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

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.

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Starch synthesis and gelatinization properties of potato tubers

Ciência Rural ◽

10.1590/0103-8478cr20210050 ◽

2022 ◽

Vol 52 (4) ◽

Author(s):

Wang Su ◽

Guangji Ye ◽

Yun Zhou ◽

Jian Wang

Keyword(s):

Gene Expression ◽

Enzyme Activity ◽

Starch Granule ◽

Starch Content ◽

Starch Synthesis ◽

Starch Accumulation ◽

Enzyme Gene ◽

Middle Stage ◽

Pasting Temperature ◽

Starch Synthesis Enzyme

ABSTRACT: Biosynthesis is the only source of potato starch which is an important raw material for food processing, modified starch and biomass energy. However, it is not clear about the evolution of starch synthesis with tuber development in potato. The present study evaluated the differences of starch synthesis and gelatinization properties of potato tubers with different starch content. Relative to cultivars of medium and low starch content, cultivars of high starch content showed significantly higher SBEII gene expression, AGPase and SSS enzyme activity, and total starch content after middle stage of starch accumulation, and had smaller average starch granule size during whole process of tuber development, and had higher pasting temperature before late stages of tuber growth, and had lower pasting temperature after middle stage of starch accumulation. Path analysis showed that, after middle stage of starch accumulation, effects on starch gelatinization of cultivars with high, medium and low starch content represented starch synthesis enzyme activity > starch accumulation > starch granule distribution > starch synthesis enzyme gene expression, starch synthesis enzyme gene expression > starch synthesis enzyme activity > starch accumulation > starch granule distribution, starch synthesis enzyme gene expression > starch granule distribution > starch synthesis enzyme activity > starch accumulation, respectively. In the study, phases existed in the starch biosynthesis of potato tuber, and the starch quality and its formation process were different among varieties with different starch content. The findings might contribute to starch application and potato industries.

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Expression of Maize MADS Transcription Factor ZmES22 Negatively Modulates Starch Accumulation in Rice Endosperm

International Journal of Molecular Sciences ◽

10.3390/ijms20030483 ◽

2019 ◽

Vol 20 (3) ◽

pp. 483 ◽

Cited By ~ 4

Author(s):

Kangyong Zha ◽

Haoxun Xie ◽

Min Ge ◽

Zimeng Wang ◽

Yu Wang ◽

...

Keyword(s):

Transcription Factor ◽

Mrna Expression ◽

Starch Content ◽

Soluble Sugar ◽

Starch Synthesis ◽

Synthesis Process ◽

Starch Accumulation ◽

Rice Grain ◽

Altered Expression ◽

Rice Endosperm

As major component in cereals grains, starch has been one of the most important carbohydrate consumed by a majority of world’s population. However, the molecular mechanism for regulation of biosynthesis of starch remains elusive. In the present study, ZmES22, encoding a MADS-type transcription factor, was modestly characterized from maize inbred line B73. ZmES22 exhibited high expression level in endosperm at 10 days after pollination (DAP) and peaked in endosperm at 20 DAP, indicating that ZmES22 was preferentially expressed in maize endosperm during active starch synthesis. Transient expression of ZmES22 in tobacco leaf revealed that ZmES22 protein located in nucleus. No transactivation activity could be detected for ZmES22 protein via yeast one-hybrid assay. Transformation of overexpressing plasmid 35S::ZmES22 into rice remarkedly reduced 1000-grain weight as well as the total starch content, while the soluble sugar was significantly higher in transgenic rice lines. Moreover, overexpressing ZmES22 reduced fractions of long branched starch. Scanning electron microscopy images of transverse sections of rice grains revealed that altered expression of ZmES22 also changed the morphology of starch granule from densely packed, polyhedral starch granules into loosely packed, spherical granules with larger spaces. Furthermore, RNA-seq results indicated that overexpressing ZmES22 could significantly influence mRNA expression levels of numerous key regulatory genes in starch synthesis pathway. Y1H assay illustrated that ZmES22 protein could bind to the promoter region of OsGIF1 and downregulate its mRNA expression during rice grain filling stages. These findings suggest that ZmES22 was a novel regulator during starch synthesis process in rice endosperm.

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Suppression of starch synthesis in rice stems splays tiller angle due to gravitropic insensitivity but does not affect yield

Functional Plant Biology ◽

10.1071/fp14159 ◽

2015 ◽

Vol 42 (1) ◽

pp. 31 ◽

Cited By ~ 12

Author(s):

Masaki Okamura ◽

Tatsuro Hirose ◽

Yoichi Hashida ◽

Ryu Ohsugi ◽

Naohiro Aoki

Keyword(s):

Double Mutant ◽

Oryza Sativa L ◽

Starch Content ◽

Large Subunit ◽

Starch Synthesis ◽

Starch Accumulation ◽

Gravitropic Response ◽

Rice Mutant ◽

Matter Production ◽

Tiller Angle

In rice (Oryza sativa L.), tiller angle – defined as the angle between the main culm and its side tillers – is one of the important factors involved in light use efficiency. To clarify the relationship between tiller angle, gravitropism and stem-starch accumulation, we investigated the shoot gravitropic response of a low stem-starch rice mutant which lacks a large subunit of ADP-glucose pyrophosphorylase (AGP), called OsAGPL1 and exhibits relatively spread tiller angle. The insensitive gravitropic response exhibited by the mutant led us to the conclusion that insensitivity of gravitropism caused by stem-starch reduction splayed the tiller angle. Furthermore, since another AGP gene called OsAGPL3 was expressed at considerable levels in graviresponding sites, we generated a double mutant lacking both OsAGPL1 and OsAGPL3. The double mutant exhibited still lower stem-starch content, less sensitive gravitropic response and greater tiller angle spread than the single mutants. This indicated that the expansion of the tiller angle caused by the reduction in starch level was intense according to the extent of the reduction. We found there were no significant differences between the double mutant and wild-type plants in terms of dry matter production. These results provided new insight into the importance of stem-starch accumulation and ideal plant architecture.

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

Functional Plant Biology ◽

10.1071/pp01161 ◽

2002 ◽

Vol 29 (8) ◽

pp. 975 ◽

Cited By ~ 7

Author(s):

Kathryn A. Vardy ◽

Michael J. Emes ◽

Michael M. Burrell

Keyword(s):

Solanum Tuberosum L ◽

Starch Content ◽

Starch Synthesis ◽

Small Subunit ◽

Starch Biosynthesis ◽

Potato Tubers ◽

Potato Plants ◽

Adpglucose Pyrophosphorylase ◽

Plastid Targeting

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.

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Over-Expressing TaSPA-B Reduces Prolamin and Starch Accumulation in Wheat (Triticum aestivum L.) Grains

International Journal of Molecular Sciences ◽

10.3390/ijms21093257 ◽

2020 ◽

Vol 21 (9) ◽

pp. 3257 ◽

Cited By ~ 1

Author(s):

Dandan Guo ◽

Qiling Hou ◽

Runqi Zhang ◽

Hongyao Lou ◽

Yinghui Li ◽

...

Keyword(s):

Triticum Aestivum ◽

Leucine Zipper ◽

Protein Biosynthesis ◽

Starch Content ◽

Starch Synthesis ◽

Triticum Aestivum L ◽

Luciferase Reporter ◽

Starch Accumulation ◽

Basic Leucine Zipper ◽

Wheat Lines

Starch and prolamin composition and content are important indexes for determining the processing and nutritional quality of wheat (Triticum aestivum L.) grains. Several transcription factors (TFs) regulate gene expression during starch and protein biosynthesis in wheat. Storage protein activator (TaSPA), a member of the basic leucine zipper (bZIP) family, has been reported to activate glutenin genes and is correlated to starch synthesis related genes. In this study, we generated TaSPA-B overexpressing (OE) transgenic wheat lines. Compared with wild-type (WT) plants, the starch content was slightly reduced and starch granules exhibited a more polarized distribution in the TaSPA-B OE lines. Moreover, glutenin and ω- gliadin contents were significantly reduced, with lower expression levels of related genes (e.g., By15, Dx2, and ω-1,2 gliadin gene). RNA-seq analysis identified 2023 differentially expressed genes (DEGs). The low expression of some DEGs (e.g., SUSase, ADPase, Pho1, Waxy, SBE, SSI, and SS II a) might explain the reduction of starch contents. Some TFs involved in glutenin and starch synthesis might be regulated by TaSPA-B, for example, TaPBF was reduced in TaSPA-B OE-3 lines. In addition, dual-luciferase reporter assay indicated that both TaSPA-B and TaPBF could transactivate the promoter of ω-1,2 gliadin gene. These results suggest that TaSPA-B regulates a complex gene network and plays an important role in starch and protein biosynthesis in wheat.

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Differential effects of synthetic media on long-term growth, starch accumulation and transcription of ADP-glucosepyrophosphorylase subunit genes in Landoltia punctata

Scientific Reports ◽

10.1038/s41598-019-51677-w ◽

2019 ◽

Vol 9 (1) ◽

Author(s):

Chokchai Kittiwongwattana

Keyword(s):

Growth Rate ◽

Starch Content ◽

Morphological Characteristics ◽

Correlation Coefficients ◽

Starch Biosynthesis ◽

Starch Accumulation ◽

Ms Medium ◽

Expression Of Genes ◽

Synthetic Media

Abstract Murashige & Skoog (MS) and Hoagland’s media were previously used for in vitro culture of Landoltia punctata. During subsequent ex vitro culture, the use of MS medium resulted in a higher growth rate, compared to Hoagland’s medium. Thus, a higher starch content of L. punctata in MS medium was previously hypothesized. Here, L. punctata strain 5632 was isolated and characterized using morphological characteristics and the atpF-atpH intergenic region. During early cultivation stage, fresh weight and relative growth rate in MS medium were lower than Hoagland’s medium. Conversely, starch content in MS medium was considerably higher than in Hoagland’s medium. Medium effects on expression of genes coding for starch-biosynthesis ADP-glucosepyrophosphorylase (AGPase) were determined. Genomic fragments of small (LeAPS) and large (LeAPL1) AGPase subunits were characterized. Differential expression between each AGPase subunit genes was observed in both media. Additionally, in MS medium, the highest correlation coefficients between starch content and gene expression was found with LeAPS (0.81) and followed by LeAPL3 (0.67), LeAPL2 (0.65) and LeAPL1 (0.28). In Hoagland’s medium, the coefficients of LeAPL3 (0.83) and LeAPL2 (0.62) were higher than LeAPS (0.18) and LeAPL1 (−0.62). This suggested different levels of contributions of these genes in starch biosynthesis in both media.

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Genetic dissection of the developmental behaviour of total starch content and its components in wheat grain

Crop and Pasture Science ◽

10.1071/cp14059 ◽

2015 ◽

Vol 66 (5) ◽

pp. 445 ◽

Cited By ~ 5

Author(s):

Bin Tian ◽

Zhiying Deng ◽

Quangang Xie ◽

Jichun Tian

Keyword(s):

Starch Content ◽

Starch Synthesis ◽

Triticum Aestivum L ◽

Genetic Dissection ◽

Wheat Grain ◽

Epistatic Qtls ◽

Potential Marker ◽

A Minor ◽

Additive Qtls ◽

Total Starch

Starch in wheat is an important component of flour and is related to grain yield and wheat end-products. In this study, a doubled haploid (DH) population with 168 lines derived from a cross of elite Chinese wheat (Triticum aestivum L.) cultivars Huapei 3 and Yumai 57 was used to identify dynamic quantitative trait loci (QTLs) for total starch content (TSC), amylose (AMS) and amylopectin (AMP) in wheat grain. Traits were measured at stages, grown under three treatments in two seasons, and were assessed by unconditional and conditional QTL analyses. Thirty-three additive QTLs and 21 pairs of epistatic QTLs for TSC, AMS and AMP were detected by unconditional mapping, whereas 19 additive QTLs and 15 pairs of epistatic QTLs were identified by conditional mapping. Of these, QTsc4A.1 and QAms4A.1 were detected continuously at five stages under three treatments in two seasons by unconditional mapping, indicating that the accumulated effects of these QTLs were expressed stably from 12 days after flowering (DAF) and were little affected by nitrogen and water agronomic treatment. These two QTLs also showed net expression from 12 to 22 DAF by conditional mapping. The results indicate that the two loci play an important role in starch synthesis. Most of the epistatic QTLs belonged to a minor QTL, but played an important role in the target traits. Therefore, the development of starch is mainly affected by additive effects besides the epistasis effect. The data are useful for potential marker-assisted selection and cloning of the target gene in further fine mapping, and provide a foundation to understand the genetic mechanism underlying the development of starch in wheat and to increase yield.

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Starch synthesis and localization in post-germination Pinusedulis seedlings

Canadian Journal of Forest Research ◽

10.1139/x94-188 ◽

1994 ◽

Vol 24 (7) ◽

pp. 1457-1463 ◽

Cited By ~ 6

Author(s):

J. Brad Murphy ◽

Mark F. Hammer

Keyword(s):

Seed Germination ◽

Starch Content ◽

Starch Synthesis ◽

Minor Component ◽

Dry Weight ◽

Starch Synthase ◽

Starch Accumulation ◽

Low Levels ◽

Starch Conversion ◽

A Minor

Following pine seed germination, lipids in the megagametophyte are converted to sucrose, which is transported to the emerging seedling to support its growth. In several conifer species, an increase in the seedling starch content following germination has been reported. To further characterize this phenomenon, starch accumulation and localization, starch synthase (EC 2.4.1.21) activity (both soluble and granule-bound), and partitioning of exogenous 14C-sucrose were determined following germination of pinyon (Pinusedulis Engelm.) seeds. Starch was a minor component in dry embryos, accounting for only 3% of the dry weight. Starch levels increased 22-fold and 15-fold in the cotyledons and hypocotyl, respectively, by 8 days after germination. Starch accumulated to 65% of the dry weight in the cotyledons and 46% in the hypocotyl. The root and epicotyl accumulated relatively low levels of starch, only about 7%. Starch was localized primarily in the cortex and pith of the hypocotyl, the cortex of the cotyledons, and the root cap. Only granule-bound starch synthase showed a significant increase in activity during germination, and its changes more closely followed the pattern of starch accumulation. Exogenous 14C-sucrose was partitioned primarily into starch. After a 24-h labeling period, starch in both the cotyledons and hypocotyl accounted for 38% of total label (61% of the incorporated label) in these organs. In the roots, starch accounted for only 2.5 and 14%, respectively, of the total and incorporated label. The spatial and temporal pattern of starch accumulation closely paralleled previously reported patterns for the activity of sucrose synthase, which is apparently associated with the sucrose–starch conversion. Starch accumulation in the seedling accounts for approximately 50% of the sucrose transported from the megagametophyte following pinyon seed germination. Thus, starch appears to serve as an important transitory carbon pool for the growing seedling and may serve additional functions during seedling development.

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NTRC and Thioredoxin f Overexpression Differentially Induces Starch Accumulation in Tobacco Leaves

Plants ◽

10.3390/plants8120543 ◽

2019 ◽

Vol 8 (12) ◽

pp. 543 ◽

Cited By ~ 1

Author(s):

María Ancín ◽

Luis Larraya ◽

Alicia Fernández-San Millán ◽

Jon Veramendi ◽

Tessa Burch-Smith ◽

...

Keyword(s):

Starch Content ◽

Starch Synthesis ◽

Genetically Engineered ◽

Starch Accumulation ◽

Starch Metabolism ◽

Reductive Activation ◽

Amylolytic Enzyme ◽

Tobacco Plants ◽

Tobacco Leaves ◽

The Impact

Thioredoxin (Trx) f and NADPH-dependent Trx reductase C (NTRC) have both been proposed as major redox regulators of starch metabolism in chloroplasts. However, little is known regarding the specific role of each protein in this complex mechanism. To shed light on this point, tobacco plants that were genetically engineered to overexpress the NTRC protein from the chloroplast genome were obtained and compared to previously generated Trx f-overexpressing transplastomic plants. Likewise, we investigated the impact of NTRC and Trx f deficiency on starch metabolism by generating Nicotiana benthamiana plants that were silenced for each gene. Our results demonstrated that NTRC overexpression induced enhanced starch accumulation in tobacco leaves, as occurred with Trx f. However, only Trx f silencing leads to a significant decrease in the leaf starch content. Quantitative analysis of enzyme activities related to starch synthesis and degradation were determined in all of the genotypes. Zymographic analyses were additionally performed to compare the amylolytic enzyme profiles of both transplastomic tobacco plants. Our findings indicated that NTRC overexpression promotes the accumulation of transitory leaf starch as a consequence of a diminished starch turnover during the dark period, which seems to be related to a significant reductive activation of ADP-glucose pyrophosphorylase and/or a deactivation of a putative debranching enzyme. On the other hand, increased starch content in Trx f-overexpressing plants was connected to an increase in the capacity of soluble starch synthases during the light period. Taken together, these results suggest that NTRC and the ferredoxin/Trx system play distinct roles in starch turnover.

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