Microtuber Formation Research Articles

Regulation of Different Lights on Energy Acquisitions, Microtuber Formation, and Growth of In Vitro-Grown Solanum tuberosum L.

Limited research has been conducted on the regulation of light quality on heterotrophy in in vitro-grown potato plantlets. Here, we investigated the effect of light quality on photosynthetic and heterotrophic abilities as well as microtuber formation and growth of potato plantlets (Solanum tuberosum L. cv. Shepody). Potato plantlets pre-cultivated under white light for 30 days were then transferred to grow under blue (B), green (G), red (R), yellow (Y), and white (W) lights, and parameters including dry weight, photosynthetic pigment, medium solute consumption, δ13C value, root activity, and sucrose transport (SUT) gene expression of these plantlets were measured. The results showed that B, G, and W were conducive to the rapid induction of microtubers, while R, and especially Y, delayed microtuber formation. Higher photosynthetic ability was observed in the W treatment, whereas the opposite effect was seen in the monochromatic light treatments. Microtuber growth was primarily dependent on heterotrophy, and B was conducive to microtuber growth. The delay in microtuber formation was related to the high expression of StSUT4 in the root, and better microtuber growth was associated with higher root activity, more medium solute consumption, and a higher expression level of StSUT1 in the roots.

Improvement of the potato seed production system on a virus-free basis in Almaty region

This article presents data on the induction of potato microtubers and the potency of different varieties to form microtubers in vitro. It has been established that the main factors influencing the process of tuberization in potato regenerated plants are: the concentration of carbohydrates and plant growth regulators in the nutrient medium and physiological state. Experiments were carried out to obtain microtubers from regenerated plants of 4 potato varieties of domestic selection (Alliance, Babaev, Miras and Pamyaty Konaeva) for the selection of virus-free primary material for seed production.As a result, a modified nutrient medium Murasige and Skoog (MS) containing 20 mg/L orotic acid was developed to accelerate the formation of microtuber for-mation of potato plants in vitro.

Improvement of potato (Solanum tuberosum L.) micro-tubers formation as effected by nano-particles in-vitro

Background Applying nano-fertilizers in the agricultural sector may lead to sustainable development through lower inputs and waste generation, diminishing nutrient losses, and increasing nutrient use efficiency by releasing nutrients at a suitable rate for plant demand compared with conventional chemical fertilizers. Objective The current study’s objective was to develop the ideal procedure for the in vitro creation of virus-free micro-tubers of two potato cultivars using varied doses of phosphorus and potassium nanoparticles (K-NPs) added to the Murashige and Skoog (MS) medium. Materials and methods The research was conducted at the Tissue Culture Laboratory, Vegetable Crops Department, Faculty of Agriculture, Cairo University, Egypt, from January 2020 to July 2021. The meristem tips of two potato cultivars were excised and cultured in solid MS medium supplemented with sucrose and agar. The multiplication stage involved re-propagation of the cultivars using nodal segments, which were cultured on MS medium. Results and conclusion The effects of potassium 25, 35, and 45 mM or phosphorus 2, 3, and 4 mM nanoparticles on in-vitro micro-tuber formation and growth of two potato cultivars (Lady Rosetta and Spunta) were cultured. Data on the number of branches, plant length, and number of leaflets were recorded after 40 days of culture. The number of micro-tubers/jar, and the fresh weight of micro-tubers were also determined. 25 mM potassium nanoparticles (K-NPs) resulted in the highest number of tubers for both cultivars, while the concentrations (35 mM and 45 mM) decreased tuber formation. For phosphorus nanoparticles (P-NPS), 4 mM resulted in the highest number of tubers and root lengths for both cultivars.

In vitro propagation and microtuberization of potato (Solanum tuberosum L.) Spunta variety in Lebanon

One of the factors that causes low productivity of potatoes in Lebanon is the limited availability of certified seeds. The aim of this study was to establish a rapid protocol for in vitro propagation and microtuberization of potato (Solanum tuberosum L.) of Spunta variety. Meristems culture associated to thermotherapy (one month/37°C) constituted the first step. The highest percentage of reactive meristem (92%) was observed on MS medium devoid of growth regulators while MS medium containing Kin 0.4 mg.l-1, GA3 0.5 mg.l-1 and IBA 0.5 mg.l-1 yielded the highest average number of shootlets (7.8) in the seventh subculture. The lowest number of days obtained for microtuber formation was 10 and the highest average number of microtuber (1.49) was obtained with shootlets incubated under C2 culture conditions (16-h day/8-h night for initial 7 days at 25±2°C; for remaining period: continuous dark at 17±2°C). Contrary the highest microtubers average length (10.75 mm), average width (7.41 mm) and average weight (646.26 mg) were produced under C1 culture conditions (16-h day/8-h night at 25±2°C). Medium supplemented with 5 mg.l-1 BAP and 6% sucrose presented the highest average number of microtubers of 2.36 and 1.94 respectively. Type and concentration of cytokines and sucrose concentration did not have significant effect on the average length, width and weight of microtubers produced.

Transcriptome Profiling Reveals Differential Gene Expression during the Process of Microtuber Formation in Pinellia ternata.

Using petiole material as explants and directly inducing the formation of microtubers without going through the callus stage is an essential way to rapidly expand scarce medical plants such as Pinellia ternata. However, the early molecular mechanism underlying the formation of the microtuber is largely elusive. Here, we conducted cytology and dynamic transcriptome analyses of inchoate microtubers in Pinellia explants and identified 1092 differentially expressed genes after their cultivation in vitro for 0, 5, and 15 days. Compared with 0 day, the number and size of the microtuber cells were larger at 5 and 15 days of culture. Detailed categorization revealed that the differentially expressed genes were mainly related to responses to stimulus, biological regulation, organelles, membranes, transcription factor activity, and protein binding. Further analysis revealed that the microtuber at different incubation days exhibited quite a difference in both hormone signaling pathway transduction and the regulation pattern of transcription factors. Therefore, this study contributes to a better understanding of the early molecular regulation during the formation of the microtuber and provides new insights for the study of the rapid expansion of P. ternata and other medical plants.

Identification of BBX gene family and its function in the regulation of microtuber formation in yam

BBX proteins play important roles in all of the major light-regulated developmental processes. However, no systematic analysis of BBX gene family regarding the regulation of photoperiodic microtuber formation has been previously performed in yam. In this study, a systematic analysis on the BBX gene family was conducted in three yam species, with the results, indicating that this gene plays a role in regulating photoperiodic microtuber formation. These analyses included identification the BBX gene family in three yam species, their evolutionary relationships, conserved domains, motifs, gene structure, cis-acting elements, and expressional patterns. Based on these analyses, DoBBX2/DoCOL5 and DoBBX8/DoCOL8 showing the most opposite pattern of expression during microtuber formation were selected as candidate genes for further investigation. Gene expression analysis showed DoBBX2/DoCOL5 and DoBBX8/DoCOL8 were highest expressed in leaves and exhibited photoperiod responsive expression patterns. Besides, the overexpression of DoBBX2/DoCOL5 and DoBBX8/DoCOL8 in potato accelerated tuber formation under short-day (SD) conditions, whereas only the overexpression of DoBBX8/DoCOL8 enhanced the accelerating effect of dark conditions on tuber induction. Tuber number was increased in DoBBX8/DoCOL8 overexpressing plants under dark, as well as in DoBBX2/DoCOL5 overexpressing plants under SD. Overall, the data generated in this study may form the basis of future functional characterizations of BBX genes in yam, especially regarding their regulation of microtuber formation via the photoperiodic response pathway.

Highly efficient microtuber formation, direct shoot regeneration, and root induction in Cyclamen persicum Mill. from in vitro seedling-derived tuber and leaf segments

Highly efficient microtuber formation, direct shoot regeneration, and root induction in Cyclamen persicum Mill. from in vitro seedling-derived tuber and leaf segments

In-vitro effects of sucrose and ascorbic acid on induction and shelf-life of micro-tuber of cassava (Manihot esculenta Crantz) genotypes

Background: Cassava production faces threat from postharvest physiological deterioration (PPD). The PPD is usually observed within the first 72 hours of harvest. Therefore, extending the shelf-life of cassava root-tubers by few days could reduce appreciable financial losses. Objective: This study is aimed to investigate effects of sucrose and ascorbic acid on induction and shelf-life of micro-tubers of cassava cultivars using an In-vitro model. Method: Effect of sucrose (30, 45, 60, 75 and 90 g/L) on the micro-tuber induction was determined after 45 days in these cultivars (TME 1333 and TME 2060). The optimal level was later combined with ascorbic acid (0, 25, 50, 75 and 100 mg/L) to investigate its effect on micro-tubers shelf-life during a 10-day storage. Each study was laid out in factorial under CRD with 5 replications. Results: The 30 g/L sucrose (control) produced the utmost number of micro-tubers (4.33), highest length (6.68 cm), and fresh weight (0.1495 g). The cultivar ‘TME 2060’ had longer (5.26 cm) and higher fresh weight (0.1079 g) than ‘TME 1333’ with 5.04 cm and 0.0977 g respectively. Ascorbic acid (100 mg/L) significantly delayed the discolouration of micro-tubers over a 10-day storage. Also, the 100 mg/L ascorbic acid produced the least percentage of deteriorated micro-tubers. Conclusion: Results demonstrate the roles of sucrose and ascorbic acid in micro-tuber formation and antioxidant activity in delaying PPD. Therefore, we propose for In-situ production (via breeding strategy) of vitamin C-fortified cassava varieties in order to control the incidence of PPD and in turn improve farmer`s economy.

Solanum tuberosum Microtuber Development under Darkness Unveiled through RNAseq Transcriptomic Analysis.

Potato microtuber (MT) development through in vitro techniques are ideal propagules for producing high quality potato plants. MT formation is influenced by several factors, i.e., photoperiod, sucrose, hormones, and osmotic stress. We have previously developed a protocol of MT induction in medium with sucrose (8% w/v), gelrite (6g/L), and 2iP as cytokinin under darkness. To understand the molecular mechanisms involved, we performed a transcriptome-wide analysis. Here we show that 1715 up- and 1624 down-regulated genes were involved in this biological process. Through the protein-protein interaction (PPI) network analyses performed in the STRING database (v11.5), we found 299 genes tightly associated in 14 clusters. Two major clusters of up-regulated proteins fundamental for life growth and development were found: 29 ribosomal proteins (RPs) interacting with 6 PEBP family members and 117 cell cycle (CC) proteins. The PPI network of up-regulated transcription factors (TFs) revealed that at least six TFs-MYB43, TSF, bZIP27, bZIP43, HAT4 and WOX9-may be involved during MTs development. The PPI network of down-regulated genes revealed a cluster of 83 proteins involved in light and photosynthesis, 110 in response to hormone, 74 in hormone mediate signaling pathway and 22 related to aging.

Expressing the Saccharomyces cerevisiae SUC2 gene encoding invertase apoplastic localization in the transgenic potato (Solanum tuberosum L.) does not contribute to microtubers production of identical physiological age

Study was aimed at assessing the role of apoplastic invertase in synchronization of the microtuber formation in potato plants in vitro. A non-transgenic potato (Solanum tuberosum L.) plants (hereinafter nonTPs) and a line of potato plants, which expressed the SUC2 gene of Saccharomyces cerevisiae encoding invertase apoplastic localization under the control of the B33 promoter of the patatin gene (hereinafter TPs), was used to achieve this purpose. Cell divisions in the axillary meristems of single-node cuttings were synchronized by exposing to 7°C for 24 h in a MS medium (without agar). After the low-temperature, the synchronization (LTS) of proportion of simultaneously dividing cells in meristems of nonTPs was four-fold greater than without chilling. The LTS did not change the number of dividing cells in the axillary meristems of TPs. The LTS contributed to an increase in the mass and size of microtubers in both potato lines. All microtubers of nonTPs were of physiological maturity. At the same time, microtubers of TPs were physiologically immature, with high glucose content. During the tuber formation, the activity of acidic invertases in microtubers of TPs was higher than that of nonTPs. Microtubers of TPs were larger than the nonTPs, more hydrated with low starch amount. Propably glucose accumulated in the microtubers of the TPs may act as a signal to trigger cell division. It indicates the regulatory function of apoplastic invertase and sugars. The high activity of apoplastic invertase plays a negative role in the production of potato microtubers of identical physiological age.

Influence of Indole-3 butyric acid and 6- benzylaminopurine with Sucrose on in vitro Potato Microtuber Formation

Influence of Indole-3 butyric acid and 6- benzylaminopurine with Sucrose on in vitro Potato Microtuber Formation

Optimization of microclonal reproduction of potato wart cultivar-differentiators

Goal. To study the influence of ammonium salts of dihydropyrimidine to the formation of microtubers and the productivity of potato wart cultivator differentiators in vitro.
 Methods. The research was conducted in 2019—2020 in the Laboratory of Biotechnology for Agricultural Crops of Ukrainian Plant Quarantine Research Station Institute of Plant Protection of NAAS. Derivatives of ammonium salts of dihydropyrimidine were synthesized at the Department of Organic Chemistry Institute of Biology, Chemistry and Bioresources of Chernivtsi National University. The material for the research was potato wart cultivar-differentiators of different maturity groups Slovyanka (medium ripe), Chervona Ruta (medium late). The plants were grown on Murashige-Skuga nutrient medium with addition of ammonium salts of dihydropyrimidine at different concentrations (0.1; 0.2; 0.3 mg/l) in a cultivation room at 16-hour photoperiod with a light intensity of 2000—2500 lux, temperature 22—25°C and humidity of 60—80%.
 Results. It was determined that high morphometric parameters and intensity of tuber formation of different varieties of maturity Slavyanka and Chervona Ruta in vitro culture provides the addition to the nutrient medium of ammonium salts of dihydropyrimidine with a concentration of 0.3 mg/l: plant height was 4.6 and 4.1 cm compared with the control of 4.0 and 3.7 cm, respectively. The number of internodes in both varieties were 5.3 pieces (in control — 4.5 pcs.) and the optimal number of microtubers on the 60th day — 79.1 and 81.3%.
 Conclusions. The effect study of different concentrations of ammonium salts of dihydropyrimidine on the productivity of potatoes in vitro in different varieties of maturity Slavyanka and Chervona Ruta showed that the optimal performance provides cultivation at a concentration of ammonium salts of dihydropyrimidine 0.3 mg/l: weight of the average microtuber is 22 and 195.4 mg, the mass of microtubers per plant — 185.5 and 174.4 mg, the number of microtubers per plant — 1.01 and 0.87 pcs.

Effect of photoperiod and KNO3 concentration on the induction and development of potato (Solanum tuberosum) microtuber in vitro

Abstract. Choirunnisa JP, Wardana R. 2021. Effect of photoperiod and KNO3 concentration on the induction and development of potato (Solanum tuberosum) microtuber in vitro. Cell Biol Dev 5: 70-75. Potato (Solanum tuberosum L.) is a carbohydrate source plant that was developed as an alternative to food diversification. The availability of quality potato seeds is very limited due to the high attack rate of bacteria and viruses. The demand for potato seeds can be fulfilled by developing potato microtuber through the application of plant tissue culture. The purpose of this research was to determine the response of potato microtuber formation with different photoperiods and KNO3 concentrations. This study design uses a factorial Completely Randomized Design (CRD) with 5 replicates. The first factor is 3 levels of photoperiod (8 hours/day, 12 hours/day, 16 hours/day). The second factor is 3 levels of KNO3 (1900 mg/L, 2850 mg/L, 3800 mg/L). The study was conducted by observing the age of microtubers initiation, number of shoots, number of roots, number of microtubers, the diameter of microtubers, and wet weight of microtubers were analyzed using SPSS. The results showed that the combination treatment of 8 hours/day photoperiod and KNO3 concentration of 3800 mg/L could accelerate the initiation of microtubers at 8 DAP (Days After Planting). The concentration of 3800 mg/L KNO3 can increase the number of roots and microtubers, the diameter of microtubers, and the wet weight of microtubers. The highest diameter of microtubers (17.89 mm) and the highest wet weight of microtubers (278.81 mg) were found in the photoperiod of 16 hours/day. This study concludes that the higher concentration of KNO3 and the longer photoperiod could be used for the induction and development of potato microtubers, while the short photoperiod could be used to accelerate microtubers initiation

Effect of Modified Tissue Culture Medium by Nanomaterial on Microtuber Formation of Potato Cultivar Hermes

Effect of Modified Tissue Culture Medium by Nanomaterial on Microtuber Formation of Potato Cultivar Hermes

Effect of Paclobutrazol concentration on initial formation stolon in potato plants by in vitro at different temperature conditions

The increase in potato production is constrained condition in Indonesia grow in the area with an altitude of 1500m above sea level. It is known that at high temperatures the gibberellin acid (GA) content in plants will increase, thus inhibiting tuber formation. The use of growth retardants such as paclobutrazol can inhibit GA biosynthesis so that it can stimulate tuber formation. In this study, the aim of this study was to determine the effect of paclobutrazol concentration on the initial formation of potato plant stolons by in vitro applied at different temperatures. The seeding stage was carried out on potato explants that had been kept for 4 weeks under 16 h of radiation. Paclobutrazol was given by pouring it into an explant bottle and keeping it in dark conditions at different temperatures for 8 weeks. From the results of the study, it is known that the application of paclobutrazol concentration and different temperatures affect the formation of micro tubers. where at a concentration of 3 ppm (P1) paclobutrazol was able to inhibit stolon elongation, stimulating subapical stolon and tuber swelling. The interactions between the application of paclobutrazol concentrations and different temperatures affected subapical stolon and tuber swelling.

In vitro tuberization in potato varieties of different ripe time

The formation of potato microtubers in vitro is discrete, and in order to increase its efficiency, it is important to ensure a regular supply of nutrients in a sterile vessel during plant ontogenesis. The aim of the research was to study the effect of phytohormones kinetin and IAA on the formation of microtubers in 20 potato varieties of different ripen time using two compositions of liquid media MS with 2% and 8% sucrose in the process of plant ontogenesis. The biomaterial was grown in plastic containers, the design of which allows the exchange of the nutrient medium in different phases of plant growth. The ontogeny of plants in tissue culture was significantly influenced by the ripening period of varieties. The early varieties were characterized by more intensive growth, their multiplication factor was 1.1-1.7 times higher than that of the middle early and mid-season varieties. The introduction of 0.4 mg/l kinetin into the nutrient medium had a positive effect on the formation of microtubers. For early varieties, the number of formed microtubers per plant increased by 1.2-1.8 pcs. compared to a hormone-free environment. The excess in later varieties was 0.8-0.9 pcs. per plant. The use of IAA without the addition of kinetin did not increase the number of microtubers. Complex application of phytoharmones promoted the growth of the fractional composition.

Use of growth inhibitor chlormequat chloride in potato culture in vitro

The publication presents data on the use of growth inhibitor chlormequat chloride in in vitro potato culture on varieties of different maturity groups: Meteor (early), Zekura (mid-early), and Northern Lights (mid-season). Five dosages of the investigational product were studied, ranging from 0.1125 to 1.8 g/l. It was found that in maximum doses of the product there was a strong inhibition of all growth processes in all varieties. The research results showed that the most optimal concentration of chlormequat chloride is 0.225 g per 1 liter of Murashige and Skoog medium. At this dose, on 30th day of cultivation, there was a decrease in the height of microplants from the control by 63.2-85.1%, in the root length - up to 15.0% and their number - up to 22.8% and an increase in the number of internodes by 6.5-22,0 % depending on the variety. The investigational product had an effect on formation of microtubers; in the Meteor variety, their largest number was 89.5% in the nutrient medium with a dose of 1.8 g/l, in the Zekura variety - 93.0% in the nutrient medium with a dose of 0.9 g/l. The new technique makes it possible to lengthen the periods between cuttings of test-tube plants by 2.3 times. This, in turn, reduces the cost of maintaining the in vitro collection material of potatoes in the summer-autumn period, and improves its quality, since each additional cutting cycle affects a more rapid degeneration of the variety. Also, microplants grown with growth inhibitor during subsequent relocation to a standard Murashige and Skoog medium did not show an aftereffect.

Poly (ADP-ribose) polymerase inhibitor 3-methoxybenzamide enhances in vitro plant growth, microtuberization, and transformation efficiency of blue potato (Solanum tuberosum L. subsp. andigenum)

Poly(ADP-ribose) polymerases (PARP) are involved in the regulation of plant growth and development, especially under stress conditions. These enzymes post-translationally modify target proteins by adding ADP-ribose polymers. This study presents the effect of PARP chemical inhibitor 3-methoxybenzamide (3 MB) on in vitro plant growth, microtuber formation, and Agrobacterium-mediated transformation of blue potato (Solanum tuberosum L. subsp. andigenum). The addition of 3 MB (0.2 to 0.6 mM) significantly increased the growth and microtuber formation of in vitro propagated plants. The highest gain in plant fresh weight, root mass, and microtuberization was observed in clonal propagation medium with 0.4 mM 3 MB. Transformation frequency of blue potato internodes increased to 43%, 2.7-fold over the non-treated control (16%), when 0.2 mM 3 MB was included in the culture medium during the whole process. The addition of 3 MB during Agrobacterium transformation did not affect transgene copy number in regenerated plants. Southern blot analyses and histochemical staining for s-glucuronidase activity confirmed the presence and expression, respectively, of the uidA transgene in plant tissues. From these results, it can be concluded that the inhibition of PARP activity can increase biomass production and transformation rates for genetic improvement of blue potato.

Effect of Different Concentrations of BAP and Putrescine on Potato Microtuberization (cv. Agria)

One of the most critical stages of produced virus free potato plants is rapid and efficient in vitro microtuberization. Plant growth regulators and their concentration is important factor on potato microtuberization. This study was conducted to develop a protocol for rapid microtuber formation for potato micropropagation by different concentrations of 6-Benzylaminopurine (BAP) (0, 1 and 2 mg.l-1) and five concentrations of Putrescine (0, 20, 40, 80 and 160 mg.l-1) with 8% sucrose and 8 g.l-1 agar. Present study was conducted as a factorial experiment based on completely randomized design with three replications in tissue culture laboratory to investigate the effect of different BAP and Putrescine concentrations. Lateral buds of cv. Agria from in vitro shoots were cultured as explants. Cultures were kept in germinator with constant darkness and temperature of 17±2°C. Variance analysis showed that none of the traits were affected by different concentrations of the Putrescine other than weight of the shoots. Also, the interaction effect of PUT×BAP on shoot weight was significant. However, the effect of different levels of BAP was significantly associated with the most trait of microtuberization. In this experiment, the best concentration of BAP for microtuberization was 1 mg.l-1. Also, the appropriate Putrescine level for increasing of microtuberization number and percentage was 80 mg.l-1 but the effect of Putrescine on microtuberization number and percentage was non-significant.

Transcriptome Analysis Reveals Key Pathways and Hormone Activities Involved in Early Microtuber Formation of Dioscorea opposita.

Chinese yam (Dioscorea opposita) is an important tuberous crop used for both food and medicine. Despite a long history of cultivation, the understanding of D. opposita genetics and molecular biology remains scant, which has limited its genetic improvement. This work presents a de novo transcriptome sequencing analysis of microtuber formation in D. opposita. We assembled cDNA libraries from different stages during the process of microtuber formation, designated as initial explants (EXP), axillary bud proliferation after three weeks (BUD), and microtuber visible after four weeks (MTV). More differentially expressed genes (DEGs) and pathways were identified between BUD vs. EXP than in MTV vs. BUD, indicating that proliferation of the axillary bud is the key stage of microtuber induction. Gene classification and pathway enrichment analysis showed that microtuber formation is tightly coordinated with primary metabolism, such as amino acid biosynthesis, ribosomal component biosynthesis, and starch and sucrose metabolism. The formation of the microtuber is regulated by a variety of plant hormones, including ABA. Combined with analysis of physiological data, we suggest that ABA positively regulates tuberization in D. opposita. This study will serve as an empirical foundation for future molecular studies and for the propagation of D. opposita germplasm in field crops.