025 Ansari, Krishna, Kashyap, Al-Anazi, Abul Farah, Jaiswal, Yadav, Zeyad and Verma.
Review - Recent Advances in Nanostructured Graphitic Carbon Nitride as a Sensing Material for Heavy Metal Ions
(Institute of Physics Publishing, 2020) Rafiq Ahmad; Nirmalya Tripathy; Ajit Khosla; Marya Khan; Prabhash Mishra; Waquar Akhter Ansari; Mansoor Ali Syed; Yoon-Bong Hahn
Graphitic carbon nitride (g-C3N4), as a crucial sensing material has attracted intense interest for sensor devices development. Owing to its large specific surface area, excellent physicochemical stability, exceptional electronic band structure, and outstanding electronic, thermal, optical, and mechanical properties. In addition, excellent biocompatibility, unique electroluminescent and photoelectrochemical properties, g-C3N4 nanomaterials contribute to the development of fast, accurate, cost-effective, and reliable sensors. Herein, we provide a comprehensive review on the development of g-C3N4 nanomaterials-based sensors and their potential detection applications for various heavy metal analytes. Furthermore, a comparative sensing performance of sensors, current challenges and prospective of g-C3N4 based nanomaterials are outlined in detail. © The Author(s) 2019. Published by ECS.
Standardization of screening technique and evaluation of muskmelon genotypes for drought tolerance
(Cambridge University Press, 2018) Sudhakar Pandey; Waquar Akhter Ansari; Neelam Atri; Bijendra Singh; Sunil Gupta; Kangila Venkataraman Bhat
A five-point drought stress screening methodology for muskmelon based on visual observation has been standardized by modifying an earlier field screening method. The scale (1 to 5), were categorized into five groups, namely, highly drought tolerant (1), drought tolerant (2), average drought tolerant (3), drought susceptible (4) and highly drought susceptible (5). To validate and standardized the technique, 48 genotypes of muskmelon were evaluated for two successive years. Important physiological parameters, i.e.: relative water content (RWC), electrolyte leakage, photosynthetic efficiency (Fv/Fm), chlorophyll concentration index (CCI), root and shoot length were measured and correlated to make screening results more reliable. Drought tolerance efficiency of genotypes was calculated based on yield, and drought-tolerant genotypes were identified with better yield efficiency and ranking on visual scale. Whereas, yield efficiency of some drought-tolerant genotypes were less, althouth they came under drought-tolerant scale. Being a tolerant genotype, these may not be economical for commercial cultivation. Under water-deficit condition a significant positive correlation was observed between drought tolerance efficiency, and RWC, Fv/Fm, CCI and root length. Out of 48 genotypes, 14 genotypes were came under highly drought-tolerant category based on 5 point scale. © Copyright NIAB 2016.
Transcriptional response of otsA, P5CR, glgX, nodC, and molecular chaperone genes under the PEG-induced drought stress in Mesorhizobium ciceri Ca181
(Elsevier Ltd, 2020) Akhilesh Yadav; Waquar Akhter Ansari; Asha Lata Singh; Major Singh
This study was carried out to elucidate the mechanism of drought stress tolerance in bacterium Mesorhizobium ciceri Ca181, and further to correlate the finding with various salts impacts on the survival. Expression analysis of genes otsA, P5CR, glgX, major chaperone; groELS, dnaKJ, and nodulation protein-coding nodC genes were carried to reveal their roles in enhancing the PEG-induced drought tolerance. Yeast extract mannitol (YEM) broth supplemented with 47% polyethylene glycol (PEG-6000; w/v) was used to create the drought stress environment in the medium and strain Ca181 was able to tolerate PEG-induced drought stress for up to 5 days of incubation at 28 °C. PEG-induced desiccated cells showed variable expression patterns at the time interval of 5 min, 15 min, 1 h, 4 h, 8 h, 48 h, and 120 h. All the genes showed low levels of expression when the cells were grown until exponential growth phase in the presence of PEG-induced drought stress. However, when cells at the exponential phase of growth were incubated with PEG, maximum expression occurred after 5 min and 15 min, followed by a rapid decrease in the expression of otsA, P5CR, nodC, and molecular chaperone genes while the maximum expression of glgX was observed after 1 h of PEG-induced drought stress. The present study expands our information related to PEG-induced drought stress tolerance in strain Ca181, and impacts of salts additionally, expression analysis of these genes will contribute to our understanding of the molecular mechanism. © 2019 Elsevier Ltd