scholarly journals Changes in Starch Synthesis and the Characteristics of Photosynthate Translocation at High Temperature during the Ripening Stage in Barley

2017 ◽  
Vol 62 (2) ◽  
pp. 124-133
Author(s):  
Hyeon-Seok Lee ◽  
◽  
Woon-Ha Hwang ◽  
Dae-Wook Kim ◽  
Jae-Hyeok Jeong ◽  
...  
Keyword(s):  
High Temperature ◽  
Starch Synthesis ◽  
Ripening Stage ◽  
Photosynthate Translocation

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.

Change of Physicochemical Properties in Barley Kernels By High Temperature During the Ripening Stage

2016 ◽  
Vol 28 (3) ◽  
pp. 358-363
Author(s):  
Hyeon-Seok Lee ◽  
◽  
Dae-Wook Kim ◽  
Woon-Ha Hwang ◽  
Jae-Hyeok Jeong ◽  
...  
Keyword(s):  
High Temperature ◽  
Physicochemical Properties ◽  
Ripening Stage

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 Genetic Control and High Temperature Effects on Starch Biosynthesis and Grain Quality in Rice

2021 ◽  
Vol 12 ◽  
Author(s):  
Hua Zhang ◽  
Heng Xu ◽  
Yingying Jiang ◽  
Heng Zhang ◽  
Shiyu Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Molecular Mechanisms ◽  
Grain Quality ◽  
Amylose Content ◽  
Starch Synthesis ◽  
Grain Filling ◽  
Eating Quality ◽  
Starch Structure ◽  
Long Time ◽  
Cooking And Eating Quality

Grain quality is one of the key targets to be improved for rice breeders and covers cooking, eating, nutritional, appearance, milling, and sensory properties. Cooking and eating quality are mostly of concern to consumers and mainly determined by starch structure and composition. Although many starch synthesis enzymes have been identified and starch synthesis system has been established for a long time, novel functions of some starch synthesis genes have continually been found, and many important regulatory factors for seed development and grain quality control have recently been identified. Here, we summarize the progress in this field as comprehensively as possible and hopefully reveal some underlying molecular mechanisms controlling eating quality in rice. The regulatory network of amylose content (AC) determination is emphasized, as AC is the most important index for rice eating quality (REQ). Moreover, the regulatory mechanism of REQ, especially AC influenced by high temperature which is concerned as a most harmful environmental factor during grain filling is highlighted in this review.

Effects of High Temperature and Water Deficiency during Grain Filling on Activities of Key Starch Synthesis Enzymes and Starch Accumulation in Wheat

2018 ◽  
Vol 44 (4) ◽  
pp. 591
Author(s):  
Yang-Yang HU ◽  
Hong-Fang LU ◽  
Wei-Xing LIU ◽  
Juan KANG ◽  
Geng MA ◽  
...  
Keyword(s):  
High Temperature ◽  
Starch Synthesis ◽  
Grain Filling ◽  
Starch Accumulation ◽  
Water Deficiency

Effect of High Temperature at Ripening Stage on the Reserve Accumulation in Seed in Some Rice Cultivars

2002 ◽  
Vol 5 (2) ◽  
pp. 160-168 ◽  
Author(s):  
Sabaruddin Zakaria ◽  
Toshiaki Matsuda ◽  
Shingo Tajima ◽  
Youji Nitta
Keyword(s):  
High Temperature ◽  
Rice Cultivars ◽  
Ripening Stage ◽  
Reserve Accumulation

scholarly journals Effect of high temperature on the expressions of genes encoding starch synthesis enzymes in developing rice endosperms

2015 ◽  
Vol 14 (4) ◽  
pp. 642-659 ◽  
Author(s):  
Zhen-zhen CAO ◽  
Gang PAN ◽  
Fu-biao WANG ◽  
Ke-su WEI ◽  
Zhao-wei LI ◽  
...  
Keyword(s):  
High Temperature ◽  
Starch Synthesis ◽  
Genes Encoding

Effect of Thermal History on Photosynthate Translocation and Photosynthesis

1978 ◽  
Vol 5 (4) ◽  
pp. 547 ◽  
Author(s):  
LK Fussell ◽  
CJ Pearson
Keyword(s):  
High Temperature ◽  
Thermal History ◽  
Leaf Structure ◽  
Pennisetum Americanum ◽  
Photosynthetic Rates ◽  
Lower Temperature ◽  
Photosynthate Translocation

Plants of Pennisetum americanum, previously grown at a lower temperature, exhibited relatively low 14C translocation and photosynthetic rates when moved to a warmer environment. The source leaves retained the same amount of photosynthate as did leaves of plants that were grown continuously at high temperature. We hypothesize that the lack of adaptation is due to leaf structure, determined during pretreatment, limiting the above processes.

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