Potato Tubers Research Articles

Multi-omics analysis reveals the effects of three application modes of plant growth promoting microbes biofertilizer on potato (Solanum tuberosum L.) growth under alkaline loess conditions

Potato is an important crop due to its high contents of starch, protein, and various vitamins and minerals. Biofertilizers are composed of plant growth promoting microbes (PGPMs) which are essential for improving the growth and resistance of potato. However, little information has focused on the modes of inoculation of biofertilizers on plant growth and microecology. This study aims to reveal the response mechanism of the potato to three modes of inoculation of biofertilizers all containing PGPM Bacillus amyloliquefaciens EZ99, i.e. scattered mode of 5 kg/ha biofertilizer (M5), soaking seed tubers with dissolved 5 kg/ha biofertilizer (MZG), and scattered mode of 3 kg/ha biofertilizer + 2 kg/ha sucrose (MY34) in alkaline loess field through multi-omics analysis of transcriptome, metabolome and microbiome. The physiological result revealed that two application modes of equal amount of biofertilizer M5 and MZG significantly improved the growth and yield of potatoes. Furthermore, the transcriptome of potato exhibited sets of differentially expressed genes enriched in photosynthesis, sugar metabolism, and phenylpropanoid biosynthesis among the three modes, with the M5 mode exhibiting overall up-regulation of 828 genes. Based on the untargeted metabolomic analysis of potato tuber, M5 mode significantly accumulated sucrose, while MZG and MY34 mode significantly accumulated the stress metabolites euchrenone b6 and mannobiose, respectively. Besides, the microbial structure of potato rhizosphere showed that the diversity of bacteria and fungi was similar in all soils, but their abundances varied significantly. Specifically, beneficial Penicillium was enriched in M5 and MZG soils, whereas MY34 soil accumulated potential pathogens Plectosphaerella and saccharophilic Mortierella. Collectively, these e findings highlight that MZG is the most effective mode to promote potato growth and stimulate rhizosphere effect. The present study not only encourages sustainable agriculture through agroecological practices, but also provides broad prospects for the application of PGPM biofertilizer in staple foods.

Metagenomic analysis of endophytic bacteria in seed potato (Solanum tuberosum).

To date, the association of potato tuber microbiota is poorly understood. In this study, the endophytic bacterial flora of seed potato tubers was identified and the diversity of healthy and unhealthy tubers was compared. Metagenomic DNA extracted from healthy and unhealthy samples of seed potato tubers was used for the analysis of microbial communities. Next generation sequencing of the ∼460 bp v3-v4 region of the 16S rRNA gene was carried out using the Illumina Miseq platform. The data were analysed using the Divisive Amplicon Denoising Algorithm 2 pipeline. Sequence analysis of the potato metagenome identified amplicon sequence variants (ASVs) assigned to 745 different taxa belonging to eight Phyla: Firmicutes (46.2%), Proteobacteria (36.9%), Bacteroidetes (1.8%), Actinobacteria (0.1%), Tenericutes (0.005%), Saccharibacteria (0.003%), Verrucomicrobiota (0.003%), and Acidobacteria (0.001%). In healthy seed potato tubers, 55-99% of ASVs belonged to Firmicutes, including Bacillus, Salinibacillus, Staphylococcus, Lysinibacillus, Paenibacillus, and Brevibacillus genera within the taxonomic order Bacillales. However, in the visually unhealthy tubers, only 0.5-3.9% of ASVs belonged to Firmicutes while 84.1-97% of ASVs belonged to Proteobacteria. This study highlights that diverse bacterial communities colonize potato tubers, which contributes to the understanding of plant-microbe interactions and underscores the significance of metagenomic approaches in agricultural research.

Physicochemical, Phytochemical and Antioxidant Properties of Organic Sweet Potato Flour and Its Application in Breadstick

Sweet potato flour (SPF) is used to produce food products worldwide due to good biological activity in the human diet and low cost. In this experiment, sweet potato tubers were processed into flour including purple-SPF, yellow-SPF and orange-SPF and applied in breadsticks. The proximate, physical, phytochemical and antioxidant properties of flour and breadsticks were investigated. The carbohydrate, moisture, ash, fat, protein and fiber contents of SPF ranged from 82.19 - 85.21, 4.12 - 5.78, 1.30 - 2.46, 0.32 - 0.86, 4.07 - 4.74 and 3.58 - 5.65 %, respectively. The water activity (aw) of SPF ranged from 0.2277 - 0.2695. The phytochemical analysis showed that purple-SPF and purple-SPF based breadstick products exhibited the highest total phenolic contents (TPC), total flavonoid contents (TFC) and total anthocyanin contents (TAC), while total carotenoid contents (TCC) was observed in both orange-SPF and breadstick made from orange-SPF. In addition, purple-SPF and breadstick produced from purple-SPF had the highest antioxidant activity against ABTS, FRAP, DPPH and metal chelating activity. The X-ray diffraction patterns of SPF samples showed a C-type crystal structure, with a crystallinity ranging from 19.43 - 31.05 %. The scanning electron micrographs of SPF granules revealed that they were mostly round and spherical, with a size range between 5 - 28 µm. The viscosity characteristics of yellow-SPF had the highest peak viscosity (307.97 ± 9.87 RVU), trough viscosity (200.81 ± 10.07 RVU), breakdown (108.42 ± 3.13 RVU), final viscosity (277.75 ± 8.60 RVU) and setback (76.95 ± 4.03 RVU). The physical quality showed breadstick from yellow-SPF had the highest hardness and fracturability with values of 11,537.67 ± 190.58 g and 11,143.33 ± 161.97 g, respectively. These results indicate that sweet potato flour composite breadstick has high phytochemical and antioxidant potential and may be applied in the food industry.

Research on Estimating Potato Fraction Vegetation Coverage (FVC) Based on the Vegetation Index Intersection Method

The acquisition of vegetation coverage information is crucial for crop field management, and utilizing visible light spectrum vegetation indices to extract vegetation coverage information is a commonly used method. However, most visible light spectrum vegetation indices do not fully consider the relationships between the red, green, and blue bands during their construction, making it difficult to ensure the accurate extraction of coverage information throughout the crop’s entire growth cycle. To rapidly and accurately obtain potato vegetation coverage information, drones were used in this study to obtain high-resolution digital orthoimages of potato growth stages. Based on the differences in the grayscale values of potato plants, soil, shadows, and drip irrigation belts, this study presents a combination index of blue and green bands (BGCI) and a combination index of red and green bands (RGCI). The vegetation index intersection method was used with 10 vegetation information indices to extract vegetation coverage, and the differences in extraction accuracy were compared with those of the maximum entropy method and bimodal histogram method. Based on the high-precision fraction vegetation coverage (FVC) extraction results, the Pearson correlation coefficient method and random forest feature selection were used to screen 10 vegetation and 24 texture features, and the top six vegetation indices most strongly correlated with the FVC were selected for potato growth stage FVC estimation and accuracy verification. A high-precision potato vegetation coverage estimation model was successfully established. This study revealed that during the potato tuber formation and expansion stages, the BGCI combined with the vegetation index intersection method achieved the highest vegetation coverage extraction accuracy, with overall accuracies of 99.61% and 98.84%, respectively. The RGCI combined with the vegetation index intersection method achieved the highest accuracy, 98.63%, during the maturation stage. For the potato vegetation coverage estimation models, the model based on the BGCI achieved the highest estimation accuracy (R2 = 0.9116, RMSE = 5.7903), and the RGCI also achieved good accuracy in terms of vegetation coverage estimation (R2 = 0.8987, RMSE = 5.8633). In the generality verification of the models, the R2 values of the FVC estimation models based on the BGCI and RGCI were both greater than 0.94. A potato vegetation coverage estimation model was constructed based on two new vegetation information indices, demonstrating good accuracy and universality.

Effects of Blended NPSZnB Fertilizer Rates on Yield and Quality Traits of Potato (<i>Solanum tuberosum</i> L) at Assosa District

Potato is ranked third after rice and wheat in terms of consumption in the world, and first among root and tuber crops. However, the production is limited by several factors including low in soil fertility, lack of improved varieties, inappropriate spacing, and other poor agronomic management. The objective of the present study is to recognize the optimum rate of the blended NPSZnB and potassium fertilizers for profitable production of potato at Assosa area. The experiment was laid out in RCBD with arrangement of split plot in three replications. The main plot consisted of two potato varieties i.e. Belete and Gudane varieties. The subplot consisted of four levels of blended NPSZnB with potassium chloride rates, one recommended NPK (nitrogen, phosphorus and potassium) and unfertilized plot. The interaction effects of potato tuber size distribution and quality traits were not significantly (P>0.05) affected by different rates of NPSZnB with adjusted nitrogen, phosphorus and potassium chloride fertilizers and different potato varieties. Out of different potato varieties, Belete variety gave the highest yield as compared to Gudane variety. The highest total tuber yield and large sized tuber yield were obtained by the application of 200% NPSZnB (35.4N+70.6P<sub>2</sub>O<sub>5</sub>+15.2S+0.5B+4.4Zn) +138 kg<sub> </sub>K<sub>2</sub>O ha<sup>-1</sup>, with adjusted 184.6kg N+ 109.6kg P<sub>2</sub>O<sub>5 </sub>per ha therefore, we are tentatively recommended for beneficiaries at Assosa area.

StSnRK1.1 protein kinase positively regulates tuber dormancy release of potato

SnRK1 is a plant-specific serine/threonine protein kinase, that plays a vital role in maintaining the energy balance, nutrient distribution, growth, and development of organisms for survival. The period of tuber dormancy seriously affects potato production. To elucidate the effect of the StSnRK1.1 gene on dormancy release, the gene was cloned from the potato cultivar 'Desiree', and the overexpression and interfering expression lines were obtained through genetic transformation. StSnRK1.1 promoted early dormancy release and sprouting of potato tubers in the overexpression line, while it delayed tuber sprouting in the StSnRK1.1-interfering expression line. In addition, it was discovered that abscisic acid (ABA) in the StSnRK1.1 overexpression line was significantly reduced compared with the wild type plants, while the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were increased. Conversely, the opposite result was found in the StSnRK1.1 gene interference expression line, which indicated that the dormancy release was accelerated, the reactive oxygen species metabolism efficiency was high, and the reactive oxygen species could be quickly removed and the accumulation of reactive oxygen species could be avoided during the dormancy release process. The positive regulatory genes StSnRK2.2 and StABI5 of ABA signal transduction were lower than those of wild type in the overexpression line and higher than that of the wild type in the interfering expression line, while the negative regulatory genes StPP2CA1 and StPP2CA3 of ABA signal transduction were higher than those of the wild type in the overexpression line and lower than that of the wild type in the interfering expression line. In summary, StSnRK1.1 affects ABA signaling by mediating the expression of StSnRK2.2, StABI5, StPP2CA1 and StPP2CA3, which provides a theoretical basis for the molecular mechanism of StSnRK1.1 to positively regulate the release of potato tuber dormancy. Through yeast two-hybrid (YH2) screening, two interacting proteins, StCAT3 and StFBA1, were identified. The interaction between StCAT3, StFBA1 and StSnRK1.1 was confirmed through bimolecular fluorescence complementation. These results provide novel information for further study on the molecular mechanism of StSnRK1.1 regulating dormancy and germination of potato tubers.

Elevated Carbon Dioxide only Partly Alleviates the Negative Effects of Elevated Temperature on Potato Growth and Tuber Yield

Elevated Carbon Dioxide only Partly Alleviates the Negative Effects of Elevated Temperature on Potato Growth and Tuber Yield

Methods to Induce Sprouting in Dormant Potato Tubers for Direct Tuber Testing of Potato Virus Y

The ability to initiate sprouting soon after harvest to enable direct tuber testing for potato virus Y (PVY) could aid in acquiring more rapid results compared to the traditional winter grow out tests currently used. Methods to break dormancy for PVY detection using laboratory direct tuber testing by ELISA in commercially produced Ranger Russet, Clearwater Russet, and Umatilla Russet seed lots were tested over two years and compared to leaf testing results obtained from the winter grow out and spring grow out. At harvest, three 400 tuber samples from each cultivar were obtained for the trial and included (1) untreated control (UTC), (2) application of cold aerosol smoke, or (3) application of Rindite. Tuber samples were held at 18.3 C and sprout development was monitored weekly. Treatments were direct tuber tested for PVY when one treatment of that cultivar achieved three sprouts elongating to six millimeters. A fourth 400 tuber sample was collected, treated with Rindite, and included in the Idaho winter grow out plots in Waialua, Hawaii and leaves were sampled and evaluated for PVY using ELISA. Laboratory tested seed was stored and planted in a spring grow out (Kimberly, Idaho) and leaf samples were analyzed for PVY by ELISA. Rindite treated tubers had greater sprout rating and number of sprouts elongating compared to UTC tubers and tubers receiving the smoke treatment at time of PVY testing. Smoke had a greater sprout rating but did not always significantly differ in the number of sprouts elongating compared to the untreated tubers. Overall, estimates of PVY prevalence from direct tuber testing showed limited significant differences to those obtained in the winter grow out for each cultivar, year, and PVY incidence. However, in year two, the incidence of PVY in the winter grow out (7% PVY) significantly differed from direct tuber testing (16% PVY) in Ranger Russet. In both years, the spring grow out PVY results for all cultivars were not significantly different than the direct tuber testing, except in year one the Ranger Russet direct tuber tested UTC showed 10% lower PVY detection compared to the spring grow out. This study identified a novel dormancy breaking treatment to promote earlier and accurate PVY detection by direct tuber testing using ELISA and provided data to support direct tuber testing for post-harvest evaluation of PVY in seed certification.

Virulence determinants are unevenly distributed within Streptomyces species and strains causing potato common scab in the province of Quebec, Canada.

Potato common scab is an important bacterial disease afflicting potatoes around the world. Better knowledge of the local Streptomyces spp. populations causing this disease is key to developing durable control strategies. In this study, we isolated 230 Streptomyces strains from scab-infected potato tubers harvested from commercial potato fields located across the province of Quebec, Canada. The genetic diversity of this collection was first studied using repetitive element-based PCR fingerprinting, and the genomes of 36 representative strains were sequenced using PacBio's sequencing technology. This enabled us to identify the strains to the species level, to study the distribution of previously characterized virulence-associated genes and clusters, and to explore the repertoires of putative plant cell wall-degrading enzymes. In parallel, the virulence of the 36 strains was evaluated using a potato tuber slice assay. The diversity was higher than previously reported, as eleven phytopathogenic species were found across the province. Among them, S. scabiei and S. acidiscabies were the most abundant as well as the most virulent. Strains belonging to these two species harbored numerous virulence determinants, including the thaxtomin biosynthetic gene cluster. By contrast, most weakly virulent strains lacked this cluster but harbored at least one known virulence determinant. The results obtained suggest that a higher number of virulence-associated genes and clusters in the genome of phytopathogenic Streptomyces spp. is associated with greater virulence. This study contributes to increasing the publicly available genomic resources of scab-causing Streptomyces spp., and expand our knowledge on the diversity and virulence of this important bacterial pathogen.

Heat stress reprograms herbivory-induced defense responses in potato plants

Climate change is predicted to increase the occurrence of extreme weather events such as heatwaves, which may thereby impact the outcome of plant-herbivore interactions. While elevated temperature is known to directly affect herbivore growth, it remains largely unclear if it indirectly influences herbivore performance by affecting the host plant they feed on. In this study, we investigated how transient exposure to high temperature influences plant herbivory-induced defenses at the transcript and metabolic level. To this end, we studied the interaction between potato (Solanum tuberosum) plants and the larvae of the potato tuber moth (Phthorimaea operculella) under different temperature regimes. We found that P. operculella larvae grew heavier on leaves co-stressed by high temperature and insect herbivory than on leaves pre-stressed by herbivory alone. We also observed that high temperature treatments altered phylotranscriptomic patterns upon herbivory, which changed from an evolutionary hourglass pattern, in which transcriptomic responses at early and late time points after elicitation are more variable than the ones in the middle, to a vase pattern. Specifically, transcripts of many herbivory-induced genes in the early and late defense stage were suppressed by HT treatment, whereas those in the intermediate stage peaked earlier. Additionally, we observed that high temperature impaired the induction of jasmonates and defense compounds upon herbivory. Moreover, using jasmonate-reduced (JA-reduced, irAOC) and -elevated (JA-Ile-elevated, irCYP94B3s) potato plants, we showed that high temperature suppresses JA signaling mediated plant-induced defense to herbivore attack. Thus, our study provides evidences on how temperature reprograms plant-induced defense to herbivores.

A novel genus of Pectobacterium bacteriophages display broad host range by targeting several species of Danish soft rot isolates

The bacterial diseases black leg and soft rot in potatoes cause heavy losses of potatoes worldwide. Bacteria within the genus Pectobacteriaceae are the causative agents of black leg and soft rot. The use of antibiotics in agriculture is heavily regulated and no other effective treatment currently exists, but bacteriophages (phages) have shown promise as potential biocontrol agents. In this study we isolated soft rot bacteria from potato tubers and plant tissue displaying soft rot or black leg symptoms collected in Danish fields. We then used the isolated bacterial strains as hosts for phage isolation. Using organic waste, we isolated phages targeting different species within Pectobacterium. Here we focus on seven of these phages representing a new genus primarily targeting P. brasiliense; phage Ymer, Amona, Sabo, Abuela, Koroua, Taid and Pappous. TEM image of phage Ymer showed siphovirus morphotype, and the proposed Ymer genus belongs to the class Caudoviricetes, with double-stranded DNA genomes varying from 39 kb to 43 kb. In silico host range prediction using a CRISPR-Cas spacer database suggested both P. brasiliense, P. polaris and P. versatile as natural hosts for phages within the proposed Ymer genus. A following host range experiment, using 47 bacterial isolates from Danish tubers and plants symptomatic with soft rot or black leg disease verified the in silico host range prediction, as the genus as a group were able to infect all three Pectobacterium species. Phages did, however, primarily target P. brasiliense isolates and displayed differences in host range even within the species level. Two of the phages were able to infect two or more Pectobacterium species. Despite no nucleotide similarity with any phages in the NCBI database, the proposed Ymer genus did share some similarity at the protein level, as well as gene synteny, with currently known phages. None of the phages encoded integrases or other genes typically associated with lysogeny. Similarly, no virulence factors nor antimicrobial resistance genes were found, and combined with their ability to infect several soft rot-causing Pectobacterium species from Danish fields, demonstrates their potential as biocontrol agents against soft rot and black leg diseases in potatoes.

Nutritional Value of Coloured Flesh Potato Tubers in Terms of Their Micronutrient Content

The aim of this study was to compare Fe, Zn, Mn, Al and Li contents in table potato tubers, obtained from seven potato cultivars with different flesh colour, and one cultivar characterised by light-coloured flesh. The study material consisted of potato tubers produced in a one-factor field experiment carried out at the Agricultural Experimental Station in Zawady belonging to the University of Siedlce, Poland (52°03′ N, 22°33′ E) in 2021–2023. The following cultivars were tested: Eurostar (light yellow flesh), Rote Emmalie and Herbie 26 (red flesh), Provita, Salad Blue, Blaue Annelise, Vitelotte Noire and Bora Valley (purple and blue flesh). The study showed that the genetic characteristics of the cultivars determined the nutrient content and uptake with tuber yield. Of the tested minerals which are important for human nutrition (Fe, Zn, Mn), red and purple cultivars accumulated more Fe than the light yellow-fleshed Eurostar. Zn content was the highest in red-fleshed cultivars compared with light and purple-fleshed cultivars. Mn content was the highest in the tubers of the light yellow-fleshed Eurostar and lowest in red Rote Emmalie. Fe, Zn, Mn and Al contents and uptake with tuber yield were influenced by weather conditions during the growing season.

Small soil wetted proportion and emitter flow rate of drip irrigation enhance potato yield by improving soil water and aeration in the sandy loam in arid Northwest China

Creating an ideal soil microclimate through appropriate drip irrigation management practices is crucial for enhancing potato production. Field experiments were conducted during 2021 and 2022 in Wuwei, Gansu Province, Northwest China, with two soil wetted proportion levels (P1: 35 %, and P2: 55 %) and three emitter flow rates (F1: 1.3 L/h, F2: 2.0 L/h, and F3: 3.0 L/h). Results showed that for the same soil wetted proportion, soil water content was reduced in the 0–20 cm soil layer and increased in the 20–40 cm for F1 compared to F2 and F3, with no differences in the 40–60 cm depth. During the tuber initiation and bulking stages, the soil wetted proportion P1 increased soil oxygen saturation by 2.8 % and 0.7 % and reduced CO2 concentration by 26.7 % and 19.2 % in 2021 and 2022, respectively, compared to P2 in the 20–40 cm soil layer. The emitter flow rate F1 exhibited significantly greater soil oxygen (0.7–4.6 %) and lower CO2 concentration (16–46 %) than F2 and F3 in the 0–20 cm. Soil oxygen was significantly higher (0.5–2.1 %) and CO2 concentration was significantly lower (10–39 %) in the 20–40 cm in F1 than in F3. In the 0–40 cm soil layer, both the highest soil oxygen concentration and lowest CO2 concentration were observed for the P1F1 combination. The soil wetted proportion P1 increased average yield by 5.6 % in 2021 and 11.9 % in 2022 compared to P2, while F2 and F3 reduced yield by 2.4 % and 4.6 % in 2021, 4.1 % and 13.8 % in 2022 compared to F1. The soil wetted proportion P2 promoted source growth compared to P1 but limited sink expansion. Source capacity, sink growth, and average tuber growth rates decreased from F1 to F3. Overall, the 35 % soil wetted proportion and 1.3 L/h emitter flow rate are recommended for potato cultivation in sandy loam. This study clarified the importance of coordinating soil water and aeration by drip irrigation management to improve potato tuber production.

Heterologous expression of distinct insecticidal genes in potato cultivars encodes resistance against potato tuber moth, Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae)

AbstractThe potato tuber moth, Phthorimaea operculella (Zeller), is a notorious insect pest of potato incurring substantial yield losses in the field as well as in storage. Chemical control is difficult to exercise due to the latent feeding of the caterpillars and their ability to develop resistance against insecticides. One of the essential components of efficient insect-resistant management is using two or more different insecticidal genes in transgenic crops to effectively avoid and delay the resistance development in insect pests. Two constructs, namely DS-1 (cry3A + SN-19 genes) and DS-2 (OCII + SN-19 genes) in pCAMBIA1301 binary vector, were developed and were transformed in potato cultivars (Agria and Lady Olympia) via Agrobacterium-mediated transformation. The molecular analysis confirmed gene integration and expression of the introduced genes in transgenic plants. The insecticidal effects of incorporated genes in transgenic plants were assessed against 1st, 2nd, 3rd, and 4th instar potato tuber moth (PTM) larvae. The transgenic plants endured significantly high mortalities (100%) of larval stages of PTM within 72 h. Our results show that these transgenic potato plants have the potential to control populations of PTM and are also useful tools in managing PTM that would ultimately reduce the dependency on conventional chemical pesticides with potentially less or minimal hazards. These lines can also serve as an excellent source of germplasm for potato breeding program.

Encapsulated predatory bacteria efficiently protect potato tubers from soft rot disease.

Soft rot Pectobacteriaceae (SRP) are a group of destructive Gram-negative phytopathogens that can infect a wide range of plant hosts, including potatoes. There are no effective control agents available against SRP, making their management challenging. We have developed a novel approach to protect potato tubers against SRP. It makes use of encapsulated predatory Bdellovibrio bacteriovorus bacteria that upon release from a polymeric carrier, prey upon SRP. We applied a carrageenan-trehalose-based formulation containing a B. bacteriovorus HD100 predator to prevent soft-rot disease development in potato tubers, under various conditions. The dried formulation exhibited very high stability over an eighteen-month period at room temperature (˜25ºC), in contrast to unencapsulated suspensions of the predator, in which viability decreased rapidly below detection level. The rehydrated formulation was as efficient as freshly grown unencapsulated predators, and provided high protection in potted potato tubers, displaying an average of 50% reduction in disease parameters (e.g. tissue decay and disease index) under controlled conditions at 7-days post-inoculation and planting. The protective effect provided by this formulation was maintained in longer-term trials (28 days) conducted in larger vessels within a net-house under natural climate conditions, highlighting its potential for practical application in the field.

Chitosan as an Antimicrobial, Anti-Insect, and Growth-Promoting Agent for Potato (Solanum tuberosum L.) Plants.

A growing trend in plant protection is replacing chemical preparations with environmentally friendly biological compositions. Chitosan, due to its biocompatibility, biodegradability, and bioactivity, is an effective agent against plant diseases. The purpose of the study was to evaluate chitosan as a potential biopesticide for potato plants. Three variants of chitosan were tested: high (310-375 kDa, >75% deacetylated), medium (190-310 kDa, 75-85% deacetylated), and low (50-190 kDa, 75-85% deacetylated) molecular weight. The chitosan variants were dissolved in lactic and succinic acids and tested for antibacterial and antifungal properties against eight strains of mould and two strains of bacteria responsible for potato diseases. The possible cytotoxicity of chitosan was evaluated against different cell lines: insect Sf-9, human keratinocyte HaCaT, and human colon carcinoma Caco-2. The bioprotective activities of the chitosan were also evaluated in situ on potato tubers. Chitosan inhibited the growth of almost all the selected phytopathogens. The most active was medium molecular chitosan in lactic acid. This formula was characterized by low toxicity towards human cells and high toxicity towards Sf-9 cells. It was also found to have positive effects on the growth of stems and roots, gas exchange, and chlorophyll index in potato plants. Selected chitosan formulation was proposed as a functional biopesticide for potato protection against phytopathogens.

Genome-wide identification and expression analysis of the CONSTANS-like family in potato (Solanum tuberosum L.).

The CONSTANS-like (COL) gene plays important roles in plant growth, development, and abiotic stress. A total of 15 COL genes are unevenly distributed on eight chromosomes in the potato genome. The amino acid length of the family members was 347-453 aa, the molecular weight was 38.65-49.92 kD, and the isoelectric point was 5.13-6.09. The StCOL family can be divided into three subfamilies by evolutionary tree analysis, with conserved motifs and similar gene structure positions in each subfamily. The analysis of promoter cis-acting elements showed 17 cis-acting elements related to plant hormones, stress, and light response. Collinearity analysis of COL genes of tomato, potato, and Arabidopsis showed that 13 StCOL genes in the different species may have a common ancestor. A total of 10 conserved motifs and six kinds of post-translational modifications in the 15 StCOL proteins were identified. The 15 StCOL genes exhibit a genomic structure consisting of exons and introns, typically ranging from two to four in number. The results showed that 10 genes displayed significant expression across all potato tissues, while the remaining five genes were down-expressed in potato transcriptome data. The quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis exhibited differential expression of 8 StCOL genes in the potato leaves and tubers at different growth stages, as well as 7 StCOL genes under 2°C treatment conditions. These results suggested that the StCOL gene family may play an important role in regulating potato tuberization and responding to cold stress.

Transcriptomics Identifies Differentially Expressed Genes Inducing Tuber Formation in Early- and Late-Maturing Potatoes.

The timing of potato tuberization is affected by potato ripeness, environmental factors, and polygene regulation. The accurate control of the transition to tuberization has both scientific and practical production value, but the key factors regulating this transition remain unclear. This study grafted an early-maturing potato variety (Favorita) scion to the late-maturing Qingshu 9 variety and demonstrated that a heterologous early-maturing scion can induce early potato formation on a late-maturing rootstock. The transcriptome of functional leaves and stolons of grafted plants was comprehensively analyzed and 593 differentially expressed genes (DEGs) were identified, including 38 transcription factors. Based on gene molecular function analysis and previous reports, we propose that PIF5, bHLH93, CBF3, ERF109, TCP19, and YABBY1 are the key DEGs that induce tuber formation in early- and late-maturing potatoes. The YABBY1 gene was subjected to functional verification. The leaf area of StYABBY1-overexpressing plants was smaller than the wild type and no potato tubercles were formed, while an RNA interference plant line showed no change in leaf area and formed tubers, indicating that StYABBY1 has a role in leaf size regulation and tuber formation.

Identification of iodothyronines in plant tissues

It has become widespread knowledge that many signaling molecules are common to organisms of different groups. This is likely to be valid for such important metabolism regulators as iodothyronines. A number of studies have confirmed the presence of thyroid hormone activity in compounds of plant origin. However, these studies do not explain whether the compounds under consideration are iodine derivatives of thyronine, similar to animal and human thyroid hormones, or whether they are mimetics of thyroid hormones. In this work, we aim to verify the presence of iodothyronine analogs with different degrees of iodization in plant tissues. We also aim to determine iodine concentrations in plant tissue lysates and to compare them with the theoretically calculated values in order to test the assumption about the identity of their structure to human thyroid hormones. It was shown that tetraiodothyronine (T4) and triiodothyronine (T3) analogs are simultaneously present in potato tubers and wheat leaves. In potato tubers at dormancy, the concentration of T4 was 118 ± 16 nmol/L (n = 15), while the concentration of T3 in the same samples was 4.01 ± 0.96 nmol/L. T4 and T3 concentrations in wheat leaf lysates were 60.24 ± 79 and 6.76 nmol/L (n = 15), respectively. According to the results of inductively coupled plasma mass spectrometry, the studied samples contain iodine in the amounts consistent with the assumption about the presence of tetraiodinated tyronine derivatives.

Potato Berries as a Valuable Source of Compounds Potentially Applicable in Crop Protection and Pharmaceutical Sectors: A Review.

Potato (Solanum tuberosum) is a major agricultural crop cultivated worldwide. To meet market demand, breeding programs focus on enhancing important agricultural traits such as disease resistance and improvement of tuber palatability. However, while potato tubers get a lot of attention from research, potato berries are mostly overlooked due to their level of toxicity and lack of usefulness for the food production sector. Generally, they remain unused in the production fields after harvesting the tuber. These berries are toxic due to high levels of glycoalkaloids, which might confer some interesting bioactivities. Berries of various solanaceous species contain bioactive secondary metabolites, suggesting that potato berries might contain similarly valuable metabolites. Therefore, possible applications of potato berries, e.g., in the protection of plants against pests and pathogens, as well as the medical exploitation of their anti-inflammatory, anticarcinogenic, and antifungal properties, are plausible. The presence of valuable compounds in potato berries could also contribute to the bioeconomy by providing a novel use for otherwise discarded agricultural side streams. Here we review the potential use of these berries for the extraction of compounds that can be exploited to produce pharmaceuticals and plant protection products.