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Key Message: Transgenic Crambe abyssinica lines overexpressing γ-ECS significantly enhance tolerance to and accumulation of toxic metal(loid)s, improving phytoremediation potential and offering an effective solution for contaminated soil management. Phytoremediation is an attractive environmental-friendly technology to remove metal(loid)s from contaminated soils and water. However, tolerance to toxic metals in plants is a critical limiting factor. Transgenic Crambe abyssinica lines were developed that overexpress the bacterial γ-glutamylcysteine synthetase (γ-ECS) gene to increase the levels of non-protein thiol peptides such as γ-glutamylcysteine (γ-EC), glutathione (GSH), and phytochelatins (PCs) that mediate metal(loid)s detoxification. The present study investigated the effect of γ-ECS overexpression on the tolerance to and accumulation of toxic As, Cd, Pb, Hg, and Cr supplied individually or as a mixture of metals. Compared to wild-type plants, γ-ECS transgenics (γ-ECS1-8 and γ-ECS16-5) exhibited a significantly higher capacity to tolerate and accumulate these elements in aboveground tissues, i.e., 76-154% As, 200-254% Cd, 37-48% Hg, 26-69% Pb, and 39-46% Cr, when supplied individually. This is attributable to enhanced production of GSH (82-159% and 75-87%) and PC2 (27-33% and 37-65%) as compared to WT plants under AsV and Cd exposure, respectively. The levels of Cys and γ-EC were also increased by 56-67% and 450-794% in the overexpression lines compared to WT plants under non-stress conditions, respectively. This likely enhanced the metabolic pathway associated with GSH biosynthesis, leading to the ultimate synthesis of PCs, which detoxify toxic metal(loid)s through chelation. These findings demonstrate that γ-ECS overexpressing Crambe lines can be used for the enhanced phytoremediation of toxic metals and metalloids from contaminated soils., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Key Message: OsLec-RLK overexpression enhances cell signalling and salt stress tolerance in pigeon pea, enhancing seed yield and harvest index and thus, enabling marginal lands to increase food and nutritional security. Lectin Receptor-like kinases (Lec-RLKs) are highly effective cell signaling molecules that counteract various stresses, including salt stress. We engineered pigeon pea by overexpressing OsLec-RLK gene for enhancing salt tolerance. The OsLec-RLK overexpression lines demonstrated superior performance under salt stress, from vegetative to reproductive phase, compared to wild types (WT). The overexpression lines had significantly higher K + /Na +  ratio than WT exposed to 100 mM NaCl. Under salt stress, transgenic lines showed higher levels of chlorophyll, proline, total soluble sugars, relative water content, and peroxidase and catalase activity than WT plants. Membrane injury index and lipid peroxidation were significantly reduced in transgenic lines. Analysis of phenological and yield attributes confirmed that the OsLec-RLK pigeon pea lines maintain plant vigor, with 10.34-fold increase in seed yield (per plant) and 4-5-fold increase in harvest index of overexpression lines, compared to wild type. Meanwhile, the overexpression of OsLec-RLK up-regulated the expression levels of histone deacetylase1, acyl CoA, ascorbate peroxidase, peroxidase, glutathione reductase and catalase, which were involved in the K + /Na +  homeostasis pathway. This study showed the potential of OsLec-RLK gene for increasing crop productivity and yields under salt stress and enabling the crops to be grown on marginal lands for increasing food and nutritional security., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Nanoenabled strategies have recently attracted attention as a sustainable platform for agricultural applications. Here, we present a mechanistic understanding of nanobiointeraction through an orthogonal investigation. Pristine (nS) and stearic acid surface-modified (cS) sulfur nanoparticles (NPs) as a multifunctional nanofertilizer were applied to tomato ( Solanum lycopersicum L.) through soil. Both nS and cS increased root mass by 73% and 81% and increased shoot weight by 35% and 50%, respectively, compared to the untreated controls. Bulk sulfur (bS) and ionic sulfate (iS) had no such stimulatory effect. Notably, surface modification of S NPs had a positive impact, as cS yielded 38% and 51% greater shoot weight compared to nS at 100 and 200 mg/L, respectively. Moreover, nS and cS significantly improved leaf photosynthesis by promoting the linear electron flow, quantum yield of photosystem II, and relative chlorophyll content. The time-dependent gene expression related to two S bioassimilation and signaling pathways showed a specific role of NP surface physicochemical properties. Additionally, a time-dependent Global Test and machine learning strategy applied to understand the NP surface modification domain metabolomic profiling showed that cS increased the contents of IA, tryptophan, tomatidine, and scopoletin in plant leaves compared to the other treatments. These findings provide critical mechanistic insights into the use of nanoscale sulfur as a multifunctional soil amendment to enhance plant performance as part of nanoenabled agriculture.

Background: Chickpea is prone to many abiotic stresses such as heat, drought, salinity, etc. which cause severe loss in yield. Tolerance towards these stresses is quantitative in nature and many studies have been done to map the loci influencing these traits in different populations using different markers. This study is an attempt to meta-analyse those reported loci projected over a high-density consensus map to provide a more accurate information on the regions influencing heat, drought, cold and salinity tolerance in chickpea., Results: A meta-analysis of QTL reported to be responsible for tolerance to drought, heat, cold and salinity stress tolerance in chickpeas was done. A total of 1512 QTL responsible for the concerned abiotic stress tolerance were collected from literature, of which 1189 were projected on a chickpea consensus genetic map. The QTL meta-analysis predicted 59 MQTL spread over all 8 chromosomes, responsible for these 4 kinds of abiotic stress tolerance in chickpea. The physical locations of 23 MQTL were validated by various marker-trait associations and genome-wide association studies. Out of these reported MQTL, CaMQAST1.1, CaMQAST4.1, CaMQAST4.4, CaMQAST7.8, and CaMQAST8.2 were suggested to be useful for different breeding approaches as they were responsible for high per cent variance explained (PVE), had small intervals and encompassed a large number of originally reported QTL. Many putative candidate genes that might be responsible for directly or indirectly conferring abiotic stress tolerance were identified in the region covered by 4 major MQTL- CaMQAST1.1, CaMQAST4.4, CaMQAST7.7, and CaMQAST6.4, such as heat shock proteins, auxin and gibberellin response factors, etc. CONCLUSION: The results of this study should be useful for the breeders and researchers to develop new chickpea varieties which are tolerant to drought, heat, cold, and salinity stresses., (© 2024. The Author(s).)

Nanotechnology offers the potential to provide innovative solutions for sustainable crop production as plants are exposed to a combination of climate change factors (CO 2 , temperature, UV radiation, ozone), abiotic (heavy metals, salinity, drought), and biotic (virus, bacteria, fungi, nematode, and insects) stresses. The application of particular sizes, shapes, and concentration of nanomaterials (NMs) potentially mitigate the negative impacts in plants by modulation of photosynthetic rate, redox homeostasis, hormonal balance, and nutrient assimilation through upregulation of anti-stress metabolites, antioxidant defense pathways, and genes and genes network. The present review inculcates recent advances in uptake, translocation, and accumulation mechanisms of NMs in plants. The critical theme of this review provides detailed insights into different physiological, biochemical, molecular, and stress tolerance mechanism(s) of NMs action and their cross-talk with different phytohormones. The role of NMs as a double-edged sword for climate change factors, abiotic, and biotic stresses for nutrients uptake, hormones synthesis, cytotoxic, and genotoxic effects including chromosomal aberration, and micronuclei synthesis have been extensively studied. Importantly, this review aims to provide an in-depth understanding of the hormesis effect at low and toxicity at higher doses of NMs under different stressors to develop innovative approaches and design smart NMs for sustainable crop production., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Competing interests The authors have no relevant financial or non-financial interests to disclose., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The global population is growing rapidly, which poses a significant challenge to food security. Innovation in agricultural technologies is necessary to achieve sustainable development in agriculture and combat food insecurity. Nanotechnology has emerged as a promising tool in agriculture; compared to conventional agricultural chemicals, demonstrated benefits include increased efficiency of delivery and utilization of both nutrients and pesticides, as well as nanoscale-specific stimulation of stress tolerance pathways. Among the many studied nanomaterials, nano-sulfur has demonstrated superior effects at enhancing plant resilience to pathogens and abiotic stresses, as well as improving plant growth and nutritional quality of edible tissues. A number of published studies have investigated the physiological effects (growth promotion, disease resistance) of single or several sulfur and sulfide compounds on crop species. However, there is no systematic analysis of this literature, including the effects and specific mechanisms of various sulfur forms in agricultural applications. In this review, we will discuss the effects of sulfur (including nano-sulfur) on crop species, the underlying mechanisms of action for their transport and transformation in the soil-plant system, and evaluate their suitability in sustainable agricultural development. Additionally, we discuss the current challenges and knowledge gaps for nanoscale sulfur use in agriculture, and describe future research directions to advance our understanding of the sustainable use of this material at the scale of individual fields., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this work., (This journal is © The Royal Society of Chemistry.)

Camelinasativa has considerable promise as a dedicated industrial oilseed crop. Its oil-based blends have been tested and approved as liquid transportation fuels. Previously, we utilized metabolomic and transcriptomic profiling approaches and identified metabolic bottlenecks that control oil production and accumulation in seeds. Accordingly, we selected candidate genes for the metabolic engineering of Camelina. Here we targeted the overexpression of Camelina PDCT gene, which encodes the phosphatidylcholine: diacylglycerol cholinephosphotransferase enzyme. PDCT is proposed as a gatekeeper responsible for the interconversions of diacylglycerol (DAG) and phosphatidylcholine (PC) pools and has the potential to increase the levels of TAG in seeds. To confirm whether increased CsPDCT activity in developing Camelina seeds would enhance carbon flux toward increased levels of TAG and alter oil composition, we overexpressed the CsPDCT gene under the control of the seed-specific phaseolin promoter. Camelina transgenics exhibited significant increases in seed yield (19-56%), seed oil content (9-13%), oil yields per plant (32-76%), and altered polyunsaturated fatty acid (PUFA) content compared to their parental wild-type (WT) plants. Results from [ 14 C] acetate labeling of Camelina developing embryos expressing CsPDCT in culture indicated increased rates of radiolabeled fatty acid incorporation into glycerolipids (up to 64%, 59%, and 43% higher in TAG, DAG, and PC, respectively), relative to WT embryos. We conclude that overexpression of PDCT appears to be a positive strategy to achieve a synergistic effect on the flux through the TAG synthesis pathway, thereby further increasing oil yields in Camelina., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

The grain-filling stage in Triticum aestivum (wheat) is highly vulnerable to increasing temperature as terminal heat stress diminishes grain quality and yield. To examine the mechanism of terminal heat tolerance, we performed the biochemical and gene expression analyses using two heat-tolerant (WH730 and WH1218) and two heat-sensitive (WH711 and WH157) wheat genotypes. We observed a significant increase in total soluble sugar (25%-47%), proline (7%-15%), and glycine betaine (GB) (22%-34%) contents in flag leaf, whereas a decrease in grain-filling duration, 1000-kernel weight (8%-25%), and grain yield per plant (11%-23%) was observed under the late-sown compared to the timely sown. The maximum content of osmolytes, including total soluble sugar, proline, and GB, was observed in heat-tolerant genotypes compared to heat-sensitive genotypes. The expression of 10 heat-responsive genes associated with heat shock proteins (sHsp-1, Hsp17, and HsfA4), flavonoid biosynthesis (F3'-1 and PAL), β-glucan synthesis (CslF6 and CslH), and xyloglucan metabolism (XTH1, XTH2, and XTH5) was studied in flag leaf exposed to different heat treatments (34, 36, 38, and 40°C) at 15 days after anthesis by quantitative real-time polymerase chain reaction. A significant increase in the relative fold expression of these genes with increasing temperature indicated their involvement in providing heat-stress tolerance. The high differential expression of most of the genes in heat-tolerant genotype "WH730" followed by "WH1218" indicates the high adaptability of these genotypes to heat stress compared to heat-sensitive wheat genotypes. Based on the previous results, "WH730" performed better in terms of maximum osmolyte accumulation, grain yield, and gene expression under heat stress., (© 2023 CCS Haryana Agricultural University. The Plant Genome published by Wiley Periodicals LLC on behalf of Crop Science Society of America.)

Key Message: This study demonstrates the crucial role of OsPIP2;6 for translocation of arsenic from roots to shoots, which can decrease arsenic accumulation in rice for improved food safety. Arsenic (As) contamination in food and water, primarily through rice consumption, poses a significant health risk due to its natural tendency to accumulate inorganic arsenic (iAs). Understanding As transport mechanisms is vital for producing As-free rice. This study investigates the role of rice plasma membrane intrinsic protein, OsPIP2;6, for AsIII tolerance and accumulation. RNAi-mediated suppression of OsPIP2;6 expression resulted in a substantial (35-65%) reduction in As accumulation in rice shoots, while root arsenic levels remained largely unaffected. Conversely, OsPIP2;6 overexpression led to 15-76% higher arsenic accumulation in shoots, with no significant change in root As content. In mature plants, RNAi suppression caused (19-26%) decrease in shoot As, with flag leaves and grains showing a 16% reduction. OsPIP2;6 expression was detected in both roots and shoots, with higher transcript levels in shoots. Localization studies revealed its presence in vascular tissues of both roots and shoots. Overall, our findings highlight OsPIP2;6's role in root-to-shoot As translocation, attributed to its specific localization in the vascular tissue of roots and leaves. This knowledge can facilitate the development of breeding programs to mitigate As accumulation in rice and other food crops for improved food safety and increasing productivity on As-contaminated soils., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In the present study, experiments were conducted to assess the influence of nanoscale sulfur in the microbial community structure of metallophytes in Hg-contaminated rhizosphere soil for planting rapeseed. The results showed that the richness and diversity of the rhizobacteria community decreased significantly under Hg stress, but increased slightly after SNPs addition, with a reduction in the loss of Hg-sensitive microorganisms. Moreover, all changes in the relative abundances of the top ten phyla influenced by Hg treatment were reverted when subjected to Hg + SNPs treatment, except for Myxococcota and Bacteroidota. Similarly, the top five genera, whose relative abundance decreased the most under Hg alone compared to CK, increased by 19.05%-54.66% under Hg + SNPs treatment compared with Hg alone. Furthermore, the relative abundance of Sphingomonas , as one of the dominant genera for both CK and Hg + SNPs treatment, was actively correlated with plant growth. Rhizobacteria, like Pedobacter and Massilia , were significantly decreased under Hg + SNPs and were positively linked to Hg accumulation in plants. This study suggested that SNPs could create a healthier soil microecological environment by reversing the effect of Hg on the relative abundance of microorganisms, thereby assisting microorganisms to remediate heavy metal-contaminated soil and reduce the stress of heavy metals on plants.

Mercury (Hg) pollution has seriously threatened the crop productivity and food security. In the present research, experiments were conducted to assess the influence of nanoscale sulfur/sulfur nanoparticles and the corresponding bulk and ionic sulfur forms on the growth and Hg accumulation of oilseed rape seedlings grown on Hg-contaminated soil, as well as the transformation of soil Hg fractions. The results showed a significant reduction in fresh biomass for seedlings grown on 80-200 mg/kg Hg-polluted soil after 30 days. At 120 mg/kg Hg treatment, 100-300 mg/kg sulfur nanoparticles (SNPs) application counteracted Hg toxicity more effectively compared to the corresponding bulk sulfur particles (BSPs) and ionic sulfur (sulfate) treatments. The seedlings treated with 120 mg/kg Hg + 300 mg/kg SNPs gained 54.2 and 56.9% more shoot and root biomass, respectively, compared to those treated with Hg alone. Meanwhile, 300 mg/kg SNPs application decreased Hg accumulation by 18.9 and 76.5% in shoots and roots, respectively, relative to Hg alone treatment.SNPs treatment caused more Hg to be blocked in the soil and accumulating significantly less Hg in plants as compared to other S forms. The chemical fractions of Hg in the soil were subsequently investigated, and the solubility of Hg was significantly decreased by applying SNPs to the soil. Especially 200-300 mg/kg SNPs treatments caused the ratio of the soluble/exchangeable and the specifically absorbed fraction to be the lowest, accounting for 1.95-4.13% of the total Hg of soil. These findings suggest that adding SNPs to Hg-contaminated soils could be an effective measure for immobilizing soluble Hg and decreasing the Hg concentration in the edible parts of crops. The results of the current study hold promise for the practical application of SNPs to Hg-contaminated farmland for better yields and simultaneously increasing the food safety.

Rice straw management, along with the prevalent practice of residue burning, poses multifaceted challenges with substantial environmental and human health implications. After harvest, a considerable amount of straw is left behind, often disposed of through burning, releasing several pollutants into the environment. Carbon dioxide (CO 2 ) dominates at 70%, accompanied by methane (CH 4 ) at 0.66%, carbon monoxide (CO) at 7%, and nitrous oxide (N 2 O) at 2.09%. This process further compounds issues by depleting soil nutrients like nitrogen and organic matter. This review focuses on strategies for residue management and using straw as value-added by-products. We address research gaps and offer potential recommendations for rice straw management using economically feasible and practical routes. We elaborate that to improve rice straw digestibility, utilization in mushroom cultivation, and other value-added products, low silica (Si) rice varieties must be developed using modern technologies including marker-assisted selection breeding or genome editing. Developing low Si rice could also reduce arsenic uptake by rice, as rice plants use the same transporters for the uptake of both elements. Conversely, silica is also indispensable for quality rice production; hence, optimizing silicon content in rice is worth investigating. More research is required to understand the extent of silicon's effect on the utilization of straw for various purposes. This review also discusses the importance of educating farmers about the straw burning issue and its environmental consequences. We highlight the significance of tailoring rice straw management methods to local suitability, moving away from a universal approach. More extension work is needed to encourage farmers to opt for environmentally and economically sound options for rice straw management. Policy intervention to incentivize farmers and develop technologies for the widespread use of rice straw for various industries and product development could help in the management of rice straw and will also create a circular economy., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Key Message: Overexpressing CsGGCT2;1 in Camelina enhances arsenic tolerance, reducing arsenic accumulation by 40-60%. Genetically modified Camelina can potentially thrive on contaminated lands and help safeguard food quality and sustainable food and biofuel production. Environmental arsenic contamination is a serious global issue that adversely affects human health and diminishes the quality of harvested produce. Glutathione (GSH) is known to bind and detoxify arsenic and other toxic metals. A steady level of GSH is maintained within cells via the γ-glutamyl cycle. The γ-glutamyl cyclotransferases (GGCTs) have previously been shown to be involved in GSH degradation and increased tolerance to toxic metals in plants. In this study, we characterized the GGCT2;1 homolog from Camelina sativa for its role in arsenic tolerance and accumulation. Overexpression of CsGGCT2;1 in Camelina under CaMV35S constitutive promoter resulted in strong tolerance to arsenite (AsIII). The overexpression (OE) lines had 2.6-3.5-fold higher shoots and sevenfold to tenfold enhanced root biomass on media supplemented with AsIII, relative to wild-type plants. The CsGGCT2;1 OE lines accumulated 40-60% less arsenic in root and shoot tissues compared to wild-type plants. Further, the OE lines had ~ twofold higher chlorophyll content and 35% lesser levels of malondialdehyde (MDA), an indicator of membrane damage via lipid peroxidation. There was a slight but non-significant increase in 5-oxoproline (5-OP), a product of GSH degradation, in OE lines. However, the transcript levels of Oxoprolinase 1 (OXP1) were upregulated, indicating the accelerated conversion of 5-OP to glutamate, which is further utilized for the resynthesis of GSH to maintain GSH homeostasis. Overall, this research suggests that genetically modified Camelina may have the potential for cultivation on contaminated marginal lands to reduce As accumulation; thereby could help in addressing food safety issues as well as future food and biofuel needs., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Silver nanoparticles (AgNPs) are commonly used in many commercial products due to their antimicrobial properties, and their significant exposure in agricultural systems is anticipated. AgNPs accumulation in soil and subsequent uptake by plants can be harmful to plant growth and exposure to animals and humans through the food chain is a major concern. This study evaluated the potential protective role of nanosulfur (NS) and bulk sulfur (BS) at 200 and 400 mg/kg soil application in alleviating silver nanoparticle (AgNPs; 32 and 64 mg/kg) phytotoxicity to soybean [Glycine max (L) Merr.]. The treatments were added in the soil before soybean transplantation; growth, yield, nutrient, and silver accumulation were measured in the shoot, root, and seeds. Exposure to AgNPs significantly affected plant growth and yield, reducing nodule weight by 40%, fresh shoot weight by 66%, and seed yield by 68% when compared to controls. However, nanosulfur application in soil alleviated AgNPs toxicity, and importantly, this impact was nanoscale specific at the higher concentration because the benefits of corresponding bulk sulfur (BS) treatments were marginal. Specifically, nanosulfur at 400 mg/kg significantly increased seed yield (∼3-fold more than AgNP at 64 mg/kg) and shoot biomass (2.6-fold more than AgNP at 64 mg/kg) upon co-exposure with AgNPs, essentially alleviating AgNPs toxicity. Moreover, NS increased nodule mass by 3.5 times compared to AgNPs-treated plants, which was 170% greater than the Ag- and NS-free controls. Plants treated with NS with AgNPs co-exposure accumulated significantly less Ag in the shoots (∼80% reduction) and roots (∼95% reduction); no Ag contents were detected in seeds. These findings demonstrate the potential of sulfur, especially NS, as a sustainable soil amendment to reduce the accumulation and toxicity of AgNPs and as a valuable nano-enabled strategy to promote food safety and security., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Plant tissue culture is the primary, fundamental, and applied aspect of plant biology. It is an indispensable and valuable technique for investigating morphogenesis, embryogenesis, clonal propagation, crop improvements, generation of pathogen-free plants, gene transfer and expression, and the production of secondary metabolites. The extensive use of various nanoparticles (NPs) in fields such as cosmetics, energy, medicine, pharmaceuticals, electronics, agriculture, and biotechnology have demonstrated positive impacts in microbial decontamination, callus differentiation, organogenesis, somatic variations, biotransformation, cryopreservation, and enhanced synthesis of bioactive compounds. This review summarizes the current state of knowledge with regard to the use of nanoparticles in plant tissue culture, with a particular focus on the beneficial outcomes. The positive (beneficial) and negative (toxic) effects of engineered NPs in tissue culture medium, delivery of transgenes, NPs toxicity concerns, safety issues, and potential hazards arising from utilization of nanomaterials in agriculture through plant tissue culture are discussed in detail, along with the future prospects for these applications. In addition, the potential use of novel nanomaterials such as graphene, graphite, dendrimers, quantum dots, and carbon nanotubes as well as unique metal or metalloid NPs are proposed. Further, the potential mechanisms underlying NPs elicitation of tissue culture response in different applications are critically evaluated. The potential of these approaches in plant nanobiotechnology is only now becoming understood and it is clear that the role of these strategies in sustainably increasing crop production to combat global food security and safety in a changing climate will be significant., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationship that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

Crop diseases significantly threaten global food security and will worsen with a changing climate. Elemental sulfur nanomaterials (S NMs) were used to suppress bacterial pathogen Pectobacterium carotovorum on lettuce (Lactuca sativa L.). Foliar application with S NMs at 10-100 mg/L statistically decreased the occurrence of bacterial soft rot, where 100 mg/L exhibited the best performance with alleviating disease severity by 94.1 % as relative to infected controls. The disease suppression efficiency of S based materials (100 mg/L) and a conventional pesticide (thiophanate-methyl) followed the order of S NMs ≈ pesticide > S bulk particles (BPs) > sulfate. The disease control efficiency of S NMs was 1.33- and 3.20-fold that of S BPs and sulfate, respectively, and the shoot and root biomass with S NMs was 1.25- and 1.17-fold that of the pesticide treated plants. Mechanistically, S NMs (1) triggered jasmonic acid (JA) and salicylic acid (SA) mediated systematic induced resistance and systemic acquired resistance, thereby upregulating pathogenesis-related gene expression (enhanced by 29.3-259.7 %); (2) enhanced antioxidative enzyme activity and antioxidative gene expression (improved by 67.5-326.6 %), thereby alleviating the oxidative stress; and (3) exhibited direct in vivo antibacterial activity. Metabolomics analysis demonstrated that S NMs also promoted the tricarboxylic acid cycle and increased SA and JA metabolite biosynthesis. Moreover, S NMs application increased nutritive quality of lettuce by 20.8-191.7 %. These findings demonstrate that S NMs have potential to manage crop disease, thereby reducing the environmental burden due to decreasing use of conventional pesticides., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Chromium (VI) is one of the hazardous heavy metal, heavily discharged into the soil and severely hampers the plants yield. The TiO 2 NPs was selected due to its potential to alleviate the heavy metals toxicity. This manuscript unravels the mechanisms for Cr(VI) induced toxicity and how foliar application of TiO 2 NP S potentially ameliorate the toxicity by regulating the photosynthetic attributes, DNA damage, antioxidants defense machinery, and phytochelatins synthesis in Helianthus annuus L. Plants were exposed to Cr(VI) concentrations [0, 15, 30, and 60 mg Cr(VI) kg -1 of soil], and TiO 2 NP S (15 mg L -1 , 25 nm size ) were foliar sprayed thrice to the plants at three days interval. The maximum accumulation of total chromium was recorded in root (12.53 µg g -1 DW) followed by shoot (5.67 µg g -1 DW) at 60 mg Cr(VI) treatment. The presence and localization of TiO 2 NPs inside the plant leaf cells were confirmed by TEM-EDS analysis. The results revealed that Cr(VI) exposure had a dose-dependent inhibitory effects on photosynthetic attributes, structure of guard and epidermal cells, photosynthetic pigments; inducing impacts on H 2 O 2 and MDA productions, DNA damage, AsA-GSH cycle, and most importantly on PC 2 , and PC 3 synthesis which is rarely reported. However, TiO 2 NPs exposure minimized Cr(VI) induced toxicity through reduction of total chromium accumulation, H 2 O 2 and MDA productions, thereby reducing DNA damage reported first time under combined treatment of Cr(VI)+ TiO 2 NPs as evidenced through comet assay. It also positively regulate the photosynthetic pigments, AsA-GSH cycle, and modulates PC 2 and PC 3 synthesis which have crucial impacts on ROS quenching and Cr(VI) detoxification, respectively, and in turn, minimizes Cr(VI) toxicity in H. annuus L. Besides, this study strengthens the less acknowledged report that Cr(VI) is an inducer of PCs synthesis and also confirms that TiO 2 NPs potentially counteract Cr(VI) toxicity., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Yellow or stripe rust, caused by the fungus Puccinia striiformis f. sp. tritici (Pst) is an important disease of wheat that threatens wheat production. Since developing resistant cultivars offers a viable solution for disease management, it is essential to understand the genetic basis of stripe rust resistance. In recent years, meta-QTL analysis of identified QTLs has gained popularity as a way to dissect the genetic architecture underpinning quantitative traits, including disease resistance., Results: Systematic meta-QTL analysis involving 505 QTLs from 101 linkage-based interval mapping studies was conducted for stripe rust resistance in wheat. For this purpose, publicly available high-quality genetic maps were used to create a consensus linkage map involving 138,574 markers. This map was used to project the QTLs and conduct meta-QTL analysis. A total of 67 important meta-QTLs (MQTLs) were identified which were refined to 29 high-confidence MQTLs. The confidence interval (CI) of MQTLs ranged from 0 to 11.68 cM with a mean of 1.97 cM. The mean physical CI of MQTLs was 24.01 Mb, ranging from 0.0749 to 216.23 Mb per MQTL. As many as 44 MQTLs colocalized with marker-trait associations or SNP peaks associated with stripe rust resistance in wheat. Some MQTLs also included the following major genes- Yr5, Yr7, Yr16, Yr26, Yr30, Yr43, Yr44, Yr64, YrCH52, and YrH52. Candidate gene mining in high-confidence MQTLs identified 1,562 gene models. Examining these gene models for differential expressions yielded 123 differentially expressed genes, including the 59 most promising CGs. We also studied how these genes were expressed in wheat tissues at different phases of development., Conclusion: The most promising MQTLs identified in this study may facilitate marker-assisted breeding for stripe rust resistance in wheat. Information on markers flanking the MQTLs can be utilized in genomic selection models to increase the prediction accuracy for stripe rust resistance. The candidate genes identified can also be utilized for enhancing the wheat resistance against stripe rust after in vivo confirmation/validation using one or more of the following methods: gene cloning, reverse genetic methods, and omics approaches., (© 2023. The Author(s).)

The significance of priming in enhancing abiotic stress tolerance is well-established in several important crops. Priming positively impacts plant growth and improves stress tolerance at multiple developmental stages, and seed priming is one of the most used methods. Seed priming influences the pre-germinative metabolism that ensures proper germination, early seedling establishment, enhanced stress tolerance and yield, even under unfavourable environmental conditions. Seed priming involves pre-exposure of seeds to mild stress, and this pre-treatment induces specific changes at the physiological and molecular levels. Interestingly, priming can improve the efficiency of the DNA repair mechanism, along with activation of specific signalling proteins and transcription factors for rapid and efficient stress tolerance. Notably, such acquired stress tolerance may be retained for longer duration, namely, later developmental stages or even subsequent generations. Epigenetic and chromatin-based mechanisms such as DNA methylation, histone modifications, and nucleosome positioning are some of the key molecular changes involved in priming/stress memory. Further, the retention of induced epigenetic changes may influence the priming-induced trans-generational stress memory. This review discusses known and plausible seed priming-induced molecular mechanisms that govern germination and stress memory within and across generations, highlighting their role in regulating the plant response to abiotic stresses. Understanding the molecular mechanism for activation of stress-responsive genes and the epigenetic changes resulting from seed priming will help to improve the resiliency of the crops for enhanced productivity under extreme environments., (© 2023 Scandinavian Plant Physiology Society.)

Metal(loid)s contamination poses a serious threat to ecosystem biosafety and human health. Phytoremediation is a cost-effective and eco-friendly technology with good public acceptance, although the process does require a significant amount of time for success. To enhance the phytoremediation efficiency, numerous approaches have been explored, including soil amendments application with chelators to facilitate remediation. Sulfur (S), a macronutrient for plant growth, plays vital roles in several metabolic pathways that can actively affect metal(loid)s phytoextraction, as well as attenuate metal(loid) toxicity. In this review, different forms of S-amendments (fertilizers) on uptake and translocation in plants upon exposure to various metal(loid) are evaluated. Possible mechanisms for S application alleviating metal(loid) toxicity are documented at the physiological, biochemical and molecular levels. Furthermore, this review highlights the crosstalk between S-assimilation and other biomolecules, such as phytohormones, polyamines and nitric oxide, which are also important for metal(loid) stress tolerance. Given the effectiveness and potential of S amendments on phytoremediation, future studies should focus on optimizing phytoremediation efficiency in long-term field studies and on investigating the appropriate S dose to maximize the food safety and ecosystem health., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Experiments were performed to explore the impact of sulfur nanoparticles (SNPs) on growth, Cu accumulation, and physiological and biochemical responses of oilseed rape (Brassica napus L.) inoculated with 5 mg/L Cu-amended MS medium supplemented with or without 300 mg/L SNPs exposure. Cu exerted severe phytotoxicity and inhibited plant growth. SNPs application enhanced the shoot height, root length, and dry weight of shoot and root by 34.6%, 282%, 41.7% and 37.1%, respectively, over Cu treatment alone, while the shoot and root Cu contents and Cu-induced lipid perodixation as the malondialdehyde (MDA) levels in shoots and roots were decreased by 37.6%, 35%, 28.4% and 26.8%. Further, the increases in superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR) and glutathione S-transferase (GST) enzyme activities caused by Cu stress were mitigated in shoots (10.9%-37.1%) and roots (14.6%-35.3%) with SNPs addition. SNPs also positively counteracted the negative effects on shoot K, Ca, P, Mg, Mn, Zn and Fe contents and root K, Ca, Mg and Mn contents from Cu exposure alone, and significantly promoted the nutrients accumulation in plant. Additionally, in comparison with common bulk sulfur particles (BSPs) and sulfate, SNPs showed more positive effects on promoting growth in shoots (6.7% and 19.5%) and roots (10.9% and 15.1%), as well as lowering the shoot Cu content (40.1% and 43.3%) under Cu stress. Thus, SNPs application has potential to be a green and sustainable technology for increasing plant productivity and reducing accumulation of toxic metals in heavy metal polluted soils., (Copyright © 2021. Published by Elsevier B.V.)

Unexpected bioaccumulation and biomagnification of heavy metal(loid)s (HMs) in the environment have become a predicament for all living organisms, including plants. The presence of these HMs in the plant system raised the level of reactive oxygen species (ROS) and remodeled several vital cellular biomolecules. These lead to several morphological, physiological, metabolic, and molecular aberrations in plants ranging from chlorosis of leaves to the lipid peroxidation of membranes, and degradation of proteins and nucleic acid including the modulation of the enzymatic system, which ultimately affects the plant growth and productivity. Plants are equipped with several mechanisms to counteract the HMs toxicity. Among them, seed priming (SP) technology has been widely tested with the use of several inorganic chemicals, plant growth regulators (PGRs), gasotransmitters, nanoparticles, living organisms, and plant leaf extracts. The use of these compounds has the potential to alleviate the HMs toxicity through the strengthening of the antioxidant defense system, generation of low molecular weight metallothionein's (MTs), and phytochelatins (PCs), and improving seedling vigor during early growth stages. This review presents an account of the sources, uptake and transport, and phytotoxic effects of HMs with special attention to different mechanism/s, occurring to mitigate the HMs toxicity in plants employing SP technology. Novelty statement: To the best of our knowledge, this review has delineated the consequences of HMs on the crucial plant processes, which ultimately affect plant growth and development. This review also compiled the up to dated information on phytotoxicity of HMs through the use of SP technology, this review discussed how different types of SP approaches help in diminishing the concentration HMs in plant systems. Also, we depicted mechanisms, represent how HMs transport and their actions on cellular levels, and emphasized, how diverse SP technology effectiveness in the mitigation of plants' phytotoxicity in unique ways.

In wheat, lodging is affected by anatomical and chemical characteristics of the stem cell wall. Plant characteristics determining the stem strength were measured in lodging tolerant mutant (PMW-2016-1) developed through mutation breeding utilizing hexaploid wheat cultivar, DPW-621-50. Various anatomical features, chemical composition, and mechanical strength of the culms of newly developed lodging-tolerant mutant (PMW-2016-1) and parent (DPW-621-50), were examined by light microscopy, the Klason method, prostate tester coupled with a Universal Tensile Machine, and Fourier Transform Infrared Spectroscopy. Significant changes in the anatomical features, including the outer radius of the stem, stem wall thickness, and the proportions of various tissues, and vascular bundles were noticed. Chemical analysis revealed that the lignin level in the PMW-2016-1 mutant was higher and exhibited superiority in stem strength compared to the DPW-621-50 parent line. The force (N) required to break the internodes of mutant PMW-2016-1 was higher than that of DPW-621-50. The results suggested that the outer stem radius, stem wall thickness, the proportion of sclerenchyma tissues, the number of large vascular bundles, and lignin content are important factors that affect the mechanical strength of wheat stems, which can be the key parameters for the selection of varieties having higher lodging tolerance. Preliminary studies on the newly identified mutant PMW-2016-1 suggested that this mutant may possess higher lodging tolerance because it has a higher stem strength than DPW-621-50 and can be used as a donor parent for the development of lodging-tolerant wheat varieties., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Bisht, Kumar, Singh, Malik, Djalovic, Dhaka, Pal, Balyan, Mir, Singh, Dhankher, Kumar and Kumar.)

Little is known about the effect of nano sulfur (NS) under field conditions as a multifunctional agricultural amendment. Pristine and surface coated NS (CS) were amended in soil at 200 mg/kg that was planted with tomato ( Solanum lycopersicum ) and infested with Fusarium oxysporum f. sp. lycopersici . Foliar exposure of CS (200 μg/mL) was also included. In healthy plants, CS increased tomato marketable yield up to 3.3∼3.4-fold compared to controls. In infested treatments, CS significantly reduced disease severity compared to the other treatments. Foliar and soil treatment with CS increased yield by 107 and 192% over diseased controls, respectively, and significantly increased fruit Ca, Cu, Fe, and Mg contents. A $33/acre investment in CS led to an increase in marketable yield from 4920 to 11,980 kg/acre for healthy plants and from 1135 to 2180 kg/acre for infested plants, demonstrating the significant potential of this nanoenabled strategy to increase food production.

Widespread use of metal-based nanoparticles (NPs) may result in the increased accumulation of metals in agricultural soil, which could affect crop productivity and contaminate the food-chain. The effect of sulfur nanoparticles (S NPs, 200 mg/L) co-exposure on the toxicity of CuO nanoparticles (CuO NPs, 25 and 50 mg/L) to wheat seedlings was investigated in a hydroponic system. CuO NPs exposure significantly inhibited the growth of wheat seedlings, causing 43.6% and 54.1% decreases in the fresh biomass of plants and 82.8% and 83.1% decrease in the total chlorophyll contents at 25 and 50 mg/L (CuONP25 and CuONP50), respectively, as compared to controls. CuO NPs exposure at both concentrations increased the malondialdehyde (MDA) content in shoot and root tissues by 66.4-67.9% and 47.7-48.8%, respectively. Further, CuO NPs exposure elevated the activities POD, SOD, and CAT by 2.19-2.27, 5.82-6.09, and 1.44-1.95 times in roots, and by 45.2-67.8%, 86.7-154.5%, and 22.5-56.1% in shoot, respectively, in comparison to control. The addition of S NPs alone increased wheat biomass by 11.0% and total chlorophyll contents by 4.4%, compared to controls. Further, simultaneous exposure to S NPs (200 mg/L) and CuO NPs (25 or 50 mg/L) alleviated the CuO NPs toxicity; wheat biomass was 47.8% and 37.7% higher in CuONP25 + SNP and CuONP50 + SNP treatments, respectively, as compared to CuO NPs alone treated plants. Co-exposed plants showed reduced levels of total reactive oxygen species (ROS), O 2 ·- and H 2 O 2 . Additionally, S NPs exposure reduced Cu uptake and accumulation in both root and shoot tissue by 32.2-54.4% and 38.3-57.5%, respectively. In summary, S NPs alleviated CuO NPs toxicity to wheat seedlings, most likely by reducing Cu bioavailability and accumulation of Cu in plant tissues, and also altered S nutrition and the modulation of antioxidant response in plants. These results showed that S NPs application has the potential to alleviate CuO NP toxicity and increase wheat productivity affected by metals toxicity., Competing Interests: Declaration of competing interest Research support: This research received no external financial or non-financial support. Relationship: There is no additional relationship to disclose. Patents and intellectual property: There is no patent to disclose. Other activities: There are no additional activities to disclose., (Copyright © 2022. Published by Elsevier B.V.)

Grain yield is one of the most important aims for combating the needs of the growing world population. The role of development and nutrient transfer in flag leaf for higher yields at the grain level is well known. It is a great challenge to properly exploit this knowledge because all the processes, starting from the emergence of the flag leaf to the grain filling stages of wheat ( Triticum aestivum L.), are very complex biochemical and physiological processes to address. This study was conducted with the primary goal of functionally and structurally annotating the candidate genes associated with different developmental stages of flag leaf in a comprehensive manner using a plethora of in silico tools. Flag leaf-associated genes were analyzed for their structural and functional impacts using a set of bioinformatics tools and algorithms. The results revealed the association of 17 candidate genes with different stages of flag leaf development in wheat crop. Of these 17 candidate genes, the expression analysis results revealed the upregulation of genes such as TaSRT1-5D , TaPNH1-7B , and TaNfl1-2B and the downregulation of genes such as TaNAP1-7B , TaNOL-4D , and TaOsl2-2B can be utilized for the generation of high-yielding wheat varieties. Through MD simulation and other in silico analyses, all these proteins were found to be stable. Based on the outcome of bioinformatics and molecular analysis, the identified candidate genes were found to play principal roles in the flag leaf development process and can be utilized for higher-yield wheat production., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Mehla, Kumar, Kapoor, Singh, Sihag, Sagwal, Balyan, Kumar, Ahalawat, Lakra, Singh, Pesic, Djalovic, Mir and Dhankher.)

Nanoscale sulfur can be a multifunctional agricultural amendment to enhance crop nutrition and suppress disease. Pristine (nS) and stearic acid coated (cS) sulfur nanoparticles were added to soil planted with tomatoes ( Solanum lycopersicum ) at 200 mg/L soil and infested with Fusarium oxysporum . Bulk sulfur, ionic sulfate, and healthy controls were included. Orthogonal end points were measured in two greenhouse experiments, including agronomic and photosynthetic parameters, disease severity/suppression, mechanistic biochemical and molecular end points including the time-dependent expression of 13 genes related to two S bioassimilation and pathogenesis-response, and metabolomic profiles. Disease reduced the plant biomass by up to 87%, but nS and cS amendment significantly reduced disease as determined by area-under-the-disease-progress curve by 54 and 56%, respectively. An increase in planta S accumulation was evident, with size-specific translocation ratios suggesting different uptake mechanisms. In vivo two-photon microscopy and time-dependent gene expression revealed a nanoscale-specific elemental S bioassimilation pathway within the plant that is separate from traditional sulfate accumulation. These findings correlate well with time-dependent metabolomic profiling, which exhibited increased disease resistance and plant immunity related metabolites only with nanoscale treatment. The linked gene expression and metabolomics data demonstrate a time-sensitive physiological window where nanoscale stimulation of plant immunity will be effective. These findings provide mechanistic understandings of nonmetal nanomaterial-based suppression of plant disease and significantly advance sustainable nanoenabled agricultural strategies to increase food production.

Among all the nutrients, nitrogen (N) and phosphorous (P) are the most limiting factors reducing wheat production and productivity world-wide. These macronutrients are directly applied to soil in the form of fertilizers. However, only 30-40% of these applied fertilizers are utilized by crop plants, while the rest is lost through volatilization, leaching, and surface run off. Therefore, to overcome the deficiency of N and P, it becomes necessary to improve their use efficiency. Marker-assisted selection (MAS) combined with traditional plant breeding approaches is considered best to improve the N and P use efficiency (N/PUE) of wheat varieties. In this study, we developed and evaluated a total of 98 simple sequence repeat (SSR) markers including 66 microRNAs and 32 gene-specific SSRs on a panel of 10 (N and P efficient/deficient) wheat genotypes. Out of these, 35 SSRs were found polymorphic and have been used for the study of genetic diversity and population differentiation. A set of two SSRs, namely miR171a and miR167a were found candidate markers able to discriminate contrasting genotypes for N/PUE, respectively. Therefore, these two markers could be used as functional markers for characterization of wheat germplasm for N and P use efficiency. Target genes of these miRNAs were found to be highly associated with biological processes (24 GO terms) as compared to molecular function and cellular component and shows differential expression under various P starving conditions and abiotic stresses., (© 2022. The Author(s), under exclusive licence to The Genetics Society.)

Seven Arabidopsis thaliana mutants with differences in cuticle thickness and stomatal density were foliar exposed to 50 mg L -1 Cu 3 (PO 4 ) 2 nanosheets (NS), CuO NS, CuO nanoparticles, and CuSO 4 . Three separate fractions of Cu (surface-attached, cuticle, interior leaf) were isolated from the leaf at 0.25, 2, 4, and 8 h. Cu transfer from the surface through the cuticle and into the leaf varied with mutant and particle type. The Cu content on the surface decreased significantly over 8 h but increased in the cuticle. Cu derived from the ionic form had the greatest cuticle concentration, suggesting greater difficulty in moving across this barrier and into the leaf. Leaf Cu in the increased-stomatal mutants was 8.5-44.9% greater than the decreased stomatal mutants, and abscisic acid to close the stomata decreased Cu in the leaf. This demonstrates the importance of nanomaterial entry through the stomata and enables the optimization of materials for nanoenabled agriculture.

Rice is the staple food for more than 3.5 billion people worldwide. The sensitivity of rice to heat, drought, and salinity is well documented. However, rice response to combinations of these stresses is not well understood. A contrasting set of rice genotypes for heat (N22, Gharib), drought (Moroberekan, Pusa 1121) and salinity (Pokkali, IR64) were selected to characterize their response under drought, and combination of drought with heat and salinity at the sensitive seedling stage. Sensitive genotypes (IR64, Pusa 1121, Gharib) recorded higher reactive oxygen species accumulation (20-40%), membrane damage (8-65%) and reduction in photosynthetic efficiency (10-23%) across the stress and stress combinations as compared to stress tolerant checks. On the contrary, N22 and Pokkali performed best under drought + heat, and drought + salinity combination, respectively. Moreover, gene expression pattern revealed the highest expression of catalase ( CAT ), ascorbate peroxidase ( APX ) and GATA28a in N22 under heat + drought, whereas the highest expression of CAT, APX , superoxide dismutase ( SOD ), DEHYDRIN , GATA28a and GATA28b in Pokkali under drought + salinity. Interestingly, the phenotypic variation and expression level of genes highlighted the role of different set of physiological traits and genes under drought and drought combination with heat and salinity stress. This study reveals that rice response to stress combinations was unique with rapid readjustment at physiological and molecular levels. Moreover, phenotypic changes under stress combinations showed substantial adaptive plasticity in rice, which warrant further investigations at molecular level., Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01162-y., Competing Interests: Conflict of interestThe authors declare no conflict of interest., (© Prof. H.S. Srivastava Foundation for Science and Society 2022.)

Nutrient deficiency in food crops severely compromises human health, particularly in under privileged communities. Globally, billions of people, particularly in developing nations, have limited access to nutritional supplements and fortified foods, subsequently suffering from micronutrient deficiency leading to a range of health issues. The green revolution enhanced crop production and provided food to billions of people but often falls short with respect to the nutritional quality of that food. Plants may assimilate nutrients from synthetic chemical fertilizers, but this approach generally has low nutrient delivery and use efficiency. Further, the overexposure of chemical fertilizers may increase the risk of neoplastic diseases, render food crops unfit for consumption and cause environmental degradation. Therefore, to address these challenges, more research is needed for sustainable crop yield and quality enhancement with minimum use of chemical fertilizers. Complex nutritional disorders and 'hidden hunger' can be addressed through biofortification of food crops. Nanotechnology may help to improve food quality via biofortification as plants may readily acquire nanoparticle-based nutrients. Nanofertilizers are target specific, possess controlled release, and can be retained for relatively long time periods, thus prevent leaching or run-off from soil. This review evaluates the recent literature on the development and use of nanofertilizers, their effects on the environment, and benefits to food quality. Further, the review highlights the potential of nanomaterials on plant genetics in biofortification, as well as issues of affordability, sustainability, and toxicity., (Copyright © 2022 Elsevier B.V. All rights reserved.)

MicroRNAs (miRNAs) play a significant role in plant response to different abiotic stresses. Thus, identification of abiotic stress-responsive miRNAs holds immense importance in crop breeding programmes to develop cultivars resistant to abiotic stresses. In this study, we developed a machine learning-based computational method for prediction of miRNAs associated with abiotic stresses. Three types of datasets were used for prediction, i.e., miRNA, Pre-miRNA, and Pre-miRNA + miRNA. The pseudo K -tuple nucleotide compositional features were generated for each sequence to transform the sequence data into numeric feature vectors. Support vector machine (SVM) was employed for prediction. The area under receiver operating characteristics curve (auROC) of 70.21, 69.71, 77.94 and area under precision-recall curve (auPRC) of 69.96, 65.64, 77.32 percentages were obtained for miRNA, Pre-miRNA, and Pre-miRNA + miRNA datasets, respectively. Overall prediction accuracies for the independent test set were 62.33, 64.85, 69.21 percentages, respectively, for the three datasets. The SVM also achieved higher accuracy than other learning methods such as random forest, extreme gradient boosting, and adaptive boosting. To implement our method with ease, an online prediction server "ASRmiRNA" has been developed. The proposed approach is believed to supplement the existing effort for identification of abiotic stress-responsive miRNAs and Pre-miRNAs.

Rice is known to accumulate arsenic (As) in its grains, posing serious health concerns for billions of people globally. We studied the effect of nanoscale sulfur (NS) on rice seedlings and mature plants under As stress. NS application caused a 40% increase in seedling biomass and a 26% increase in seed yield of mature plants compared to untreated control plants. AsIII exposure caused severe toxicity to rice; however, coexposure of plants to AsIII and NS alleviated As toxicity, and growth was significantly improved. Rice seedlings treated with AsIII + NS produced 159 and 248% more shoot and root biomass, respectively, compared to plants exposed to AsIII alone. Further, AsIII + NS-treated seedlings accumulated 32 and 11% less As in root and shoot tissues, respectively, than the AsIII-alone treatment. Mature plants treated with AsIII + NS produced 76, 110, and 108% more dry shoot biomass, seed number, and seed yield, respectively, and accumulated 69, 38, 18, and 54% less total As in the root, shoot, flag leaves, and grains, respectively, compared to AsIII-alone-treated plants. A similar trend was observed in seedlings treated with AsV and NS. The ability of sulfur (S) to alleviate As toxicity and accumulation is clearly size dependent as NS could effectively reduce bioavailability and accumulation of As in rice via modulating the gene expression activity of As transport, S assimilatory, and glutathione synthesis pathways to facilitate AsIII detoxification. These results have significant environmental implications as NS application in agriculture has the potential to decrease As in the food chain and simultaneously enable crops to grow and produce higher yields on marginal and contaminated lands.

Seed priming is a cost-effective, practical, environmental, and farmer-friendly method to improve seed germination that can potentially increase the growth and yield of plants. The priming process enhances various physiological and biochemical mechanisms of defense and empowers the seeds or seedlings to overcome different environmental stresses. However, under critical circumstances, plants are hindered from absorbing specific chemical priming reagents owing to their larger size, molecular structure, or lack of carriers. Therefore, nanoscale materials having exceptional physiochemical properties and a large surface/volume ratio are expected to be better absorbed by the seeds/seedlings as priming agents in comparison to bulk chemicals and can trigger enhanced molecular interactions at the cellular level. Further, the flexibility in altering the surface chemical properties of the nanomaterials can facilitate better interaction with the seeds/seedlings while inhibiting the wastage of priming agents. In this review, we have systematically discussed the potentiality of various nanostructured materials as priming agents in alleviating the adverse effects of various abiotic stresses, viz., drought, salinity, high temperature, cold temperature, and heavy metals, by studying the growth parameters and physiological and biochemical response of various crop plants subjected to these stress conditions. Also, we have highlighted the molecular mechanism and activation of genes involved in enabling abiotic stress tolerance in plants after being primed with nanostructured materials.

A large proportion of the Asian population fulfills their energy requirements from wheat ( Triticum aestivum L.). Wheat quality and yield are critically affected by the terminal heat stress across the globe. It affects approximately 40% of the wheat-cultivating regions of the world. Therefore, there is a critical need to develop improved terminal heat-tolerant wheat varieties. Marker-assisted breeding with genic simple sequence repeats (SSR) markers have been used for developing terminal heat-tolerant wheat varieties; however, only few studies involved the use of microRNA (miRNA)-based SSR markers (miRNA-SSRs) in wheat, which were found as key players in various abiotic stresses. In the present study, we identified 104 heat-stress-responsive miRNAs reported in various crops. Out of these, 70 miRNA-SSR markers have been validated on a set of 20 terminal heat-tolerant and heat-susceptible wheat genotypes. Among these, only 19 miRNA-SSR markers were found to be polymorphic, which were further used to study the genetic diversity and population structure. The polymorphic miRNA-SSRs amplified 61 SSR loci with an average of 2.9 alleles per locus. The polymorphic information content (PIC) value of polymorphic miRNA-SSRs ranged from 0.10 to 0.87 with a mean value of 0.48. The dendrogram constructed using unweighted neighbor-joining method and population structure analysis clustered these 20 wheat genotypes into 3 clusters. The target genes of these miRNAs are involved either directly or indirectly in providing tolerance to heat stress. Furthermore, two polymorphic markers miR159c and miR165b were declared as very promising diagnostic markers, since these markers showed specific alleles and discriminated terminal heat-tolerant genotypes from the susceptible genotypes. Thus, these identified miRNA-SSR markers will prove useful in the characterization of wheat germplasm through the study of genetic diversity and population structural analysis and in wheat molecular breeding programs aimed at terminal heat tolerance of wheat varieties., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Sihag, Sagwal, Kumar, Balyan, Mir, Dhankher and Kumar.)

In agriculture, loss of crop yield to pathogen damage seriously threatens efforts to achieve global food security. In the present work, "organic" elemental sulfur nanoparticles (SNPs) were investigated for management of the fungal pathogen Fusarium oxysporum f. sp. lycopersici on tomatoes. Foliar application and seed treatment with SNPs (30-100 mg/L, 30 and 100 nm) suppressed pathogen infection in tomatoes, in a concentration- and size-dependent fashion in a greenhouse experiment. Foliar application with 1 mg/plant of 30 nm SNPs (30-SNPs) exhibited the best performance for disease suppression, significantly decreasing disease incidence by 47.6% and increasing tomato shoot biomass by 55.6% after 10 weeks application. Importantly, the disease control efficacy with 30-SNPs was 1.43-fold greater than the commercially available fungicide hymexazol. Mechanistically, 30-SNPs activated the salicylic acid-dependent systemic acquired resistance pathway in tomato shoots and roots, with subsequent upregulation of the expression of pathogenesis-related and antioxidase-related genes (upregulated by 11-352%) and enhancement of the activity and content of disease-related biomolecules (enhanced by 5-49%). In addition, transmission electron microscopy imaging shows that SNPs were distributed in the tomato stem and directly inactivated in vivo pathogens. The oxidative stress in tomato shoots and roots, the root plasma membrane damage, and the growth of the pathogen in stem were all significantly decreased by SNPs. The findings highlight the significant potential of SNPs as an eco-friendly and sustainable crop protection strategy.

In nature, plants are exposed to an ever-changing environment with increasing frequencies of multiple abiotic stresses. These abiotic stresses act either in combination or sequentially, thereby driving vegetation dynamics and limiting plant growth and productivity worldwide. Plants' responses against these combined and sequential stresses clearly differ from that triggered by an individual stress. Until now, experimental studies were mainly focused on plant responses to individual stress, but have overlooked the complex stress response generated in plants against combined or sequential abiotic stresses, as well as their interaction with each other. However, recent studies have demonstrated that the combined and sequential abiotic stresses overlap with respect to the central nodes of their interacting signaling pathways, and their impact cannot be modelled by swimming in an individual extreme event. Taken together, deciphering the regulatory networks operative between various abiotic stresses in agronomically important crops will contribute towards designing strategies for the development of plants with tolerance to multiple stress combinations. This review provides a brief overview of the recent developments in the interactive effects of combined and sequentially occurring stresses on crop plants. We believe that this study may improve our understanding of the molecular and physiological mechanisms in untangling the combined stress tolerance in plants, and may also provide a promising venue for agronomists, physiologists, as well as molecular biologists.

To ensure global food security under the changing climate, there is a strong need for developing 'climate resilient crops' that can thrive and produce better yields under extreme environmental conditions such as drought, salinity, and high temperature. To enhance plant productivity under the adverse conditions, we constitutively overexpressed a bifunctional wax synthase/acyl-CoA:diacylglycerol acyltransferase ( WSD1 ) gene, which plays a critical role in wax ester synthesis in Arabidopsis stem and leaf tissues. The qRT-PCR analysis showed a strong upregulation of WSD1 transcripts by mannitol, NaCl, and abscisic acid (ABA) treatments, particularly in Arabidopsis thaliana shoots. Gas chromatography and electron microscopy analyses of Arabidopsis seedlings overexpressing WSD1 showed higher deposition of epicuticular wax crystals and increased leaf and stem wax loading in WSD1 transgenics compared to wildtype (WT) plants. WSD1 transgenics exhibited enhanced tolerance to ABA, mannitol, drought and salinity, which suggested new physiological roles for WSD1 in stress response aside from its wax synthase activity. Transgenic plants were able to recover from drought and salinity better than the WT plants. Furthermore, transgenics showed reduced cuticular transpirational rates and cuticle permeability, as well as less chlorophyll leaching than the WT. The knowledge from Arabidopsis was translated to the oilseed crop Camelina sativa (L.) Crantz. Similar to Arabidopsis, transgenic Camelina lines overexpressing WSD1 also showed enhanced tolerance to drought stress. Our results clearly show that the manipulation of cuticular waxes will be advantageous for enhancing plant productivity under a changing climate.

The present study investigated the role of graphitic carbon nitride (C 3 N 4 ) in alleviating cadmium (Cd)- and arsenic (As)-induced phytotoxicity to rice ( Oryza sativa L.). A high-temperature pyrolysis was used to synthesize the C 3 N 4 , which was characterized by transmission electron microscopy, Fourier-transform infrared spectroscopy, and dynamic light scattering. Rice seedlings were exposed to C 3 N 4 at 50 and 250 mg/L in half-strength Hoagland's solution amended with or without 10 mg/L Cd or As for 14 days. Both Cd and As alone resulted in 26-38% and 49-56% decreases in rice root and shoot biomass, respectively. Exposure to 250 mg/L C 3 N 4 alone increased the root and shoot fresh biomass by 17.5% and 25.9%, respectively. Upon coexposure, Cd + C 3 N 4 and As + C 3 N 4 alleviated the heavy metal-induced phytotoxicity and increased the fresh weight by 26-38% and 49-56%, respectively. Further, the addition of C 3 N 4 decreased Cd and As accumulation in the roots by 32% and 25%, respectively, whereas the metal contents in the shoots were 30% lower in the presence of C 3 N 4 . Both As and Cd also significantly altered the macronutrient (K, P, Ca, S, and Mg) and micronutrient (Cu, Fe, Zn, and Mn) contents in rice, but these alterations were not evident in plants coexposed to C 3 N 4 . Random amplified polymorphic DNA analysis suggests that Cd significantly altered the genomic DNA of rice roots, while no difference was found in shoots. The presence of C 3 N 4 controlled Cd and As uptake in rice by regulating transport-related genes. For example, the relative expression of the Cd transporter OsIRT1 in roots was upregulated by approximately threefold with metal exposure, but C 3 N 4 coamendment lowered the expression. Similar results were evident in the expression of the As transporter OsNIP1;1 in roots. Overall, these findings facilitate the understanding of the underlying mechanisms by which carbon-based nanomaterials alleviate contaminant-induced phyto- and genotoxicity and may provide a new strategy for the reduction of heavy metal contamination in agriculture.

Cadmium pollution has become a serious environmental problem. Iris lactea var. chinensis showed strong Cd tolerance and accumulation ability, which has significant potential to be applied for the phytoremediation of Cd-contaminated soil. However, the lack of molecular information on the mechanism of I. lactea response to Cd limited the improvement of phytoremediation efficiency. In this study, label-free proteomics analysis of Cd response in I. lactea showed that there were 163 and 196 differentially expressed proteins (DEPs) in the shoots and roots, respectively. Bioinformatics analysis indicated the DEPs responding to Cd stress mainly involved in signal transduction, ion transport, redox etc., and participate in the pathway of amino acid biosynthesis, lignin biosynthesis, glycerolipid metabolism and glutathione metabolism. Besides, differential expression of seven DEPs was validated via gene expression analysis. Finally, we found that a Cd-induced mannose-specific lectin (IlMSL) from I. lactea enhanced the Cd sensitivity and increased Cd accumulation in yeast. The results of this study will enhance our understanding of the molecular mechanism of Cd tolerance and accumulation in I. lactea and ultimately provide valuable resources for using Cd tolerant genes for developing efficient strategies for phytoremediation of Cd-contaminated soils or limiting Cd accumulation in food crops., (Copyright © 2020 Elsevier B.V. All rights reserved.)

With the rising global population growth and limitation of traditional agricultural technology, global crop production could not provide enough nutrients to assure adequate intake for all people. Nano-fertilizers and nano-pesticides have 20-30% higher efficacy than conventional products, which offer an effective solution to the above-mentioned problem. Rhizosphere is where plant roots, soil, and soil biota interact, and is the portal of nutrients transporting from soil into plants. The rhizosphere processes could modify the bioavailability of all nutrients and nanomaterials (NMs) before entering the food plants. However, to date, the overall rhizosphere processes regulating the behaviors and bioavailability of NMs to enhance the nutritional quality are still uncertain. In this review, a meta-analysis is conducted to quantitatively assess NMs-mediated changes in nutritional quality from food plants. Furthermore, the current knowledge and related mechanisms of the behavior and bioavailability of NMs driven by rhizosphere processes, e.g., root secretions, microbial and earthworm activities, are summarized. A series of rhizosphere processes can influence how NMs enter plants and change the biological responses, including signal transduction and nutrient absorption and transport. Moreover, future perspectives are presented to maximize the potentials of NMs applications for the enhancement of food crop production and global food security., (Published by Elsevier Ltd.)

Among various abiotic stresses, heat stress is one of the most damaging, threatening plant productivity and survival all over the world. Warmer temperatures due to climatic anomalies above optimum growing temperatures have detrimental impacts on crop yield potential as well as plant distribution patterns. Heat stress affects overall plant metabolism in terms of physiology, biochemistry, and gene expression. Membrane damage, protein degradation, enzyme inactivation, and the accumulation of reactive oxygen species are some of the harmful effects of heat stress that cause injury to various cellular compartments. Although plants are equipped with various defense strategies to counteract these adversities, their defensive means are not sufficient to defend against the ever-rising temperatures. Hence, substantial yield losses have been observed in all crop species under heat stress. Here, we describe the involvement of various plant growth-regulators (PGRs) (hormones, polyamines, osmoprotectants, antioxidants, and other signaling molecules) in thermotolerance, through diverse cellular mechanisms that protect cells under heat stress. Several studies involving the exogenous application of PGRs to heat-stressed plants have demonstrated their role in imparting tolerance, suggesting the strong potential of these molecules in improving the performance of food crops grown under high temperature., (© The Author(s) 2019. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Climate change will negatively affect crop production by exacerbating the incidence of disease and decreasing the efficacy of conventional approaches to disease control. Nanotechnology is a promising new strategy for plant disease management that has many advantages over conventional products and approaches, such as better efficacy, reduced input requirements, and lower eco-toxicity. Studies on crop plants using various nanomaterials (NMs) as protective agents have produced promising results. This review focuses on the use of NMs in disease management through three different mechanisms: (i) as antimicrobial agents; (ii) as biostimulants that induce plant innate immunity; and (iii) as carriers for active ingredients such as pesticides, micronutrients, and elicitors. The potential benefits of nanotechnology are considered, together with the role that NMs might play in future disease management and crop adaptation measures., (© The Author(s) 2019. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Abiotic stresses, including drought, salinity, temperature, and heavy metals, pose a major challenge for crop production and cause substantial yield reduction worldwide. Breeding tolerant cultivars against these abiotic stresses is the most sustainable and eco-friendly approach to cope with this challenge. Advances in genome editing technologies provide new opportunities for crop improvement by employing precision genome engineering for targeted crop traits. However, the selection of the candidate genes is critical for the success of achieving the desired traits. Broadly speaking, these genes could fall into two major categories, structural and regulatory genes. Structural genes encode proteins that provide stress tolerance directly, whereas regulatory genes act indirectly by controlling the expression of other genes involved in different cellular processes. Additionally, cis-regulatory sequences are also vital for achieving stress tolerance. We propose targeting of these regulatory and/or structural genes along with the cis-regulatory sequences via the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) system as a robust, efficient, and practical approach for developing crop varieties resilient to climate change. We also discuss the possibility of creating novel quantitative trait loci for abiotic stress tolerance via the CRISPR/Cas-mediated targeting of promoters. It is hoped that these genome editing tools will not only make a significant contribution towards raising novel plant types having tolerance to multiple abiotic stresses but will also aid in public acceptance of these products in years to come. This article is an attempt to critically evaluate the suitability of available tools and the target genes for obtaining plants with improved tolerance to abiotic stresses., (© The Author(s) 2019. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Camelina sativa has attracted much interest as alternative renewable resources for biodiesel, other oil-based industrial products and a source for edible oils. Its unique oil attributes attract research to engineering new varieties of improved oil quantity and quality. The overexpression of enzymes catalyzing the synthesis of the glycerol backbone and the sequential conjugation of fatty acids into this backbone is a promising approach for increasing the levels of triacylglycerol (TAG). In a previous study, we co-expressed the diacylglycerol acyltransferase (DGAT1) and glycerol-3-phosphate dehydrogenase (GPD1), involved in TAG metabolism, in Camelina seeds. Transgenic plants exhibited a higher-percentage seed oil content, a greater seed mass, and overall improved seed and oil yields relative to wild-type plants. To further increase seed oil content in Camelina, we utilized metabolite profiling, in conjunction with transcriptome profiling during seed development to examine potential rate-limiting step(s) in the production of building blocks for TAG biosynthesis., Results: Transcriptomic analysis revealed approximately 2518 and 3136 transcripts differentially regulated at significant levels in DGAT1 and GPD1 transgenics, respectively. These transcripts were found to be involved in various functional categories, including alternative metabolic routes in fatty acid synthesis, TAG assembly, and TAG degradation. We quantified the relative contents of over 240 metabolites. Our results indicate major metabolic switches in transgenic seeds associated with significant changes in the levels of glycerolipids, amino acids, sugars, and organic acids, especially the TCA cycle and glycolysis intermediates., Conclusions: From the transcriptomic and metabolomic analysis of DGAT1, GPD1 and DGAT1 + GPD1 expressing lines of C. sativa , we conclude that TAG production is limited by (1) utilization of fixed carbon from the source tissues supported by the increase in glycolysis pathway metabolites and decreased transcripts levels of transcription factors controlling fatty acids synthesis; (2) TAG accumulation is limited by the activity of lipases/hydrolases that hydrolyze TAG pool supported by the increase in free fatty acids and monoacylglycerols. This comparative transcriptomics and metabolomics approach is useful in understanding the regulation of TAG biosynthesis, identifying bottlenecks, and the corresponding genes controlling these pathways identified as limitations, for generating Camelina varieties with improved seed and oil yields.

Long- and short-term hydroponic experiments were conducted to study the effect of different concentrations of exogenous glutathione (GSH) on Pb uptake, translocation, and gene expresses in Iris lactea var. chinensis exposed to excess lead (Pb). Exogenous GSH remarkedly promoted Pb uptake and translocation in long-term (14 d) experiment, and the GSH-dose-dependent increases in shoot and root Pb contents existed obviously when GSH concentrations were lower than 800 mg·L -1 . The fresh weight in gradual rise in plants was observed with the increase of exogenous GSH concentration. In short-term (24 h) experiment, Pb contents in roots under Pb with L -buthionine sulfoximine (BSO, a known inhibitor of GSH biosynthesis) treatments were significantly lower than that under Pb exposure alone. The transcript levels of three genes (Ilγ-ECS, IlGS, and IlPCS) involved in GSH synthesis and metabolism, showed no significant change in expression pattern except that upregulation after 24 h of treatment with Pb and GSH in comparison with that of the single Pb treatment. Further, the level of IlGS transcript after exposure for 4 h was much higher than that of Ilγ-ECS and IlPCS transcripts. All these results obtained here suggest that exogenous GSH can increase Pb accumulation, detoxification, and translocation to the shoot.

This study investigated the growth, physiological changes, and the transcript levels of NHX1 gene of Iris halophila in response to low NaCl concentration (50 mM) and high NaCl concentration (150 mM). Our results showed that both 50 and 150 mM NaCl had no obvious negative effects on plant growth; what is more, low NaCl concentration (50 mM) increased root length, root fresh weight, and the ratio of root length to leaf length compared with the control group. The malondialdehyde (MDA) contents in leaves and roots of I. halophila had no obvious difference as compared with control. Proline levels of I. halophila exhibited basically an enhancement under salt stress conditions. Particularly at 4 days, the proline contents in leaves reached 1.85 to 2.31-fold higher and the contents in roots reached 1.27 to 1.62-fold higher than that of control at 50 and 150 mM NaCl, respectively. The contents of the soluble sugar in leaves and roots of I. halophila under 150 mM NaCl at 7 days were 32.4 and 98.7% higher than that of control, respectively. The increase rate of K + contents with the increasing concentration of salt was less than that of Na + contents, but K + contents in the seedlings under NaCl stress was still higher than Na + contents and the ratio of K + to Na + was also greater than 1. The transcript levels of IhNHX1 in leaves of I. halophila at 4 and 7 days under 150 mM NaCl were higher than that of control; however, the transcript levels of IhNHX1 in roots had no significant difference compared with the control under low and high salt stress at 1, 4, and 7 days. Therefore, salt tolerance in I. halophila could be partially due to higher proline, soluble sugar, and K + accumulation.