Co-expression of AGPS and AGPL genes encoded for AGPase from cassava to enhance starch accumulation in transgenic tobacco

2016 ◽  
Vol 14 (2) ◽  
pp. 287-293
Author(s):  
Nguyễn Văn Đoài ◽  
Nguyễn Minh Hồng ◽  
Lê Thu Ngọc ◽  
Nguyễn Thị Thơm ◽  
Nguyễn Đình Trọng ◽  
...  

The AGPase (ADP-Glucose pyrophosphorylase) is one of the ubiquitous enzymes catalyzing the first step in starch biosynthesis. It plays an important role in regulation and adjusts the speed of the entire cycle of glycogen biosynthesis in bacteria and starch in plants. In higher plants, it is a heterotetramer and tetrameric enzyme consisting two large subunits (AGPL) and two small subunits (AGPS) and encoded by two genes. In this paper, both AGPS and AGPL genes were sucessfully isolated from cassava varieties KM140 and deposited in Genbank with accession numbers KU243124 (AGPS) and KU243122 (AGPL), these two genes were fused with P2a and inserted into plant expression vector pBI121 under the control of 35S promoter. The efficient of this construct was tested in transgenic N. tabacum. The presence and expression of AGPS and AGPL in transgenic plants were confirmed by PCR and Western hybridization. The starch content was quantified by the Anthrone method. Transgenic plant analysis indicated that that two targeted genes were expressed simultaneously in several transgenic tobacco lines under the control of CaMV 35S promoter.  The starch contents in 4 analyzed tobacco transgenic lines displays the increase 13-116%  compared to WT plants. These results indicated that the co-expression of AGPS and AGPL is one of effective strategies for enhanced starch production in plant. These results can provide a foundation for developing other genetically modified crops to increase starch accumulation capacity.

2016 ◽  
Vol 14 (1) ◽  
pp. 139-148
Author(s):  
Lê Thu Ngọc ◽  
Nguyễn Mậu Hưng ◽  
Đinh Văn Hùng ◽  
Nguyễn Thị Minh Hồng ◽  
Phạm Bích Ngọc ◽  
...  

Starch is the primary storage polysaccharide in plants.  It not only plays a role as the most important nutritional component in the diet of humans and many animal species, but is also a raw material in the food processing industry or material industry. Therefore, a current research direction is the improvement of crops by increasing starch yields based on enhancing the activity of key enzymes involved in starch biosynthesis by genetic engineering. ADP-Glc pyrophosphorylase (AGPase) is an important regulatory enzyme for synthesis of glycogen in bacteria and starch in plants. In this paper, the 1.5 kb synthetic mutant of AGPopt gene derived from E. coli AGPase was inserted into the plant expression vector pBI121 under the control of 35S promoter. The efficiency of this construct was tested in transgenic Nicotiana tabacum. The integration of AGPopt into the plant genome was confirmed by PCR and Southern hybridization, and the expression of bacterial AGPase in transgenic lines was detected by Western hybridization. Interestingly, starch assays in 7 tobacco transgenic lines resulted in 5 lines displaying an increase in the levels of starch accumulated in the leaves, approximately 18%–56% higher than those of WT plants. These results indicate that the expression of AGPopt is one of effective strategies for enhanced starch production in plant.


Biologia ◽  
2014 ◽  
Vol 69 (7) ◽  
Author(s):  
Hongli Li ◽  
Diqiu Liu ◽  
Jian Rao ◽  
Yalong Liu ◽  
Feng Ge ◽  
...  

AbstractDrought and salinity are the major abiotic stresses, which reduce agricultural productivity. In plants, 14-3-3s function as regulators of many target proteins through direct protein-protein interactions and play an important role during response to abiotic stresses. Here we report that CaMV 35S promoter driven overexpression of a Pyrus pyrifolia 14-3-3 gene, Pp14-3-3, improves drought and NaCl tolerance in T1 generation plants of transgenic tobacco (Nicotiana tabacum L. cv Xanthi). Under drought and NaCl stresses, the Pp14-3-3 was largely expressed in T1 transgenic tobacco lines, and compared with the wild-type (WT), transgenic tobacco plants showed relatively normal growth condition. In addition, the levels of membrane lipid peroxidation in T1 transgenic lines were definitely lower than that in WT according to the significantly decreased content of malondialdehyde. Meanwhile, the T1 transgenic tobacco lines showed significantly slower superoxide anion production rate than the WT under abiotic stress. Moreover, both the glutathione S-transferase (GST) and ascorbate peroxidase (APX) activities in T1 transgenic lines were markedly higher than those in WT. GSTs and APXs are important components of plant antioxidant system, and the results of present study suggested that Pp14-3-3 should play a crucial role in reducing oxidative damage caused by drought and salt stresses.


2020 ◽  
Vol 26 ◽  
pp. 164-168
Author(s):  
A. Yu. Buziashvili ◽  
A. I. Yemets

Aim. Obtaining of tobacco lines (Nicotiana tabacum L.) stably transformed with human lactoferrin gene (hLf), analysis of transgenic lines. Methods. Agrobacterium-mediated transformation of tobacco was carried out with the use of pBin35LF plasmid containing human lactoferrin gene under control of 35S promoter of cauliflower mosaic virus (CaMV 35S) and selective npt II gene encoding neomicyne phosphotransferase II providing the resistance to kanamycin. The selection of transgenic lines was carried out for 3 months on MS medium supplemented with 100 mg/l of kanamycin. Integration of lactoferrin gene was confirmed with the use of PCR with primers specific to hLf gene. The investigation of karyotype of transgenic lines was carried out after the staining of the root cells with 1 % solution of acetoorseine. Results. After selection, 2 transgenic tobacco lines with confirmed integration of hLf gene were obtained. The transformation efficiency was 6.4 %. The chromosome number in transgenic and control lines was 2n=48. Conclusions. The obtained transgenic tobacco lines have the similar morphology and karyotype to control lines, so they could be considered to use as plant systems for the expression of recombinant human lactoferrin. Keywords: human lactoferrin gene hLf, Nicotiana tabacum L., Agrobacterium-mediated transformation, PCR, chromosomes, transgenic plants.


Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1084
Author(s):  
Ivan N. Ivanov ◽  
Vilém Zachleder ◽  
Milada Vítová ◽  
Maria J. Barbosa ◽  
Kateřina Bišová

An increase in temperature can have a profound effect on the cell cycle and cell division in green algae, whereas growth and the synthesis of energy storage compounds are less influenced. In Chlamydomonas reinhardtii, laboratory experiments have shown that exposure to a supraoptimal temperature (39 °C) causes a complete block of nuclear and cellular division accompanied by an increased accumulation of starch. In this work we explore the potential of supraoptimal temperature as a method to promote starch production in C. reinhardtii in a pilot-scale photobioreactor. The method was successfully applied and resulted in an almost 3-fold increase in the starch content of C. reinhardtii dry matter. Moreover, a maximum starch content at the supraoptimal temperature was reached within 1–2 days, compared with 5 days for the control culture at the optimal temperature (30 °C). Therefore, supraoptimal temperature treatment promotes rapid starch accumulation and suggests a viable alternative to other starch-inducing methods, such as nutrient depletion. Nevertheless, technical challenges, such as bioreactor design and light availability within the culture, still need to be dealt with.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yerong Zhu ◽  
Xiaoxue Li ◽  
Xuan Gao ◽  
Jiqi Sun ◽  
Xiaoyuan Ji ◽  
...  

Abstract Background Duckweed is considered a promising feedstock for bioethanol production due to its high biomass and starch production. The starch content can be promoted by plant growth regulators after the vegetative reproduction being inhibited. Maleic hydrazide (MH) has been reported to inhibit plant growth, meantime to increase biomass and starch content in some plants. However, the molecular explanation on the mechanism of MH action is still unclear. Results To know the effect and action mode of MH on the growth and starch accumulation in Spirodela polyrrhiza 7498, the plants were treated with different concentrations of MH. Our results showed a substantial inhibition of the growth in both fronds and roots, and increase in starch contents of plants after MH treatment. And with 75 µg/mL MH treatment and on the 8th day of the experiment, starch content was the highest, about 40 mg/g fresh weight, which is about 20-fold higher than the control. The I2-KI staining and TEM results confirmed that 75 µg/mL MH-treated fronds possessed more starch and big starch granules than that of the control. No significant difference for both in the photosynthetic pigment content and the chlorophyll fluorescence parameters of PII was found. Differentially expressed transcripts were analyzed in S. polyrrhiza 7498 after 75 µg/mL MH treatment. The results showed that the expression of some genes related to auxin response reaction was down-regulated; while, expression of some genes involved in carbon fixation, C4 pathway of photosynthesis, starch biosynthesis and ABA signal transduction pathway was up-regulated. Conclusion The results provide novel insights into the underlying mechanisms of growth inhibition and starch accumulation by MH treatment, and provide a selective way for the improvement of starch production in duckweed.


2017 ◽  
Vol 37 (2) ◽  
pp. 517-529 ◽  
Author(s):  
Ya-Jing Guo ◽  
Xing-Lu Luo ◽  
Mao-Gui Wei ◽  
Zhao-Liang Liu ◽  
Wu-Jing Fan ◽  
...  

2010 ◽  
Vol 100 (6) ◽  
pp. 573-581 ◽  
Author(s):  
Tingquan Wu ◽  
An Guo ◽  
Yanying Zhao ◽  
Xiaomeng Wang ◽  
Ying Wang ◽  
...  

Lumazine synthase (LS) catalyzes the penultimate reaction in the multistep riboflavin biosynthesis pathway, which is involved in plant defenses. Plant defenses are often subject to synergistic effects of jasmonic acid and ethylene whereas LS is a regulator of jasmonic acid signal transduction. However, little is known about whether the enzyme contributes to defense responses. To study the role of LS in plant pathogen defenses, we generated transgenic tobacco expressing the rice (Oryza sativa) LS gene, OsLS. OsLS was cloned and found to have strong identity with its homologues in higher plants and less homology to microbial orthologues. The OsLS protein localized to chloroplasts in three OsLS-expressing transgenic tobacco (LSETT) lines characterized as enhanced in growth and defense. Compared with control plants, LSETT had higher content of both riboflavin and the cofactors flavin mononucleotide and flavin adenine dinucleotide. In LSETT, jasmonic acid and ethylene were elevated, the expression of defense-related genes was induced, levels of resistance to pathogens were enhanced, and resistance was effective to viral, bacterial, and oomycete pathogens. Extents of OsLS expression correlated with increases in flavin, jasmonic acid, and ethylene content, and correlated with increases in resistance levels, suggesting a role for OsLS in defense responses.


2012 ◽  
Vol 39 (9) ◽  
pp. 764 ◽  
Author(s):  
Gi-Ho Lee ◽  
Seong-Han Sohn ◽  
Eun-Young Park ◽  
Young-Doo Park

The chemical modification of DNA by methylation is a heritable trait and can be subsequently reversed without altering the original DNA sequence. Methylation can reduce or silence gene expression and is a component of a host’s defence response to foreign nucleic acids. In our study, we employed a plant transformation strategy using Nicotiana benthamiana Domin to study the heritable stability of the introduced transgenes. Through the introduction of the cauliflower mosaic virus (CaMV) 35S promoter and the green fluorescent protein (GFP) reporter gene, we demonstrated that this introduced promoter often triggers a homology-dependent gene-silencing (HDGS) response. These spontaneous transgene-silencing phenomena are due to methylation of the CaMV 35S promoter CAAT box during transgenic plant growth. This process is catalysed by SU(VAR)3–9 homologue 9 (SUVH9), histone deacetylase 1 (HDA1) and domains rearranged methylase 2 (DRM2). In particular, we showed from our data that SUVH9 is the key regulator of methylation activity in epigenetically silenced GFP transgenic lines; therefore, our findings demonstrate that an introduced viral promoter and transgene can be subject to a homology-dependent gene-silencing mechanism that can downregulate its expression and negatively influence the heritable stability of the transgene.


2016 ◽  
Vol 10 (1) ◽  
pp. 63-70
Author(s):  
Palupi Puspitorini ◽  
Dyah Pitaloka ◽  
Tri Kurniastuti

This study aims to find out the results of cassava tuber crop UJ5 variety at different harvest ages. Research direction is that cassava varieties have been planted throughout Indonesia as the best producer of cassava varieties. High levels of starch and high HCN content makes this variety was selected by the factory - tapioca factory in Indonesia. Research design used randomized block design with 7 treatments of harvesting (UP) were repeated 3 times. UP6 (harvesting 6 MAP), UP7 (harvesting 7 MAP), UP8 (harvesting 8 MAP), UP9 (harvesting 9 MAP), UP10 (harvesting 10 MAP), UP11 (harvesting 11 MAP), UP12 ( harvesting 12 MAP). The research variables are the fresh weight of tuber, tuber starch content (%), the weight of biomass, harvest index, number of tubers per plant. The results showed that the best harvesting time is UP9 the results did not differ with UP10, UP11 and UP12


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