Molecular Cloning and Spatial Expression of an ApL1 cDNA for the Large Subunit of ADP-Glucose Pyrophosphorylase from Arabidopsis thaliana

1999 ◽  
Vol 54 (5-6) ◽  
pp. 353-358 ◽  
Author(s):  
Leszek A. Kleszkowski ◽  
Lubomir N. Sokolov ◽  
Cheng Luo ◽  
Per Villand
Keyword(s):  
Arabidopsis Thaliana ◽  
Large Subunit ◽  
Critical Role ◽  
Starch Synthesis ◽  
Transit Peptide ◽  
Homologous Proteins ◽  
Peptide Cleavage ◽  
Reading Frame ◽  
Calculated Molecular Weight ◽  
Adp Glucose Pyrophosphorylase

Abstract A cDNA, A p L 1a , corresponding to a homologue of the large subunit of ADP-glucose pyrophosphorylase (AG Pase), has been isolated/characterised by screening a cDNA library prepared from leaves of Arabidopsis thaliana, followed by rapid amplification of cDNA 3′-ends (3′-RACE). Within the 1685 nucleotide-long sequence (excluding polyA tail), an open reading frame encodes a protein of 522 amino acids (aa), with a calculated molecular weight of 57.7 kDa. The derived aa sequence does not contain any discernible transit peptide cleavage site motif, similarly to two other recently sequenced full-length Arabidopsis homo-logues for AGPase, and shows ca. 58–78 % identity to homologous proteins from other plants/tissues. The corresponding gene was found (rosette and stem leaves, stems, flowers and fruits), consistent with its critical role in starch synthesis in

scholarly journals Structure and expression analysis of genes encoding ADP-glucose pyrophosphorylase large subunit in wheat and its relatives

Genome ◽  
2016 ◽  
Vol 59 (7) ◽  
pp. 501-507 ◽  
Author(s):  
Xiao-Wei Zhang ◽  
Si-Yu Li ◽  
Ling-Ling Zhang ◽  
Qiang Yang ◽  
Qian-Tao Jiang ◽  
...  
Keyword(s):  
Large Subunit ◽  
Full Length ◽  
Starch Accumulation ◽  
Coding Region ◽  
D Genome ◽  
Reading Frame ◽  
B Genome ◽  
Genome Donor ◽  
Adp Glucose Pyrophosphorylase ◽  
Donor Species

ADP-glucose pyrophosphorylase (AGP), which consists of two large subunits (AGP-L) and two small subunits (AGP-S), controls the rate-limiting step in the starch biosynthetic pathway. In this study, a full-length open reading frame (ORF) of AGP-L gene (named as Agp2) in wheat and a series of Agp2 gene sequences in wheat relatives were isolated. The coding region of Agp2 contained 15 exons and 14 introns including a full-length ORF of 1566 nucleotides, and the deduced protein contained 522 amino acids (57.8 kDa). Generally, the phylogenetic tree of Agp2 indicated that sequences from A- and D-genome donor species were most similar to each other and sequences from B-genome donor species contained more variation. Starch accumulation and Agp2 expression in wheat grains reached their peak at 21 and 15 days post anthesis (DPA), respectively.

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 A single gene encodes two different transcripts for the ADP-glucose pyrophosphorylase small subunit from barley (Hordeum vulgare)

1996 ◽  
Vol 313 (1) ◽  
pp. 149-154 ◽  
Author(s):  
Tine THORBJØRNSEN ◽  
Per VILLAND ◽  
Leszek A. KLECZKOWSKI ◽  
Odd-Arne OLSEN
Keyword(s):  
Hordeum Vulgare ◽  
Genomic Library ◽  
Single Gene ◽  
Starch Synthesis ◽  
Transit Peptide ◽  
Small Subunit ◽  
Peptide Sequence ◽  
Subunit Gene ◽  
Starchy Endosperm ◽  
Adp Glucose Pyrophosphorylase

ADP-glucose pyrophosphorylase (AGPase), a heterotetrameric enzyme composed of two small and two large subunits, catalyses the first committed step of starch synthesis in plant tissues. In an attempt to learn more about the organization and expression of the small-subunit gene of AGPase, we have studied the small-subunit transcripts as well as the structure of the gene encoding these transcripts in barley (Hordeum vulgare L. cv. Bomi). Two different transcripts (bepsF1 and blps14) were identified: bepsF1 was abundantly expressed in the starchy endosperm but not in leaves, whereas blps14 was isolated from leaves but was also found to be present at a moderate level in the starchy endosperm. The sequences for the two transcripts are identical over approx. 90% of the length, with differences being confined solely to their 5ʹ ends. In blps14, the unique 5ʹ end is 259 nt long and encodes a putative plastid transit peptide sequence. For the 178-nt 5ʹ end of bepsF1, on the other hand, no transit peptide sequence could be recognized. A lambda clone that hybridized to the AGPase transcripts was isolated from a barley genomic library and characterized. The restriction map has suggested a complex organization of the gene, with alternative exons encoding the different 5ʹ ends of the two transcripts followed by nine exons coding for the common part of the transcripts. The sequence of a portion of the genomic clone, covering the alternative 5ʹ-end exons as well as upstream regions, has verified that both transcripts are encoded by the gene. The results suggest that the small-subunit gene of barley AGPase transcribes two different mRNAs by a mechanism classified as alternative splicing.

Cloning and expression analysis of cDNAs encoding ADP-glucose pyrophosphorylase large and small subunits from hulless barley (Hordeum vulgare L. var. nudum)

2018 ◽  
Vol 73 (5-6) ◽  
pp. 191-197 ◽  
Author(s):  
Dongmei Li ◽  
Zhimin Yang ◽  
Xinchun Liu ◽  
Zhen Song ◽  
Zongyun Feng ◽  
...  
Keyword(s):  
Accumulation Rate ◽  
Large Subunit ◽  
Starch Synthesis ◽  
Small Subunit ◽  
Cloning And Expression ◽  
Starch Accumulation ◽  
Hordeum Vulgare L ◽  
Hulless Barley ◽  
Expression Levels ◽  
Adp Glucose Pyrophosphorylase

Abstract As an important plateau cereal crop, hulless barley is the principal food for the Tibetan people in China. ADP-glucose pyrophosphorylase (AGPase) is considered as the key enzyme for starch biosynthesis in plants. In this study, cDNAs encoding the small subunit (SSU I) and large subunit (LSU I) of AGPase were isolated from hulless barley. The results showed that SSU I and LSU I were 1438 and 1786 bp in length with a complete open reading frame (ORF) of 1419 and 1572 bp. The ORF-encoded polypeptides of 472 and 523 amino acids were having calculated molecular masses of 52.01 and 58.23 kDa, and the pI values were 5.59 and 6.30. In addition, phylogenetic analysis showed that SSU I and LSU I had the same phylogenetic trends with some species. Furthermore, expression levels in different growth periods and tissues of two hulless barley varieties were analyzed by quantitative reverse transcription-polymerase chain reaction. Gene expression levels of SSU I and LSU I were consistent with the total starch accumulation rate in endosperm. In conclusion, our data confirmed that SSU I and LSU I played an important role in hulless barley starch synthesis.

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.

scholarly journals Programmed chloroplast destruction during leaf senescence involves 13-lipoxygenase (13-LOX)

2016 ◽  
Vol 113 (12) ◽  
pp. 3383-3388 ◽  
Author(s):  
Armin Springer ◽  
ChulHee Kang ◽  
Sachin Rustgi ◽  
Diter von Wettstein ◽  
Christiane Reinbothe ◽  
...  
Keyword(s):  
Leaf Senescence ◽  
Critical Role ◽  
Transit Peptide ◽  
Physiological Changes ◽  
Pathogen Defense ◽  
Chloroplast Transit Peptide ◽  
Selective Destruction ◽  
Plastid Envelope ◽  
Volatile Aldehydes

Leaf senescence is the terminal stage in the development of perennial plants. Massive physiological changes occur that lead to the shut down of photosynthesis and a cessation of growth. Leaf senescence involves the selective destruction of the chloroplast as the site of photosynthesis. Here, we show that 13-lipoxygenase (13-LOX) accomplishes a key role in the destruction of chloroplasts in senescing plants and propose a critical role of its NH2-terminal chloroplast transit peptide. The 13-LOX enzyme identified here accumulated in the plastid envelope and catalyzed the dioxygenation of unsaturated membrane fatty acids, leading to a selective destruction of the chloroplast and the release of stromal constituents. Because 13-LOX pathway products comprise compounds involved in insect deterrence and pathogen defense (volatile aldehydes and oxylipins), a mechanism of unmolested nitrogen and carbon relocation is suggested that occurs from leaves to seeds and roots during fall.

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