Reduced Starch Content and Sucrose Synthase Activity in Developing Endosperm of Barley Plants Grown at Elevated Temperatures

1988 ◽  
Vol 15 (3) ◽  
pp. 367 ◽  
Author(s):  
LC MacLeod ◽  
CM Duffus
Keyword(s):  
Elevated Temperatures ◽  
Starch Content ◽  
Grain Filling ◽  
Starch Accumulation ◽  
Grain Development ◽  
Irreversible Reduction ◽  
Short Period ◽  
Cleavage Enzyme ◽  
Grain Filling Period ◽  
Sucrose Cleavage

Starch accumulation is reduced when endosperms develop at elevated temperatures. Reduced starch deposition does not appear to be due to limiting assimilate levels during the grain filling period; on the contrary, endosperm sucrose may even be increased at the elevated temperature. Results indicate that elevated temperatures significantly reduce the activity of the sucrose cleavage enzyme UDPsucrose synthase (EC 2.4.1.13), found in the endosperm during grain development, and that these effects may be initiated by a relatively short period of thermal stress applied close to anthesis. It would appear that, when developing barley ears are exposed to elevated temperatures, there is an irreversible reduction in the capacity of the endosperm to convert sucrose to starch, caused by a decrease in the activity of at least one of the enzymes involved in this conversion pathway.

Effect of Timing of Heat Stress During Grain Filling on Two Wheat Varieties Differing in Heat Tolerance. I. Grain Growth

1995 ◽  
Vol 22 (6) ◽  
pp. 927 ◽  
Author(s):  
PJ Stone ◽  
ME Nicolas
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Grain Growth ◽  
Heat Tolerance ◽  
Grain Filling ◽  
Dry Matter Accumulation ◽  
Varietal Differences ◽  
Short Period ◽  
Grain Filling Period ◽  
Very High

Short periods of very high temperature (> 35�C) are common in many of the world's wheat growing areas and can be a significant factor in reducing yield and quality of wheat. This study was designed to determine the stage at which grain growth is most sensitive to a short period of high temperature and to examine whether varietal differences in heat tolerance are expressed throughout the whole grain-filling period. Two varieties of wheat differing in heat tolerance (cvv. Egret and Oxley) were exposed to a short (5 days) period of very high temperature (40�C max. for 6 h each day) at 5-day intervals throughout grain filling, starting from 15 days after anthesis (DAA) and concluding at 50 DAA. Responses of grain dry matter accumulation and water content to high temperature were monitored throughout grain filling, and the results compared with controls maintained at 21/16�C day/night. Varietal differences in heat tolerance were expressed throughout the grain-filling period. Mature individual kernel mass was most sensitive to heat stress applied early in grain filling and became progressively less sensitive throughout grain filling, for both varieties. Reductions in mature kernel mass resulted primarily from reductions in duration rather than rate of grain filling.

scholarly journals Activities of sucrose to starch metabolizing enzymes during grain filling in late sown wheat under water stress

2017 ◽  
Vol 9 (1) ◽  
pp. 338-343 ◽  
Author(s):  
Reena Mahla ◽  
Shashi Madan ◽  
Vikender Kaur ◽  
Renu Munjal ◽  
Rishi Kumar Behl ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Water Deficit ◽  
Starch Content ◽  
Grain Filling ◽  
Triticum Aestivum L ◽  
Starch Accumulation ◽  
Metabolizing Enzymes ◽  
Late Planting ◽  
Filling Stage ◽  
Grain Filling Stage

Tolerance to water deficit in relation to activities of sucrose-to- starch metabolizing enzymes and starch accumulation was studied in the grains of contrasting wheat (Triticum aestivum L.) genotypes (WH1021 and WH1080; tolerant) and (WH711 and HD2687; susceptible) under late planting conditions. The activities of starch metabolizing enzymes i.e. sucrose synthase (SuSase), ADP-glucose pyrophosphorylase (AGPase), soluble starch synthase (SSS) and starch branching enzymes (SBE) were substantially enhanced by water deficit in all genotypes at early to mid-grain filling stage showing peaks at 14 to 21 days after anthesis (DAA); while decreased significantly at mid-late grain filling stage with maximum decline at 35 DAA. Activities of all the enzymes under study showed maximum decline in activity (28.4–60%) in susceptible genotype WH711; whereas WH1021 proved to be most tolerant one with minimum decline in enzyme activity (14.9–32.8%). Starch content was also markedly reduced (21%) in WH711 due to drought while WH1021 reported 12% decline corresponding well with enzyme activity. A faster pre-mature cessation of starch deposition occurred in susceptible wheat genotypes compared to tolerant ones. A significant and positive correlation of the enzyme activities with starch accumulation (r = 0.491–0.555 at P0.05 for SuSase, AGPase, SSS and r = 0.638 at P0.01 for SBE) under well watered conditions indicated that enhancing the activities of the enzymes would lead to increase in starch accumulation and thus faster grain filling. Genotype WH1021 proved to be most efficient based on comparatively higher enzyme activity and least yield penalty under late planting conditions combined with water scarcity.

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.

ACCUMULATION AND TRANSLOCATION OF SOLUBLE SOLIDS IN CORN STALKS

1972 ◽  
Vol 52 (3) ◽  
pp. 363-368 ◽  
Author(s):  
D. J. HUME ◽  
D. K. CAMPBELL
Keyword(s):  
Zea Mays L ◽  
Grain Filling ◽  
Growing Season ◽  
Soluble Solids ◽  
Grain Development ◽  
Plant Populations ◽  
Total Soluble Solids ◽  
Solids Concentration ◽  
Grain Filling Period ◽  
Soluble Solids Concentration

Soluble solids in stalks of two short-season corn (Zea mays L.) hybrids accumulated until 2–3 weeks after anthesis, and then declined rapidly during the grain-filling period. Soluble solids concentration was unaffected by plant population, but greatest total soluble solids accumulated at high plant populations. Most of the soluble solids that accumulated and disappeared were in internodes below the ear. When pollination and grain development were prevented, total soluble solids in stalks increased until the end of the growing season, indicating that the decline in stalk soluble solids during grain filling was caused primarily by translocation of metabolites from the stalk to the grain.

Rapid endosperm development promotes early maturity in weedy rice (Oryza sativa f. spontanea)

Weed Science ◽  
2020 ◽  
Vol 68 (2) ◽  
pp. 168-178
Author(s):  
Can Zhao ◽  
Wenrong Xu ◽  
Lingchao Meng ◽  
Sheng Qiang ◽  
Weimin Dai ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Cell Division ◽  
Grain Filling ◽  
Endosperm Development ◽  
Starch Accumulation ◽  
Weedy Rice ◽  
Endosperm Cell ◽  
Cultivated Rice ◽  
Early Maturity ◽  
Grain Filling Period

AbstractEarly maturity allows weedy rice (Oryza sativa L. f. spontanea) to persist by escaping harvest in paddy fields. A shorter grain-filling period contributes to the early maturity of weedy rice. However, the differences in morphology and endosperm development in the caryopsis between weedy and cultivated rice are largely unexplored. Here, we selected four biotypes of weedy rice and associated cultivated rice (ACR; Oryza sativa) from different latitudes to conduct a common garden experiment. The endosperm development process of the caryopsis was observed by optical microscopy and electron microscopy. Endosperm cell division and starch accumulation rate during grain filling were also measured. The grain development progress in weedy rice was more rapid and earlier than that in ACR. The endosperm development progress of weedy rice was 6 to 8 d earlier than that of ACR. The endosperm cells of weedy rice cellularized earlier and more rapidly than those of ACR, and the starch grains of weedy rice were more sharply polygonal and compactly arranged than those of ACR. The active endosperm cell division period in weedy rice was 4 to 7 d shorter than that in ACR, while the active starch accumulation period of weedy rice was 2 to 8 d shorter than that of ACR. The rapid development of endosperm cells and starch grains leads to the shorter grain-filling period of weedy rice. weedy rice.

scholarly journals RGB1 Regulates Grain Development and Starch Accumulation Through Its Effect on OsYUC11-Mediated Auxin Biosynthesis in Rice Endosperm Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Dongping Zhang ◽  
Minyan Zhang ◽  
Jiansheng Liang
Keyword(s):  
Grain Size ◽  
G Protein ◽  
Grain Filling ◽  
Auxin Biosynthesis ◽  
Starch Accumulation ◽  
Grain Development ◽  
Filling Process ◽  
Filling Stage ◽  
Grain Filling Stage ◽  
Lower Expression

RGB1, a subunit of heterotrimeric G protein, plays important roles in regulating grain size and weight of rice. However, the molecular mechanisms underlying controlling grain filling process by G protein are still largely unclear. In the present study, we show that RGB1 controls not only the grain size but also the grain filling process. Knock-down of RGB1 significantly delayed grain development and reduced starch accumulation and grain weight, which was closely related to the delayed and the lower expression of genes encoding sucrose metabolism and starch biosynthesis related enzymes during grain filling stage. Suppression of RGB1 expression also resulted in the lower auxin content in grains, which was correlated with the lower expression of OsNF-YB1 and OsYUC11 during grain filling stage. Further biochemical evidence showed that OsYUC11 expression was under control of OsNF-YB1 by its interaction with promoter of OsYUC11. Taken together, we propose that RGB1 controls rice grain development and grain filling process by changing auxin homeostasis in endosperm cells. OsNF-YB1, which acts as a key downstream effector of RGB1, interacts directly with the promoter of OsYUC11 and stimulates the OsYUC11 expression, thereby regulating auxin biosynthesis and starch accumulation and grain size.

Effects of grain position on the panicle on starch biosynthetic enzyme activity in developing grains of rice cultivar Tainung 67 and its NaN3-induced mutant

2003 ◽  
Vol 141 (3-4) ◽  
pp. 303-311 ◽  
Author(s):  
T. L. JENG ◽  
C. S. WANG ◽  
C. L. CHEN ◽  
J. M. SUNG
Keyword(s):  
Enzyme Activities ◽  
Initial Period ◽  
Grain Filling ◽  
Rice Cultivar ◽  
Starch Biosynthesis ◽  
Starch Accumulation ◽  
Grain Filling Period ◽  
Starch Conversion ◽  
Developing Grains ◽  
Induced Mutant

The content of starch and the activities of enzymes involved in starch biosynthesis were examined in developing grains of field grown rice (Oryza sativa L.) plants. Enzyme activities were monitored throughout the grain filling period of cultivar Tainung 67 and its NaN3-induced mutant SA419. The activities of most of the grain enzymes involved in starch biosynthesis increased and reached their maxima during the initial period of grain development, then gradually declined towards the later stages of grain filling. Both Tainung 67 and SA419 showed different starch and amylose accumulation patterns in different grain positions. In cultivar Tainung 67, reduced activities of grain enzymes involved in starch biosynthesis, particularly during the early phase of grain filling, were related to the decreased starch accumulation for the grains located on proximal secondary branches as compared with the grains located on distal primary branches. The decreased amylose contents in the grains of Tainung 67 located on proximal secondary branches were attributable to their lower granule bound starch synthase and starch debranching enzyme activities at early and mid phases of grain filling. In mutant SA419, no significant changes were observed in the activities of grain enzymes involved in sucrose to starch conversion between the grains located on distal primary and proximal secondary branches of the panicle. As a result, grain setting position was found to have little effect on the contents of starch and amylose for these developing grains located on different branches. Thus, the mutant SA419 did have some agronomic and physiological traits that were superior to its wild type cultivar Tainung 67.

Co-expression of AGPS and AGPL genes encoded for AGPase from cassava to enhance starch accumulation in transgenic tobacco

2016 ◽  
Vol 14 (2) ◽  
pp. 287-293
Author(s):  
Nguyễn Văn Đoài ◽  
Nguyễn Minh Hồng ◽  
Lê Thu Ngọc ◽  
Nguyễn Thị Thơm ◽  
Nguyễn Đình Trọng ◽  
...  
Keyword(s):  
Transgenic Tobacco ◽  
Higher Plants ◽  
Starch Content ◽  
Genetically Modified Crops ◽  
Starch Accumulation ◽  
35S Promoter ◽  
Effective Strategies ◽  
Plant Expression Vector ◽  
Transgenic Lines ◽  
Cassava Varieties

The AGPase (ADP-Glucose pyrophosphorylase) is one of the ubiquitous enzymes catalyzing the first step in starch biosynthesis. It plays an important role in regulation and adjusts the speed of the entire cycle of glycogen biosynthesis in bacteria and starch in plants. In higher plants, it is a heterotetramer and tetrameric enzyme consisting two large subunits (AGPL) and two small subunits (AGPS) and encoded by two genes. In this paper, both AGPS and AGPL genes were sucessfully isolated from cassava varieties KM140 and deposited in Genbank with accession numbers KU243124 (AGPS) and KU243122 (AGPL), these two genes were fused with P2a and inserted into plant expression vector pBI121 under the control of 35S promoter. The efficient of this construct was tested in transgenic N. tabacum. The presence and expression of AGPS and AGPL in transgenic plants were confirmed by PCR and Western hybridization. The starch content was quantified by the Anthrone method. Transgenic plant analysis indicated that that two targeted genes were expressed simultaneously in several transgenic tobacco lines under the control of CaMV 35S promoter.  The starch contents in 4 analyzed tobacco transgenic lines displays the increase 13-116%  compared to WT plants. These results indicated that the co-expression of AGPS and AGPL is one of effective strategies for enhanced starch production in plant. These results can provide a foundation for developing other genetically modified crops to increase starch accumulation capacity.

Influence of Canopy Temperature (CT) During Grain-Filling Period on Yield and Effects of Several CT-Associated SSR Loci

2015 ◽  
Vol 41 (4) ◽  
pp. 548 ◽  
Author(s):  
Dong-Ling ZHANG ◽  
Hong-Na ZHANG ◽  
Chen-Yang HAO ◽  
Lan-Fen WANG ◽  
Tian LI ◽  
...  
Keyword(s):  
Canopy Temperature ◽  
Grain Filling ◽  
Ssr Loci ◽  
Grain Filling Period
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