Molecular characterization of Pectobacterium atrosepticum infecting potato and its management through chemicals.

Potato farming is a vital component of food security and the economic stability especially in the under developing countries but it faces many challenges in production, blackleg disease caused by Pectobacterium atrosepticum (Pa) is one of the main reason for damaging crop yield of the potato. Effective management strategies are essential to control these losses and to get sustainable potato crop yield. This study was focused on characterizing the Pa and the investigating new chemical options for its management. The research was involved a systematic survey across the three district of Punjab, Pakistan (Khanewal, Okara, and Multan) to collect samples exhibiting the black leg symptoms. These samples were analyzed in the laboratory where gram-negative bacteria were isolated and identified through biochemical and pathogenicity tests for Pa. DNA sequencing further confirmed these isolates of Pa strains. Six different chemicals were tested to control blackleg problem in both vitro and vivo at different concentrations. In vitro experiment, Cordate demonstrated the highest efficacy with a maximum inhibition zones of 17.139 mm, followed by Air One (13.778 mm), Profiler (10.167 mm), Blue Copper (7.7778 mm), Spot Fix (7.6689 mm), and Strider (7.0667 mm). In vivo, Cordate maintained its effectiveness with the lowest disease incidence of 14.76%, followed by Blue Copper (17.49%), Air One (16.98%), Spot Fix (20.67%), Profiler (21.45%), Strider (24.99%), and the control group (43.00%). The results highlight Cordate's potential as a most effective chemical against Pa, offering promising role for managing blackleg disease in potato and to improve overall productivity.

Biocontrol potential and growth-promoting effect of endophytic fungus Talaromyces muroii SD1-4 against potato leaf spot disease caused by Alternaria alternata.

BACKGROUND: Alternaria alternata is the primary pathogen of potato leaf spot disease, resulting in significant potato yield losses globally. Endophytic microorganism-based biological control, especially using microorganisms from host plants, has emerged as a promising and eco-friendly approach for managing plant diseases. Therefore, this study aimed to isolate, identify and characterize the endophytic fungi from healthy potato leaves which had great antifungal activity to the potato leaf spot pathogen of A. alternata in vitro and in vivo. RESULTS: An endophytic fungal strain SD1-4 was isolated from healthy potato leaves and was identified as Talaromyces muroii through morphological and sequencing analysis. The strain SD1-4 exhibited potent antifungal activity against the potato leaf spot pathogen A. alternata Lill, with a hyphal inhibition rate of 69.19%. Microscopic and scanning electron microscope observations revealed that the strain SD1-4 grew parallel to, coiled around, shrunk and deformed the mycelia of A. alternata Lill. Additionally, the enzyme activities of chitinase and ß-1, 3-glucanase significantly increased in the hyphae of A. alternata Lill when co-cultured with the strain SD1-4, indicating severe impairment of the cell wall function of A. alternata Lill. Furthermore, the mycelial growth and conidial germination of A. alternata Lill were significantly suppressed by the aseptic filtrate of the strain SD1-4, with inhibition rates of 79.00% and 80.67%, respectively. Decrease of leaf spot disease index from 78.36 to 37.03 was also observed in potato plants treated with the strain SD1-4, along with the significantly increased plant growth characters including plant height, root length, fresh weight, dry weight, chlorophyll content and photosynthetic rate of potato seedlings. CONCLUSION: The endophyte fungus of T. muroii SD1-4 isolated from healthy potato leaves in the present study showed high biocontrol potential against potato leaf spot disease caused by A. alternata via direct parasitism or antifungal metabolites, and had positive roles in promoting potato plant growth.

Densovirus infection facilitates plant-virus transmission by an aphid.

The interactions among plant viruses, insect vectors, and host plants have been well studied; however, the roles of insect viruses in this system have largely been neglected. We investigated the effects of MpnDV infection on aphid and PVY transmission using bioassays, RNA interference (RNAi), and GC-MS methods and green peach aphid (Myzus persicae (Sulzer)), potato virus Y (PVY), and densovirus (Myzus persicae nicotianae densovirus, MpnDV) as model systems. MpnDV increased the activities of its host, promoting population dispersal and leading to significant proliferation in tobacco plants by significantly enhancing the titer of the sesquiterpene (E)-ß-farnesene (EßF) via up-regulation of expression levels of the MpFPPS1 gene. The proliferation and dispersal of MpnDV-positive individuals were faster than that of MpnDV-negative individuals in PVY-infected tobacco plants, which promoted the transmission of PVY. These results combined showed that an insect virus may facilitate the transmission of a plant virus by enhancing the locomotor activity and population proliferation of insect vectors. These findings provide novel opportunities for controlling insect vectors and plant viruses, which can be used in the development of novel management strategies.

Optimizing agricultural sustainability: enriched organic formulations for growth, yield, and soil quality in a multi-crop system.

Utilizing agricultural and industrial wastes, potent reservoirs of nutrients, for nourishing the soil and crops through composting embodies a sustainable approach to waste management and organic agriculture. To investigate this, a 2-year field experiment was conducted at ICAR-IARI, New Delhi, focusing on a pigeon pea-vegetable mustard-okra cropping system. Seven nutrient sources were tested, including a control (T1), 100% recommended dose of nitrogen (RDN) through farmyard manure (T2), 100% RDN through improved rice residue compost (T3), 100% RDN through a paddy husk ash (PHA)-based formulation (T4), 75% RDN through PHA-based formulation (T5), 100% RDN through a potato peel compost (PPC)-based formulation (T6), and 75% RDN through PPC-based formulation (T7). Employing a randomized block design with three replications, the results revealed that treatment T4 exhibited the significantly highest seed (1.89 ± 0.09 and 1.97 ± 0.12 t ha-1) and stover (7.83 ± 0.41 and 8.03 ± 0.58 t ha-1) yield of pigeon pea, leaf yield (81.57 ± 4.69 and 82.97 ± 4.17 t ha-1) of vegetable mustard, and fruit (13.54 ± 0.82 and 13.78 ± 0.81 t ha-1) and stover (21.64 ± 1.31 and 22.03 ± 1.30 t ha-1) yield of okra during both study years compared to the control (T1). Treatment T4 was on par with T2 and T6 for seed and stover yield in pigeon pea, as well as okra, and leaf yield in vegetable mustard over both years. Moreover, T4 demonstrated notable increase of 124.1% and 158.2% in NH4-N and NO3-N levels in the soil, respectively, over the control. The enhanced status of available nitrogen (N) and phosphorus (P) in the soil, coupled with increased soil organic carbon (0.41%), total bacteria population (21.1%), fungi (37.2%), actinomycetes (44.6%), and microbial biomass carbon (28.5%), further emphasized the positive impact of T4 compared to the control. Treatments T2 and T6 exhibited comparable outcomes to T4 concerning changes in available N, P, soil organic carbon, total bacteria population, fungi, actinomycetes, and microbial biomass carbon. In conclusion, treatments T4 and T6 emerge as viable sources of organic fertilizer, particularly in regions confronting farmyard manure shortages. These formulations offer substantial advantages, including enhanced yield, soil quality improvement, and efficient fertilizer utilization, thus contributing significantly to sustainable agricultural practices.

Preparation and characterization of intelligent and active bi-layer film based on carrageenan/pectin for monitoring freshness of salmon.

This work aimed to develop and characterize a novel bi-layer film (BIF) for monitoring the freshness of salmon. The indicator layer consists of carrageenan (Car), pectin (PEC) and purple sweet potato anthocyanin (PSPA), and the antibacterial layer consists of Car and magnolol (Mag). The results showed that the Car/Mag2 had the optimal water resistance: the static water contact angle of 80.36 ± 0.92 °, moisture content of 31.38 ± 0.86 %, swelling degree of 92.96 ± 0.46 %, and water solubility of 40.08 ± 1.17 %, and showed excellent antibacterial properties against E. coli and S. aureus with antibacterial rate of 86.13 % ± 0.10 % and 97.53 % ± 0.02 %, respectively. Then BIFs with different PSPA concentration were tested. The morphology, mechanical and water vapor properties (WVP) of the BIFs were studied, and its application in salmon preservation was evaluated. The mechanical properties and WVP test results showed that the BIF0.2 had the optimal Tensile strength (TS) and WVP values. The BIFs showed distinguishable color changes between the pH ranges of 3-10. The shelf life of salmon packaged by BIF0.2 was prolonged by 2 days. Moreover, the BIF0.2 was able to effectively monitor salmon freshness. In conclusion, the BIF has great potential for monitoring salmon meat freshness.

Investigating the Roles of Coat Protein and Triple Gene Block Proteins of Potato Mop-Top Virus Using a Heterologous Expression System.

Potato mop-top virus (PMTV) is an emerging viral pathogen that causes tuber necrosis in potatoes. PMTV is composed of three single-stranded RNA segments: RNA1 encodes RNA-dependent RNA polymerase, RNA2 contains the coat protein (CP), and RNA3 harbors a triple gene block (TGB 1, TGB2, and TGB3). CP plays a role in viral transmission, while TGB is known to facilitate cell-to-cell and long-distance systemic movement. The role of CP in symptom development, specifically in the presence of TGB genes, was investigated using potato virus X (PVX) as a delivery vehicle to express PMTV genes in the model plant Nicotiana benthamiana. Plants expressing individual genes showed mild symptoms that included leaf curling and crumpling. Interestingly, symptom severity varied among plants infected with three different combinations: CP with TGB1, CP with TGB2, and CP with TGB3. Notably, the combination of CP and TGB3 induced a hypersensitive response, accompanied by stunted growth and downward curling and crumpling. These results suggest the potential role of TGB co-expressed with CP in symptom development during PMTV infection. Additionally, this study demonstrates the use of the PVX-based expression system as a valuable platform for assessing the role of unknown genes in viral pathogenicity.

Hot air treatment alleviates chilling injury of sweet potato tuberous roots by regulating osmoregulatory substances and inducing antioxidant defense system.

Sweet potato tuberous roots are susceptible to chilling injury (CI) when stored below 10 °C. In this study, we investigated the mitigating effects of hot air (HA) treatment on CI. Results showed that HA45°C-3h treatment delayed the CI and internal browning during cold storage. After HA45°C-3h treatment, the cells' structural integrity was maintained, malondialdehyde accumulation and ion leakage were inhibited. Additionally, the osmoregulatory substances, such as total soluble solids, proline were maintained, and soluble protein was enhanced. Higher activity of antioxidant enzymes including superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase, and the antioxidant substances including ascorbic acid, glutathione, total phenols, and flavonoids were observed in sweet potato tuberous roots treated by HA45°C-3h than untreated group. Our study suggested that HA45°C-3h treatment could reduce CI and maintain a better quality of sweet potato tuberous roots following cold storage.

Biocontrol potential of endophytic fungi against phytopathogenic nematodes on potato (Solanum tuberosum L.).

Root-knot nematodes (RKNs) are a vital pest that causes significant yield losses and economic damage to potato plants. The use of chemical pesticides to control these nematodes has led to environmental concerns and the development of resistance in the nematode populations. Endophytic fungi offer an eco-friendly alternative to control these pests and produce secondary metabolites that have nematicidal activity against RKNs. The objective of this study is to assess the efficacy of Aspergillus flavus (ON146363), an entophyte fungus isolated from Trigonella foenum-graecum seeds, against Meloidogyne incognita in filtered culture broth using GC-MS analysis. Among them, various nematicidal secondary metabolites were produced: Gadoleic acid, Oleic acid di-ethanolamide, Oleic acid, and Palmitic acid. In addition, biochemical compounds such as Gallic acid, Catechin, Protocatechuic acid, Esculatin, Vanillic acid, Pyrocatechol, Coumarine, Cinnamic acid, 4, 3-indol butyl acetic acid and Naphthyl acetic acid by HPLC. The fungus was identified through morphological and molecular analysis, including ITS 1-4 regions of ribosomal DNA. In vitro experiments showed that culture filtrate of A. flavus had a variable effect on reducing the number of egg hatchings and larval mortality, with higher concentrations showing greater efficacy than Abamectin. The fungus inhibited the development and multiplication of M. incognita in potato plants, reducing the number of galls and eggs by 90% and 89%, respectively. A. flavus increased the activity of defense-related enzymes Chitinas, Catalyse, and Peroxidase after 15, 45, and 60 days. Leaching of the concentrated culture significantly reduced the second juveniles' stage to 97% /250 g soil and decreased the penetration of nematodes into the roots. A. flavus cultural filtrates via soil spraying improved seedling growth and reduced nematode propagation, resulting in systemic resistance to nematode infection. Therefore, A. flavus can be an effective biological control agent for root-knot nematodes in potato plants. This approach provides a sustainable solution for farmers and minimizes the environmental impact.

Genome-wide characterization of the GRF transcription factors in potato (Solanum tuberosum L.) and expression analysis of StGRF genes during potato tuber dormancy and sprouting.

Growth-regulating factors (GRFs) are transcription factors that play a pivotal role in plant growth and development. This study identifies 12 Solanum tuberosum GRF transcription factors (StGRFs) and analyzes their physicochemical properties, phylogenetic relationships, gene structures and gene expression patterns using bioinformatics. The StGRFs exhibit a length range of 266 to 599 amino acids, with a molecular weight of 26.02 to 64.52 kDa. The majority of StGRFs possess three introns. The promoter regions contain a plethora of cis-acting elements related to plant growth and development, as well as environmental stress and hormone response. All the members of the StGRF family contain conserved WRC and QLQ domains, with the sequences of these two conserved domain modules exhibiting high levels of conservation. Transcriptomic data indicates that StGRFs play a significant role in the growth and development of stamens, roots, young tubers, and other tissues or organs in potatoes. Furthermore, a few StGRFs exhibit differential expression patterns in response to Phytophthora infestans, chemical elicitors, heat, salt, and drought stresses, as well as multiple hormone treatments. The results of the expression analysis indicate that StGRF1, StGRF2, StGRF5, StGRF7, StGRF10 and StGRF12 are involved in the process of tuber sprouting, while StGRF4 and StGRF9 may play a role in tuber dormancy. These findings offer valuable insights that can be used to investigate the roles of StGRFs during potato tuber dormancy and sprouting.

Enhancing agricultural output: Investigating the impact of advanced organic formulations on crop productivity, nutrient use efficiency, and profitability in a multi-crop system.

The significance of integrating agricultural by-products such as paddy husk ash (PHA) and potato peels with organic fertilizers lies in enhancing soil fertility, increasing crop yields, and reducing reliance on traditional organic fertilizers like farmyard manure (FYM) or compost alone. Grounded in sustainable agriculture and nutrient management frameworks, this study examines the impact of diverse formulations derived from agricultural waste on productivity, nutrient efficiency, and profitability in a pigeon pea-vegetable mustard-okra cropping system. A two-year field experiment (2020-2022) at ICAR-IARI, New Delhi tested seven nutrient sources viz., (T1) control, (T2) 100% RDN through FYM, (T3) 100% RDN through improved RRC, (T4) 100% RDN through PHA based formulation, (T5) 75% RDN through PHA based formulation, (T6) 100% RDN through PPC based formulation and (T7) 75% RDN through PPC based formulation that were tested in RBD and replicated thrice. Treatment T4 had significant effect on seed yield of pigeon pea (1.89 ± 0.09 and 1.97 ± 0.12 t ha-1), leaf yield of vegetable mustard (81.57 ± 4.59 and 82.97 ± 4.17 t ha-1), and fruit yield of okra (13.54 ± 0.82 and 13.78 ± 0.81 t ha-1) grown in rotation, followed by treatment T6 and T2 during both the years respectively over control. Enhanced system uptake of N, P and K along with system gross and net returns in T4, showed increases of 78.9%, 83.8%, 72.4%, 54.4% and 56.8% in the first year and 77.5%, 80.8%, 77.7%, 54.8% and 57.4% in the second year, respectively, over control. Treatment T4 significantly improved apparent recovery by 66.3% and 69.2% in pigeon pea, 64.7% and 47.9% in vegetable mustard, and 72.7% and 79.4% in okra over T3, averaged across two years. Based on the above findings, (T4) 100% RDN through PHA-based formulation, and (T6) 100% RDN through PPC-based formulation can be recommended for areas with a shortage of FYM but availability of rice husk ash/potato peels for sustainable agricultural wastes and improved sustainability.

Investigating the involvement of potato (Solanum tuberosum L.) StPHR1 gene in the combined stress response to phosphorus deficiency and aluminum toxicity.

Phosphorus deficiency and aluminum toxicity in acidic soils are important factors that limit crop yield. To further explore this issue, we identified 18 members of the StPHR gene family in the potato genome in this study. Through bioinformatics analysis, we found that the StPHR1 gene, an important member of this family, exhibited high expression levels in potato roots, particularly under conditions of phosphorus deficiency and aluminum toxicity stress. This suggested that the StPHR1 gene may play a crucial regulatory role in potato's resistance to phosphorus deficiency and aluminum toxicity. To validate this hypothesis, we conducted a series of experiments on the StPHR1 gene, including subcellular localization, GUS staining for tissue expression, heterologous overexpression, yeast two-hybrid hybridization, and bimolecular fluorescence complementation (BiFC). The results demonstrated that the StPHR1 gene is highly conserved in plants and is localized in the nucleus of potato cells. The heterologous overexpression of the gene in Arabidopsis plants resulted in a growth phenotype that exhibited resistance to both aluminum toxicity and phosphorus deficiency. Moreover, the heterologous overexpressing plants showed reduced aluminum content in the root system compared to the control group. Furthermore, we also identified an interaction between StPHR1 and StALMT6. These results highlight the potential application of regulating the expression of the StPHR1 gene in potato production to enhance its adaptation to the dual stress of phosphorus deficiency and high aluminum toxicity in acidic soils.

N-terminal truncated trehalose-6-phosphate synthase 1 gene (△NIbTPS1) enhances the tolerance of sweet potato to abiotic stress.

Sweet potato [Ipomoea batatas (L.) Lam], the crop with the seventh highest annual production globally, is susceptible to various adverse environmental influences, and the study of stress-resistant genes is important for improving its tolerance to abiotic stress. The enzyme trehalose-6-phosphate synthase (TPS) is indispensable in the one pathway for synthesizing trehalose in plants. TPS is known to participate in stress response in plants, but information on TPS in sweet potato is limited. This study produced the N-terminal truncated IbTPS1 gene (△NIbTPS1) overexpression lines of Arabidopsis thaliana and sweet potato. Following salt and mannitol-induced drought treatment, the germination rate, root elongation, and fresh weight of the transgenic A. thaliana were significantly higher than that in the wild type. Overexpression of △NIbTPS1 elevated the photosynthetic efficiency (Fv/Fm) and the activity of superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase in sweet potato during drought and salt treatments, while reducing malondialdehyde and O2∙- contents, although expression of the trehalose-6-phosphate phosphatase gene IbTPP and trehalose concentrations were not affected. Thus, overexpressing the △NIbTPS1 gene can improve the stress tolerance of sweet potato to drought and salt by enhancing the photosynthetic efficiency and antioxidative enzyme system. These results will contribute to understand the functions of the △NIbTPS1 gene and trehalose in the response mechanism of higher plants to abiotic stress.

Accumulation patterns of flavonoids and phenolic acids in different colored sweet potato flesh revealed based on untargeted metabolomics.

Sweet potatoes are rich in flavonoids and phenolic acids, showing incomparable nutritional and health value. In this investigation, we comprehensively analyzed the secondary metabolite profiles in the flesh of different-colored sweet potato flesh. We determined the metabolomic profiles of white sweet potato flesh (BS), orange sweet potato flesh (CS), and purple sweet potato flesh (ZS) using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The CS vs. BS, ZS vs. BS, and ZS vs. CS comparisons identified a total of 4447 secondary metabolites, including 1540, 1949, and 1931 differentially accumulated metabolites. Among them, there were significant differences in flavonoids and phenolic acids. There were 20 flavonoids and 13 phenolic acids that were common differential metabolites among the three comparison groups. The accumulation of paeoniflorin-like and delphinidin-like compounds may be responsible for the purple coloration of sweet potato flesh. These findings provide new rationale and insights for the development of functional foods for sweet potatoes. List of compounds: Kaempferol (PubChem CID: 5280863); Peonidin 3-(6"-p-coumarylglucoside) (PubChem CID: 44256849); Swerchirin (PubChem CID: 5281660); Trilobatin (PubChem CID: 6451798); 3-Geranyl-4-hydroxybenzoate (PubChem CID: 54730540); Eupatorin (PubChem CID: 97214); Icaritin (PubChem CID: 5318980); Isorhamnetin (PubChem CID: 5281654); Glucoliquiritin apioside (PubChem CID: 74819335); Brazilin (PubChem CID: 73384).

Harnessing the health benefits of purple and yellow-fleshed sweet potatoes: Phytochemical composition, stabilization methods, and industrial utilization- A review.

Purple-fleshed sweet potato (PFSP) and yellow-fleshed sweet potato (YFSP) are crops highly valued for their nutritional benefits and rich bioactive compounds. These compounds include carotenoids, flavonoids (including anthocyanins), and phenolic acids etc. which are present in both the leaves and roots of these sweet potatoes. PFSP and YFSP offer numerous health benefits, such as antioxidant, anti-inflammatory, anti-cancer, and neuroprotective properties. The antioxidant activity of these sweet potatoes holds significant potential for various industries, including food, pharmaceutical, and cosmetics. However, a challenge in utilizing PFSP and YFSP is their susceptibility to rapid oxidation and color fading during processing and storage. To address this issue and enhance the nutritional value and shelf life of food products, researchers have explored preservation methods such as co-pigmentation and encapsulation. While YFSP has not been extensively studied, this review provides a comprehensive summary of the nutritional value, phytochemical composition, health benefits, stabilization techniques for phytochemical, and industrial applications of both PFSP and YFSP in the food industry. Additionally, the comparison between PFSP and YFSP highlights their similarities and differences, shedding light on their potential uses and benefits in various food products.

The integral role of de novo lipogenesis in the preparation for seasonal dormancy.

Animals can alter their body compositions in anticipation of dormancy to endure seasons with limited food availability. Accumulation of lipid reserves, mostly in the form of triglycerides (TAGs), is observed during the preparation for dormancy in diverse animals, including insects (diapause) and mammals (hibernation). However, the mechanisms involved in the regulation of lipid accumulation and the ecological consequences of failure to accumulate adequate lipid stores in preparation for animal dormancy remain understudied. In the broadest sense, lipid reserves can be accumulated in two ways: the animal either receives lipids directly from the environment or converts the sugars and amino acids present in food to fatty acids through de novo lipogenesis and then to TAGs. Here, we show that preparation for diapause in the Colorado potato beetle (Leptinotarsa decemlineata) involves orchestrated upregulation of genes involved in lipid metabolism with a transcript peak in 8- and 10-d-old diapause-destined insects. Regulation at the transcript abundance level was associated with the accumulation of substantial fat stores. Furthermore, the knockdown of de novo lipogenesis enzymes (ACCase and FAS-1) prolonged the preparatory phase, while the knockdown of fatty acid transportation genes shortened the preparatory phase. Our findings suggest a model in which the insects dynamically decide when to transition from the preparation phase into diapause, depending on the progress in lipid accumulation through de novo lipogenesis.

Evidence for human-caused founder effect in populations of Solanum jamesii at archaeological sites: II. Genetic sequencing establishes ancient transport across the Southwest USA.

PREMISE: The domestication of wild plant species can begin with gathering and transport of propagules by Indigenous peoples. The effect on genomic composition, especially in clonal, self-incompatible perennials would be instantaneous and drastic with respect to new, anthropogenic populations subsequently established. Reductions in genetic diversity and mating capability would be symptomatic and the presence of unique alleles and genetic sequences would reveal the origins and ancestry of populations associated with archaeological sites. The current distribution of the Four Corners potato, Solanum jamesii Torr. in the Southwestern USA, may thus reflect the early stages of a domestication process that began with tuber transport. METHODS: Herein genetic sequencing (GBS) data are used to further examine the hypothesis of domestication in this culturally significant species by sampling 25 archaeological and non-archaeological populations. RESULTS: Archaeological populations from Utah, Colorado and northern Arizona have lower levels of polymorphic loci, unique alleles, and heterozygosity than non-archaeological populations from the Mogollon region of central Arizona and New Mexico. Principle components analysis, Fst values, and structure analysis revealed that genetic relationships among archaeological populations did not correspond to geographic proximity. Populations in Escalante, Utah were related to those on the Mogollon Rim (400 km south) and had multiple origins and significant disjunctions with those populations in Bears Ears, Chaco Canyon, and Mesa Verde sites. CONCLUSIONS: Movement of tubers from the Mogollon region may have occurred many times and in multiple directions during the past, resulting in the complex genetic patterns seen in populations from across the Four Corners region.

Induction of necrosis symptoms by potato virus X in AGO2-silenced tomato plants associates with reduced transcript accumulation of copper chaperon for superoxide dismutase gene.

RNA silencing is a prominent antiviral defense mechanism in plants. When infected with a virus, RNA silencing-deficient plants tend to show exacerbated symptoms along with increased virus accumulation. However, how symptoms are exacerbated is little understood. Here, we investigated the role of the copper chaperon for superoxide dismutase (CCS) 1, in systemic necrosis observed in Argonaute (AGO)2-silenced tomato plants infected with potato virus X (PVX). While infection with the UK3 strain of PVX induced mosaic symptoms in tomato plants, systemic necrosis occurred when AGO2 was silenced. The CCS1 mRNA level was reduced and micro RNA398 (miR398), which potentially target CCS1, was increased in AGO2-knockdown tomato plants infected with PVX-UK3. Ectopic expression of CCS1 using recombinant PVX attenuated necrosis, suggesting that CCS1 alleviates systemic necrosis by activating superoxide dismutases to scavenge reactive oxygen species. Previous reports have indicated a decrease in the levels of CCS1 and superoxide dismutases along with an increased level of miR398 in plants infected with other viruses and viroids, and thus might represent shared regulatory mechanisms that exacerbate symptoms in these plants.

The synergistic effects of organic composts and microelements co-application in enhancing potato productivity in saline soils.

Soil salinity is a major threat hindering the optimum growth, yield, and nutritional value of potato. The application of organic composts and micronutrients can effectively ameliorate the salinity-deleterious effects on potato growth and productivity. Herein, the combined effect of banana and soybean composts (BCo and SCo) application alongside foliar supplementation of boron (B), selenium (Se), cobalt (Co), and titanium (Ti) were investigated for improving growth, physiology, and agronomical attributes of potato plants grown in saline alluvial soil. Salinity stress significantly reduced biomass accumulation, chlorophyll content, NPK concentrations, yield attributes, and tuber quality, while inducing malondialdehyde and antioxidant enzymes. Co-application of either BCo or SCo with trace elements markedly alleviated salinity-adverse effects on potato growth and productivity. These promotive effects were also associated with a significant reduction in malondialdehyde content and activities of peroxidase and superoxide dismutase enzymes. The co-application of BCo and B/Se was the most effective among other treatments. Principle component analysis and heatmap also highlighted the efficacy of the co-application of organic composts and micronutrients in improving the salinity tolerance of potato plants. In essence, the co-application of BCo with B and Se can be adopted as a promising strategy for enhancing the productivity of potato crops in salt-affected soils.

Nanoscopic Characterization of Starch-Based Biofilms Extracted from Ecuadorian Potato (Solanum tuberosum) Varieties.

Synthetic plastic polymers are causing considerable emerging ecological hazards. Starch-based biofilms are a potential alternative. However, depending on the natural source and extraction method, the properties of starch can vary, affecting the physicochemical characteristics of the corresponding casted films generated from it. These differences might entail morphological changes at the nanoscale, which can be explored by inspecting their surfaces. Potato (Solanum tuberosum) is a well-known tuber containing a high amount of starch, but the properties of the biofilms extracted from it are dependent on the specific variety. In this research, four Ecuadorian potato varieties (Leona Blanca, Única, Chola, and Santa Rosa) were analyzed and blended with different glycerol concentrations. The amylose content of each extracted starch was estimated, and biofilms obtained were characterized at both macroscopic and nanoscopic levels. Macroscopic tests were conducted to evaluate their elastic properties, visible optical absorption, water vapor permeability, moisture content, and solubility. It was observed that as the glycerol percentage increased, both moisture content and soluble matter increased, while tensile strength decreased, especially in the case of the Chola variety. These results were correlated to a surface analysis using atomic force microscopy, providing a possible explanation based on the topography and phase contrast observations made at the nanoscale.