Starch Accumulation and Enzyme Activities Associated with Starch Synthesis in Maize Kernels

2007 ◽  
Vol 6 (7) ◽  
pp. 808-815 ◽  
Author(s):  
Hai-yan ZHANG ◽  
Shu-ting DONG ◽  
Rong-qi GAO ◽  
Qing-quan SUN
Keyword(s):  
Enzyme Activities ◽  
Starch Synthesis ◽  
Starch Accumulation ◽  
Maize Kernels

Heat Stress During Grain Filling in Maize: Effects on Carbohydrate Storage and Metabolism

1994 ◽  
Vol 21 (6) ◽  
pp. 829 ◽  
Author(s):  
GW Singletary ◽  
R Banisadr ◽  
PL Keeling
Keyword(s):  
Heat Stress ◽  
Seed Size ◽  
Starch Synthesis ◽  
Dry Weight ◽  
Grain Filling ◽  
Soluble Starch ◽  
Effect Of Temperature ◽  
Starch Accumulation ◽  
Maize Kernels

Heat stress during maize seed development can interfere with endosperm starch biosynthesis and reduce seed size, an important component of yield. Our objectives were to evaluate the direct influence of temperature during grain filling on kernel growth, carbohydrate accumulation, and corresponding endosperm metabolism. Kernels of maize were grown in vitro at 25�C until 15 or 16 days after pollination and then subjected to various temperatures for the remainder of their development. Mature kernel dry weight declined 45% in a linear fashion between 22 and 36�C. The rate of starch accumulation reached a maximum at approximately 32�C, and when measured at frequent intervals, declined only slightly with further temperature increase to 35�C. Reduced seed size resulted from an abbreviated duration of starch-related metabolism, which did not appear to be limited by endogenous sugars. Instead, a survey of 12 enzymes of sugar and starch metabolism indicated that ADP glucose pyrophosphorylase and soluble starch synthase were unique in displaying developmental peaks of activity which were compressed both in amount and time, similar to the effect of temperature on starch accumulation. We conclude that decreased starch synthesis in heat-stressed maize kernels results from a premature decline in the activity of these enzymes.

Activities of key enzymes involved in starch synthesis in grains of wheat under different irrigation patterns

2009 ◽  
Vol 147 (4) ◽  
pp. 437-444 ◽  
Author(s):  
Z. DAI ◽  
Y. YIN ◽  
Z. WANG
Keyword(s):  
Water Deficit ◽  
Enzyme Activities ◽  
Starch Synthesis ◽  
Grain Filling ◽  
Starch Accumulation ◽  
Wheat Cultivars ◽  
Wheat Grains ◽  
Key Enzymes ◽  
Grain Starch ◽  
Irrigation Patterns

SUMMARYIt is generally accepted that sucrose phosphate synthase (SPS), sucrose synthase (SuSy), ADP-glucose pyrophosphorylase (AGPase), soluble starch synthase (SSS), granule-bound starch synthase (GBSS) and starch branching enzyme (SBE) play a key role in starch synthesis in wheat grains. Starch synthesis in wheat grains is influenced by genotype and environment. However, what is not known is the degree of variation in enzyme activities during starch accumulation of wheat cultivars field-grown in different water regimes. The present study was undertaken to determine whether irrigation patterns could cause differences in starch accumulation and activities of key enzymes involved in starch synthesis. Starch accumulation and related enzyme activities were investigated in two winter wheat varieties, JM20 and BY535, differing in grain starch content, under two irrigation patterns. Results showed that soil water deficit led to an increase at early grain filling and decrease during late grain filling in starch accumulation rate (SAR) and activities of key enzymes involved in starch synthesis, especially AGPase, SSS and SBE. Water deficit enhanced grain starch accumulation in two wheat cultivars, suggesting that rainfed treatments increase physiological activities during early grain filling and promote starch accumulation. Furthermore, the change of SAR is consistent with SuSy, AGPase, SSS and GBSS. The results suggest that these enzymes play a key role in starch synthesis, and the decrease of photosynthate produced in the source organ is not the factor inhibiting starch accumulation.

Multilevel genomics analysis of carbon signalling during low carbon availability: coordinating the supply and utilisation of carbon in a fluctuating environment

2007 ◽  
Vol 34 (6) ◽  
pp. 526 ◽  
Author(s):  
Mark Stitt ◽  
Yves Gibon ◽  
John E. Lunn ◽  
Maria Piques
Keyword(s):  
Enzyme Activities ◽  
Translational Regulation ◽  
Starch Synthesis ◽  
Starch Accumulation ◽  
Carbon Limitation ◽  
Diurnal Changes ◽  
Low Carbon ◽  
Wild Type ◽  
Carbon Supply ◽  
Inhibition Of Growth

Plants alternate between a net surplus of carbon in the light and a net deficit at night. This is buffered by accumulating starch in the light and degrading it at night. Enough starch is accumulated to support degradation throughout the night, with a small amount remaining at the end of the 24-h diurnal cycle. This review discusses how this balance between the supply and utilisation of carbon is achieved in Arabidopsis. It is important to regulate starch turnover to avoid an acute carbon deficiency. A 2–4 h extension of the night leads to exhaustion of starch, a collapse of sugars, a switch from biosynthesis to catabolism and an acute inhibition of growth by low carbon, which is not immediately reversed when carbon becomes available again. In starchless pgm mutants, where sugars are depleted each night, this leads to a recurring inhibition of growth that is not reversed until 5–6 h into the following light period. Several lines of evidence show that starch accumulation is regulated in response to events that are initiated during periods of low carbon. Starch accumulation is decreased when small amounts of sucrose are included in the growth medium. Sets of sugar-responsive genes were identified by supplying sugars to carbon-starved seedlings, or by illuminating 5-week-old plants in the presence of 350 or 50 ppm [CO2]. Almost all of these genes show large diurnal changes in starchless pgm mutants, which are driven by the depletion of carbon during the night. Many show significant diurnal changes in wild type plants, showing that ‘anticipatory’ changes in signalling pathways occur before acute carbon limitation develops. However, these diurnal changes of transcripts do not lead to immediate changes of enzyme activities. Whereas an extension of the night leads to major changes of transcripts within 4–6 h, changes in enzyme activities require several days. In pgm, enzyme activities and the levels of >150 metabolites resemble those found in wild type plants after several days in the dark. It is concluded that diurnal changes in transcript levels are integrated, over days, as changes in the levels of enzymes. We hypothesise that this facilitates an adjustment of metabolism to a mid-term shift in the conditions, while ignoring noise due to diurnal changes and day-to-day fluctuations. The rapid adjustment of starch synthesis after a period of acute carbon depletion is a consequence of the transient inhibition of growth. This leads to accumulation of sugars when carbon becomes available again, which triggers a large increase in trehalose-6-phosphate. This signal metabolite promotes thioredoxin-dependent post-translational activation of ADP glucose pyrophosphorylase. Mid-term acclimation to a decreased carbon supply may be mediated by a combination of post-translational regulation, longer-term changes in enzyme activities, and a decrease in the rate of growth.

scholarly journals Effects of Antisense Thioredoxin s on Starch Accumulation and Expressions of Enzymes Related to Starch Synthesis in Weak-gluten Wheat Cultivar Yumai 18

2013 ◽  
Vol 39 (10) ◽  
pp. 1856
Author(s):  
Jiang-Ping REN ◽  
Ya-Ying WANG ◽  
Xin-Guo WANG ◽  
Na WANG ◽  
Xin CHEN ◽  
...  
Keyword(s):  
Wheat Cultivar ◽  
Starch Synthesis ◽  
Starch Accumulation

scholarly journals Engineering 6-phosphogluconate dehydrogenase improves grain yield in heat-stressed maize

2020 ◽  
Vol 117 (52) ◽  
pp. 33177-33185
Author(s):  
Camila Ribeiro ◽  
Tracie A. Hennen-Bierwagen ◽  
Alan M. Myers ◽  
Kenneth Cline ◽  
A. Mark Settles
Keyword(s):  
Heat Stress ◽  
Grain Yield ◽  
Fusion Proteins ◽  
Starch Synthesis ◽  
Starch Accumulation ◽  
Chloroplast Targeting ◽  
Phosphogluconate Dehydrogenase ◽  
Heat Stable ◽  
Endosperm Starch

Endosperm starch synthesis is a primary determinant of grain yield and is sensitive to high-temperature stress. The maize chloroplast-localized 6-phosphogluconate dehydrogenase (6PGDH), PGD3, is critical for endosperm starch accumulation. Maize also has two cytosolic isozymes, PGD1 and PGD2, that are not required for kernel development. We found that cytosolic PGD1 and PGD2 isozymes have heat-stable activity, while amyloplast-localized PGD3 activity is labile under heat stress conditions. We targeted heat-stable 6PGDH to endosperm amyloplasts by fusing the Waxy1 chloroplast targeting the peptide coding sequence to the Pgd1 and Pgd2 open reading frames (ORFs). These WPGD1 and WPGD2 fusion proteins import into isolated chloroplasts, demonstrating a functional targeting sequence. Transgenic maize plants expressing WPGD1 and WPGD2 with an endosperm-specific promoter increased 6PGDH activity with enhanced heat stability in vitro. WPGD1 and WPGD2 transgenes complement the pgd3-defective kernel phenotype, indicating the fusion proteins are targeted to the amyloplast. In the field, the WPGD1 and WPGD2 transgenes can mitigate grain yield losses in high–nighttime-temperature conditions by increasing kernel number. These results provide insight into the subcellular distribution of metabolic activities in the endosperm and suggest the amyloplast pentose phosphate pathway is a heat-sensitive step in maize kernel metabolism that contributes to yield loss during heat stress.

Gene expression during maize kernel development

1994 ◽  
Vol 4 (3) ◽  
pp. 299-305 ◽  
Author(s):  
Douglas C. Doehlert ◽  
Leslie J. Smith ◽  
Edwin R. Duke
Keyword(s):  
Gene Expression ◽  
Enzyme Activities ◽  
Dry Weight ◽  
Transcript Abundance ◽  
Starch Accumulation ◽  
Lag Phase ◽  
Gene Transcript ◽  
Kernel Development ◽  
Storage Product ◽  
Product Accumulation

AbstractRelationships have been investigated between gene transcript abundance, enzyme activities and storage product accumulation in developing maize (Zea maysL.) kernels from 10 to 55 days postpollination (DPP). At the early stages of kernel development, there was very little increase in dry weight but kernels accumulated high concentrations of sugars and amino acids. At the end of this ‘lag’ phase (at 15 DPP), many transcripts appeared with little evidence of their translation. The initiation of the kernel-fill period at 20 DPP was characterized by a sudden rise in total RNA, increases in enzyme activities, and the initiation of storage product accumulation. Zein accumulation during this phase was highly correlated with α-zein transcript abundance. Starch accumulation was correlated with both the activity of ADP-GIc pyrophosphorylase and the abundance of gene transcripts encoding this enzyme (Shrunken-2andBrittle-2). DNA content of kernels increased linearly up to 30 DPP as a result of endoreplication, but had no apparent relationship to gene expression. DNA may accumulate as a storage product. Kernel-fill terminated when the moisture content fell below 36% and was marked by a decline of transcripts and a reduction of enzyme activities.

scholarly journals Transcriptomic Analysis of Starch Biosynthesis in the Developing Grain of Hexaploid Wheat

2009 ◽  
Vol 2009 ◽  
pp. 1-23 ◽  
Author(s):  
Boryana S. Stamova ◽  
Debbie Laudencia-Chingcuanco ◽  
Diane M. Beckles
Keyword(s):  
Gene Expression ◽  
Dna Microarrays ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Soluble Sugars ◽  
Starch Synthesis ◽  
Gene Families ◽  
Starch Accumulation ◽  
Protein Accumulation ◽  
High Accumulation

The expression of genes involved in starch synthesis in wheat was analyzed together with the accumulation profiles of soluble sugars, starch, protein, and starch granule distribution in developing caryopses obtained from the same biological materials used for profiling of gene expression using DNA microarrays. Multiple expression patterns were detected for the different starch biosynthetic gene isoforms, suggesting their relative importance through caryopsis development. Members of the ADP-glucose pyrophosphorylase, starch synthase, starch branching enzyme, and sucrose synthase gene families showed different expression profiles; expression of some members of these gene families coincided with a period of high accumulation of starch while others did not. A biphasic pattern was observed in the rates of starch and protein accumulation which paralleled changes in global gene expression. Metabolic and regulatory genes that show a pattern of expression similar to starch accumulation and granule size distribution were identified, suggesting their coinvolvement in these biological processes.

scholarly journals Starch synthesis and gelatinization properties of potato tubers

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.

scholarly journals Proteomics reveals the effects of drought stress on the kernel development and starch formation of waxy maize

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jian Guo ◽  
Lingling Qu ◽  
Yifan Hu ◽  
Weiping Lu ◽  
Dalei Lu
Keyword(s):  
Drought Stress ◽  
Rice Genome ◽  
Starch Synthesis ◽  
Reduction Process ◽  
Endosperm Development ◽  
Starch Accumulation ◽  
Kernel Development ◽  
Waxy Maize ◽  
Yield And Quality ◽  
Starch Formation

Abstract Background Kernel development and starch formation are the primary determinants of maize yield and quality, which are considerably influenced by drought stress. To clarify the response of maize kernel to drought stress, we established well-watered (WW) and water-stressed (WS) conditions at 1–30 days after pollination (dap) on waxy maize (Zea mays L. sinensis Kulesh). Results Kernel development, starch accumulation, and activities of starch biosynthetic enzymes were significantly reduced by drought stress. The morphology of starch granules changed, whereas the grain filling rate was accelerated. A comparative proteomics approach was applied to analyze the proteome change in kernels under two treatments at 10 dap and 25 dap. Under the WS conditions, 487 and 465 differentially accumulated proteins (DAPs) were identified at 10 dap and 25 dap, respectively. Drought induced the downregulation of proteins involved in the oxidation–reduction process and oxidoreductase, peroxidase, catalase, glutamine synthetase, abscisic acid stress ripening 1, and lipoxygenase, which might be an important reason for the effect of drought stress on kernel development. Notably, several proteins involved in waxy maize endosperm and starch biosynthesis were upregulated at early-kernel stage under WS conditions, which might have accelerated endosperm development and starch synthesis. Additionally, 17 and 11 common DAPs were sustained in the upregulated and downregulated DAP groups, respectively, at 10 dap and 25 dap. Among these 28 proteins, four maize homologs (i.e., A0A1D6H543, B4FTP0, B6SLJ0, and A0A1D6H5J5) were considered as candidate proteins that affected kernel development and drought stress response by comparing with the rice genome. Conclusions The proteomic changes caused by drought were highly correlated with kernel development and starch accumulation, which were closely related to the final yield and quality of waxy maize. Our results provided a foundation for the enhanced understanding of kernel development and starch formation in response to drought stress in waxy maize.

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