Effects of low temperature on grain filling, amylose content, and activity of starch biosynthesis enzymes in endosperm of basmati rice

2008 ◽  
Vol 59 (7) ◽  
pp. 599 ◽  
Author(s):  
Nisar Ahmed ◽  
Masahiko Maekawa ◽  
Ian J. Tetlow
Keyword(s):  
Low Temperature ◽  
Amylose Content ◽  
Oryza Sativa L ◽  
Starch Content ◽  
Grain Filling ◽  
Soluble Starch ◽  
Starch Biosynthesis ◽  
Starch Synthase ◽  
Basmati Rice ◽  
Starch Phosphorylase

The effects of low temperature on amylose contents and activities of key enzymes related to starch biosynthesis in basmati rice (Oryza sativa L.) endosperm were investigated. Low temperature treatment prolonged the grain-filling period from 32 days to 53 days, but had no significant effect on the final grain weight. Results showed that low temperature during grain filling had no significant effect on total starch content but increased the amylose content in the mature endosperm of hulled rice by 21%. The measurable activities of sucrose synthase (SuSy), ADP-glucose pyrophosphorylase (AGPase), starch phosphorylase (SPase), starch branching enzyme (SBE), and soluble starch synthase (SS) in endosperms developed at 12°C were lower than those at 22°C when compared at a similar ripening stage on an endosperm basis, but the activity of granule-bound starch synthase (GBSS) was significantly higher than the corresponding activity in endosperms developing at 22°C. These findings suggest that GBSS might play a crucial role in increasing amylose during low-temperature growth conditions.

Changes in Some Carbohydrate Fractions and Some Related Enzymic Activities in Plump and Shrivelled Triticale and in Wheat Grains

1986 ◽  
Vol 13 (2) ◽  
pp. 249 ◽  
Author(s):  
AS Dhaliwal ◽  
HL Sharma
Keyword(s):  
Starch Content ◽  
Soluble Sugars ◽  
Grain Filling ◽  
Starch Synthase ◽  
Starch Phosphorylase ◽  
Total Soluble Sugars ◽  
Final Maturation ◽  
Triticale Line ◽  
Grain Filling Period ◽  
Developing Grains

Activities of α-amylase (EC 3.2.1.1), β-amylase (EC 3.2.1.2), soluble ADPglucose-starch synthase (EC 2.4.1.21), starch phosphorylase (EC 2.4.1.1), sucrose synthase (EC 2.4.1.13) and invertase (EC 3.2.1.26), and amounts of reducing sugars, total soluble sugars and starch, were studied in the developing grains of wheat and triticale lines. A triticale line (TL1) with shrivelled grains contained a low starch content, increased reducing and total soluble sugars during the final grain-filling period as well as a higher moisture at maturity than wheat and a plump-grain triticale line (TL2). The overall activities of soluble ADPglucose-starch synthase and starch phosphorylase remained lower and that of α- and β-amylases higher in TL1 than wheat and TL2 throughout grain development. The higher amylolytic activity retained during the final maturation period appears to be at least partly due to the higher moisture content of the grain in the triticale line TL1 with shrivelled grains.

Allelic variations in the soluble starch synthase II gene family result in changes of grain quality and starch properties in rice (Oryza sativa L.)

2016 ◽  
Vol 155 (1) ◽  
pp. 129-140 ◽  
Author(s):  
X. Y. FAN ◽  
M. GUO ◽  
R. D. LI ◽  
Y. H. YANG ◽  
M. LIU ◽  
...  
Keyword(s):  
Gene Family ◽  
Grain Quality ◽  
Amylose Content ◽  
Oryza Sativa L ◽  
Soluble Starch ◽  
Granule Size ◽  
Starch Synthase ◽  
Relative Crystallinity ◽  
Starch Properties ◽  
Soluble Starch Synthase Ii

SUMMARYSoluble starch synthase II (SSII) plays an important role in the biosynthesis of starch and in rice it consists of three isoforms encoded by SSII-1, SSII-2 and SSII-3. However, the genetic effects of various SSII alleles on grain quality have not been systematically characterized. In the present study, the japonica alleles on SSII-1, SSII-2 and SSII-3 (SSIIa) loci from a japonica cultivar, Suyunuo, were respectively introgressed by molecular marker-assisted selection into a typical indica cultivar, Guichao2, through successive backcrossing, generating three sets of near-isogenic lines (NILs). Grain quality and starch property analysis showed that NIL-SSII-3j exhibited significant decreases in the following parameters: amylose content, average granule size, and setback viscosity and consistency; but increases in peak viscosity, hot paste viscosity, gelatinization temperature and relative crystallinity. Moreover, the proportion of short amylopectin chains and branching degree also increased when compared with those of NIL-SSII-3i (Guochao2). Similar effects were observed in NIL-SSII-1j, and certain alterations in the fine structure of starch (granule size) were revealed. However, NIL-SSII-2j did not exert significant effect on grain quality and starch properties. In brief, among the SSII gene family, the functional diversity occurred on SSII-1 and SSII-3, and not on SSII-2. Therefore, it appears that more attention should be directed to SSII-1 and SSII-3 loci for improving the eating and cooking quality of rice.

scholarly journals Evaluation of indigenous aromatic rice cultivars from sub-Himalayan Terai region of India for nutritional attributes and blast resistance

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Debayan Mondal ◽  
Prudveesh Kantamraju ◽  
Susmita Jha ◽  
Gadge Sushant Sundarrao ◽  
Arpan Bhowmik ◽  
...  
Keyword(s):  
Nutritive Value ◽  
Amylose Content ◽  
Blast Resistance ◽  
Starch Content ◽  
Low Cost ◽  
Principal Component ◽  
Blast Disease ◽  
Basmati Rice ◽  
Phenotypic Traits ◽  
Rice Cultivars

AbstractIndigenous folk rice cultivars often possess remarkable but unrevealed potential in terms of nutritional attributes and biotic stress tolerance. The unique cooking qualities and blissful aroma of many of these landraces make it an attractive low-cost alternative to high priced Basmati rice. Sub-Himalayan Terai region is bestowed with great agrobiodiversity in traditional heirloom rice cultivars. In the present study, ninety-nine folk rice cultivars from these regions were collected, purified and characterized for morphological and yield traits. Based on traditional importance and presence of aroma, thirty-five genotypes were selected and analyzed for genetic diversity using micro-satellite marker system. The genotypes were found to be genetically distinct and of high nutritive value. The resistant starch content, amylose content, glycemic index and antioxidant potential of these genotypes represented wide variability and ‘Kataribhog’, ‘Sadanunia’, ‘Chakhao’ etc. were identified as promising genotypes in terms of different nutritional attributes. These cultivars were screened further for resistance against blast disease in field trials and cultivars like ‘Sadanunia’, ‘T4M-3-5’, ‘Chakhao Sampark’ were found to be highly resistant to the blast disease whereas ‘Kalonunia’, ‘Gobindabhog’, ‘Konkanijoha’ were found to be highly susceptible. Principal Component analysis divided the genotypes in distinct groups for nutritional potential and blast tolerance. The resistant and susceptible genotypes were screened for the presence of the blast resistant pi genes and association analysis was performed with disease tolerance. Finally, a logistic model based on phenotypic traits for prediction of the blast susceptibility of the genotypes is proposed with more than 80% accuracy.

scholarly journals QTL-seq identifies cooked grain elongation QTLs near soluble starch synthase and starch branching enzymes in rice (Oryza sativa L.)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Siwaret Arikit ◽  
Samart Wanchana ◽  
Srisawat Khanthong ◽  
Chatree Saensuk ◽  
Tripop Thianthavon ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Oryza Sativa L ◽  
Soluble Starch ◽  
Starch Synthase ◽  
Starch Branching Enzymes ◽  
Branching Enzymes

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.

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.

Starch content and activities of starch-metabolizing enzymes in effective and ineffective root nodules of soybean

1991 ◽  
Vol 69 (4) ◽  
pp. 697-701 ◽  
Author(s):  
Sharon I. Forrest ◽  
Desh Pal S. Verma ◽  
Rajinder S. Dhindsa
Keyword(s):  
Nitrogen Fixation ◽  
Starch Content ◽  
Root Nodules ◽  
Starch Synthase ◽  
Nodule Development ◽  
Wild Type ◽  
Starch Phosphorylase ◽  
High Concentration ◽  
Key Words Nitrogen Fixation ◽  
Glycine Max L

Starch content and activities of some enzymes of starch metabolism were determined in wild-type, N2-fixing (fix+) nodules and in two non-N2-fixing (fix−) nodules induced by Bradyrhizobium japonicum mutant strains, T5-95 and T8-1, on soybean (Glycine max L.) roots. The T5-95 nodules are similar to wild type in ultrastructure, but the T8-1 nodules are different in that the bacteroids are not released from the infection thread. After initial accumulation to relatively high concentration, starch was depleted during nitrogen fixation in fix+ nodules. However, in fix− nodules, the accumulated starch was not metabolized. The activity of starch-bound starch synthase (EC 2.4.1.21) declined in fix+ nodules but remained high in fix− nodules. The activity of α-amylase (EC 3.2.1.1) was only slightly higher than wild type in T5-95 but was four times higher than wild type in T8-1 nodules. The activity of starch phosphorylase (EC 2.4.1.1) increased in all nodule types from 14 to 21 days postinfection. A positive correlation was observed between the capacity of nodules to fix N2 and their capacity to degrade starch. Collectively, these results support the concept that starch accumulated during early stages of nodule development is metabolized to supply energy for nitrogen fixation and to meet the metabolic demands of bacteroids. Key words: nitrogen fixation, starch content, effective and ineffective nodules, starch synthase, starch phosphorylase, α-amylase.

scholarly journals Genetic divergence analysis in basmati rice genotypes (Oryza sativa L.) for agro-morphological and quality traits using multivariate approach

2021 ◽  
Vol 58 (1) ◽  
pp. 1-7
Author(s):  
Vinod Kumar ◽  
Dhirendra Singh
Keyword(s):  
Genetic Divergence ◽  
Amylose Content ◽  
Oryza Sativa L ◽  
Grain Weight ◽  
Basmati Rice ◽  
Quality Traits ◽  
Grain Length ◽  
Cluster Distance ◽  
Rice Genotypes ◽  
1000 Grain Weight

Genetic diversity of 30 basmati rice genotypes was analysed based on nine agro-morphological and six quality traits. The results of the principal component analysis showed that the first six principal components explained 89.16% of the total variation in the experimental material. These 30 basmati genotypes were grouped into six clusters which indicated the presence of sufficient diversity among the tested genotypes. Cluster I and cluster III was found to be the largest comprising of 10 genotypes each followed by cluster II having seven genotypes. The highest average intra-cluster distance was observed in cluster III. Highest inter-cluster distance (D2) was observed between clusters III and VI followed by clusters III and V, III and IV & clusters II and III. Cluster II showed high mean value for grain yield per plant, 1000 grain weight, and grain length. The characters viz., amylose content, grain length after cooking, spikelet per panicle, grain width, grain length and 1000 grain weight contributed maximum towards total genetic divergence, suggest their suitability of selection.

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.

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