scholarly journals The Effects of Short-Term Exposure to Low Temperatures During the Booting Stage on Starch Synthesis and Yields in Wheat Grain

2021 ◽  
Vol 12 ◽  
Author(s):  
Wenjing Zhang ◽  
Yan Zhao ◽  
Lingyu Li ◽  
Xu Xu ◽  
Li Yang ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Dry Matter ◽  
Starch Content ◽  
Starch Synthesis ◽  
Grain Filling ◽  
Starch Synthase ◽  
Wheat Grain ◽  
Short Term ◽  
Booting Stage ◽  
Grain Starch

Low temperatures (LT) in spring can have a major impact on the yields of wheat in winter. Wheat varieties with different cold sensitivities (the cold-tolerant Yannong 19 variety and the cold-sensitive Yangmai 18 variety) were used to study the responses of the wheat grain starch synthesis and dry material accumulation to short-term LT during the booting stage. The effects of short-term LT on the activities of key wheat grain starch synthesis enzymes, starch content and grain dry-matter accumulation were determined by exposing the wheat to simulated LT of from −2 to 2°C. Short-term LT stress caused a decrease in the fullness of the wheat grains along with decreased activities of adenosine diphosphate glucose pyrophosphorylase (AGPase, EC2.7.7.27), soluble starch synthase (SSS, EC2.4.1.21), granule-bound starch synthase (GBSS, EC2.4.1.21), and starch branching enzyme (SBE, EC2.4.1.18) at different spike positions during the filling stage. The rate of grain starch accumulation and starch content decreased with decreasing temperatures. Also, the duration of grain filling increased, the mean and the maximum filling rates were reduced and the quality of the grain dry-matter decreased. The number of grains per spike and the thousand-grain weight of the mature grains also decreased. Our data showed that short-term LT stress at the booting stage caused a decrease in the activities of key starch synthesis enzymes at the grain-filling stage. These changes reduced the accumulation of starch, decreased the filling rate, and lowered the accumulation of grain dry matter to ultimately decrease grain yields.

Starch Synthesis in the Kernel of Wheat Under High Temperature Conditions

1994 ◽  
Vol 21 (6) ◽  
pp. 791 ◽  
Author(s):  
CF Jenner
Keyword(s):  
High Temperature ◽  
Dry Matter ◽  
Starch Content ◽  
Starch Synthesis ◽  
Temperature Response ◽  
Grain Filling ◽  
Soluble Starch ◽  
Grain Weight ◽  
Temperature Range ◽  
Temperature Responses

As temperature rises above 18-22�C, the observed decrease in the duration of deposition of dry matter in the kernel is not accompanied by a compensating increase in the rate of grain filling with the result that grain weight (and yield) is diminished at high temperature. Reduced starch content accounts for most of the reduction in grain dry matter at high temperature. Responses to temperature in the low temperature range, 20-30�C (the LTR), could possibly be ascribed to the temperature response characteristics of the reaction catalysed by soluble starch synthase (SSS), the enzyme synthesising starch. However, the rate of cell enlargement and the rate of accumulation of nitrogen in the grain also do not increase much as temperature rises, so other explanations are conceivable for the temperature responses in the LTR. Variation amongst cultivars of wheat in tolerance of high temperature is evident in the LTR. At temperatures above 30�C (in the high temperature range (HTR) between 30 and 40�C), even for short periods, the rate of starch deposition is slower than that observed at lower temperatures, an effect which is carried over after transfer from high to lower temperatures. This response is attributable to a reduction in the activity, possibly due to thermal denaturation, of SSS. Several forms of SSS are found in cereal endosperm, and some forms may be more tolerant of high temperature than others. Loss of enzyme activity at high temperature is swift, but is partly restored some time after transfer from hot to cool conditions. There appear to be two distinct mechanisms of response to elevated temperature, both resulting in a reduced grain weight through reduced starch deposition, but one of them is important only in the range of temperature above 30�C.

scholarly journals Variation of Wheat Cultivars in Their Response to Elevated Temperature on Starch and Dry Matter Accumulation in Grain

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Soyema Khatun ◽  
Jalal Uddin Ahmed ◽  
Tofazzal Hossain ◽  
M. Rafiqul Islam ◽  
Mohammed Mohi-Ud-Din
Keyword(s):  
Elevated Temperature ◽  
Open Field ◽  
Dry Matter ◽  
Starch Synthesis ◽  
Grain Filling ◽  
Dry Matter Accumulation ◽  
Wheat Cultivars ◽  
Temperature Regimes ◽  
Grain Starch ◽  
Chamber Temperature

Three wheat cultivars, namely, BARI Gom 25, BARI Gom 26, and Pavon 76, were sown in experimental field of Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, in Bangladesh, on 18 November, 2013. Two temperature regimes, namely, normal (23°C in open field) and elevated (6 ± 1°C higher compared to open field mean air temperature in polythene chamber) temperature, were created immediately after anthesis to investigate the response of wheat cultivars to heat stress. Elevated temperature cuts back the duration of grain filling by 5 days in BARI Gom 25 and BARI Gom 26 and 10 days in Pavon 76. Starch synthesis was also cut back by the same duration in respective cultivars under elevated temperature condition. Results indicate that failure of conversion of sugar to starch rather than limited supply of sugar under high temperature condition was responsible for shortening of grain filling duration in all wheat cultivars. However, the response of elevated temperature on grain starch and main stem grain dry matter was less profound in BARI Gom 25 and BARI Gom 26 compared to Pavon 76 indicating their better tolerance to elevated temperature.

Effects of Irrigation Amount on Grain Starch Content, Starch Synthase Activity, and Water Use Efficiency in Wheat

2009 ◽  
Vol 35 (2) ◽  
pp. 324-333 ◽  
Author(s):  
Peng-Fei CHU ◽  
Zhen-Wen YU ◽  
Xiao-Yan WANG ◽  
Tong-Hua WU ◽  
Xi-Zhi WANG
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Starch Content ◽  
Starch Synthase ◽  
Irrigation Amount ◽  
Grain Starch ◽  
Use Efficiency

scholarly journals Triple null mutations in starch synthase SSIIa gene homoeologs lead to high amylose and resistant starch in hexaploid wheat

2020 ◽  
Author(s):  
Adam Schoen ◽  
Anupama Joshi ◽  
Vijay K Tiwari ◽  
Bikram S. Gill ◽  
Nidhi Rawat
Keyword(s):  
Resistant Starch ◽  
Amylose Content ◽  
Starch Content ◽  
Wheat Variety ◽  
Starch Synthesis ◽  
Starch Synthase ◽  
Single Individual ◽  
Individual Genome ◽  
Mutant Genotype ◽  
Knock Out

Abstract Background: Lack of nutritionally appropriate foods is one of the leading causes of obesity in the US and worldwide. Wheat (Triticum aestivum) provides 20% of the calories consumed daily across the globe. The nutrients in the wheat grain come primarily from the starch composed of amylose and amylopectin. Resistant starch content, which is known to have significant human health benefits, can be increased by modifying starch synthesis pathways. Starch synthase enzyme SSIIa, also known as starch granule protein isoform-1 (SGP-1), is integral to the biosynthesis of the branched and readily digestible glucose polymer amylopectin. The goal of this work was to develop a triple null mutant genotype for SSIIa locus in the elite hard red winter wheat variety ‘Jagger’ and evaluate the effect of the knock-out mutations on resistant starch content in grains with respect to wild type. Results: Knock-out mutations in SSIIa in the three genomes of wheat variety ‘Jagger’ were identified using TILLING. Subsequently, these loss-of function mutations on A, B, and D genomes were combined by crossing to generate a triple knockout mutant genotype Jag-ssiia-∆ABD. The Jag-ssiia-∆ABD had an amylose content of 35.70% compared to 31.15% in Jagger, leading to ~118% increase in resistant starch in the Jag-ssiia-∆ABD genotype of Jagger wheat. The single individual genome mutations also had various effects on starch composition. Conclusions: Our full null Jag-ssiia-∆ABD mutant showed a significant increase in RS without the shriveled grain phenotype seen in other ssiia knockouts in elite wheat cultivars. Moreover, this study shows the potential for developing nutritionally improved foods in a non-GM approach. Since all the mutants have been developed in an elite wheat cultivar, their adoption in production and supply will be feasible in future.

Effects of Elevated Temperature and Reduced Water Uptake on Enzymes of Starch Synthesis in Developing Wheat Grains

1990 ◽  
Vol 17 (4) ◽  
pp. 431 ◽  
Author(s):  
CY Caley ◽  
CM Duffus ◽  
B Jeffcoat
Keyword(s):  
Elevated Temperatures ◽  
Starch Content ◽  
Starch Synthesis ◽  
Dry Weight ◽  
Endosperm Development ◽  
Starch Synthase ◽  
Temperature Regimes ◽  
Endosperm Starch ◽  
Rate Limiting ◽  
Reduced Water

The mechanism of temperature regulation of endosperm development has been investigated by studying the effects of two temperature regimes on starch deposition and starch synthase activity during grain development in two cultivars of wheat. Most of the starch synthase activity was present throughout development as the granule-bound form using ADPglucose as the principal substrate. That starch synthase may be a rate-limiting enzyme for accumulation of starch, and hence dry weight, is suggested by: (1) rates are proportionately less in the cultivar with the lower final endosperm dry weight; (2) at elevated temperatures when starch content and dry weight are reduced, starch synthase activity falls; (3) the rate of starch deposition calculated to be possible from measured rates of starch synthase activity is close to the observed rate of starch deposition. On the other hand, it was concluded that it is not lack of starch synthase activity that causes termination of starch deposition, since activity is maintained well after starch deposition has ceased. Using the same two wheat cultivars, grown as detached ears in liquid culture, the effects of reduced endosperm water content, induced by the presence of polyethylene glycol in the culture medium, were investigated. Endosperm starch synthase activity was unaffected but ADPglucose pyrophosphorylase activity was greatly reduced, suggesting a possible role in the termination of starch synthesis.

Effects of Exposure of Wheat Ears to High Temperature on Dry Matter Accumulation and Carbohydrate Metabolism in the Grain of Two Cultivars. I. Immediate Responses

1991 ◽  
Vol 18 (2) ◽  
pp. 165 ◽  
Author(s):  
CF Jenner
Keyword(s):  
High Temperature ◽  
Sucrose Synthase ◽  
Dry Matter ◽  
Starch Synthesis ◽  
Grain Filling ◽  
Mass Action ◽  
Dry Matter Accumulation ◽  
Partial Explanation ◽  
Calculated Mass ◽  
Percentage Basis

Ears of wheat were exposed for up to 7 days during the grain-filling stage to high temperature (35�C day/25�C night) and metabolic responses in the grain were compared to those in ears maintained at lower temperatures (21�C day/16�C night). Two cultivars of wheat known to differ in their post-anthesis tolerance of high temperature were compared. Raising the temperature resulted in a small increase in the rate of dry matter accumulation: both cultivars responded similarly. Sucrose content of the endosperm was either not affected or increased by raising the temperature. Raising the temperature had differential effects on glucose and fructose content: fructose was substantially reduced while glucose was either unaffected or slightly increased. After raising the temperature the concentrations of all three hexose phosphates measured, glucose-6-phosphate (G-6-P), glucose-1-phosphate (G-1-P) and fructose-6-phosphate (F-6-P), were reduced similarly on a percentage basis and to about the same extent as fructose. The concentration of the sugar nucleotide (UDP-glucose) resulting from the breakdown of sucrose by sucrose synthase was also reduced at high temperature. Judging from calculated mass-action ratios, all three catalytic steps involved in the interconversion of the metabolites mentioned above were close to equilibrium, and only one mass action ratio (for sucrose synthase) was affected by heating: it was doubled. Although temperature clearly resulted in changes in the reaction catalysed by sucrose synthase, it was not clear how temperature had acted. Concentration of the precursor for starch synthesis (ADP-glucose) was slightly lower in both cultivars at the higher temperature. Taken together the responses could provide at least a partial explanation for the smallness of the increase in starch deposition with increase in temperature, but do not explain the different responses of these two cultivars to high temperature.

scholarly journals Triple null mutations in starch synthase SSIIa gene homoeologs lead to high amylose and resistant starch in hexaploid wheat

2021 ◽  
Author(s):  
Adam Schoen ◽  
Anupama Joshi ◽  
Vijay K Tiwari ◽  
Bikram S. Gill ◽  
Nidhi Rawat
Keyword(s):  
Resistant Starch ◽  
Amylose Content ◽  
Starch Content ◽  
Wheat Variety ◽  
Starch Synthesis ◽  
Starch Synthase ◽  
Single Individual ◽  
Individual Genome ◽  
Mutant Genotype ◽  
Knock Out

Abstract Background: Lack of nutritionally appropriate foods is one of the leading causes of obesity in the US and worldwide. Wheat (Triticum aestivum) provides 20% of the calories consumed daily across the globe. The nutrients in the wheat grain come primarily from the starch composed of amylose and amylopectin. Resistant starch content, which is known to have significant human health benefits, can be increased by modifying starch synthesis pathways. Starch synthase enzyme SSIIa, also known as starch granule protein isoform-1 (SGP-1), is integral to the biosynthesis of the branched and readily digestible glucose polymer amylopectin. The goal of this work was to develop a triple null mutant genotype for SSIIa locus in the elite hard red winter wheat variety ‘Jagger’ and evaluate the effect of the knock-out mutations on resistant starch content in grains with respect to wild type. Results: Knock-out mutations in SSIIa in the three genomes of wheat variety ‘Jagger’ were identified using TILLING. Subsequently, these loss-of function mutations on A, B, and D genomes were combined by crossing to generate a triple knockout mutant genotype Jag-ssiia-∆ABD. The Jag-ssiia-∆ABD had an amylose content of 35.70% compared to 31.15% in Jagger, leading to ~118% increase in resistant starch in the Jag-ssiia-∆ABD genotype of Jagger wheat. The single individual genome mutations also had various effects on starch composition. Conclusions: Our full null Jag-ssiia-∆ABD mutant showed a significant increase in RS without the shriveled grain phenotype seen in other ssiia knockouts in elite wheat cultivars. Moreover, this study shows the potential for developing nutritionally improved foods in a non-GM approach. Since all the mutants have been developed in an elite wheat cultivar, their adoption in production and supply will be feasible in future.

Biogas production from silage maize hybrids

2011 ◽  
Vol 59 (3) ◽  
pp. 223-229
Author(s):  
Z. Hegyi ◽  
Z. Zsubori-Tóth ◽  
J. Pintér ◽  
C. Marton
Keyword(s):  
Dry Matter ◽  
Anaerobic Fermentation ◽  
Biogas Production ◽  
Starch Content ◽  
Sugar Content ◽  
Grain Filling ◽  
Strong Positive Correlation ◽  
Vegetative Period ◽  
Positive Correlation ◽  
Biogas Yield

Experiments have been underway in Martonvásár for many years to develop leafy silage hybrids, which have a greater aboveground mass than conventional silage hybrids. The best hybrids for biogas production would be those that produce a large quantity of biomass and are rich in starch. The chief characteristic of leafy hybrids is that they have more leaves than normal hybrids. Due to this enhanced leaf area above the ear, the vegetative period of leafy genotypes is shorter, while the grain-filling period is longer, which has a positive effect on both yield and grain quality. The results of the present experiment show that during the anaerobic fermentation of the silage, leafy hybrids produced more biogas (640 l per 1000 g dry matter) than conventional hybrids (606 l per 1000 g dry matter). There were no significant differences between the methane contents of the leafy and non-leafy hybrids tested in the experiment. A strong positive correlation was found between biogas yield and the starch content of the silage, and a moderate positive correlation between biogas yield and the sugar content. The correlation between biogas yield and the lignin and protein contents was negative, in accordance with other literary data.

scholarly journals Maize endosperm-specific transcription factors O2 and PBF network the regulation of protein and starch synthesis

2016 ◽  
Vol 113 (39) ◽  
pp. 10842-10847 ◽  
Author(s):  
Zhiyong Zhang ◽  
Xixi Zheng ◽  
Jun Yang ◽  
Joachim Messing ◽  
Yongrui Wu
Keyword(s):  
Transcription Factors ◽  
Double Mutant ◽  
Starch Content ◽  
Starch Synthesis ◽  
Starch Synthase ◽  
Maize Endosperm ◽  
Protein Levels ◽  
Pyruvate Orthophosphate Dikinase ◽  
Branching Enzymes ◽  
Critical Components

The maize endosperm-specific transcription factors opaque2 (O2) and prolamine-box binding factor (PBF) regulate storage protein zein genes. We show that they also control starch synthesis. The starch content in the PbfRNAi and o2 mutants was reduced by ∼5% and 11%, respectively, compared with normal genotypes. In the double-mutant PbfRNAi;o2, starch was decreased by 25%. Transcriptome analysis reveals that >1,000 genes were affected in each of the two mutants and in the double mutant; these genes were mainly enriched in sugar and protein metabolism. Pyruvate orthophosphate dikinase 1 and 2 (PPDKs) and starch synthase III (SSIII) are critical components in the starch biosynthetic enzyme complex. The expression of PPDK1, PPDK2, and SSIII and their protein levels are further reduced in the double mutants as compared with the single mutants. When the promoters of these genes were analyzed, we found a prolamine box and an O2 box that can be additively transactivated by PBF and O2. Starch synthase IIa (SSIIa, encoding another starch synthase for amylopectin) and starch branching enzyme 1 (SBEI, encoding one of the two main starch branching enzymes) are not directly regulated by PBF and O2, but their protein levels are significantly decreased in the o2 mutant and are further decreased in the double mutant, indicating that o2 and PbfRNAi may affect the levels of some other transcription factor(s) or mRNA regulatory factor(s) that in turn would affect the transcript and protein levels of SSIIa and SBEI. These findings show that three important traits—nutritional quality, calories, and yield—are linked through the same transcription factors.

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.

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