RESUMO

The global market of sweet potato (Ipomoea batatas (L.) Lam.) is continuously growing and, consequently, demands greater productivity from the agricultural sector. The use of biofertilizers facilitates plant growth by making essential nutrients available to crops or providing resistance against different abiotic and biotic factors. The strains Bacillus safensis T052-76 and Bacillus velezensis T149-19 have previously been inoculated in the sweet potato cultivar Ourinho, showing positive effects on plant shoot growth and inhibiting the phytopathogen Plenodomus destruens. To elucidate the effects of these strains on sweet potato growth, four different cultivars of sweet potato were selected: Capivara, IAPAR 69, Rosinha de Verdan and Roxa. The plants were grown in pots in a greenhouse and inoculated with the combined strains according to a randomized block design. A control (without the inoculation of both strains) was also used. A slight positive effect of the inoculation of the two Bacillus strains was observed on the aerial parts of some of the cultivars. An increase in the fresh weight of the sweet potatoes of the inoculated plants was obtained, varying from 2.7 to 11.4 %. The number of sweet potatoes obtained from the inoculated cultivars IAPAR 69 and Roxa increased 15.2 % and 16.7 %, respectively. The rhizosphere soil of each cultivar was further sampled for DNA extraction, and the 16S rRNA gene metabarcoding technique was used to determine how the introduction of these Bacillus strains influenced the rhizosphere bacterial community. The bacterial communities of the four different cultivars were dominated by Actinobacteria, Proteobacteria and Firmicutes. Nonmetric multidimensional scaling (NMDS) revealed that the rhizosphere bacterial communities of plants inoculated with Bacillus strains were more similar to each other than to the bacterial communities of uninoculated plants. This study highlights the contribution of these Bacillus strains to the promotion of sweet potato growth.

RESUMO

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.

RESUMO

Southern Chile native potatoes are an interesting raw material to produce novel snacks like colored potato chips. These novel products should be comprehensively evaluated for the presence of undesirable compounds such as acrylamide, 5-hydroxymethylfurfural and furan, the main neoformed contaminants in starchy rich fried foods. This study evaluated the neoformed contaminant levels and oil content on chips made from eleven Chilean potato accessions and compared them with commercial samples. The neoformed contaminant contents were related to Maillard reaction precursor levels (reducing sugars and asparagine) and secondary metabolites (phenolic compounds and carotenoids). Neoformed contaminants correlated well among them and were weakly correlated with reducing sugars and asparagine. Acrylamide level in native potato chips ranged from 738.2 to 1998.6 µg kg-1 while from 592.6 to 2390.5 µg kg-1 in commercial samples. Thus, there is need to implement neoformed contaminant mitigation strategies at different steps of the production chain of colored potato chips.

Assuntos

RESUMO

Blackleg and soft rot diseases represent a major threat to the health of potato (Solanum tuberosum) and other vegetable, ornamental and fruit crops worldwide; their main causal agents are species of Pectobacterium and Dickeya. In May 2022, 60% of potato plants (cv. Spunta) in a production field in Córdoba, Argentina (31°32'36''S 64°09'46''W) showed soft rot, blackleg and wilt. To isolate the causal agent, decayed plant tissues were disinfected in 2% NaClO, macerated in sterile water and streaked on crystal violet pectate (CVP) medium. Plates were incubated at 28°C for 48 h. Colonies that produced a pit on CVP medium were purified on nutrient agar. Two of the isolates, called 1Aia and 1B, were characterized by tests commonly employed for the identification of pectinolytic bacteria (Schaad et al. 2001). Both produced Gram-negative rods that were facultatively anaerobic, oxidase negative, nonfluorescent on King´s B, resistant to erythromycin and caused soft rot of potato slices. In addition, these isolates did not produce the blue pigment indigoidine and grew on nutrient glucose agar containing 5% NaCl. Phenotypic characteristics of the isolates 1Aia and 1B were compatible with Pectobacterium spp. Genomic DNA was extracted using the commercially available Wizard® Genomic DNA Purification Kit (Promega) according to the manufacturer's instructions for the purification of DNA from Gram-negative bacteria. The isolates were positive in a PCR assay for Pectobacterium brasiliense (Duarte et al. 2004). The purified DNA of isolate 1Aia was used to construct a pooled Illumina library, which was sequenced at the Genomics Unit from the National Institute of Agricultural Technology (INTA, Argentina), by using high-throughput Illumina sequencing technology. Average nucleotide identity (ANI) calculation performed by FastANI v0.1.3 (Jain et al. 2018) showed 96.11% identity between the genome of the type strain LMG 21371 of P. brasiliense (Acc. no. JQOE00000000) and our strain 1Aia (Acc. no. JAYGXQ000000000). For pathogenicity test, 3-weeks-old potato plants (cv. Spunta) planted in pots were infiltrated with 10 µl of a bacterial suspension (1x107 CFU/ml) 5 cm above the base of the stem using a sterile syringe. Negative controls were infiltrated with sterile water. Plants were kept under greenhouse conditions and regularly watered. The experiment was performed twice with six plants per treatment. Two days after inoculation, plants treated with P. brasiliense strain 1Aia or 1B showed necrotic lesions on the stems and tubers soft rot symptoms while control plants remained asymptomatic. To fulfill Koch´s postulates, bacteria were re-isolated from symptomatic plants. Re-isolated bacteria, called 1Aia d and 1B d, were confirmed as P. brasiliense according to biochemical and PCR results, as outlined above. Also, the % ANI value between P. brasiliense isolates 1Aia and 1Aia d was 99.99% (Acc. no. JAYGXR000000000). To our knowledge, this is the first report of the occurrence of P. brasiliense in Argentina. This pathogen has been observed causing blackleg and tuber soft rot on potato in Brazil (Duarte et al. 2004), Netherlands (Nunes Leite et al. 2014), Switzerland (de Werra et al. 2015), Russia (Voronina et al. 2019), Serbia (Loc et al. 2022) and USA (Zhang et al. 2023), among other countries worldwide. Due to the important economic and nutritional value of the crop, the distribution of P. brasiliense needs to be investigated and monitored in order to develop effective control strategies.

RESUMO

The evolution of new variants of plant pathogens is one of the biggest challenges to controlling and managing plant diseases. Of the forces driving these evolutionary processes, global migration events are particularly important for widely distributed diseases such as potato late blight, caused by the oomycete Phytophthora infestans. However, little is known about its migration routes outside North America and Europe. This work used genotypic data from population studies to elucidate the migration history originating the Colombian P. infestans population. For this purpose, a dataset of 1,706 P. infestans genotypes was recollected, representing North and South America, Europe, and Asia. Descriptive analysis and historical records from North America and Europe were used to propose three global migration hypotheses, differing on the origin of the disease (Mexico or Peru) and the hypothesis that it returned to South America from Europe. These scenarios were tested using approximate Bayesian computation. According to this analysis, the most probable scenario (posterior probability = 0.631) was the one proposing a Peruvian origin for P. infestans, an initial migration toward Colombia and Mexico, and a later event from Mexico to the United States and then to Europe and Asia, with no return to northern South America. In Colombia, the scenario considering a single migration from Peru and posterior migrations within Colombia was the most probable, with a posterior probability of 0.640. The obtained results support the hypothesis of a Peruvian origin for P. infestans followed by rare colonization events worldwide.

Assuntos

RESUMO

Severe typical deep-pitted lesions of Potato Common Scab (PCS) disease were observed in two locations in China, Dingxi, Gansu Province, and Shuozhou, Shaanxi Province, in 2021. Potato farms in Dingxi growing cultivar Huangxin 226 (26 hectares) exhibited a scab disease incidence of 10%, while cultivar Jinshu 15# (4 hectares) in Shuozhou showed a disease incidence of 30% (Fig. 1). During harvest, tubers displaying PCS symptoms were collected for pathogen isolation. To obtain pathogen isolates, surface-sterilized tuber tissue with scab lesions was ground in sterile water, serially diluted, and plated onto ISP5 agar medium plates (Handique et al. 2022). Five pure colonies of Streptomyces isolate were obtained, designated as ZRIMU1503, ZRIMU1502, ZRIMU1320, ZRIMU1321and ZRIMU791. Genomic DNA was extracted and sequenced using Illumina technology. Sequencing data of the 5 isolates were uploaded to NCBI GenBank and annotated (Accession numbers: JBBAYL010000000, JBBAYM010000000, JBBAYN010000000, JBBAYO010000000 and JBBAYP010000000, respectively) using the PGAP pipeline (Tatusova et al. 2016). Average Nucleotide Identity (ANI) values (97.52 %, 97.53 %,97.54 %,97.57 % and 97.52 %, respectively) indicated the identity of the five isolates to the type strain S. brasiliscabiei IBSBF 2867T. Additionally, pairwise comparisons of Digital DNA Hybridization (DDH) value (76.2%, 76.3%, 76.4%, 76.4% and 76.2% respectively) of all the Streptomyces type strains show the highest identity to S. brasiliscabiei IBSBF 2867T. Twelve housekeeping genes (acnA, atpD, dnaN, gap, gyrA, gyrB , infB, mdh, recA, rplB, rpoB, and trpB) were extracted from the genome sequence of the five isolates to construct a multi-locus sequence analysis (MLSA) tree. The evolutionary distance of the five isolates was constructed using MEGAX software (Kumar et al., 1994), along with other Streptomyces strains that are known to cause PCS. The resulting cladogram demonstrated the isolated strains clustered together with S. brasiliscabiei IBSBF 2867T (Fig.2). Koch's postulates were fulfilled by inoculating a perlite potting mix with spore suspensions of each isolate (104 CFU/ml), planting tubers (cv. Favorita), and reproducing PCS symptoms at harvest after three months. Negative control received water treatment. The plants were kept in greenhouse with 12 h of light per day and irrigated regularly. The experiment was repeated twice, once in April 2022 and again in April 2023. On harvest, all five isolates exhibited development of severe symptoms of PCS (Fig.1), while the negative controls had no lesions. The pathogen was reisolated from the lesions and confirmed to be identical to the original isolate by 16S rRNA gene sequences. To our knowledge, this is the first report of S. brasiliscabiei causing PCS in China. S. brasiliscabiei was identified as a new species to cause PCS in Brazil and was identified based on morphology, pathogenicity, and genetic features (Corrêa et al. 2021). Multiple pathogen-causing PCS has been recognized in China and a surge of disease incidence in potato fields has been reported (Handique et al. 2022; Wu et al. 2023). S. brasiliscabiei causes severe symptoms which makes potatoes unmarketable. The disease epidemiology of this pathogen needs to be investigated.

RESUMO

Background: Potato peel extract has demonstrated the ability to reduce platelet aggregation in vitro, suggesting its potential as a dietary intervention for preventing atherothrombotic disorders. Objective: This study aims to evaluate the impact of a potato peel-rich diet on platelet aggregation. Methods: A randomized, crossover-controlled, open two-period study was carried out with the participation of 12 healthy volunteers. Platelet aggregation was assessed before and after a seven-day dietary intervention. Participants consumed either a diet rich in potato peel (2 g/kg/d) or acetylsalicylic acid (ASA) as a reference (100 mg/d). Platelet aggregation percentages were measured following stimulation with arachidonic acid (AA, 150 µg/mL), adenosine diphosphate (ADP, 10 µM), and collagen (COL, 10 µg/mL). Results: The potato peel-rich diet resulted in a slight but significant reduction in platelet aggregation when stimulated with arachidonic acid compared to baseline values (85.0±2.0% vs. 91.3±1.7%, p<0.05). This effect was less pronounced than the reduction achieved with ASA (16±1.9%, p<0.001). Conclusion: The administration of a diet rich in potato peel reduces platelet aggregation induced by arachidonic acid, suggesting its potential role in the prevention of atherothrombotic disorders.

Introducción: El extracto de cáscara de patata ha demostrado su capacidad para reducir la agregación plaquetaria in vitro, lo que sugiere su potencial como intervención dietética para prevenir trastornos aterotrombóticos. Objetivo: Evaluar el impacto de una dieta rica en cáscara de patata en la agregación plaquetaria. Materiales y métodos: Se llevó a cabo un estudio aleatorizado, controlado, cruzado y abierto con la participación de 12 voluntarios sanos. Se evaluó la agregación plaquetaria antes y después de una intervención dietética de siete días. Los participantes consumieron una dieta rica en cáscara de patata (2 g/kg/d) o ácido acetilsalicílico (ASA) como referente (100 mg/d). Se midieron los porcentajes de agregación plaquetaria después de la estimulación con ácido araquidónico (AA, 150 µg/mL), difosfato de adenosina (ADP, 10 µM) y colágeno (COL, 10 µg/mL). Resultados: La dieta rica en cáscara de patata resultó en una ligera pero significativa reducción en la agregación plaquetaria cuando se estimuló con ácido araquidónico en comparación con los valores iniciales (85,0 ± 2,0% vs. 91,3 ± 1,7%, p <0,05). Este efecto fue menos pronunciado que la reducción lograda con ASA (16 ± 1,9%, p <0,001). Conclusión: La administración de una dieta rica en cáscara de patata reduce la agregación plaquetaria inducida por ácido araquidónico, lo que sugiere su papel potencial en la prevención de trastornos aterotrombóticos.

Assuntos

RESUMO

Potato soft rot caused by Pectobacterium spp. are devastating diseases of potato which cause severe economic losses worldwide. Pectobacterium brasiliense is considered as one of the most virulent species. However, the virulence mechanisms and pathogenicity factors of this strain have not been fully elucidated. Here, through pathogenicity screening, we identified two Pectobacterium brasiliense isolates, SM and DQ, with distinct pathogenicity levels. SM exhibits higher virulence compared to DQ in inducing aerial stem rot, blackleg and tuber soft rot. Our genomic and transcriptomic analyses revealed that SM encodes strain specific genes with regard to plant cell wall degradation and express higher level of genes associated with bacterial motility and secretion systems. Our plate assays verified higher pectinase, cellulase, and protease activities, as well as fast swimming and swarming motility in SM. Importantly, a unique endoglucanase S specific to SM was identified. Expression of this cellulase in DQ greatly enhances its virulence compared to wild type strain. Our study sheds light on possible determinants causing different pathogenicity of Pectobacterium brasiliense species with close evolutionary distance and provides new insight into the direction of genome evolution in response to host variation and environmental stimuli.

RESUMO

Soil infertility is a global problem, amendments such as organic fertilizers and mineral fertilizers are used to improve crop yields. However, these fertilizers contain heavy metals as well as essential mineral elements. The objective of the study was to determine the effect of organic and inorganic fertilizer on the accumulation and health risk of heavy metals in tubers. The plants were cultivated at an altitude of 3970 m using four treatments (poultry manure, alpaca manure, island guano and inorganic fertilizer) and a control group. Soil contamination levels and the degree of metal accumulation in the tubers were also determined. As a result, it was found that the use of inorganic fertilizer and poultry manure increased the values of Cu and Zn in soils, exceeding the recommended standards. The accumulation of heavy metals in potato tubers did not exceed the maximum recommended limits with the exception of Pb, which exceeded the limit allowed by the FAO/WHO (0.1 mg kg-1). Poultry manure contributed to the highest accumulation of Zn, Cu and Pb in tubers with 11.62±1.30, 3.48±0.20 and 0.12 ±0.02 mg kg-1 respectively. The transfer of metals from the soil to the tubers was less than 1. Individual and total non-carcinogenic risk values were less than 1, indicating a safe level of consumption for children and adults. The cancer risk was found to be within an acceptable range. However, poultry manure and inorganic fertilizer treatments had the highest total cancer risk values in both age groups, suggesting a long-term carcinogenic risk.

RESUMO

Potato and its wild relatives are distributed mainly in the Mexican highlands and central Andes of South America. The South American A-genome species, including cultivated potatoes, are reproductively isolated from Mexican diploid species. Whole-genome sequencing has disclosed genome structure and similarity, mostly in cultivated potatoes and their closely related species. In this study, we generated a chromosome-scale assembly of the genome of a Mexican diploid species, Solanum bulbocastanum Dun., using PacBio long-read sequencing, optical mapping, and Hi-C scaffolding technologies. The final sequence assembly consisted of 737.9 Mb, among which 647.0 Mb were anchored to the 12 chromosomes. Compared with chromosome-scale assemblies of S. lycopersicum (tomato), S. etuberosum (non-tuber-bearing species with E-genome), S. verrucosum, S. chacoense, S. multidissectum, and S. phureja (all four are A-genome species), the S. bulbocastnum genome was the shortest. It contained fewer transposable elements (56.2%) than A-genome species. A cluster analysis was performed based on pairwise ratios of syntenic regions among the seven chromosome-scale assemblies, showing that the A-genome species were first clustered as a distinct group. Then, this group was clustered with S. bulbocastanum. Sequence similarity in 1,624 single-copy orthologous gene groups among 36 Solanum species and clones separated S. bulbocastanum as a specific group, including other Mexican diploid species, from the A-genome species. Therefore, the S. bulbocastanum genome differs in genome structure and gene sequences from the A-genome species. These findings provide important insights into understanding and utilizing the genetic diversity of S. bulbocastanum and the other Mexican diploid species in potato breeding.

Assuntos

RESUMO

In this article we can observe the scanning by the literature for the pretreatment of steam explosion applied to lignocellulose biomass. A comparison of the chemical and physical characterization of potato peel as a lignocellulose biomass. Besides, the innovative design of a continuous reactor for the potato peel steam explosion process is shown, with specific temperature and pressure conditions on a pilot scale, detailing its parts. Finally, a finite element analysis was performed where stress results were obtained from the reactor material, severity factor, structural analysis and thermal analysis, providing a panorama of the reactor's behavior with the conditions specific.

Assuntos

RESUMO

Solanum tuberosum is one of the most widely cropped plant species worldwide; unfortunately, drought is one of the major constraints on potato productivity because it affects the physiology, biochemical processes, and yield. The use of arbuscular mycorrhizal fungi (AMF) has exhibited beneficial effects on plants during drought. The objective of this study was to analyse the effect of AMF inoculation on two genotypes of potato plants exposed to water stress, and the photosynthetic traits, enzymatic antioxidant activity, and exudation of low-molecular-weight organic acids (LMWOAs) of potato plants inoculated with two strains of AMF, Claroideoglomus claroideum (CC) and Claroideoglomus lamellosum (HMC26), were evaluated. Stomatal conductance exhibited a similar trend in the CC and HMC26 treatments for both potato genotypes; moreover, the photosynthetic rate significantly increased by 577.9% between the 100% soil humidity (S0) and 40% soil humidity (S2) stress levels for the VR808 genotype under the CC treatment. The activities of the enzymes catalase (CAT) and ascorbate peroxidase (APX) showed similar trends. In this study, there were different responses among genotypes and treatments. Inoculation with CC under S2 stress levels is a promising potential approach for improving potato growth under drought conditions.

RESUMO

This breeding project, initiated at the United States Potato Genebank (USPG) in collaboration with Peruvian partners Instituto Nacional de Innovacion Agraria (INIA), International Potato Center, Peru (CIP), and local farmers, sought to enhance cold hardiness and frost tolerance in native potato cultivars in Peru. The Andes and Altiplano are often affected by frost, which causes significant reduction in yield; creating varieties with superior resilience is a critical undertaking. The goal was to transfer outstanding non-acclimated cold tolerance and acclimation capacity found in wild potato species Solanum commersonii (cmm). Breeding families segregating for cold hardiness were created using (a) a somatic hybrid cmm + haploid Solanum tuberosum (tbr) (cv. Superior, US variety from Wisconsin) as male and (b) seven cultivars native to Peru of the species S. tuberosum sbsp. andigenum (adg) as females. All plant materials were part of the USPG germplasm collection. Sexual seeds of each family were sent to Peru for evaluations under the natural conditions of the Andean highlands and Altiplano. The plants were assessed for their response to frost, and genotypes showing exceptional tolerance were selected. Plants were also evaluated for good tuber traits and yield. Initial planting involving ~2,500 seedlings in five locations resulted in selecting 58 genotypes with exceptional frost tolerance, good recovery capacity after frost, and good tuber traits. Over the years, evaluations continued and were expanded to replicated field trials in the harsher conditions of the Altiplano (Puno). All trials confirmed consistency of frost tolerance over time and location, tuber quality, and yield. After 8 years, two advanced clones were considered for cultivar release because of their exceptional frost tolerance and superior field productivity that outyielded many of the established cultivars in the region. In November 2018, a new native cultivar named Wiñay, a Quechua word meaning "to grow" was released in Peru. In 2022, a second cultivar followed with the name Llapanchispaq (meaning "for all of us"). This project evidenced that a multinational and all-encompassing approach to deploy valuable genetic diversity can work and deliver effective results. This is even more significant when outcomes can promote food security and sustainability in very vulnerable regions of the world.

RESUMO

KEY MESSAGE: The shock produced by the allopolyploidization process on a potato interspecific diploid hybrid displays a non-random remobilization of the small RNAs profile on a variety of genomic features. Allopolyploidy, a complex process involving interspecific hybridization and whole genome duplication, significantly impacts plant evolution, leading to the emergence of novel phenotypes. Polyploids often present phenotypic nuances that enhance adaptability, enabling them to compete better and occasionally to colonize new habitats. Whole-genome duplication represents a genomic "shock" that can trigger genetic and epigenetic changes that yield novel expression patterns. In this work, we investigate the polyploidization effect on a diploid interspecific hybrid obtained through the cross between the cultivated potato Solanum tuberosum and the wild potato Solanum kurtzianum, by assessing the small RNAs (sRNAs) profile of the parental diploid hybrid and its derived allopolyploid. Small RNAs are key components of the epigenetic mechanisms involved in silencing by RNA-directed DNA Methylation (RdDM). A sRNA sequencing (sRNA-Seq) analysis was performed to individually profile the 21 to 22 nucleotide (21 to 22-nt) and 24-nt sRNA size classes due to their unique mechanism of biogenesis and mode of function. The composition and distribution of different genomic features and differentially accumulated (DA) sRNAs were evaluated throughout the potato genome. We selected a subset of genes associated with DA sRNAs for messenger RNA (mRNA) expression analysis to assess potential impacts on the transcriptome. Interestingly, we noted that 24-nt DA sRNAs that exclusively mapped to exons were correlated with differentially expressed mRNAs between genotypes, while this behavior was not observed when 24-nt DA sRNAs were mapped to intronic regions. These findings collectively emphasize the nonstochastic nature of sRNA remobilization in response to the genomic shock induced by allopolyploidization.

Assuntos

RESUMO

This work reports on the extraction and characterization of the behavior of starch from residues of several potato varieties (Criolla, Sabanera and Pastusa) of Colombian origin from the Andean region using different techniques and the evaluation of the effect of citric acid (CA) on the grain morphology. Additionally, films were produced with each one of the extracted starches and glycerol. Pastusa variety starch shows a higher granule size than the other varieties and Pastusa starch shows lower amylose content compared to Sabanera and Criolla. Criolla and Pastusa starches exhibit more thermal stability than Sabanera starch. Starch-glycerol films were also produced using the cast solving method. The films were mechanically analyzed by tensile test and the barrier properties were assessed by water vapor permeability (WVP). The tensile strength of the films varied in the 2.0-2.4 MPa range, while the elongation at break was comprised between 25 and 32 %. With regard to water vapor permeability, the obtained values fall within the 4-7 × 10-10 g m-1 s-1 Pa-1 range. It was observed that the thickness of the films and the protein content affected water vapor permeability, increasing this value at higher levels of thickness.

Assuntos

RESUMO

Artificial intelligence techniques are now widely used in various agricultural applications, including the detection of devastating diseases such as late blight (Phytophthora infestans) and early blight (Alternaria solani) affecting potato (Solanum tuberorsum L.) crops. In this paper, we present a mobile application for detecting potato crop diseases based on deep neural networks. The images were taken from the PlantVillage dataset with a batch of 1000 images for each of the three identified classes (healthy, early blight-diseased, late blight-diseased). An exploratory analysis of the architectures used for early and late blight diagnosis in potatoes was performed, achieving an accuracy of 98.7%, with MobileNetv2. Based on the results obtained, an offline mobile application was developed, supported on devices with Android 4.1 or later, also featuring an information section on the 27 diseases affecting potato crops and a gallery of symptoms. For future work, segmentation techniques will be used to highlight the damaged region in the potato leaf by evaluating its extent and possibly identifying different types of diseases affecting the same plant.

RESUMO

KEY MESSAGE: The first in-depth characterization of a subfamily III Snakin/GASA member was performed providing experimental evidence on promoter activity and subcellular localization and unveiling a role of potato Snakin-3 in defense Snakin/GASA proteins share 12 cysteines in conserved positions in the C-terminal region. Most of them were involved in different aspects of plant growth and development, while a small number of these peptides were reported to have antimicrobial activity or participate in abiotic stress tolerance. In potato, 18 Snakin/GASA genes were identified and classified into three groups based on phylogenetic analysis. Snakin-1 and Snakin-2 are members of subfamilies I and II, respectively, and were reported to be implicated not only in defense against pathogens but also in plant development. In this work, we present the first in-depth characterization of Snakin-3, a member of the subfamily III within the Snakin/GASA gene family of potato. Transient co-expression of Snakin-3 fused to the green fluorescent protein and organelle markers revealed that it is located in the endoplasmic reticulum. Furthermore, expression analyses via pSnakin-3::GUS transgenic plants showed GUS staining mainly in roots and vascular tissues of the stem. Moreover, GUS expression levels were increased after inoculation with Pseudomonas syringae pv. tabaci or Pectobacterium carotovorum subsp. carotovorum and also after auxin treatment mainly in roots and stems. To gain further insights into the function of Snakin-3 in planta, potato overexpressing lines were challenged against P. carotovorum subsp. carotovorum showing enhanced tolerance to this bacterial pathogen. In sum, here we report the first functional characterization of a Snakin/GASA gene from subfamily III in Solanaceae. Our findings provide experimental evidence on promoter activity and subcellular localization and reveal a role of potato Snakin-3 in plant defense.

Assuntos

RESUMO

Alcohol dehydrogenases (ADHs) catalyze the oxidation of alcohols and reduction of aldehydes and ketones. Primarily ADHs mitigate aldehydes and alcohol toxicity but they may also perform other functions. we listed all ADHs in the genome of strain BD163 of P. brasiliense submitted in www.ncbi.nlm.nih.gov. In total, 11 ADHs or alcohol dehydrogenase catalytic domain-containing proteins from the 4897858-length genome sequence of strain BD163 of P. brasiliense (GenBank JAKNTB000000000.1) were extracted, and when comparing with other strains, it was found that other P. brasiliense strains have similar or slightly different alcohol dehydrogenase capability. Still, other species had varying numbers of ADHs.

RESUMO

Using biopolymers functionalized with antibacterial agents to manufacture active packaging is a clean alternative to mitigate food losses due to postharvest plant diseases. In this study, two mycosynthetized AgNPs impregnation methodologies on cotton (cationization and in situ biochemical reduction) were used to obtain the antibacterial fibers (A-AgNPs-C and A-AgNPs-IBR), which, in addition to being characterized by SEM-EDX, XRD, were evaluated as antibacterial materials. The cotton fibers showed growth inhibition of Pectobacterium carotovorum at 48 h. The reuse tests of these cotton fibers showed that the two types of fibers could have up to three successive uses without losing their effectiveness, regardless of the impregnation method used. Is important to highlight that the retention tests indicated that the AgNPs remain attached to the A-AgNPs-C and A-AgNPs-IBR fibers after several successive washes. Finally, the mycosynthesized AgNPs were also impregnated on fique fibers (Fique-AgNPs) by cationization to obtain little antibacterial sacks. Nanostructured materials that in in vivo tests on potatoes showed only 7.8 % of affectation, while the tubers stored in the traditional sacks had an affectation of 25 %. This immobilization of AgNPs in natural fibers will allow the development of a nanobiotechnological application in the storage and transport of potatoes, after performing some additional cytotoxicity tests to guarantee its safety.

RESUMO

High Energy Ball-Milling (HEBM) modifies starchs' granule morphology, physicochemical properties, and chemical structure. However, understanding how the HEBM changes the starch chemical structure is necessary to control these modifications. Therefore, this study aimed to investigate the changes in potato starch's long- and short-range molecular order during HEBM at different environmental conditions such as oxygen (Air) and humidity content. Due to the correlation between the starch modification and the energy supplied (Esupp) by the HEBM, Burgio's equation was used to calculate this energy. The starch transformation was followed by X-ray diffraction, Fourier Transform-Infrared Spectroscopy, and Raman spectroscopy. A Principal Component Analysis (PCA) was conducted to reduce the HEBM variables. PAC analysis demonstrated that the different oxygen-humidity conditions do not affect the HEBM of potato starch. Based on the starch chemical structure transformation correlated with Esupp during HEBM, four stages were observed: orientation, modification, mechanolysis, and over-destruction. It was identified for the first time that at low milling energy (<1.5 kJ/g, orientation stage), the glycosidic rings change their orientation, and starch-water interaction increases while the starch's organization reduces. Ergo, the potato starch could be more susceptible to chemical modifications during the first two stages.

Assuntos