scholarly journals MePHD1 as a PHD-Finger Protein Negatively Regulates ADP-Glucose Pyrophosphorylase Small Subunit1a Gene in Cassava

2018 ◽  
Vol 19 (9) ◽  
pp. 2831 ◽  
Author(s):  
Ping’an Ma ◽  
Xin Chen ◽  
Chen Liu ◽  
Zhiqiang Xia ◽  
Yu Song ◽  
...  
Keyword(s):  
Starch Content ◽  
Starch Synthesis ◽  
Transcript Level ◽  
Negative Regulator ◽  
Luciferase Assay ◽  
Translation Initiation Site ◽  
Storage Root ◽  
Manihot Esculenta Crantz ◽  
Adp Glucose Pyrophosphorylase

ADP-glucose pyrophosphorylase (AGPase) is an important enzyme in the starch synthesis pathway. Its enzyme activity can determine the efficiency of starch biosynthesis. Cassava (Manihot esculenta Crantz) is the main staple crop worldwide and has a high starch content in its storage root. However, the inner regulatory mechanism of AGPase gene family is unclear. MePHD1; a plant homeodomain transcription factor; was isolated through a yeast one-hybrid screening using the promoter of ADP-glucose pyrophosphorylase small subunit1a (MeAGPS1a) as bait, and cassava storage root cDNA library as prey. This factor could bind to the MeAGPS1a promoter in vitro and in vivo, and its predicted binding region ranged from −400 bp to −201 bp, at the translation initiation site. The transcript level of MePHD1 could be induced by five plant hormones, and a temperature of 42 °C. This was down-regulated during the maturation process of the storage root. MePHD1 protein could repress the promoter activity of MeAGPS1a gene by a dual-luciferase assay; which indicated that MePHD1 is a negative regulator for the transcript level of MeAGPS1a gene.

The NAC transcription factor NAC019-A1 is a negative regulator of starch synthesis in wheat developing endosperm

2020 ◽  
Vol 71 (19) ◽  
pp. 5794-5807
Author(s):  
Yunchuan Liu ◽  
Jian Hou ◽  
Xiaolu Wang ◽  
Tian Li ◽  
Uzma Majeed ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Oryza Sativa L ◽  
Starch Content ◽  
Wheat Yield ◽  
Starch Synthesis ◽  
Kernel Weight ◽  
Nac Transcription Factor ◽  
Negative Regulator ◽  
Starch Granules ◽  
Wheat Endosperm

Abstract Starch is a major component of wheat (Triticum aestivum L.) endosperm and is an important part of the human diet. The functions of many starch synthesis genes have been elucidated. However, little is known about their regulatory mechanisms in wheat. Here, we identified a novel NAC transcription factor, TaNAC019-A1 (TraesCS3A02G077900), that negatively regulates starch synthesis in wheat and rice (Oryza sativa L.) endosperms. TaNAC019-A1 was highly expressed in the endosperm of developing grains and encoded a nucleus-localized transcriptional repressor. Overexpression of TaNAC019-A1 in rice and wheat led to significantly reduced starch content, kernel weight, and kernel width. The TaNAC019-A1-overexpression wheat lines had smaller A-type starch granules and fewer B-type starch granules than wild-type. Moreover, TaNAC019-A1 could directly bind to the ‘ACGCAG’ motif in the promoter regions of ADP-glucose pyrophosphorylase small subunit 1 (TaAGPS1-A1, TraesCS7A02G287400) and TaAGPS1-B1 (TraesCS7B02G183300) and repress their expression, thereby inhibiting starch synthesis in wheat endosperm. One haplotype of TaNAC019-B1 (TaNAC019-B1-Hap2, TraesCS3B02G092800) was positively associated with thousand-kernel weight and underwent positive selection during the Chinese wheat breeding process. Our data demonstrate that TaNAC019-A1 is a negative regulator of starch synthesis in wheat endosperm and provide novel insight into wheat yield improvement.

A mutant of rice lacking the leaf large subunit of ADP-glucose pyrophosphorylase has drastically reduced leaf starch content but grows normally

2007 ◽  
Vol 34 (6) ◽  
pp. 480 ◽  
Author(s):  
Sandrine Rösti ◽  
Brendan Fahy ◽  
Kay Denyer
Keyword(s):  
Environmental Conditions ◽  
No Reduction ◽  
Starch Content ◽  
Large Subunit ◽  
Starch Synthesis ◽  
Small Subunit ◽  
Wild Type ◽  
Gene Encoding ◽  
Subunit Protein ◽  
Adp Glucose Pyrophosphorylase

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.

scholarly journals Structural and functional characterizations of activin type 2B receptor (acvr2b) ortholog from the marine fish, gilthead sea bream, Sparus aurata: evidence for gene duplication of acvr2b in fish

2012 ◽  
Vol 49 (3) ◽  
pp. 175-192 ◽  
Author(s):  
Bruria Funkenstein ◽  
Ekaterina Krol ◽  
Elena Esterin ◽  
Yong-soo Kim
Keyword(s):  
Transforming Growth Factor ◽  
Sparus Aurata ◽  
Fish Larvae ◽  
Larval Growth ◽  
Amino Acid Sequences ◽  
Negative Regulator ◽  
Gilthead Sea Bream ◽  
Sea Bream ◽  
Luciferase Assay

Myostatin (MSTN), a negative regulator of muscle growth and a member of the transforming growth factor-β superfamily, can bind the two activin type 2 receptors (ACVR2). It has been previously shown that WT mice injected with ACVR2B extracellular domain (ACVR2B-ECD) had higher muscle mass. Likewise, fish larvae immersed inPichia pastorisculture supernatant, containing goldfish Acvr2b-ECD, showed enhanced larval growth. However, it is not clear whether fish Mstn1 and Mstn2 signal through the same receptor and whether fish express more than oneacvr2bgene. In the current study, three cDNAs encodingacvr2b(saacvr2b-1, saacvr2b-2a, and saacvr2b-2b) were cloned from gilthead sea bream. All three contain the short extracellular binding domain, a short transmembrane region, and a conserved catalytic domain of serine/threonine protein kinase. Bioinformatics analysis provided evidence for the existence of twoacvr2bgenes (acvr2b-1 andacvr2b-2) in several other fish species as well, probably as a result of gene or genome duplication. The two isoforms differ in their amino acid sequences. The direct inhibitory effect of Acvr2b-ECD on Mstn activity was testedin vitro. The saAcvr2b-1-ECD was expressed in the yeastP. pastoris. Evidence is provided for N-glycosylation of Acvr2b-1-ECD. The affinity-purified Acvr2b-1-ECD inhibited recombinant mouse/rat/human mature MSTN activity when determinedin vitrousing the CAGA-luciferase assay in A204 cells. A lower inhibitory activity was obtained when unprocessed purified, furin-digested, and activated saMstn1 was used. Results of this study demonstrate for the first time the existence of twoacvr2bgenes in fish. In addition, the study shows that bioactive fish Acvr2b-ECD can be produced fromP. pastoris.

scholarly journals VviWRKY40, a WRKY Transcription Factor, Regulates Glycosylated Monoterpenoid Production by VviGT14 in Grape Berry

Genes ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 485 ◽  
Author(s):  
Xiangyi Li ◽  
Lei He ◽  
Xiaohui An ◽  
Keji Yu ◽  
Nan Meng ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Transcript Level ◽  
Wrky Transcription Factor ◽  
Grape Berry ◽  
Luciferase Assay ◽  
Yeast Fermentation ◽  
Regulation Mechanism ◽  
Grape Berries ◽  
Arabidopsis Protoplast

Glycosylated volatile precursors are important, particularly in wine grape berries, as they contribute to the final aroma in wines by releasing volatile aglycones during yeast fermentation and wine storage. Previous study demonstrated that VviGT14 was functioned as a critical monoterpene glucosyltransferase in grape berry, while the transcriptional regulation mechanism of VviGT14 was still unknown. Here we identified VviWRKY40 as a binding factor of VviGT14 promoter by both DNA pull-down and yeast one-hybrid screening, followed by a series of in vitro verification. VviWRKY40 expression pattern negatively correlated with that of VviGT14 in grape berries. And the suppressor role of VviWRKY40 was further confirmed by using the dual luciferase assay with Arabidopsis protoplast and grape cell suspension system. Furthermore, the grape suspension cell ABA treatment study showed that ABA downregulated VviWRKY40 transcript level but promoted that of VviGT14, indicating that VviWRKY40 was at the downstream of ABA signal transduction network to regulate monoterpenoid glycosylation. These data extend our knowledge of transcriptional regulation of VviGT14, and provide new targets for grape breeding to alter monoterpenoid composition.

scholarly journals NnABI4-Mediated ABA Regulation of Starch Biosynthesis in Lotus (Nelumbo nucifera Gaertn)

2021 ◽  
Vol 22 (24) ◽  
pp. 13506
Author(s):  
Peng Wu ◽  
Ailian Liu ◽  
Yongyan Zhang ◽  
Kai Feng ◽  
Shuping Zhao ◽  
...  
Keyword(s):  
Theoretical Basis ◽  
Plant Hormone ◽  
Nuclear Protein ◽  
Starch Content ◽  
Starch Synthesis ◽  
Starch Biosynthesis ◽  
Luciferase Assay ◽  
Starch Accumulation ◽  
Exogenous Aba ◽  
Total Starch

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.

scholarly journals Studies toward the identification of transcription factors in cassava storage root

2003 ◽  
Vol 15 (3) ◽  
pp. 167-170 ◽  
Author(s):  
Cláudia Regina Batista de Souza ◽  
Elionor Rita Pereira de Almeida ◽  
Luiz Joaquim Castelo Branco Carvalho ◽  
Eugen Silvano Gander
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Manihot Esculenta ◽  
Plant Traits ◽  
Storage Root ◽  
Brazil Nut ◽  
Manihot Esculenta Crantz ◽  
Physiological Processes ◽  
Cassava Storage Root

Transcription factors play important roles in several physiological processes. In recent years many transcription factors have been isolated from plants and they are emerging as powerful tools in the manipulation of plant traits. In this work we initiated studies in order to isolate transcription factors from cassava (Manihot esculenta Crantz), an important tropical and subtropical crop. Our results show three kinds of proteins expressed differentially in cassava storage root and immunologically related to the opaque-2 transcription factor from maize. Southwestern experiments showed two proteins capable of interacting in vitro with the DNA sequence of the be2S1 gene from the Brazil nut tree.

scholarly journals Silencing GhAGPL1 Reduces the Quality and Quantity of Corms and Cormels in Gladiolus

2017 ◽  
Vol 142 (2) ◽  
pp. 119-125 ◽  
Author(s):  
Shanshan Seng ◽  
Jian Wu ◽  
Jiahui Liang ◽  
Fengqin Zhang ◽  
Qiuyan Yang ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Abscisic Acid ◽  
Starch Content ◽  
Large Subunit ◽  
Starch Synthesis ◽  
Transcript Level ◽  
Starch Accumulation ◽  
Sucrose Content ◽  
Gladiolus Hybridus ◽  
Rate Limiting

Starch accumulation is important during com development. ADP-glucose pyrophosphorylase (AGPase) is the rate-limiting enzyme in starch synthesis. AGPL is the large subunit of AGPase. Here, we isolated and characterized the large subunit of AGPase gene GhAGPL1 in gladiolus (Gladiolus hybridus). GhAGPL1 was highly expressed in sink organs (cormels and corms). The expression of GhAGPL1 was induced by glucose, sucrose, and mannitol, and it was repressed by abscisic acid (ABA). Overexpression of GhAGPL1 in the arabidopsis (Arabidopsis thaliana) apl1 mutant resulted in complementation of AGPase activity and thus starch synthesis. Silencing GhAGPL1 in gladiolus decreased the transcript level of GhAGPL1 and GhSus, and resulted in the reduction of AGPase activity and starch content in gladiolus corm and cormel. Meanwhile, sucrose content was higher in GhAGPL1-silenced corm. Surprisingly, silencing GhAGPL1 in gladiolus produced smaller corms and fewer number of cormels. Overall, GhAGPL1 contributed to the quality and quantity of gladiolus corms and cormels.

The Effects of Calcium on the In Vitro Cassava Storage Root Formation

2013 ◽  
Vol 726-731 ◽  
pp. 4529-4533 ◽  
Author(s):  
Yuan Yao ◽  
Yi Min ◽  
Meng Ting Geng ◽  
Xiao Hui Wu ◽  
Xin Wen Hu ◽  
...  
Keyword(s):  
Starch Content ◽  
Starch Synthesis ◽  
Starch Accumulation ◽  
Storage Roots ◽  
Synthesis Mechanism ◽  
Culture Techniques ◽  
Root Starch ◽  
Cassava Storage Root ◽  
Tissue Culture Techniques

Calcium can affect in vitro cassava storage roots formation and starch accumulation. Low concentration of calcium stimulates to induce in vitro cassava storage roots formation and the accumulation of starches. With the addition of calcium concentration, the diameter of the in vitro cassava storage roots was increased, but the induction rate and starch content was decreased. The scanning electron microscope observations SC124 in vitro cassava storage roots starch and field cultivation of cassava root starch, starch grains formed by these two different ways is very similar in size and shape. Our findings show that, apply tissue culture techniques to study the cassava starch synthesis mechanism is feasible.

PREPARATION AND CHARACTERISATION OF ACETYLATED WHEAT STARCH SUPPORTING FOR DIABETES TREATMENT

2018 ◽  
Vol 8 (5) ◽  
pp. 78-84
Author(s):  
Uyen Tran Thi Ngoc ◽  
Nam Nguyen Khac ◽  
Dung Tran Huu
Keyword(s):  
Physicochemical Properties ◽  
Resistant Starch ◽  
Starch Content ◽  
Degree Of Substitution ◽  
Wheat Starch ◽  
Diabetes Treatment ◽  
Glucose Response ◽  
Swelling Capacity ◽  
Wheat Starches

Background: The purpose of the study was to prepare acetylated wheat starches which have amylase hydrolysis resistant capacity to use as functional food supporting for diabetes treatment. Method: Acetate wheat starches were prepared by acetylation reaction of native wheat starch with different mole ratios of acetic anhydride. These starches were determined for the physicochemical properties by 1H-NMR, SEM, X-ray, DSC, solubility and swelling capacity, the resistant capacity by amylase hydrolysis in-vitro. Results: Acetate wheat starches were prepared successfully with the increase in acetyl content and degree of substitution corresponding with the increase of anhydride acetic, which resulted in the change of physicochemical properties of the wheat starches, including constitution, solubility, swelling capacity and contributed to the increase in resistant starch content in the acetate wheat starches. The AC150-9 containing 2.42% acetyl with degree of substitution 0,094 and resistant starch 32,11% is acceptable by FDA guideline about food safety. Conclusion: Acetate wheat starches contain low rate of digestive starch, while containing a higher proportion of resistant starch than natural wheat starch, possessing a high resistance to amylase activities. Thus, it is hope that this kind of starch to control the rapid increase of postprandual blood glucose response for diabetes treatments effectively. Key words: Acetate wheat starch, substitution, DS, RS, amylase

High-Pressure Homogenization Alters Physicochemical Properties and In Vitro Digestibility of Chinese Yam (Dioscorea Opposita Thunb.) Starch

2018 ◽  
Vol 18 (1) ◽  
pp. 10-15
Author(s):  
Wang Yi-Wei ◽  
He Yong-Zhao ◽  
An Feng-Ping ◽  
Huang Qun ◽  
Zeng Feng ◽  
...  
Keyword(s):  
High Pressure ◽  
Physicochemical Properties ◽  
Starch Content ◽  
In Vitro Digestibility ◽  
High Pressure Homogenization ◽  
Starch Granules ◽  
Cross Polarization ◽  
Chinese Yam ◽  
Crystal Type

In this study, Chinese yam starch-water suspension (8%) were subjected to high-pressure homogenization (HPH) at 100 MPa for increasing cycle numbers, and its effect of on the physicochemical properties of the starch was investigated. Results of the polarizing microscope observations showed that the starch granules were disrupted (i.e. greater breakdown value) after HPH treatment, followed by a decrease in cross polarization. After three HPH cycles, the crystallinity of starch decreased, while the crystal type remained unaltered. Meanwhile, the contents of rapidly digestible starch and slowly digestible starch were increased. On the contrary, resistant starch content was decreased. Our results indicate that HPH treatment resulted in reduction of starch crystallinity and increase of starch digestibility.

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