Drought Stress Induces Changes in the Non-Structural Carbohydrate Composition of Wheat Stems

1991 ◽  
Vol 18 (3) ◽  
pp. 239 ◽  
Author(s):  
JM Virgona ◽  
EWR Barlow
Keyword(s):  
Molecular Weight ◽  
Drought Stress ◽  
Flag Leaf ◽  
Grain Filling ◽  
Triticum Aestivum L ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Structural Carbohydrate ◽  
Water Soluble Carbohydrate ◽  
Hydrolysis Of

The effect of drought stress on the non-structural carbohydrate (NSC) composition and water relations of the wheat (Triticum aestivum L.) stem has been investigated. Five separate parts of the stem were sampled: the unsheathed portion of the peduncle (Stem 1a), the sheathed portion of the peduncle (Stem 1b), the penultimate internode (Stem 2), the lower internodes (Stem 3+4) and the flag-leaf-pulvinus (pulvinus). The NSC was analysed as two fractions, an ethanol-soluble carbohydrate (ESC) fraction containing mono- and di-saccharides and some low molecular weight oligosaccharides, and a water-soluble carbohydrate (WSC) fraction containing mostly fructans and some high molecular weight oligosaccharides. In Stems 1b, 2 and 3 +4, the imposition of drought midway through grain filling resulted in a shift in soluble carbohydrate from the WSC to the ESC fraction indicating hydrolysis of fructans. In Stem 2 on day 29 of grain filling, the WSC/ESC ratio was 7.6 � 1.5 in well watered plants in contrast to 0.5 � 0.1 in droughted plants on day 30, even though NSC concentration did not differ. The NSC content of Stem la and the pulvinus increased threefold under drought, although levels were significantly lower than in the rest of the stem. The WSC/ESC ratio in these tissues was low com- pared to the rest of the stem but still declined noticeably under drought stress. Turgor (P) was fully maintained in Stem 2 and the pulvinus of droughted plants. Under drought, P in the pulvinus was maintained at higher levels (1.9-2.4 MPa) than in Stem 2 (0.8-1.2 MPa).

scholarly journals Improving Grain Yield via Promotion of Kernel Weight in High Yielding Winter Wheat Genotypes

Biology ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 42
Author(s):  
Cong Zhang ◽  
Bangyou Zheng ◽  
Yong He
Keyword(s):  
Grain Yield ◽  
Flag Leaf ◽  
Grain Filling ◽  
Kernel Weight ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Leaf Photosynthesis ◽  
Wheat Genotypes ◽  
Water Soluble Carbohydrate ◽  
Grain Filling Stage

Improving plant net photosynthetic rates and accelerating water-soluble carbohydrate accumulation play an important role in increasing the carbon sources for yield formation of wheat (Triticum aestivum L.). Understanding and quantify the contribution of these traits to grain yield can provide a pathway towards increasing the yield potential of wheat. The objective of this study was to identify kernel weight gap for improving grain yield in 15 winter wheat genotypes grown in Shandong Province, China. A cluster analysis was conducted to classify the 15 wheat genotypes into high yielding (HY) and low yielding (LY) groups based on their performance in grain yield, harvest index, photosynthetic rate, kernels per square meter, and spikes per square meter from two years of field testing. While the grain yield was significantly higher in the HY group, its thousand kernel weight (TKW) was 8.8% lower than that of the LY group (p < 0.05). A structural equation model revealed that 83% of the total variation in grain yield for the HY group could be mainly explained by TKW, the flag leaf photosynthesis rate at the grain filling stage (Pn75), and flag leaf water-soluble carbohydrate content (WSC) at grain filling stage. Their effect values on yield were 0.579, 0.759, and 0.444, respectively. Our results suggest that increase of flag leaf photosynthesis and WSC could improve the TKW, and thus benefit for developing high yielding wheat cultivars.

Assimilate Supply and Floret Development Within the Spike of Wheat (Triticum aestivum L.)

1983 ◽  
Vol 10 (6) ◽  
pp. 585 ◽  
Author(s):  
YM Stockman ◽  
RA Fischer ◽  
EG Brittain
Keyword(s):  
Flag Leaf ◽  
Dry Weight ◽  
Triticum Aestivum L ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Controlled Environment ◽  
Lower Priority ◽  
Carbohydrate Concentration ◽  
Leaf Emergence ◽  
Water Soluble Carbohydrate

The effect of increased as well as reduced assimilate on floret growth and development in wheat (cv. Yecora) was investigated in a controlled environment. Plants from which all tillers were removed were grown at 21/10°C with a 14 h photoperiod. At flag leaf emergence, an additional light (15% above control) and two shading treatments (40 and 70% below control) were applied to the plants for an 8-day period, ending 6 days before anthesis. The additional light and the 70% shade treatments had significant effects (+37%, -43% respectively), on the number of competent florets (as judged by anther appearance at anthesis) and subsequently similar effects on the number of kernels per spike at maturity. The changes in competent floret numbers were closely related to changes in spike dry weight at anthesis and in turn, during the treatment period. The heavy shading decreased grain yield significantly. Within the spike, treatment effects on floret and kernel number were greater in basal spikelets than in distal and especially central spikelets, in both an absolute as well as relative sense. These effects were paralleled by greater changes in basal spikelet dry weight and water-soluble carbohydrate concentration. They may be related to the smaller size or later development of basal spikelets at the onset of treatment, and suggest that the base of the spike is normally a lower priority sink for assimilate at that time.

scholarly journals Diurnal Changes in Water Soluble Carbohydrate Components in Leaves and Sucrose Associated TaSUT1 Gene Expression during Grain Development in Wheat

2020 ◽  
Vol 21 (21) ◽  
pp. 8276
Author(s):  
Sarah Al-Sheikh Ahmed ◽  
Jingjuan Zhang ◽  
Hussein Farhan ◽  
Yingquan Zhang ◽  
Zitong Yu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Developmental Stages ◽  
Grain Filling ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Diurnal Changes ◽  
Flag Leaves ◽  
Diurnal Patterns ◽  
Carbohydrate Components ◽  
Water Soluble Carbohydrate

In plant tissues, sugar levels are determined by the balance between sugar import, export, and sugar synthesis. So far, water soluble carbohydrate (WSC) dynamics have not been investigated in a diurnal context in wheat stems as compared to the dynamics in flag leaves during the terminal phases of grain filling. Here, we filled this research gap and tested the hypothesis that WSC dynamics interlink with gene expression of TaSUT1. The main stems and flag leaves of two genotypes, Westonia and Kauz, were sampled at four hourly intervals over a 24 h period at six developmental stages from heading to 28 DAA (days after anthesis). The total levels of WSC and WSC components were measured, and TaSUT1 gene expression was quantified at 21 DAA. On average, the total WSC and fructan levels in the stems were double those in the flag leaves. In both cultivars, diurnal patterns in the total WSC and sucrose were detected in leaves across all developmental stages, but not for the fructans 6-kestose and bifurcose. However, in stems, diurnal patterns of the total WSC and fructan were only found at anthesis in Kauz. The different levels of WSC and WSC components between Westonia and Kauz are likely associated with leaf chlorophyll levels and fructan degradation, especially 6-kestose degradation. High correlation between levels of TaSUT1 expression and sucrose in leaves indicated that TaSUT1 expression is likely to be influenced by the level of sucrose in leaves, and the combination of high levels of TaSUT1 expression and sucrose in Kauz may contribute to its high grain yield under well-watered conditions.

Genotypic variation in water-soluble carbohydrate accumulation in wheat

2006 ◽  
Vol 33 (9) ◽  
pp. 799 ◽  
Author(s):  
Sari A. Ruuska ◽  
Greg J. Rebetzke ◽  
Anthony F. van Herwaarden ◽  
Richard A. Richards ◽  
Neil A. Fettell ◽  
...  
Keyword(s):  
Genotypic Variation ◽  
Dry Weight ◽  
Grain Filling ◽  
Water Soluble ◽  
Soluble Carbohydrates ◽  
Soluble Carbohydrate ◽  
Broad Sense Heritability ◽  
Carbohydrate Accumulation ◽  
Sequential Mechanism ◽  
Water Soluble Carbohydrate

The water-soluble carbohydrate (WSC) that accumulates in the stems of wheat during growth can be an important contributor to grain filling, particularly under conditions when assimilation is limited, such as during end-of-season drought. WSC concentration was measured at anthesis across a diverse set of wheat genotypes over multiple environments. Environmental differences in WSC concentration were large (means for the set ranging between 108 and 203 mg g–1 dry weight), and there were significant and repeatable differences in WSC accumulation among genotypes (means ranging from 112 to 213 mg g–1 dry weight averaged across environments), associated with large broad-sense heritability (H = 0.90 ± 0.12). These results suggest that breeding for high WSC should be possible in wheat. The composition of the WSC, examined in selected genotypes, indicated that the variation in total WSC was attributed mainly to variation in the fructan component, with the other major soluble carbohydrates, sucrose and hexose, varying less. The degree of polymerisation (DP) of fructo-oligosaccharides was up to ~13 in samples where higher levels of WSC were accumulated, owing either to genotype or environment, but the higher DP components (DP > 6) were decreased in samples of lower total WSC. The results are consistent with fructan biosynthesis occurring via a sequential mechanism that is dependent on the availability of sucrose, and differences in WSC contents of genotypes are unlikely to be due to major mechanistic differences.

Effect of spraytopping applications of paraquat and glyphosate on the nutritive value and regeneration of vulpia (Vulpia bromoides (L.) S.F. Gray)

1991 ◽  
Vol 42 (8) ◽  
pp. 1405 ◽  
Author(s):  
AR Leys ◽  
BR Cullis ◽  
B Plater
Keyword(s):  
Nutritive Value ◽  
Grain Filling ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Wagga Wagga ◽  
Time Of Application ◽  
Water Soluble Carbohydrate ◽  
Subsequent Regeneration ◽  
Earlier Application

The effects of paraquat and glyphosate on the nutritive value of dry residues of vulpia [Vulpia bromoides (L.) S. F. Gray], and its subsequent regeneration the following year were examined at Wagga Wagga during the spring, summer and winter of 1986/87 and 1987/88. Paraquat (100 and 200 g a.i./ha) and glyphosate (135 and 270 g a.i./ha) were applied as spraytopping treatments at heading, anthesis and early grain filling stages of vulpia. For both herbicides, time of application was critical to the level of regeneration obtained. Glyphosate gave 84 and 83% control when applied at heading and anthesis respectively, delaying application until early grain filling reduced the level of vulpia control to 28%. Paraquat gave 81% control when applied at anthesis, while delaying application until early grain filling, or earlier application at heading, gave 59% control. Crude protein (CP) and water-soluble carbohydrate (WSC) concentrations, and in vitro organic matter digestibilities (OMD) were measured in vulpia residues collected for 16 weeks after herbicide application. Paraquat increased CP levels most when applied at heading (from 4-8 to 7.2% in 1986, and from 4.9 to 6.5% in 1987). Glyphosate increased CP levels most when applied at heading in 1986 (from 4.8 to 5.4%), but at anthesis in 1987 (from 4.9 to 6.5%). Glyphosate increased WSC most when applied at heading (from 5.7 to 10.6% in 1986, and from 3.5 to 6.3% in 19871, while paraquat reduced WSC in both years. Application of glyphosate at heading was the only treatment to increase OMD (from 50.5 to 54.7%).

scholarly journals The growth of maize in the cool temperate climate of the Netherlands: Effect of grain filling on production of dry matter and on chemical composition and nutritive value.

1979 ◽  
Vol 27 (2) ◽  
pp. 116-130 ◽  
Author(s):  
B. Deinum ◽  
J. Knoppers
Keyword(s):  
Cell Wall ◽  
Nutritive Value ◽  
Plant Density ◽  
Grain Filling ◽  
Water Soluble ◽  
Temperate Climate ◽  
Soluble Carbohydrate ◽  
Forage Maize ◽  
High Plant Density ◽  
Structural Carbohydrate

In a trial in 1975 the effect of grain filling on productivity and nutritive value of forage maize was studied in 3 hybrid cv. Variation in grain filling was obtained by periodic sampling after silking (end-July) of pollinated (fertile) and unpollinated (sterile) crops. Production of DM of fertile and sterile maize was the same until end-Aug. but in Sept. production rate of the sterile crop lagged behind the fertile crop by c. 100 kg DM/ha day, the difference mainly consisting of non-structural carbohydrate. In the fertile crop, carbohydrate mainly accumulated in the ear as starch, but in the sterile crop it was almost completely stored in the stover as water-soluble carbohydrate. In contrast to the fertile crop, cell-wall production in the sterile stem proceeded throughout Sept. Cell-wall digestibility in the stover was not affected by pollination, so because of the smaller yield of non-structural carbohydrate, yield of DM and DOM of the sterile crop were 14 and 17%, resp. less than of the fertile crop at the final sampling. These differences might become greater in the silage. These data collected in the sunny season of 1975 and from the literature suggest that in bright and warm weather yield of sterile maize will greatly lag behind fertile maize, but in adverse conditions (lower irradiance and temp., high plant density, unhealthy leaves) this yield lag would be smaller. So grain filling is important for good production and nutritive value of forage maize in cool regions with little sun, but it is less essential than in brighter and warmer climates. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals FRUCTANS ISOLATED FROM FLOWERS AND STEMS OF CHRYSANTHEMUM MORIFOLIUM

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1077c-1077
Author(s):  
Susan E. Trusty ◽  
William B. Miller ◽  
Dale Smith
Keyword(s):  
Water Extract ◽  
Chrysanthemum Morifolium ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Flower Bud ◽  
Medium Chain Length ◽  
Flower Growth ◽  
Reserve Carbohydrate ◽  
Water Soluble Carbohydrate ◽  
Hydrolysis Of

In order to more fully understand flower growth and development, we are interested in carbohydrate partitioning and metabolism in floricultural crops. In recent work with Chrysanthemum, we noted the occurrence of several early-eluting carbohydrate peaks (as detected by HPLC with a resin-based column in the calcium form). These peaks were present in flowers and stems, and in lesser amounts in leaves. Acid hydrolysis of the unknowns liberated large amounts of fructose and much smaller amounts of glucose, indicating that these peaks are fructans, or medium chain-length fructose polymers. Fructans represented 10% and 25% of the carbohydrate in a 12:5:3 methanol: chloroform: water extract of leaves and stems, respectively. Flower petals were extracted with 95%. ethanol, then with water. Fructans accounted for more than 40'% of the water soluble carbohydrate in flower bud tissue. It is likely that fructans serve as a major reserve carbohydrate in Chrysanthemum. Additional studies are underway to better characterize flower petal fructans, and to understand their role in flower development.

Kernel Number Per Spike in Wheat (Triticum aestivum L.): Responses to Preanthesis Shading

1980 ◽  
Vol 7 (2) ◽  
pp. 169 ◽  
Author(s):  
RA Fischer ◽  
YM Stockman
Keyword(s):  
Dry Weight ◽  
Triticum Aestivum L ◽  
Water Soluble ◽  
Sensitive Period ◽  
Soluble Carbohydrate ◽  
Kernel Number ◽  
Maximum Water ◽  
Total Dry Weight ◽  
Water Soluble Carbohydrate ◽  
Unit Spike

Several cultivars of wheat, grown in pots in a controlled environment, were subject to single shading periods of 8-11 days within the interval from 36 days before anthesis until anthesis. The aim was to confirm sensitivity of kernel number to reduced irradiance as observed in the field and to investigate its causes. Shading periods centred 10-13 days before anthesis had biggest effects on kernel number per spike through effects on kernels per spikelet. This was associated with greatest reductions in the spike dry weight at anthesis and with reductions in the number of competent florets (florets with full anther development) per unit spike dry weight; floret fertility (kernels per competent floret) was unaffected. Approximately 30% of the total dry weight increment of the plant was being allocated to the spike at the stage of greatest sensitivity to shading, but shading did not alter this partitioning. Maximum water soluble carbohydrate (WSC) content of the spike (30-40% on a dry basis in unshaded plants) occurred at 15 days before anthesis. Shading at the most sensitive period reduced temporarily WSC concentration in the spike, reduced stainable starch in carpels of florets of central spikelets, and reduced floret survival by increasing degeneration of distal florets. Shading before or after this period reduced kernel number less, reducing spike dry weight but not competent florets per unit spike dry weight. Reduced assimilate supply is probably the cause of these responses in the spike.

Sign in / Sign up

Export Citation Format

Share Document