Tuberosum Cv Research Articles

"Comparative characterization of somatic hybrids of solanum bulbocastanum + s. Tuberosum Cv. ‘rasant’ with their parents in relation to biochemical responses to wound stress and trichome composition "

"Comparative characterization of somatic hybrids of solanum bulbocastanum + s. Tuberosum Cv. ‘rasant’ with their parents in relation to biochemical responses to wound stress and trichome composition "

Homologs of vacuolar invertase inhibitor INH2 in tuber-bearing wild potato species and Solanum tuberosum: gene polymorphism and co-expression with saccharolytic enzyme genes in response to cold stress

Wild tuber-bearing species are commonly used as a source of valuable traits to develop new potato cultivars. One of the trends in potato breeding is elimination of cold-induced sweetening, which depends on the balance between activities of saccharolytic enzymes (vacuolar invertase PAIN-1 and sucrose synthase SUS4 that hydrolyze sucrose) and vacuolar invertase inhibitor INH2 that regulates the PAIN-1 activity. To clarify the mechanisms underlying cold resistance, we investigated INH2 polymorphism and tissue-specific expression, and co-expression profiles of INH2, PAIN-1, and SUS4 in wild tuber-bearing potatoes and Solanum tuberosum cultivars. Novel INH2 homologs were identified in eight wild species and four cultivars. Structural analysis predicted an N-terminal signal peptide and showed that nucleotide and amino acid polymorphisms (13.09% and 18.91%, respectively) did not affect the INH2 tertiary structure, suggesting that the INH2 function may be conserved in potato both at the intra- and inter-specific levels. INH2 and PAIN-1 mRNA were detected in buds, flowers, leaves, stems, roots, and tubers of S. tuberosum cv. Nadezhda, showing the highest (INH2) and lowest (PAIN-1) levels in the roots. During cold storage, tubers of four cultivars accumulated glucose and fructose, while the sucrose content changed insignificantly; INH2, PAIN-1, and SUS4 co-expression patterns in freshly harvested and cold-stored tubers differed among the cultivars. Cold exposure also caused distinct effects on INH2, PAIN-1, and SUS4 co-expression patterns in the leaves of four wild species differing in cold resistance. These data indicate that cold response in potato may depend on specific combinations of INH2, PAIN-1, and SUS4 activities.

Differences in the Amylase Inhibitor Gene SbAI Expression in Potato during Long-Term Tuber Cold Storage and in Response to Short-Term Cold Stress

Expression analysis of the amylase inhibitor gene SbAI in five potato cultivars (S. tuberosum) revealed SbAI downregulation in tubers during long-term (seven months) cold storage. Estimation of SbAI gene expression and starch content in leaves of S. tuberosum cv. Nadezhda and four wild potato species (Solanum sect. Petota) showed a dramatic increase in SbAI transcription accompanied by starch content drop in response to short-term cold stress.

The Opposite Effect of Low Temperature on the Pho1a Starch Phosphorylase Gene Expression in Solanum tuberosum L. Tubers and Petota Species Leaves

Starch turnover is important for plant response to abiotic stresses and plastidic starch phosphorylase Pho1a is a key enzyme regulating starch metabolism. In this study, we identified Pho1a coding sequences in seven wild tuber-bearing potato species. In Solanum tuberosum cv. Nadezhda grown at normal conditions, Pho1a transcription was low; it was detected in stems, leaves, flowers, and roots. After harvest, Pho1a expression in tubers of 16 S. tuberosum cultivars was either absent or low but progressively increased during storage at +4 °C, which corresponded to an increase in the content of reducing sugars. In the leaves of both cultivated and wild potato species, exposure to short-term cold stress downregulated Pho1a expression, especially at night, and stimulated starch degradation, but there was no uniform diurnal pattern in Pho1a expression dynamics. These findings indicate that Pho1a may have different functions in storage and photosynthetic organs of potato.

Genetic Mapping of Steroidal Glycoalkaloids Using Selective Genotyping in Potato

Steroidal glycoalkaloids (SGAs) are important secondary metabolites in potato which are associated with constitutive host defense mechanism. SGAs like leptines and dehydrocommersonine (DHC) present in wild S. chacoense and S. oplocense, respectively, are known to deter Colorado potato beetle (CPB) feeding. In the current study, LC-MS analysis led to tentative identification of a new SGA with the same molecular mass as α-solanine, solanidenol-chacotriose (SC), which was present in high levels in the CPB susceptible S. tuberosum cv. Shepody, but not in S. oplocense. In a progeny derived from a cross between S. tuberosum, cv. Shepody and S. oplocense derived F1 hybrid, 13213–07, SC was one of the highly variable metabolites along with DHC. Selective genotyping was used for genetic mapping of QTL controlling SC and DHC to chromosome 1. Selective genotyping is dependent on variation between extremes in populations, and it was not effective for QTL mapping of α-solanine and α-chaconine where differences between extremes was low.

Understanding the Properties of Starch in Potatoes (Solanum tuberosum var. Agria) after Being Treated with Pulsed Electric Field Processing.

The purpose of this study was to investigate the properties of starch in potatoes (Solanum tuberosum cv. Agria) after being treated with pulsed electric fields (PEF). Potatoes were treated at 50 and 150 kJ/kg specific energies with various electric field strengths of 0, 0.5, 0.7, 0.9 and 1.1 kV/cm. Distilled water was used as the processing medium. Starches were isolated from potato tissue and from the PEF processing medium. To assess the starch properties, various methods were used, i.e., the birefringence capability using a polarised light microscopy, gelatinisation behaviour using hot-stage light microscopy and differential scanning calorimetry (DSC), thermal stability using thermogravimetry (TGA), enzyme susceptibility towards α-amylase and the extent of starch hydrolysis under in vitro simulated human digestion conditions. The findings showed that PEF did not change the properties of starch inside the potatoes, but it narrowed the temperature range of gelatinisation and reduced the digestibility of starch collected in the processing medium. Therefore, this study confirms that, when used as a processing aid for potato, PEF does not result in detrimental effects on the properties of potato starch.

Host-induced gene silencing of Pectobacterium carotovorum quorum sensing gene enhances soft rot disease resistance in potato plants

Quorum sensing is a regulatory mechanism of gene expression in bacteria which regulated many physiological processes such as production of virulence factors in Pectobacterium carotovorum. In this research, the plant expression vector, pBI121, harbouring the anti-quorum sensing gene, aiiA, was transformed into Potato (Solanum tuberosum cv. Agria) explants by Agrobacterium mediated transformation procedure and putative transformants containing pBI121/aiiA were obtained. The results of bioassay test revealed that the expression of aiiA gene in potato plant induces the resistance to the early stage of bacterium pathogenesis. The soft rot symptoms such as wilting, yellowing and tissue maceration were not observed until 48 hr after inoculation of transgenic potatoes with P. carotovorum. Although in non-transgenic plants, the disease symptoms were appeared after 24 hr of plants infection. Hence, this study proves that the heterologous expression of aiiA gene enhances the resistance against potato soft rot disease.

Organ-specific differences in endogenous phytohormone and antioxidative responses in potato upon PSTVd infection

Although structurally simple, viroids can trigger numerous changes in host plants and cause loss of yield in agronomically important crops. This study investigated changes in the endogenous status of phytohormones and antioxidant enzyme activity in Solanum tuberosum cv. Désirée in response to Potato spindle tuber viroid (PSTVd) infection. Phytohormone analysis showed that the content of endogenous jasmonic acid (JA) and its precursor cis-OPDA significantly increased in leaves, while the content of castasterone (CS) increased in both leaves and tubers of systemically infected plants compared to mock-inoculated control plants at 8 weeks post-inoculation. The indole-3-acetic acid content moderately increased only in tubers, while no differences in salicylic acid and abscisic acid content were observed between infected and control plants. Changes in endogenous phytohormone content were associated with upregulated expression of genes involved in the biosynthesis of JA and brassinosteroids, and the metabolism of auxins. Additionally, PSTVd infection provoked overproduction of hydrogen peroxide, which coincided with increased activity of guaiacol peroxidase in leaves and ascorbate peroxidase in potato tubers. The activity of catalase decreased in leaves, while superoxide dismutase activity remained steady regardless of the treatment and organ type. Total ascorbate and glutathione did not change significantly, although a shift towards oxidized forms was observed. Results suggest the existence of organ-specific differences in phytohormone and antioxidative responses in potato upon PSTVd infection. Possible effects of the observed changes on symptom development are discussed.

Anti-freezing-protein type III strongly influences the expression of relevant genes in cryopreserved potato shoot tips.

AFP improved cryopreservation efficiency of potato (Solanum tuberosum cv. Superior) by regulating transcript levels of CBF1 and DHN1. However, the optimal AFP concentration required for strong induction of the genes was dependent on the type of vitrification solution to which the AFP was added: This finding suggests that AFP increased cryopreservation efficiency by transcriptional regulation of these genes, which might protect plant cell membranes from cold stress during cryopreservation. Despite the availability of many studies reporting the benefits of anti-freeze protein III (AFP III) as a cryoprotectant, the role of AFP III in this process has not been well demonstrated using molecular analysis. In addition, AFP III has not been exploited in the cryopreservation of potato thus far. Therefore, we studied the effects of AFP III on the cryopreservation of potato (Solanum tuberosum cv. Superior). We found that CBF1 and DHN1 genes are low temperature-inducible in potato leaves (S. tuberosum cv. Superior). Transcript levels of these genes expressed in shoot tips cryopreserved with AFP III were higher than those of the controls. However, the optimal AFP III concentration required for strong induction of the genes was dependent on the type of cryoprotection solution to which the AFP III was added: 500ng/mL worked best for PVS2, while 1500ng/mL was optimal for LS. Interestingly, the involvement of AFP III in the cryoprotection solutions improved cryopreservation efficiency as compared to the control, and expression levels of the detected genes were associated with cryopreservation efficiency. This finding suggests that AFP III increased cryopreservation efficiency by transcriptional regulation of these genes, which might protect plant cell membranes from cold stress during cryopreservation. Therefore, we expect that our findings will lead to the successful application of AFP III as a potent cryoprotectant in the cryopreservation of rare and commercially important plant germplasms.

Isolation and functional characterization of the SpCBF1 gene from Solanum pinnatisectum.

Low temperature causes a negative impact on plant growth and development, but plants evolve a series of mechanisms to respond to chilling stress, and one of them is CBF [C-repeat (CRT)/dehydration-responsive element (DRE) binding factor] gene family which has been well studied in different crops. In this paper, a new CBF1 gene, named as SpCBF1, was isolated from frost-tolerant Solanum pinnatisectum by PCR and analyzed for its function in cold-tolerance by over-expression technique. The ORF of SpCBF1 was 666bp long and encoded a protein of 221 amino acids with a predicted molecular mass 24.5821kDa and theoretically isoelectric point 5.0. SpCBF1 protein contained a highly conserved specific AP2/ERF domain. SpCBF1 was expressed in all tested tissues with the highest level in tuber and the lowest in root, and induced by chilling stress (0°C). Under natural low temperature condition (1-10°C), plants over-expressing SpCBF1 (OE) exhibited slighter necrotic lesion and lower necrotic injury, compared with untransformed Solanum tuberosum cv. Désirée (WT) and antisense-StCBF1 control lines. Over-expression of CBF1 increased the level of COR (cold-regulated) gene transcripts in OE lines, and the physiological indexes related to cold tolerance like the contents of SOD, soluble protein, MDA, proline and soluble sugar were higher in OE lines than in WT except RWC which was lower. All these results indicated that SpCBF1 gene plays a promoting role in potato responding to cold stress.

RNAi-mediated silencing of endogenous Vlnv gene confers stable reduction of cold-induced sweetening in potato (Solanum tuberosum L. cv. Désirée)

Potato tubers must be cold-stored to extend their shelf life and maintain an uninterrupted supply chain for food processors. However, a side-effect of low-temperature storage is manifested in terms of cold-induced sweetening (CIS) of potato tubers, which reduces the processing quality and the commercial value of the end-products. RNA interference (RNAi) technology, whereby transgene-derived small interfering RNAs can trigger the homology-based knockdown of cognate host genes and can initiate gene silencing, has been successfully applied in crop improvement through targeted gene knockout in host plants. In the current study, transgenic potato plants (Solanum tuberosum cv. Desiree) were generated, expressing a 300 bp hairpin loop nucleotide sequence targeting the potato vacuolar invertase gene (VInv), under the constitutive Cauliflower mosaic virus 35S promoter. Tubers collected from transgenic lines showed a significant reduction in reducing sugar content after 180 days of cold storage, without showing any measurable off-target effects on plant morphology and tuberization compared to non-transformed control plants. The cold-stored tubers were further assayed for chip color, which showed a fairly light colored quality in the samples originating from RNAi lines. Together with similar effects seen in previously published experiments involving other potato varieties, the Desiree results described here establish the efficacy of using RNAi for the successful reduction of CIS in potato tubers.

Susceptible and tolerant potato leaf-responses post challenge with Pectobacterium carotovorum subsp. brasiliense 1692

Leaf responses of a susceptible potato cultivar (S. tuberosum cv. Valor) were compared to those of a tolerant potato cultivar (S. tuberosum cv. BP1) following challenge by Pectobacterium carotovorum subsp. brasiliense 1692 (Pcb 1692). Leaves of the susceptible cultivar showed excessive maceration and water soaking symptoms as well as increased proliferation of the bacteria. In leaves of the tolerant cultivar, bacteria appeared to be restricted to the point of inoculation,subsequently; there was very little multiplication of bacterial cells. Furthermore we demonstrated that disease is associated with the extensive spread of cell death in S. tuberosum cv. Valor while in S. tuberosum cv. BP1 cell death was observed to be associated with lack of disease development. Another response associated with challenge by Pcb 1692 in the susceptible and tolerant potato cultivar leaf tissue was the oxidative burst. Generally, the accumulation of hydrogen peroxide and superoxide in leaf-tissue appeared to correlate with tolerance levels.

A new virus, classifiable in the family Tombusviridae, found infecting Solanum tuberosum in the UK.

A novel virus was discovered in a freeze-dried collection held at SASA, UK, originating from potato (Solanum tuberosum) cv. Nadine. The complete sequence of the viral RNA was determined to be 3674 nucleotides in length encoding five predicted proteins. Based on the deduced genome organization and phylogenetic analysis, this virus represents a putative new member of the genus Alphanecrovirus, family Tombusviridae, most closely related to isolates of Olive mild mosaic virus. The virus was easily transmitted to indicator plants with symptoms that were slower to develop and less severe than those of related viruses. To distinguish this virus, the clearest symptom differences occurred with Nicotiana debneyi, Chenopodium amaranticolor and Ch. quinoa. The virus was detected with antisera to the related viruses tobacco necrosis virus A and tobacco necrosis virus D. The close association to the tobacco necrosis viruses would suggest this virus is not a new introduction to potato but in the past has been misidentified as one of these viruses. The virus isolate has been named potato necrosis virus.

Identificación molecular de Potyvirus infectando cultivos de papa en el oriente de Antioquia (Colombia)

Los potyvirus son uno de los grupos de virus más limitantes en los cultivos de papa (Solanum tuberosum y S. phureja) en el mundo, siendo PVY, PVV y PVA las especies más prevalentes. En este trabajo se evaluó la presencia de estos potyvirus en cuatro lotes de S. tuberosum cv. Diacol-Capiro y cuatro lotes de S. phureja cv. Criolla-Colombia ubicados en el oriente de Antioquia, analizando la cápside viral mediante RT-PCR/secuenciación Sanger y secuenciación de nueva generación (NGS) para S. tuberosum. Los resultados indicaron la ocurrencia de los potyvirus PVY y PVV en las muestras de S. tuberosum y S. phureja, respectivamente; siendo detectadas mediante cebadores específicos la presencia de tres diferentes cepas de PVY (PVYN, PVYNTN y PVYO) en la región de estudio. Este hallazgo fue confirmado por NGS, obteniendo las secuencias completas de los genomas de estas tres cepas, lo que representa el primer reporte de PVYO en Colombia. Por su parte, los análisis de secuencias de la región CP de PVV indicaron niveles de identidad superiores a 99% con respecto a aislamientos del linaje PVVPhu reportado previamente en Antioquia. Estos hallazgos evidencian la necesidad de ajustar los sistemas de detección de virus en los programas de certificación de tubérculo-semilla de papa adelantados en el país.

Optimum irrigation regime to maximize the yield, water use efficiency and quality of potato [Solanum tuberosum (L.) cv. Spunta

This study investigated the effects of different irrigation regimes on the yield, water use efficiency and quality of potato [Solanum tuberosum (L.) cv. Spunta] grown at the experimental field of Deir Alla Agricultural Research Station, Jordan during 2012–13 and 2013–14 growing seasons. Five different drip irrigation regimes were compared: 50% (I50), 75% (I75), 100% (I100) and 125% (I125) of crop evapotranspiration assessed according to the class A pan equation (which equated to 184, 274, 366 and 458 mm, respectively), and farmer irrigation (506 mm). The results indicated that irrigation to 100% of evapotranspiration (I100) was the optimum regime for maximizing potato production. The specific gravity and water use efficiency, as well as most nutritional contents of potato decreased with increasing amounts of water, and the maximum ash content was achieved with I100. Thus, use of the I100 regime would improve water use efficiency in potato crops compared with farmer irrigation levels that are currently used, allowing significant reductions in water use while maintaining production levels.

Effects of Solanum sisymbriifolium on potato cyst nematode populations in Portugal

This study was undertaken to evaluate the effects of Solanum sisymbriifolium cvs Melody, Pion, Sharp, Sis 4004 and Sis 6001 on potato cyst nematode (PCN), Globodera spp., populations in the field in Portugal, to improve crop protection systems based on trap crops. Two PCN infested fields (Bolho and Barcouco) were selected. Solanum sisymbriifolium root exudates effects on PCN hatching were evaluated by in vitro assays and their susceptibility/resistance to PCN was assessed. Field trials were performed during 2 years using the following rotation: S. tuberosum cv. Desiree followed by S. sisymbriifolium. Solanum sisymbriifolium root exudates promoted hatching of second-stage juveniles (J2). The cultivars tested were resistant to both species of PCN. In both fields, all cultivars had the same behaviour with no statistically significant differences. As S. sisymbriifolium cultivars were resistant to G. rostochiensis and G. pallida populations in Portugal, they can be included in crop rotations and are potential candidates to incorporate in management programs against PCN. Although there were no statistical differences it seems that fallow could be the best strategy to reduce PCN populations faster and this avoids the introduction of an exotic plant that could become a problem.

Patateste (Solanum tuberosum L.) in vitro Mikrotuberizasyon Üzerine Fotoperiyot, Jasmonik Asit ve Aktif Kömürün Etkileri

In this study, effects of added agar, jasmonic acid (JA), activate charcoal (AC) with photoperiod regime on in vitro microtuber formation in Solanum tuberosum cv. Marfona. Study has actualized as 4 main steps; shoot formation of the tubers of S. tuberosum, in vitro shoot-tip culture, micropropagation and microtuberization. The effects of JA (0.0-0.2 mgL-1), agar (0.5% or 0.7%), AC (0 and 0.2%) microtuberization were investigated. The highest microtuber yield (137%) and the highest microtuber average (183 mg/tuber) were obtained at the double-layer Murashige and Skoog (MS) medium which contains 0.2% AC, 0.5% agar under darkness conditions. It has been determined that positive effect of AC on microtuber formation is higher than JA. AC was found much more effective in the dark.

ANALISIS POLA SEGREGASI DNA GENOM KLOROPLAS HASIL HIBRIDISASI SOMATIK TANAMAN KENTANG MENGGUNAKAN TEKNIK RAPD (RANDOM AMPLIFIED POLYMORPHIC DNA)

Segregation pattern of the chloroplast genome in somatic hybridization potato between S. tuberosum cv. BF-15 and the wild species of S. stenotomum was identified through RFLP analysis in 3.2 kb fragment produced from PCR amplification for specific regions of DNA chloroplast. PCR amplification was performed by using rbcL primer and ORF106, i.e. specific prim er located on konsenrvatiive sequence which flanking 3.2 kb fragment region of DNA chloroplast. PCR amplification product used two primers, in conformity with the target region on DNA chloroplast, where generated fragments or DNA bands with a size of about 3.2 kb. The 3.2 kb fragment produced from amplification was cut by using two kinds of restriction enzymes HhaI and RSAI. Restriction Enzym treatment with HhaI resulted in four bands each measuring; those were 2.0 kb, 1.2 kb, 0.8 kb and 0.4 kb. While the treatments by using RSAI restriction enzymes, also resulted in four bands each measuring, those were 1.6 kb, 0.7 kb, 0.3 kb and 0.2 kb. Band pattern that produced from restriction enzyme showed that monomorphic nature or not polymorphic at all elder fusion plant, so this method can not be used to identify the patterns of chloroplast genome segregation in plant which is produced by somatic hybridization.

In Vitro Culture as a Stressful Factor Triggers Changes in Polyphenols, Flavonoids and Antioxidant Activity in Somatic Hybrids between Solanum tuberosum and S. bulbocastanum and their Respective Parents

Phenols, important secondary metabolites in plants, are responsible for specific defence mechanisms against abiotic stress, due to their strong antioxidant activity. Flavonoids, as part of phenolic group, are also involved in plant stress responses, being primarily responsible for photo-protection against UV solar radiation. Based on these premises, the plant response to optimized in vitro culture was evaluated, by quantifying the total polyphenolic content, the total flavonoid content and the antioxidant activity, both under in vitro and ex vitro conditions. Four closely related potato genotypes were analysed: the wild species Solanum bulbocatanum, S. tuberosum cv. ‘Rasant’ and two somatic hybrids between them. For all genotypes, both total polyphenolic content and antioxidant activity were increasing under optimized in vitro culture. The shoot responses were genotype dependent and the two somatic hybrids were intermediate between the parents both as morphology and reaction to in vitro stress. The somatic hybrid 1508/5, having morphology similar to potato, was reacting as the wild species, while the somatic hybrid 1508/2, with a similar morphology to the wild species was reacting as potato to in vitro stress. The somatic hybrid 1508/5 being also resistant to late blight is of interest for further use in pre-breeding. Total flavonoid content is decreasing under in vitro as compared to ex vitro conditions, UV-B radiation, the major trigger of flavonoid biosynthesis being absent in the fluorescent light. This study reveals the effect of in vitro culture on flavonoid content and details aspects of the biochemical parameters involved in plant in vitro stress.

Carbohydrates and gibberellins relationship in potato tuberization

Potato represents the third most important crop worldwide and therefore to understand regulations of tuber onset is crucial from both theoretical and practical points of view. Photosynthesis and related carbohydrate status along with phytohormone balance belong to the essential factors in regulation of plant development including storage organ formation. In our work we used potato (Solanum tuberosum) cv. Lada and its spontaneously tuberizing mutant (ST plants) grown in vitro under low carbohydrate availability (non-inductive conditions). Small plant phenotype and readiness to tuberization of ST plants was, however, not accompanied by lower gibberellins levels, as determined by UHPLC–MS/MS. Therefore, we focused on the other inducing factor, carbohydrate status. Using HPLC, we followed changes in carbohydrate distribution under mixotrophic (2.5% sucrose in medium) and photoautotrophic conditions (no sucrose addition and higher gas and light availability) and observed changes in soluble carbohydrate allocation and starch deposition, favouring basal stem part in mutants. In addition, the determination of tuber-inducing marker gene expressions revealed increased levels of StSP6A in ST leaves. Collectively these data point towards the possibility of two parallel cross-talking pathways (carbohydrate − and gibberellin- dependent ones) with the power of both to outcompete the other one when its signal is for some reason extraordinary strong.