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Bhupenchandra I, Basumatary A, Choudhary AK, Kumar A, Sarkar D, Chongtham SK, Singh AH, Devi EL, Bora SS, Salam MD, Sahoo MR, Gudade BA, Kumar A, Devi SH, Gogoi B, Harish MN, Gupta G, Olivia LC, Devi YP, Sarika K, Thapa S, Rajawat MVS. Elucidating the impact of boron fertilization on soil physico-chemical and biological entities under cauliflower-cowpea-okra cropping system in an Eastern Himalayan acidic Inceptisol. Front Microbiol 2022; 13:996220. [PMID: 36419419 PMCID: PMC9676249 DOI: 10.3389/fmicb.2022.996220] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Accepted: 08/30/2022] [Indexed: 11/09/2022] Open
Abstract
Information on the role of boron (B) on soil physico-chemical and biological entities is scarce, and the precise mechanism in soil is still obscure. Present field investigation aimed to assessing the implication of direct and residual effect of graded levels of applied-B on soil biological entities and its concomitant impact on crop productivity. The treatments comprised of five graded levels of B with four replications. To assess the direct effect of B-fertilization, cauliflower was grown as a test crop wherein, B-fertilization was done every year. For assessment of succeeding residual effects of B-fertilization, cowpea and okra were grown as test crops and, B-fertilization was phased out in both crops. The 100% recommended dose of NPK (RDF) along with FYM was uniformly applied to all crops under CCOCS. Results indicated that the direct effect of B had the edge over residual effect of B in affecting soil physico-chemical and biological entities under CCOCS. Amongst the graded levels of B, application of the highest B level (2 kg ha–1) was most prominent in augmenting microbiological pools in soil at different crop growth stages. The order of B treatments in respect of MBC, MBN, and soil respiration at different crop growth stages was 2.0 kg B ha–1 > 1.5 kg B ha–1 > 1.0 kg B ha–1 > 0.5 kg B ha–1 > 0 kg B ha–1, respectively. Moreover, maximum recoveries of potentially mineralizable-C (PMC) and potentially mineralizable-N (PMN) were noticed under 2 kg B ha–1. Analogous trend was recorded in soil microbial populations at different crop growth stages. Similarly, escalating B levels up to 2 kg B ha–1 exhibited significantly greater soil enzymatic activities viz., arylsulphatase (AS), dehydrogenase (DH), fluorescein diacetate (FDA) and phosphomonoesterase (PMA), except urease enzyme (UE) which showed an antagonistic effect of applied-B in soil. Greater geometric mean enzyme activity (GMEA) and soil functional diversity index were recorded under 2 kg B ha–1 in CCOCS, at all crop growth stages over control. The inclusive results indicated that different soil physico-chemical and biological properties CCOCS can be invariably improved by the application of graded levels of B up to 2 kg B ha–1 in an acid Inceptisol.
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Affiliation(s)
- Ingudam Bhupenchandra
- ICAR-KVK Tamenglong, Indian Council of Agricultural Research–Research Complex for North–Eastern Hill Region, Manipur Centre, Imphal, Manipur, India
| | - Anjali Basumatary
- Department of Soil Science, Assam Agricultural University, Jorhat, Assam, India
| | - Anil K. Choudhary
- Division of Agronomy, Indian Council of Agricultural Research–Indian Agricultural Research Institute, New Delhi, India
- Division of Crop Production, Indian Council of Agricultural Research–Central Potato Research Institute, Shimla, India
- Anil K. Choudhary,
| | - Adarsh Kumar
- ICAR-National Bureau of Agriculturally Important Microorganism, Mau, India
| | - Dibyendu Sarkar
- Department of Agricultural Chemistry and Soil Science, Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, West Bengal, India
| | - Sunil Kumar Chongtham
- Multi Technology Testing Centre and Vocational Training Centre, College of Agricultural Engineering and Post Harvest Technology, Central Agricultural University, Ranipool, Sikkim, India
| | | | | | - S. S. Bora
- Regional Research Station, Indian Cardamom Research Institute, Spices Board, Tadong, Gangtok, India
| | - Menaka Devi Salam
- Amity Institute of Microbial Technology, Amity University Uttar Pradesh, Noida, India
| | - Manas Ranjan Sahoo
- Central Horticultural Experiment Station, Indian Council of Agricultural Research–Indian Institute of Horticultural Research, Bhubaneswar, Odisha, India
| | - Bharat A. Gudade
- Regional Research Station, Indian Cardamom Research Institute, Spices Board, Tadong, Gangtok, India
| | - Amit Kumar
- ICAR RC for NEH Region, Sikkim Centre, Tadong, Sikkim, India
| | - Soibam Helena Devi
- Department of Crop Physiology, Assam Agricultural University, Jorhat, Assam, India
| | - Bhabesh Gogoi
- Department of Soil Science, Assam Agricultural University, Jorhat, Assam, India
| | - M. N. Harish
- Farm Science Centre, Indian Council of Agricultural Research–Indian Institute of Horticultural Research, Kodagu, Karnataka, India
| | - Gaurendra Gupta
- ICAR-Indian Grassland and Fodder Research Institute, Jhansi, Uttar Pradesh, India
| | - Leitam Chanu Olivia
- Department of Agronomy, College of Agriculture, Central Agricultural University, Imphal, India
| | | | - Konsam Sarika
- ICAR RC for NEH Region, Manipur Centre, Imphal, Manipur, India
| | - Shobit Thapa
- ICAR-National Bureau of Agriculturally Important Microorganism, Mau, India
| | - Mahendra Vikram Singh Rajawat
- ICAR-National Bureau of Agriculturally Important Microorganism, Mau, India
- *Correspondence: Mahendra Vikram Singh Rajawat,
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Varatharajan T, Dass A, Choudhary AK, Sudhishri S, Pooniya V, Das TK, Rajanna GA, Prasad S, Swarnalakshmi K, Harish MN, Dhar S, Singh R, Raj R, Kumari K, Singh A, Sachin KS, Kumar P. Integrated management enhances crop physiology and final yield in maize intercropped with blackgram in semiarid South Asia. Front Plant Sci 2022; 13:975569. [PMID: 36212325 PMCID: PMC9538492 DOI: 10.3389/fpls.2022.975569] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 08/31/2022] [Indexed: 06/16/2023]
Abstract
Photosynthesis, crop health and dry matter partitioning are among the most important factors influencing crop productivity and quality. Identifying variation in these parameters may help discover the plausible causes for crop productivity differences under various management practices and cropping systems. Thus, a 2-year (2019-2020) study was undertaken to investigate how far the integrated crop management (ICM) modules and cropping systems affect maize physiology, photosynthetic characteristics, crop vigour and productivity in a holistic manner. The treatments included nine main-plot ICM treatments [ICM1 to ICM4 - conventional tillage (CT)-based; ICM5 to ICM8 - conservation agriculture (CA)-based; ICM9 - organic agriculture (OA)-based] and two cropping systems, viz., maize-wheat and maize + blackgram-wheat in subplots. The CA-based ICM module, ICM7 resulted in significant (p < 0.05) improvements in the physiological parameters, viz., photosynthetic rate (42.56 μ mol CO2 m-2 sec-1), transpiration rate (9.88 m mol H2O m-2 sec-1) and net assimilation rate (NAR) (2.81 mg cm-2 day-1), crop vigour [NDVI (0.78), chlorophyll content (53.0)], dry matter partitioning toward grain and finally increased maize crop productivity (6.66 t ha-1) by 13.4-14.2 and 27.3-28.0% over CT- and OA-based modules. For maize equivalent grain yield (MEGY), the ICM modules followed the trend as ICM7 > ICM8 > ICM5 > ICM6 > ICM3 > ICM4 > ICM1 > ICM2 > ICM9. Multivariate and PCA analyses also revealed a positive correlation between physiological parameters, barring NAR and both grain and stover yields. Our study proposes an explanation for improved productivity of blackgram-intercropped maize under CA-based ICM management through significant improvements in physiological and photosynthetic characteristics and crop vigour. Overall, the CA-based ICM module ICM7 coupled with the maize + blackgram intercropping system could be suggested for wider adoption to enhance the maize production in semiarid regions of India and similar agroecologies across the globe.
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Affiliation(s)
- T. Varatharajan
- Indian Agricultural Research Institute, Indian Council of Agricultural Research, New Delhi, India
| | - Anchal Dass
- Indian Agricultural Research Institute, Indian Council of Agricultural Research, New Delhi, India
| | - Anil K. Choudhary
- Indian Agricultural Research Institute, Indian Council of Agricultural Research, New Delhi, India
- Central Potato Research Institute, Indian Council of Agricultural Research, Shimla, India
| | - S. Sudhishri
- Indian Agricultural Research Institute, Indian Council of Agricultural Research, New Delhi, India
| | - V. Pooniya
- Indian Agricultural Research Institute, Indian Council of Agricultural Research, New Delhi, India
| | - T. K. Das
- Indian Agricultural Research Institute, Indian Council of Agricultural Research, New Delhi, India
| | - G. A. Rajanna
- Indian Agricultural Research Institute, Indian Council of Agricultural Research, New Delhi, India
- Directorate of Groundnut Research, Indian Council of Agricultural Research, Ananthapur, India
| | - Shiv Prasad
- Indian Agricultural Research Institute, Indian Council of Agricultural Research, New Delhi, India
| | | | - M. N. Harish
- Indian Agricultural Research Institute, Indian Council of Agricultural Research, New Delhi, India
- Farm Science Centre, Indian Institute of Horticultural Research, Indian Council of Agricultural Research, Gonikoppal, India
| | - Shiva Dhar
- Indian Agricultural Research Institute, Indian Council of Agricultural Research, New Delhi, India
| | - Raj Singh
- Indian Agricultural Research Institute, Indian Council of Agricultural Research, New Delhi, India
| | - Rishi Raj
- Indian Agricultural Research Institute, Indian Council of Agricultural Research, New Delhi, India
| | - Kavita Kumari
- Indian Agricultural Research Institute, Indian Council of Agricultural Research, New Delhi, India
| | - Arjun Singh
- Indian Agricultural Research Institute, Indian Council of Agricultural Research, New Delhi, India
- National Research Centre for Banana, Indian Council of Agricultural Research, Tiruchirappalli, India
| | - K. S. Sachin
- Indian Agricultural Research Institute, Indian Council of Agricultural Research, New Delhi, India
| | - Pramod Kumar
- Indian Agricultural Research Institute, Indian Council of Agricultural Research, New Delhi, India
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3
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Harish MN, Choudhary AK, Bhupenchandra I, Dass A, Rajanna GA, Singh VK, Bana RS, Varatharajan T, Verma P, George S, Kashinath GT, Bhavya M, Chongtham SK, Devi EL, Kumar S, Devi SH, Bhutia TL. Double zero-tillage and foliar-P nutrition coupled with bio-inoculants enhance physiological photosynthetic characteristics and resilience to nutritional and environmental stresses in maize-wheat rotation. Front Plant Sci 2022; 13:959541. [PMID: 36186084 PMCID: PMC9520575 DOI: 10.3389/fpls.2022.959541] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 08/22/2022] [Indexed: 06/16/2023]
Abstract
Conventionally tilled maize-wheat cropping system (MWCS) is an emerging cereal production system in semi-arid region of south-Asia. This system involves excessive tillage operations that result in numerous resource- and production-vulnerabilities besides impeding environmental-stresses. Likewise, phosphorus is a vital nutrient that limits crop growth and development. It's a matter of great concern when ∼80% of Indian soils are low to medium in available-P due to its sparing solubility, resulting in crop stress and low yields. Hence, crop productivity, photosynthetic parameters and resilience to nutritional and environmental stresses were assessed in a MWCS using four crop-establishment and tillage management (CETM) practices [FBCT-FBCT (Flat bed-conventional tillage both in maize and wheat); RBCT-RBZT (Raised bed-CT in maize and raised bed-zero tillage in wheat); FBZT-FBZT (FBZT both in maize and wheat); PRBZT-PRBZT (Permanent raised bed-ZT both in maize and wheat)], and five P-fertilization practices [P100 (100% soil applied-P); P50+2FSP (50% soil applied-P + 2 foliar-sprays of P through 2% DAP both in maize and wheat); P50+PSB+AM-fungi; P50+PSB+AMF+2FSP; and P0 (100% NK with no-P)] in split-plot design replicated-thrice. The results indicated that double zero-tilled PRBZT-PRBZT system significantly enhanced the grain yield (6.1; 5.4 t ha-1), net photosynthetic rate (Pn) (41.68; 23.33 μ mol CO2 m-2 s-1), stomatal conductance (SC) (0.44; 0.26 mol H2O m-2 s-1), relative water content (RWC) (83.3; 77.8%), and radiation-use efficiency (RUE) (2.9; 2.36 g MJ-1) by 12.8-15.8 and 8.5-44.4% in maize and wheat crops, respectively over conventional tilled FBCT-FBCT. P50+PSB+AMF+2FSP conjugating soil applied-P, microbial-inoculants and foliar-P, had significantly higher Pn, SC, RUE and RWC over P100 besides saving ∼34.7% fertilizer-P under MWCS. P50+PSB+AMF+2FSP practice also had higher NDVI, PAR, transpiration efficiency and PHI over P100. Whereas lower stomatal limitation index (Ls) was observed under PRBZT-PRBZT system as compared to the conventional FBCT-FBCT system indicating that P is the limiting factor but not stomata. Hence, optimum P supply through foliar P-fertilization along with other sources resulted in higher grain yield by 21.4% over control. Overall, double zero-tilled PRBZT-PRBZT with crop residue retention at 6 t/ha per year, as well as P50+PSB+AMF+2FSP in MWCS, may prove beneficial in enhancing the crop productivity and, thereby, bolstering food security in semi-arid south-Asia region.
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Affiliation(s)
- M. N. Harish
- Division of Agronomy, ICAR–Indian Agricultural Research Institute, New Delhi, India
- ICAR–Indian Institute of Horticultural Research, Farm Science Centre, Gonikoppal, India
| | - Anil K. Choudhary
- Division of Agronomy, ICAR–Indian Agricultural Research Institute, New Delhi, India
- Division of Crop Production, ICAR–Central Potato Research Institute, Shimla, India
| | - Ingudam Bhupenchandra
- ICAR–KVK, Tamenglong, ICAR Research Complex for NEH Region, Manipur Centre, Manipur, India
| | - Anchal Dass
- Division of Agronomy, ICAR–Indian Agricultural Research Institute, New Delhi, India
| | - G. A. Rajanna
- Division of Agronomy, ICAR–Indian Agricultural Research Institute, New Delhi, India
- ICAR–Directorate of Groundnut Research, Regional Station, Anantapur, India
| | - Vinod K. Singh
- Division of Agronomy, ICAR–Indian Agricultural Research Institute, New Delhi, India
- ICAR–Central Research Institute for Dryland Agriculture, Hyderabad, India
| | - R. S. Bana
- Division of Agronomy, ICAR–Indian Agricultural Research Institute, New Delhi, India
| | - T. Varatharajan
- Division of Agronomy, ICAR–Indian Agricultural Research Institute, New Delhi, India
| | - Parkash Verma
- Division of Agronomy, ICAR–Indian Agricultural Research Institute, New Delhi, India
- Agronomy Section, ICAR–National Dairy Research Institute, Karnal, India
| | - Saju George
- ICAR–Indian Institute of Horticultural Research, Farm Science Centre, Gonikoppal, India
| | - G. T. Kashinath
- Department of Agronomy, Mahatma Phule Krishi Vidyapeeth, Rahuri, India
| | - M. Bhavya
- Department of Agronomy, KSN University of Agricultural and Horticultural Sciences, Shivamogga, India
| | - S. K. Chongtham
- Multi Technology Testing Centre and Vocational Training Centre, CAEPHT, CAU, Ranipool, India
| | - E. Lamalakshmi Devi
- ICAR–Research Complex for North Eastern Region, Sikkim Centre, Tadong, India
| | - Sushil Kumar
- Division of Crop Production, ICAR–Central Potato Research Institute, Shimla, India
| | - Soibam Helena Devi
- Department of Crop Physiology, Assam Agricultural University, Jorhat, India
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Harish MN, Choudhary AK, Kumar S, Dass A, Singh VK, Sharma VK, Varatharajan T, Dhillon MK, Sangwan S, Dua VK, Nitesh SD, Bhavya M, Sangwan S, Prasad S, Kumar A, Rajpoot SK, Gupta G, Verma P, Kumar A, George S. Double zero tillage and foliar phosphorus fertilization coupled with microbial inoculants enhance maize productivity and quality in a maize-wheat rotation. Sci Rep 2022; 12:3161. [PMID: 35210519 PMCID: PMC8873388 DOI: 10.1038/s41598-022-07148-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 02/04/2022] [Indexed: 11/11/2022] Open
Abstract
Maize is an important industrial crop where yield and quality enhancement both assume greater importance. Clean production technologies like conservation agriculture and integrated nutrient management hold the key to enhance productivity and quality besides improving soil health and environment. Hence, maize productivity and quality were assessed under a maize–wheat cropping system (MWCS) using four crop-establishment and tillage management practices [FBCT–FBCT (Flat bed–conventional tillage both in maize and wheat); RBCT–RBZT (Raised bed–CT in maize and raised bed–zero tillage in wheat); FBZT–FBZT (FBZT both in maize and wheat); PRBZT–PRBZT (Permanent raised bed–ZT both in maize and wheat], and five P-fertilization practices [P100 (100% soil applied-P); P50 + 2FSP (50% soil applied-P + 2 foliar-sprays of P through 2% DAP both in maize and wheat); P50 + PSB + AM-fungi; P50 + PSB + AMF + 2FSP; and P0 (100% NK with no-P)] in split-plot design replicated-thrice. Double zero-tilled PRBZT–PRBZT system significantly enhanced the maize grain, starch, protein and oil yield by 13.1–19% over conventional FBCT–FBCT. P50 + PSB + AMF + 2FSP, integrating soil applied-P, microbial-inoculants and foliar-P, had significantly higher grain, starch, protein and oil yield by 12.5–17.2% over P100 besides saving 34.7% fertilizer-P both in maize and on cropping-system basis. P50 + PSB + AMF + 2FSP again had significantly higher starch, lysine and tryptophan content by 4.6–10.4% over P100 due to sustained and synchronized P-bioavailability. Higher amylose content (24.1%) was observed in grains under P50 + PSB + AMF + 2FSP, a beneficial trait due to its lower glycemic-index highly required for diabetic patients, where current COVID-19 pandemic further necessitated the use of such dietary ingredients. Double zero-tilled PRBZT–PRBZT reported greater MUFA (oleic acid, 37.1%), MUFA: PUFA ratio and P/S index with 6.9% higher P/S index in corn-oil (an oil quality parameter highly required for heart-health) over RBCT-RBCT. MUFA, MUFA: PUFA ratio and P/S index were also higher under P50 + PSB + AMF + 2FSP; avowing the obvious role of foliar-P and microbial-inoculants in influencing maize fatty acid composition. Overall, double zero-tilled PRBZT–PRBZT with crop residue retention at 6 t/ha per year along with P50 + PSB + AMF + 2FSP while saving 34.7% fertilizer-P in MWCS, may prove beneficial in enhancing maize productivity and quality so as to reinforce the food and nutritional security besides boosting food, corn-oil and starch industry in south-Asia and collateral arid agro-ecologies across the globe.
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Affiliation(s)
- M N Harish
- ICAR-Indian Agricultural Research Institute, New Delhi, 110 012, India
| | - Anil K Choudhary
- ICAR-Indian Agricultural Research Institute, New Delhi, 110 012, India. .,ICAR-Central Potato Research Institute, Shimla, Himachal Pradesh, 171 001, India.
| | - Sandeep Kumar
- ICAR-National Bureau of Plant Genetic Resources, New Delhi, 110012, India
| | - Anchal Dass
- ICAR-Indian Agricultural Research Institute, New Delhi, 110 012, India
| | - V K Singh
- ICAR-Indian Agricultural Research Institute, New Delhi, 110 012, India.,ICAR-Central Research Institute for Dryland Agriculture, Hyderabad, 500 059, India
| | - V K Sharma
- ICAR-Indian Agricultural Research Institute, New Delhi, 110 012, India
| | - T Varatharajan
- ICAR-Indian Agricultural Research Institute, New Delhi, 110 012, India
| | - M K Dhillon
- ICAR-Indian Agricultural Research Institute, New Delhi, 110 012, India
| | - Seema Sangwan
- CCS Haryana Agricultural University, Hisar, Haryana, 125 004, India
| | - V K Dua
- ICAR-Central Potato Research Institute, Shimla, Himachal Pradesh, 171 001, India
| | - S D Nitesh
- CSA University of Agriculture & Technology, Kanpur, Uttar Pradesh, 208 002, India
| | - M Bhavya
- University of Agricultural & Horticultural Sciences, Shivamogga, Karnataka, 577 204, India
| | - S Sangwan
- ICAR-Indian Agricultural Research Institute, New Delhi, 110 012, India
| | - Shiv Prasad
- ICAR-Indian Agricultural Research Institute, New Delhi, 110 012, India
| | - Adarsh Kumar
- ICAR-Indian Agricultural Research Institute, New Delhi, 110 012, India.,ICAR-National Bureau of Agriculturally Important Microorganisms, Kushmaur, Mau, Uttar Pradesh, 275 103, India
| | - S K Rajpoot
- ICAR-Indian Agricultural Research Institute, New Delhi, 110 012, India.,Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, 221 005, India
| | - Gaurendra Gupta
- ICAR-Indian Agricultural Research Institute, New Delhi, 110 012, India.,ICAR-Indian Grassland and Fodder Research Institute, Jhansi, Uttar Pradesh, 284 003, India
| | - Prakash Verma
- ICAR-Indian Agricultural Research Institute, New Delhi, 110 012, India.,ICAR-National Dairy Research Institute, Karnal, Haryana, 132 001, India
| | - Anil Kumar
- Farm Science Centre, GAD Veterinary and Animal Sciences University, Tarn Taran, Punjab, 143 412, India
| | - S George
- Farm Science Centre, ICAR-Indian Institute of Horticultural Research, Gonikoppal, Karnataka, 571213, India
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Bhat J, Rane R, Solapure SM, Sarkar D, Sharma U, Harish MN, Lamb S, Plant D, Alcock P, Peters S, Barde S, Roy RK. High-throughput screening of RNA polymerase inhibitors using a fluorescent UTP analog. ACTA ACUST UNITED AC 2006; 11:968-76. [PMID: 17021309 DOI: 10.1177/1087057106291978] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
RNA polymerase (RNAP) is a well-validated target for the development of antibacterial and antituberculosis agents. Because the purification of large quantities of native RNA polymerase from pathogenic mycobacteria is hazardous and cumbersome, the primary screening was carried out using Escherichia coli RNAP. The authors have developed a high-throughput screening (HTS) assay to screen for novel inhibitors of RNAP. In this assay, a fluorescent analog of UTP, gamma-amino naphthalene sulfonic acid (gamma-AmNS) UTP, was used as one of the nucleotide substrates. Incorporation of UMP in RNA results in the release of gamma-AmNS-PPi, which has higher intrinsic fluorescence than (gamma-AmNS) UTP. The assay was optimized in a 384-well format and used to screen 670,000 compounds at a concentration of 10 microM. About 0.1% of the compounds showed more than 60% inhibition in the primary HTS. All the primary actives tested for dose response using the same assay had an EC(50) below 100 microM. Eighty percent of the primary HTS actives obtained using E. coli RNAP showed comparable activity against Mycobacterium smegmatis RNAP in the conventional radioactive assay. Activity of hits selected for the hit-to-lead optimization was also confirmed against Mycobacterium bovis RNAP which has >99% sequence identity with Mycobacterium tuberculosis RNAP subunits.
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Affiliation(s)
- Jyothi Bhat
- AstraZeneca India Pvt. Ltd., Hebbal, Bangalore, India
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