Starch synthesis in potato tubers transformed with the wheat genes for ADPglucose pyrophosphorylase

2002 ◽  
Vol 29 (8) ◽  
pp. 975 ◽  
Author(s):  
Kathryn A. Vardy ◽  
Michael J. Emes ◽  
Michael M. Burrell

The aim of this work was to study the role of ADPglucose pyrophosphorylase (AGPase) in starch biosynthesis of non-photosynthetic organs. Agrobacterium tumefaciens was used to transform potato plants (Solanum tuberosum L. cv. Desire�) with the wheat AGPase genes (AGP-S and AGP-L, coding for the small and large subunits, respectively). Neither of these genes contains a recognisable plastid targeting sequence. Southern analysis and analysis of starch content identified four lines that contained both wheat sequences. Immunoblotting indicated that, in the tubers, three lines expressed the wheat small subunit (AGP-S), but AGP-L cross-reacting protein was not apparent. The fourth transgenic line had reduced AGPase activity. AGPase activity in the AGP-transgenic tubers ranged from 15 to 165% of that found in β-glucuronidase (GUS) control lines.

1996 ◽  
Vol 320 (2) ◽  
pp. 493-498 ◽  
Author(s):  
Lee J. SWEETLOVE ◽  
Michael M. BURRELL ◽  
Tom ap REES

The aim of this work was to use tubers from transgenic lines of potato (Solanum tuberosum) containing increased amounts of ADPglucose pyrophosphorylase to study the role of this enzyme in the control of starch synthesis. A 4–5-fold increase in activity of the enzyme, achieved by transformation with the Escherichia coli ADPglucose pyrophosphorylase gene glgC-16, had no detectable effect on the starch content of developing or mature tubers. No significant effects were found on the contents of ADPglucose, UDPglucose, glucose 1-phosphate, glucose 6-phosphate, PPi, ATP and ADP. Flux from [U-14C]sucrose, supplied to tubers still attached to the plant, to starch increased roughly in proportion to the increase in ADPglucose pyrophosphorylase activity. These measurements of flux gave a response coefficient close to 1 for the activity of the pyrophosphorylase in respect of starch synthesis. Pulse–chase experiments with [U-14C]sucrose showed that the increased flux into starch in the transformed tubers was accompanied by an increased rate of starch turnover. Further experiments suggested that the increased turnover was associated with an increase in the capacity of the tubers to degrade starch.


2017 ◽  
Vol 13 (24) ◽  
pp. 145
Author(s):  
Sadek Chahredine ◽  
Nadia Ykhlef

The aim of this study is to determine the effects of different concentrations and combinations of the phytohormones, 1-naphthaleneacetic acid (NAA), and 6-benzylaminopurine (BAP): M1 (0.5 mg / l +1 mg / l), M2 (1 mg / l + 0.5 mg / l) , M3 (2 mg / l +2 mg / l), M4 (0.5 mg / l + l mg / l, NAA), M5 (1.0 mg / l + l mg / l , NAA), and M6 (2.0 mg / l + l mg / l, NAA). This study was carried out in dark condition on callus induction of potato plants (Solanum tuberosum L.) cultivars from potato tuber bud so as to demonstrate the role of light. The callus initiation begins after 7 days of incubation for all studied media. After two months of incubation, the better development of callus was noted in Spunta variety by using medium M1, M2, M3, and M6. The calluses took a compact structure of brown-white color for both varieties with a callus induction rate of 20- 40%. This was collected with kondor variety for M2 and (M3, M4, M5) media respectively and 10-30% for M4 (M1, M2, M3) for Spunta variety also. The highest fresh weight was recorded on M2 medium with 0.26g for Kondor variety and 0.93g for Spunta variety.


2010 ◽  
Vol 11 (1) ◽  
pp. 38 ◽  
Author(s):  
Felix A. Cervantes ◽  
Juan M. Alvarez

The complexity of the Potato virus Y (PVY) (Potyviridae: Potyvirus) pathosystem is affected by the presence of several virus strains that differ in their ability to produce tuber necrosis and by the presence of an alternate host that could increase the amount of inoculum in potato fields. Solanum sarrachoides (Sendtner) is an invasive weed from South America present in Pacific Northwest potato agro-ecosystems. It serves as reservoir of PVY and its most efficient vectors: the green peach aphid, Myzus persicae (Sulzer), and the potato aphid, Macrosiphum euphorbiae (Thomas). The role of S. sarracoides as vector and virus reservoir in PVY epidemiology was investigated through a series of laboratory and greenhouse experiments. We studied the symptoms produced in S. sarracoides upon infection with necrotic and non-necrotic strains of PVY and looked at the percentage of infection and titer accumulation of these strains. PVY infection in S. sarrachoides produced symptoms similar to those produced in PVY-infected potato plants. Mottling and yellowing were the main symptoms of infection observed in S. sarrachoides plants, especially by PVYO and PVYNTN infection. Greenhouse transmission studies revealed that PVY-infected S. sarrachoides increased the transmission rate of PVY necrotic strains by M. persicae. The necrotic strain PVYNTN reached higher titer in S. sarrachoides than in potato plants when compared to PVYO and PVYN:O These findings have broadened our understanding of the role and importance of S. sarrachoides in the PVY epidemiology in the potato ecosystems and could potentially be included in the development or optimization of virus management programs. Accepted for publication 15 March 2010. Published 26 May 2010.


2018 ◽  
pp. 289-298
Author(s):  
Алексей (Aleksey) Геннадьевич (Gennad'yevich) Тулинов (Tulinov) ◽  
Елена (Elena) Андрияновна (Andrianovna) Михайлова (Mikhailova) ◽  
Анатолий (Anatoliy) Александрович (Aleksandrovich) Шубаков (Shubakov)

Crop yields can be significantly increased by using pectic polysaccharides – natural ecologically safe and effective plant growth stimulants. In this paper, high growth-stimulating activity of pectins with respect to potatoes is shown. The research was conducted in 2012–2015 in the Komi Republic (Syktyvkar) on sod-podzolic soils with an average humus content of 2.8–3.4%. The objects of the study in the field experiments were zoned potato varieties: early-ripening Gloria variety and the middle-aged variety Nevsky. The following pectic polysaccharides served as stimulants of potato growth and development: heracleuman – pectin of Heracleum sosnowskyi Manden., lemnan – pectin duckweed Lemna minor L. and silenan – pectin of callus tissue of campion Silene vulgaris (M.) G. Processing of potatoes with aqueous solutions of pectic polysaccharides included pre-planting soaking of potato tubers in water and spraying potato plants in the phases of 3–5 leaves and tuber formation. For processing potatoes, working solutions were used, which were prepared from 100 times diluted 0.002% aqueous solutions of pectins. The consumption of the working solutions of pectins were 10 liters on 1 ton of tubers and 300 l/ha of planting potatoes. Tubers and potato plants treated with water instead of pectins were used as control samples. It is established that all tested pectins possess growth-stimulating activity and processing of potatoes with aqueous solutions of pectic polysaccharides increases the early and overall yield of this crop, as well as the content of dry matter, starch and vitamin C in potato tubers.


2007 ◽  
Vol 34 (6) ◽  
pp. 480 ◽  
Author(s):  
Sandrine Rösti ◽  
Brendan Fahy ◽  
Kay Denyer

A mutant of rice was identified with a Tos17 insertion in OsAPL1, a gene encoding a large subunit (LSU) of ADP-glucose pyrophosphorylase (AGPase). The insertion prevents production of a normal transcript from OsAPL1. Characterisation of the mutant (apl1) showed that the LSU encoded by OsAPL1 is required for AGPase activity in rice leaf blades. In mutant leaf blades, the AGPase small subunit protein is not detectable and the AGPase activity and starch content are reduced to <1 and <5% of that in wild type blades, respectively. The mutation also leads to a reduction in starch content in the leaf sheaths but does not significantly affect AGPase activity or starch synthesis in other parts of the plant. The sucrose, glucose and fructose contents of the leaves are not affected by the mutation. Despite the near absence of starch in the leaf blades, apl1 mutant rice plants grow and develop normally under controlled environmental conditions and show no reduction in productivity.


2021 ◽  
Vol 7 (4) ◽  
pp. 312
Author(s):  
Neda Najdabbasi ◽  
Seyed Mahyar Mirmajlessi ◽  
Kevin Dewitte ◽  
Maarten Ameye ◽  
Marika Mänd ◽  
...  

Yield losses of crops due to plant pathogens are a major threat in all agricultural systems. In view of environmental issues and legislative limitations for chemical crop protection products, the need to design new environmentally friendly disease management strategies has gained interest. Despite the unique capability of green leaf volatiles (GLVs) to suppress a broad spectrum of plant pathogens, their capacity to control the potato late-blight-causing agent Phytophthora infestans has not been well studied. This study addresses the potential role of the GLV Z-3-hexenyl acetate (Z-3-HAC) in decreasing the severity of late blight and the underlying gene-based evidence leading to this effect. Nine-week-old potato plants (Solanum tuberosum L.) were exposed to Z-3-HAC before they were inoculated with P. infestans genotypes at different time points. These pre-exposed potato plants exhibited slower disease development after infection with the highly pathogenic genotype of P. infestans (EU-13-A2) over time. Qualitative assessment showed that the exposed, infected plants possessed significantly lower sporulation intensity and disease severity compared to the control plants. Hypersensitive response (HR)-like symptoms were observed on the treated leaves when inoculated with different pathogen genotypes. No HR-like lesions were detected on the untreated leaves after infection. It was shown that the transcript levels of several defense-related genes, especially those that are involved in reactive oxygen species (ROS) production pathways were significantly expressed in plants at 48 and 72 h postexposure to the Z-3-HAC. The current work provides evidence on the role of Z-3-HAC in the increased protection of potato plants against late blight through plant immunity and offers new opportunities for the sustainable control of potato diseases.


2021 ◽  
Vol 22 (24) ◽  
pp. 13506
Author(s):  
Peng Wu ◽  
Ailian Liu ◽  
Yongyan Zhang ◽  
Kai Feng ◽  
Shuping Zhao ◽  
...  

Starch is an important component in lotus. ABA is an important plant hormone, which plays a very crucial role in regulating plant starch synthesis. Using ‘MRH’ as experimental materials, the leaves were sprayed with exogenous ABA before the rhizome expansion. The results showed that stomatal conductance and transpiration rate decreased while net photosynthetic rate increased. The total starch content of the underground rhizome of lotus increased significantly. Meanwhile, qPCR results showed that the relative expression levels of NnSS1, NnSBE1 and NnABI4 were all upregulated after ABA treatment. Then, yeast one-hybrid and dual luciferase assay suggested that NnABI4 protein can promote the expression of NnSS1 by directly binding to its promoter. In addition, subcellular localization results showed that NnABI4 encodes a nuclear protein, and NnSS1 protein was located in the chloroplast. Finally, these results indicate that ABA induced the upregulated expression of NnABI4, and NnABI4 promoted the expression of NnSS1 and thus enhanced starch accumulation in lotus rhizomes. This will provide a theoretical basis for studying the molecular mechanism of ABA regulating starch synthesis in plant.


2019 ◽  
Author(s):  
hennypuspitasari ◽  
Warnita

Research on the growth and formation of potato tubers was conducted to determine the effect of rhizobacteria isolates and coumarin applications growth inhibitors. Bacteria are isolated from the roots of potato plants that grow in the healthy roots of potato plants.The study used a two-factor complete randomized design with three replications. The first factor was rhizobacterial isolates BT.4.1 isolates, BT.4.2 isolates, BT.4.3 isolates. The second factor was the concentration of coumarin 0, 50, 100 and 150 mg L-1. Thus from the results of this study obtained of rhizobacteria BT.4.1, BT.4.3 and coumarin 100 - 150 mg L-1 increases the growth and yield of potato crops. Based on the results of potato tuber produced, the combination of BT.4.1 rhizobacteria, and coumarin 150 mg L-1 can increase growth and yield.


1994 ◽  
Vol 21 (6) ◽  
pp. 783 ◽  
Author(s):  
K Denyer ◽  
CM Hylton ◽  
AM Smith

The decrease in yield which is observed when developing storage organs such as cereal grains or potato tubers are exposed to high temperatures is due to a lower final starch content. The rate of starch synthesis during the development of these storage organs at high temperature, is either reduced or fails to increase sufficiently to compensate for the shorter developmental period. This effect on the rate of starch synthesis does not seem to be due to a reduction in the supply of photosynthate. One of the enzymes in the pathway of starch synthesis, soluble starch synthase, is susceptible to heat inactivation at unusually low temperatures and may also have a low optimum temperature for maximum activity. In some storage organs, the maximum catalytic activity of soluble starch synthase is not very much greater than the rate of starch synthesis. A decrease in the activity of this enzyme is therefore, likely to affect the rate of starch synthesis. Thus, the effect of high temperature on the rate of starch synthesis may be due, at least in part, to the properties of this enzyme. This review discusses the unusual heat-sensitivity of starch synthase in the context ofthe effects of high temperature on starch synthesis in storage organs.


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