Expression patterns of two starch biosynthetic genes in in vitro cultured cassava plants and their induction by sugars

Salehuzzaman, S.N.I.M.; Jacobsen, E.; Visser, Richard G. F.

doi:10.1016/0168-9452(94)90147-3

Cited by 26 publications

(18 citation statements)

References 18 publications

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“…The observed tissue specific expression pattern of Meisa1 was similar with previously reported patterns from other starch metabolizing genes in cassava (Salehuzzaman et al, 1992;Salehuzzaman et al, 1994;Baguma et al, 2003). Meisa1 declined with increased developmental stage of the storage root (Fig.…”

Section: Spatial and Temporal Expression Of Meisa1supporting

confidence: 87%

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Characterisation and role of <i>Isoamylase1 (Meisa1</i>) gene in cassava

Beyene¹,

Baguma²,

Mukasa³

et al. 2010

African Crop Science Journal

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The current concept for starch biosynthesis in plants is that amylopectin, the major fraction of starch, is synthesised by the concerted actions of ADP-Glc pyrophosphorylase (AGPase), soluble starch synthase (SS), starch-branching enzyme (BE), and starch-debranching enzyme (DBE). We have isolated a cDNA clone of Isoamylase1 gene, a member of DBE family from cassava (Manihot esculenta Crantz) storage root. The cloned cDNA fragment sequence (764 bp) showed high identity of 90% to Rcisa1, and 81% identity to Psisa1, Stisa1 and Atisa1. The deduced protein sequence showed highest (92%) identity with RCISA1. The comparative sequence analysis confirmed the cloned fragment to be M. esculenta isoamylase1 gene (Meisa1; accession number GU229751). Genomic analysis revealed occurrence of at least two copies of the Meisa1 gene. Highest Meisa1 transcript expression levels were detected in fibrous root followed by in the stem and least detected in the leaf and petiole. Analysis of the temporal expression pattern in the storage root showed initial and maximum expression at 90 days after planting (DAP), and declined thereafter to undetectable levels by 180 DAP. The results implicate a major role of Meisa1 in storage root differentiation and early starch granule initiation.

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Section: Spatial and Temporal Expression Of Meisa1supporting

confidence: 87%

“…Total RNA was isolated from different cassava plant parts using the extraction buffer described by Salehuzzaman et al (1994) with addition of 50 mM of ß marcaptoethanol. 50 µg of total RNA was electrophoresed on denatured agarose gel and blotted onto nylon membranes (Hybond-N, Amersham) according to Sambrook et al's (1989) method.…”

Section: Methodsmentioning

confidence: 99%

Characterisation and role of <i>Isoamylase1 (Meisa1</i>) gene in cassava

Beyene¹,

Baguma²,

Mukasa³

et al. 2010

African Crop Science Journal

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“…Expression of Susy, AGPase and GBSSI genes was slightly negatively affected, due to sucrose conversion of DSRS. This might influence the expression level of these genes that are known to be transcriptionally regulated by sucrose (Geigenberger, 2003;Salehuzzaman et al, 1994). SSIII and SBEI expression levels were not significantly changed, probably because these enzymes are less sensitive to modifications in sucrose supply.…”

Section: Discussionmentioning

confidence: 99%

Production of dextran in transgenic potato plants

et al. 2005

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The production of dextran in potato tubers and its effect on starch biosynthesis were investigated. The mature dextransucrase (DsrS) gene from Leuconostoc mesenteroides was fused to the chloroplastic ferredoxin signal peptide (FD) enabling amyloplast entry, which was driven by the highly tuber-expressed patatin promoter. After transformation of two potato genotypes (cv. Kardal and the amylose-free (amf) mutant), dextrans were detected by enzyme-linked immunosorbent assay (ELISA) in tuber juices of Kardal and amf transformants. The dextran concentration appeared two times higher in the Kardal (about 1.7 mg/g FW) than in the amf transformants. No dextran was detected by ELISA inside the starch granule. Interestingly, starch granule morphology was affected, which might be explained by the accumulation of dextran in tuber juices. In spite of that, no significant changes of the physicochemical properties of the starches were detected. Furthermore, we have observed no clear changes in chain length distributions, despite the known high acceptor efficiency of DSRS.

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“…The ADP-Glc pyrophosphorylase gene (AGPase S) from potato and the genes encoding granule-bound starch synthase and SBE in cassava plants have been shown to be induced by an exogenous supply of sugars (MullerRober et al, 1990;Giroux et al, 1994;Salehuzzaman et al, 1994). This led us to speculate that the Sbe1 gene in maize may also be regulated by the external sugar concentration.…”

Section: Expression Of the Sbe1 Gene Is Sugar Regulatedmentioning

confidence: 99%

“…Gao et al (1996) showed that Sbe1 and Sbe2b are expressed in a coordinate fashion with the granule-bound starch synthase and ADP-Glc pyrophosphorylase, respectively, during maize endosperm development. The finding that many genes involved in starch biosynthesis are regulated by sugar availability (Muller-Rober et al, 1990;Koch et al, 1992;Giroux et al, 1994;Salehuzzaman et al, 1994;Fu et al, 1995b) suggests that they may share common regulatory mechanisms controlling their expression. Therefore, knowledge of the regulatory mechanisms for one of the starch biosynthetic genes aid in the understanding of how the other genes are controlled in plants.…”

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confidence: 99%

Identification ofcis-Acting Elements Important for Expression of the Starch-Branching Enzyme I Gene in Maize Endosperm

Kim

Guiltinan

1999

Plant Physiology

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The genes encoding the starch-branching enzymes (SBE) SBEI, SBEIIa, and SBEIIb in maize (Zea mays) are differentially regulated in tissue specificity and during kernel development. To gain insight into the regulatory mechanisms controlling their expression, we analyzed the 5-flanking sequences of Sbe1 using a transient gene expression system. Although the 2.2-kb 5-flanking sequence between ؊2,190 and ؉27 relative to the transcription initiation site was sufficient to promote transcription, the addition of the transcribed region between ؉28 and ؉228 containing the first exon and intron resulted in high-level expression in suspension-cultured maize endosperm cells. A series of 5 deletion and linkersubstitution mutants identified two critical positive cis elements, ؊314 to ؊295 and ؊284 to ؊255. An electrophoretic mobility-shift assay showed that nuclear proteins prepared from maize kernels interact with the 60-bp fragment containing these two elements. Expression of the Sbe1 gene is regulated by sugar concentration in suspension-cultured maize endosperm cells, and the region ؊314 to ؊145 is essential for this effect. Interestingly, the expression of mEmBP-1, a bZIP transcription activator, in suspension-cultured maize endosperm cells resulted in a 5-fold decrease in Sbe1 promoter activity, suggesting a possible regulatory role of the G-box present in the Sbe1 promoter from ؊227 to ؊220.Starch, the major form of carbon and energy reserve in plants, provides a major caloric source for the human population of the world and is also an important industrial commodity. Although the pathway of starch biosynthesis is not completely understood, there is no doubt that it involves at least four groups of committed enzymes: ADPGlc pyrophosphorylase (EC 2.7.7.23), starch synthase (EC 2.4.1.21), starch-branching enzyme (SBE; EC 2.4.1.28) and starch-debranching enzyme (EC 2.4.1.41) (for review, see Preiss, 1991;Martin and Smith, 1995).SBEs catalyze the formation of amylopectin by introducing ␣-1,6 branch points into the linear ␣-1,4-linked Glc chains. The introduction of branches not only changes many of chemical and physical properties of starch, but also facilitates starch synthesis by increasing the number of nonreducing ends, the site of Glc addition by starch synthases. Thus, SBEs are of crucial importance for the quantity and quality of starch synthesized in the plant (Edwards et al., 1988). In fact, mutations in Sbe genes of pea, maize (Zea mays), and rice severely decreases the total starch content and changes the ratio of amylose and amylopectin (Shannon and Garwood, 1984;Smith, 1988; Bhattacharyya et al., 1990;Mizuno et al., 1993).Multiple forms of SBEs, differing in enzymatic and biochemical properties, have been identified and characterized in various plants, such as spinach (Hawker, 1974), pea (Matters and Boyer, 1981;Smith, 1988), potato (Griffin and Wu, 1968;Khoshnoodi et al., 1993), teosinte (Boyer and Fisher, 1984), rice (Mizuno et al., 1992;Nakamura et al., 1992;Yamanouchi and Nakamura, 1992), and maize (Hodg...

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Expression patterns of two starch biosynthetic genes in in vitro cultured cassava plants and their induction by sugars

Cited by 26 publications

References 18 publications

Characterisation and role of <i>Isoamylase1 (Meisa1</i>) gene in cassava

Characterisation and role of <i>Isoamylase1 (Meisa1</i>) gene in cassava

Production of dextran in transgenic potato plants

Identification ofcis-Acting Elements Important for Expression of the Starch-Branching Enzyme I Gene in Maize Endosperm

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