Sustainable Rice Production Research Articles

Major challenges in widespread adaptation of aerobic rice system and potential opportunities for future sustainability

Climate change and diminishing resources are the major challenges in sustainable rice production. The aerobic rice system can be a transformational approach to replace conventional rice in the face of climate change and scarcity of resources due to its high input-use efficiency. However, it could not be adapted widely yet due to several challenges like higher weed infestation and low nitrogen (N) use efficiencies. This transformed system can only be adapted at a wider scale through investigation of associated constraints and risks and provision of potential adjustive measures. Aerobic rice crop failure can be reduced if the availability of suitable and stress-resistant cultivars with early improved vigour, and short-duration characteristics are ensured for maintaining the reproductive capability under resource stressed environment. This transformed rice system exhibits limited response to applied N because of increased losses due to higher volatilization and rapid coupled nitrification-denitrification processes under alternate wetting and drying systems. Shifting from the flooded to aerobic rice system bringing changes in crop water demand, organic matter (OM) turnover, N dynamics, weed flora, and greenhouse gases (GHGs) emissions. Along with N-losses, continuous monocropping, higher weed infestation, weedy rice emergence, nitrous oxide (N2O) emissions, nutrient disorders, higher prevalence of pathogens and diseases, increased panicle sterility, and an increase in soilborne pathogens lodging are other major constraints negatively impacting the widespread adaptation of aerobic rice. This article reviews the climate change status, its associated impacts on the sustainability of traditional rice systems, and the rationale for transforming from traditional to aerobic rice systems. Furthermore, it describes the major challenges associated with the aerobic rice system, thereby presenting management strategies ensuring its wider adaptation for sustainable rice production in the face of projected climate change and scarcity of resources.

Sustainable Rice Industry in Nepal: Comparative Analysis with South Asia

Rice, a prime crop in Nepal and other South Asian nations, plays a crucial role in ensuring food security and socio-economic development. In Nepal’s agricultural sector, rice accounts for the largest share of the Agricultural Gross Domestic Product (AGDP), comprising approximately 20%. However, the absence of appropriate policies poses a significant challenge to the sustainable production of rice in Nepal. This study aims to assess the various policy dimensions of the sustainable rice industry in Nepal and compare them with the policy implications in neighboring South Asian countries such as India, Pakistan, and Bangladesh. The study draws on secondary sources of information for its analysis. The findings reveal that Nepal lacks a comprehensive rice policy, while its existing agriculture policy is characterized by confusion and contradictions. To attain self-sufficiency in food production, it is imperative to establish a comprehensive rice policy in Nepal and implement price subsidies on diverse inputs, as observed in neighboring countries which will ultimately contribute to enhancing the sustainability of the rice industry and promote the goal of food self-sufficiency in Nepal.

Disruption of non-classically secreted protein (MoMtp) compromised conidiation, stress homeostasis, and pathogenesis of Magnaporthe oryzae

Blast disease, caused by the hemibiotrophic ascomycete fungus, Magnaporthe oryzae, is a significant threat to sustainable rice production worldwide. Studies have shown that the blast fungus secretes vast arrays of functionally diverse proteins into the host cell for a successful disease progression. However, the final destinations of these effector proteins inside the host cell and their role in advancing fungal pathogenesis remain a mystery. Here, we reported that a putative mitochondrial targeting non-classically secreted protein (MoMtp) positively regulates conidiogenesis and appressorium maturation in M. oryzae. Moreover, MoMTP gene deletion mutant strains triggered a hypersensitive response when inoculated on rice leaves displaying that MoMtp is essential for the virulence of M. oryzae. In addition, cell wall and oxidative stress results indicated that MoMtp is likely involved in the maintenance of the structural integrity of the fungus cell. Our study also demonstrates an upregulation in the expression pattern of the MoMTP gene at all stages of infection, indicating its possible regulatory role in host invasion and the infectious development of M. oryzae. Furthermore, Agrobacterium infiltration and sheath inoculation confirmed that MoMtp-GFP protein is predominantly localized in the host mitochondria of tobacco leaf and rice cells. Taken together, we conclude that MoMtp protein likely promotes the normal conidiation and pathogenesis of M. oryzae and might have a role in disturbing the proper functioning of the host mitochondria during pathogen invasion.

Irrigation Management Strategies to Increase Crop-Water Productivity and Grain Quality of Direct Seeded Rice in North West IGP: A Review

Due to its great productivity and profitability, rice (Oryza sativa L.) is farmed in alluvial irrigated tracts of northwest India. For half of the world's population as well as in our country, rice serves as the main source of calories. However, excessive groundwater use in rice farming has resulted in an alarming decline in water table, indicating overuse of groundwater. Therefore, it is necessary to investigate alternative, resource-conserving methods that can sustain rice production. Direct seeded rice presents a compelling option when the future of rice production is in jeopardy due to worldwide water constraint and rising labour costs. The oldest method of crop establishment in this regard, direct seeded rice (DSR), is becoming more and more well-liked constraints minimal input requirements. It has certain benefits, including labour savings, a reduction in water and manpower requirements, early crop maturity, cheap production costs, improved soil physical conditions for crops, a reduction in methane emissions, and greater options for being the best match in various cropping systems. For dry-seeded rice, management strategies that cut irrigation water use and boost crop-water production are needed. Some of the interventions in this respect include cultivars with short growing seasons, tillage, and irrigation scheduling. High crop-water productivity is ensured with optimal yields thanks to irrigation scheduling that aims to eliminate over- or under-irrigation. Tillage changes the edaphic environment of the soil, which impacts crop development. Because of their shallow root systems, rice plants are unable to use the water in the deeper layers of the soil. In order to increase the deep root growth of rice cultivars, deep tillage has become the preferable method. The present research evaluates irrigation management options to raise crop-water productivity and grain quality of DSR in northwest IGP based on the available evidence.

Intercomparison of Mechanical Transplanted Rice and Direct Seeded Rice in Climate Change Resilient for Improving Crop-Water Productivity and Soil Health in North West IGP: A Review

Climate change is a major issue facing humanity, and the most common method for growing rice is manual puddled transplanted rice (PTR). Direct-seeded rice (DSR) is becoming increasingly popular due to its reduced methane emissions and reduced labour costs. However, there are drawbacks to this transition, such as an increase in weeds, herbicide resistance, nitrous oxide emissions, nutritional disorders, and soil-borne diseases. To reduce these issues, appropriate weed, water, and fertilizer management practices should be applied. Chemical and biotechnological methods, such as herbicide-resistant and more competitive allelopathic variants, will be required for sustainable rice production. The development of site- and soil-specific integrated packages will increase the adoption of DSR and decrease the negative effects of PTR on the environment.

Induction of systemic resistance in rice plants against Burkholderia glumae infection by bioformulation of Streptomyces spp. under greenhouse conditions

The ability of plant growth-promoting Streptomyces (PGPS) against bacterial panicle blight (BPB) disease caused by Burkholderia glumae has been previously examined under laboratory and greenhouse conditions. To further harness their potential, the development of bioformulations containing PGPS is needed. This study investigates the efficacy of Streptomyces bioformulations in suppressing the growth of B. glumae under greenhouse conditions. The powder-based bioformulations of Streptomyces were prepared and characterized based on potential phytotoxic effect and shelf life stability. The efficacy of Streptomyces bioformulations in suppressing BPB disease was assessed according to the expression of Gns1 (β-1,3-glucanase), OsPR1a (pathogenesis-related class 1), Oswrky45 (SA-responsive) and OsJAMYB (JA-responsive) using RT-qPCR. The talc-kaolin-Streptomyces bioformulations (BioSTKR8, BioSJAS2 and BioSTBS5 containing Streptomyces corchorusii TKR8, Streptomyces corchorusii JAS2 and Streptomyces misionensis TBS5, respectively) showed no phytotoxic effect on rice plants. Bioformulations were more stable when stored under refrigeration than at room temperature, with more than 50 % spore viability at 180 days after storage. Treatment with BioSTKR8 (7 %) and BioSTBS5 (10 %) was able to reduce BPB disease severity while increasing rice yield by up to 301 % (BioSTKR8) and 170 % (BioSTBS5) relative to control (100 %). Transcript levels of Gns1, OsPR1a, Oswrky45 and OsJAMYB were up-regulated by the treatment of BioSTKR8 and BioSTBS5 at 7 DPI compared to the control. Results suggest that BioSTKR8 and BioSTBS5 are very promising bioformulations to be utilized as potential plant growth promoters and biological control agents (BCA) for sustainable rice production and BPB disease management.

Challenges and Adaptations for Resilient Rice Production under Changing Environments in Bangladesh

Rice-based food production is crucial for food security, socio-political stability, and economic development in Bangladesh. However, climate and environmental changes pose serious challenges to sustainable rice production in the country. This review paper critically reviews the status, challenges, and adaptation opportunities of Bangladeshi rice systems in changing environmental, demographic, and socio-economic settings. A mixed-methods approach (quantitative summary of secondary data on rice production, environmental changes, impact on rice productivity; and qualitative thematic synthesis) was used to review adaptation for resilient rice production. Significant agronomic and environmental challenges to rice-based cropping in Bangladesh are posed by rising temperatures, anomalous rainfall patterns, extreme weather, and increasing salinisation. Rice production, availability, and access have been further compromised by decreasing arable areas, labour shortages, crop diversification, and low profitability. Farmers are adapting through autonomous and centrally planned strategies such as efficient irrigation and input use, stress-tolerant cultivars, mechanisation, and income diversification. However, profitable and sustainable adaptation requires broader facilitation by the government (e.g., infrastructure, financial incentives) and agribusiness (e.g., extension services, contracting). This review paper recommends research and development support for efficient irrigation management and stress-tolerant cultivars, enabling policy initiatives, and equitable value chain participation. The insights of the review can be applied to policymakers to target policy design and decision-making for a sustainable rice system in years to come.

Transcriptomic and Physiological Analyses of Two Rice Restorer Lines under Different Nitrogen Supplies Provide Novel Insights into Hybrid Rice Breeding.

Improving plant nitrogen-use efficiency (NUE) has great significance for various crops, particularly in hybrid breeding. Reducing nitrogen inputs is key to achieving sustainable rice production and mitigating environmental problems. In this study, we analyzed the transcriptomic and physiological changes in two indica restorer lines (Nanhui511 [NH511] and Minghui23 [MH23]) under high nitrogen (HN) and low nitrogen (LN) conditions. Compared to MH23, NH511 was more sensitive to different nitrogen supplies and exhibited higher nitrogen uptake and NUE under HN conditions by increasing lateral root and tiller numbers in the seedling and maturation stages, respectively. NH511 also exhibited a lower survival rate than MH23 when planted in a chlorate-containing hydroponic solution, indicating its HN uptake ability under different nitrogen-supply conditions. Transcriptomic analysis showed that NH511 has 2456 differentially expressed genes, whereas MH23 had only 266. Furthermore, these genes related to nitrogen utilization showed differential expression in NH511 under HN conditions, while the opposite was observed in MH23. Our findings revealed that NH511 could be regarded as elite rice and used for breeding high-NUE restorer lines by regulating and integrating nitrogen-utilization genes, which provides novel insights for the cultivation of high-NUE hybrid rice.

Fertilization controls tiller numbers via transcriptional regulation of a MAX1-like gene in rice cultivation

Fertilization controls various aspects of cereal growth such as tiller number, leaf size, and panicle size. However, despite such benefits, global chemical fertilizer use must be reduced to achieve sustainable agriculture. Here, based on field transcriptome data from leaf samples collected during rice cultivation, we identify fertilizer responsive genes and focus on Os1900, a gene orthologous to Arabidopsis thaliana MAX1, which is involved in strigolactone biosynthesis. Elaborate genetic and biochemical analyses using CRISPR/Cas9 mutants reveal that Os1900 together with another MAX1-like gene, Os5100, play a critical role in controlling the conversion of carlactone into carlactonoic acid during strigolactone biosynthesis and tillering in rice. Detailed analyses of a series of Os1900 promoter deletion mutations suggest that fertilization controls tiller number in rice through transcriptional regulation of Os1900, and that a few promoter mutations alone can increase tiller numbers and grain yields even under minor-fertilizer conditions, whereas a single defective os1900 mutation does not increase tillers under normal fertilizer condition. Such Os1900 promoter mutations have potential uses in breeding programs for sustainable rice production.

Emergence of Rice Blast AVR-Pi9 Resistance Breaking Haplotypes in Yunnan Province, China.

The rice blast disease (caused by Magnaporthe oryzae) is a devastating disease in China. Understanding the molecular mechanisms of interaction for the cognate avirulence (AVR) gene with host resistance (R) genes, as well as their genetic evolution is essential for sustainable rice production. In the present study, we conducted a high-throughput nucleotide sequence polymorphism analysis of the AVR-Pi9 gene that was amplified from the rice-growing regions of the Yunnan Province in China. We detected the presence of seven novel haplotypes from 326 rice samples. In addition, the sequences of AVR-Pi9 were also obtained from two non-rice hosts, Eleusine coracana and Eleusine indica. The sequence analysis revealed the insertions and deletions in the coding and non-coding regions of the gene. The pathogenicity experiments of these haplotypes on previously characterized monogenic lines showed that the newly identified haplotypes are virulent in nature. The breakdown of resistance was attributed to the development of new haplotypes. Our results suggest that the mutation in the AVR-Pi9 gene is an alarming situation in the Yunnan province and thus needs attention.

Genome-wide identification of nitrate-responsive microRNAs by small RNA sequencing in the rice restorer cultivar Nanhui 511.

Rice productivity relies heavily on nitrogen fertilization, and improving nitrogen use efficiency (NUE) is important for hybrid rice breeding. Reducing nitrogen inputs is the key to achieving sustainable rice production and reducing environmental problems. Here, we analyzed the genome-wide transcriptomic changes in microRNAs (miRNAs) in the indica rice restorer cultivar Nanhui 511 (NH511) under high (HN) and low nitrogen (LN) conditions. The results showed that NH511 is sensitive to nitrogen supplies and HN conditions promoted the growth its lateral roots at the seedling stage. Furthermore, we identified 483 known miRNAs and 128 novel miRNAs by small RNA sequencing in response to nitrogen in NH511. We also detected 100 differentially expressed genes (DEGs), including 75 upregulated and 25 downregulated DEGs, under HN conditions. Among these DEGs, 43 miRNAs that exhibited a 2-fold change in their expression were identified in response to HN conditions, including 28 upregulated and 15 downregulated genes. Additionally, some differentially expressed miRNAs were further validated by qPCR analysis, which showed that miR443, miR1861b, and miR166k-3p were upregulated, whereas miR395v and miR444b.1 were downregulated under HN conditions. Moreover, the degradomes of possible target genes for miR166k-3p and miR444b.1 and expression variations were analyzed by qPCR at different time points under HN conditions. Our findings revealed comprehensive expression profiles of miRNAs responsive to HN treatments in an indica rice restorer cultivar, which advances our understanding of the regulation of nitrogen signaling mediated by miRNAs and provides novel data for high-NUE hybrid rice cultivation.

Recent Molecular Aspects and Integrated Omics Strategies for Understanding the Abiotic Stress Tolerance of Rice.

Rice is an important staple food crop for over half of the world's population. However, abiotic stresses seriously threaten rice yield improvement and sustainable production. Breeding and planting rice varieties with high environmental stress tolerance are the most cost-effective, safe, healthy, and environmentally friendly strategies. In-depth research on the molecular mechanism of rice plants in response to different stresses can provide an important theoretical basis for breeding rice varieties with higher stress resistance. This review presents the molecular mechanisms and the effects of various abiotic stresses on rice growth and development and explains the signal perception mode and transduction pathways. Meanwhile, the regulatory mechanisms of critical transcription factors in regulating gene expression and important downstream factors in coordinating stress tolerance are outlined. Finally, the utilization of omics approaches to retrieve hub genes and an outlook on future research are prospected, focusing on the regulatory mechanisms of multi-signaling network modules and sustainable rice production.

Efficacy of Public Extension and Advisory Services for Sustainable Rice Production

Agriculture is an integral constituent of Pakistan’s economy and the primary source of livelihood for nearly 65% of the population living in rural areas. Rice is the second major staple food after wheat and a significant source of foreign exchange earnings through Basmati exports. Pakistan has established an extensive network of agricultural extension to educate the farming community about modern agricultural practices for enhancing the agricultural productivity of major food crops grown in the country. The present study was undertaken to evaluate rice farmers’ views about public extension services and to identify their perspective regarding various ways of enhancing rice production in Pakistan. A multi-stage simple random sampling technique was employed, and data were collected from 193 rice farmers with the help of structured interviews using a pre-tested questionnaire. The findings revealed that a vast majority of the rice farmers were poorly satisfied with the public extension services. The results of the Spearman Rank-Order Correlation showed that landholding size had a significant effect on deciding extension contact; public extension agents are more likely to visit and serve those rice farmers who possess large landholders and therefore have the tendency to intentionally neglect small-scale rice farmers. For enhancing rice production in Pakistan, farmers believed that the provision of subsidized agricultural inputs and a minimum support price for rice is indispensable. Based on our findings, we suggest that to make public extension services more effective, public extension agents should particularly focus on the capacity building of small-scale farmers rather than large-scale farmers. Moreover, there is a need to broaden the scope of public extension services from simple crop protection measures to a set of comprehensive sustainable agricultural practices for increasing agricultural productivity, resource-use efficiency, as well as resilience toward adverse impacts of climate change.

PH-responsive/sustained release nitrogen fertilizer hydrogel improves yield, nitrogen metabolism, and nitrogen use efficiency of rice under alternative wetting and moderate drying irrigation

Rice is challenged by inefficient nitrogen (N) fertilizer and water inputs. However, pH-responsive N fertilizers (pH-RNFs) could improve rice yield and N use-efficiency under water-saving irrigation. Thus, a pot experiment was conducted without N fertilizer (0 mg N/kg, ZNF), with 175 mg/kg mineral N fertilizer (MNF), and with 175 mg/kg pH-responsive N fertilizer (pH-RNF) by using three water regimes: alternate wetting/critical drying (AWCD, 70–60% saturation, 5 cm flooded), alternate wetting/severe drying (AWSD, 80–70% saturation, 5 cm flooded), and alternate wetting/minor drying (AWMD, 100–90% saturation, 5 cm flooded). Under the same alternate wetting/drying regime, the growth traits, yield, and N utilization of rice were found to be higher in pH-RNF than in MNF. The growth attributes and yield and the N efficient use of rice were greater in the AWMD regime than in the AWCD regime under the same N fertilization. The surface area, diameter, length density, oxidation ability, reductase activity, and peroxidase activity of roots were greater in AWMD × pH-RNF than in AWCD × ZNF, because the former treatment increased the total N contents in the rhizosphere, whereas the latter reduced them. In the photosynthesis process, leaf nitrate reductase (41.7 µg/[g.h]) and leaf glutamine synthetase (1158.1 µmol/[g.h]) were larger in AWMD × pH-RNF than in AWCD × ZNF at 22.7 µg/(g.h) and 501.2 µmol/(g.h), respectively, resulting in the amelioration of oxidative leaf cell damage, as revealed by reduced radical oxidative sequence release and lower malonaldehyde level (7.2 µmol/g). Meanwhile, the optimum N nutrition enhanced the leaf mesophyll structure, cell cycle progression, and the development traits of the stem and panicle under the combination AWMD × pH-RNF. Panicle glutamine synthetase (24.35 µmol/[g.h]) and catalase activity (13.86 µg/min) were larger in AWMD × pH-RNF than in AWCD × ZNF at 14.77 µmol/[g.h] and 7.59 µg/min, respectively. The combination AWMD × pH-RNF resulted in the highest N crop removal efficiency (CREN, 49.5%), N agronomic use efficiency (AUEN, 7.97 g/g), N partial factor productivity (PFPN, 18.66 g/g), and N harvest index (HIN, 67.83%). However, the minimum values of CREN (10.3%), AUEN (1.49 g/g), PFPN (7.59 g/g), and HIN (43.48%) were observed in AWCD × MNF. This study suggests that AWMD × pH-RNF could promote root and shoot morpho-physio-biochemical traits, guaranteeing optimal overall plant growth with high yield and adequate N acquisition, and efficient N utilization for sustainable rice production.

Improving hybrid rice parental lines for blast resistance by introgression of broad‐spectrum resistance genes Pi54 and Pi9 by marker‐assisted selection

AbstractHybrid rice technology offers a great promise to produce 15% to 20% more yield than pure line varieties. The success of hybrid rice hinges on developing superior parental lines. To improve the blast resistance of hybrid rice parental line RP5933‐1‐19‐2R, crosses were made with donors of two major blast resistance genes namely, Pi54 (Tetep) and Pi9 (IR71033–121‐15) and the resulting F1s were confirmed for their hybridity by using Pi54MAS and NMSMPi9‐1 genic markers. The confirmed F1s were intercrossed to obtain ICF1s and selected positive plants by markers were backcrossed to the recurrent parent, as well as selfed for advancing further to BC1F3 and ICF4 generations. The segregating plants were phenotyped for blast resistance at Uniform Blast Nursery. The identified complete restorers namely, RP 6619‐1, RP 6616‐26, RP 6619‐3 and RP 6619‐11 with Pi9 and Pi54 genes would serve as donors for broad spectrum blast resistance. This could ultimately lead to the development of new rice hybrids with improved resistance to blast disease, which is crucial for sustainable rice production and food security.

Ecological footprint, water scarcity footprint, and benefit to cost ratio analysis towards sustainable rice production in Thailand

Thailand is a large producer of rice and the sustainable production of rice is very important. This research aimed at assessing the ecological footprint, water scarcity footprint (WSF), and benefit to cost ratio (B/C) of major and second rice cultivation and ecological footprint of packaged rice production using the life cycle assessment approach. The study areas included provinces in the northern, northeastern, central, and southern regions of Thailand. The ecological footprint of major and second rice cultivation ranged between 1.37–3.33 and 1.39–2.64 gha/t, respectively. Rainwater and irrigation water were the most important resources for the major and second rice cultivation as measured by forest productivity or ecological footprint of forest. Applying the alternate wetting and drying technique could decrease the ecological footprint of major and second rice cultivation to 0.89–2.89 and 0.90–2.14 gha/t, respectively. The ecological footprint of packaged rice ranged from 1.78 to 4.02 gha/t, contributed mainly by the ecological footprint of the forest from the water requirement in cultivation. The WSF of major and second rice cultivation ranged between 2.58–25.4 and 14.2–1021 m3 H2Oeq/t. The variation of WSF resulted from the variation in both irrigation water and water stress index. There was a significant change in the benefit of rice cultivation from 2009 to 2018 resulting in the variation of B/C of major rice from 0.75 to 1.48 and second rice from 0.76 to 1.60. To promote sustainable rice cultivation, cultivation at the provincial and regional levels must have lower ecological footprint and WSF as well as higher B/C than the national average. The ecological footprint, WSF, and B/C results can be used by policymakers to promulgate the area-based policy on reducing resource use and increasing the income for the farmers in Thailand.

Integrated management approaches enabling sustainable rice production under alternate wetting and drying irrigation

Integrated management approaches enabling sustainable rice production under alternate wetting and drying irrigation

Effects of nanobiosilica from rice husk ash application on rice growth, productivity, and milling quality

Application of different forms of silicon sources may influence rice production and quality. It is believed that properties of nanosized particles may differ significantly from those of the original bulk material. This study aimed to investigate effects of application of silica nanoparticles extracted from rice husk ash, called nanobiosilica (NBS), on the rice growth, productivity, and milling quality as compared to those of rice husk ash (RHA), sodium silicate solution (SDS), and two control treatments. NBS was produced by the sol-gel method. The five treatments were arranged on a randomized complete block design with four replicates. Application of NBS (20-50nm) and SDS significantly produced the highest stem strength, lodging tolerance, number of productive tillers, grain per-clump, and rice productivity (7.30-7.32t/ha). NBS produced better yield performances than RHA, the initial bulk material. The treatments did not influence brown rice and milled rice yield. However, the highest percentage of head rice was observed following NBS and RHA treatments. The results suggested that production of NBS from RH and its application to paddy field could be a viable strategy for supporting sustainable rice production, producing better quality of milled rice, increasing benefit of rice processors/farmers, and reducing environmental issues of underutilized rice husk.

Arbuscular Mycorrhizal Fungi Response on Soil Phosphorus Utilization and Enzymes Activities in Aerobic Rice under Phosphorus-Deficient Conditions.

The prominence of arbuscular mycorrhizal fungi (AMF) in sustainable rice production has long been recognized. However, there is little information about AMF response in aerobic rice cultivation under phosphorus (P)-deficient conditions. The aim of this experiment was to compare and determine the preeminent AMF effects on rice mycorrhizal colonization, responsiveness, P utilization, and different growth-promoting traits under P-deficient conditions. Different AMF genera viz. (Funneliformis sp., Rhizophagus sp., Glomus sp., Acaulospora sp., and Claroideoglomus sp.) in four different aerobic rice varieties developed by ICAR-NRRI, India (CR Dhan 201, CR Dhan 204, CR Dhan 205, and CR Dhan 207) were investigated using the check P-susceptible variety (IR 36) and the P-tolerant variety (Kasalath IC459373). Data analyzed through linear modeling approaches and bivariate associations found that AMF colonization was highly correlated with soil enzymes, particularly fluorescein diacetate (FDA) and plant P uptake. The microbial biomass carbon (MBC) and FDA content were significantly changed among rice varieties treated with AMF compared to uninoculated control. Out of four different rice varieties, CR Dhan 207 inoculated with AMF showed higher plant P uptake compared to other varieties. In all the rice varieties, AMF colonization had higher correlation coefficients with soil enzymes (FDA), MBC, and plant P uptake than uninoculated control. The present study indicates that AMF intervention in aerobic rice cultivation under P-deficient conditions significantly increased plant P uptake, soil enzymes activities and plant growth promotion. Thus, the information gathered from this study will help us to develop a viable AMF package for sustainable aerobic rice cultivation.

Transcriptomic and proteomic profiling reveals toxicity and molecular action mechanisms of bioengineered chitosan‑iron nanocomposites against Xanthomonas oryzae pv. oryzae

Bacterial leaf blight (BLB) pathogen, Xanthomonas oryzae pv. oryzae (Xoo) is the most devastating bacterial pathogen, which jeopardizes the sustainable rice (Oryza sativa L.) production system. The use of antibiotics and conventional pesticides has become ineffective due to increased pathogen resistance and associated ecotoxicological concerns. Thus, the development of effective and sustainable antimicrobial agents for plant disease management is inevitable. Here, we investigated the toxicity and molecular action mechanisms of bioengineered chitosan‑iron nanocomposites (BNCs) against Xoo using transcriptomic and proteomic approaches. The transcriptomic and proteomics analyses revealed molecular antibacterial mechanisms of BNCs against Xoo. Transcriptomic data revealed that various processes related to cell membrane biosynthesis, antioxidant stress, DNA damage, flagellar biosynthesis and transcriptional regulator were impaired upon BNCs exposure, which clearly showing the interaction of BNCs to Xoo pathogen. Similarly, proteomic profiling showed that BNCs treatment significantly altered the levels of functional proteins involved in the integral component of the cell membrane, catalase activity, oxidation-reduction process and metabolic process in Xoo, which is consistent with the results of the transcriptomic analysis. Overall, this study suggested that BNCs has great potential to serve as an eco-friendly, sustainable, and non-toxic alternative to traditional agrichemicals to control the BLB disease in rice.