scholarly journals Truncation of grain filling in wheat (Triticum aestivum) triggered by brief heat stress during early grain filling: association with senescence responses and reductions in stem reserves

2016 ◽  
Vol 43 (10) ◽  
pp. 919 ◽  
Author(s):  
Hamid Shirdelmoghanloo ◽  
Daniel Cozzolino ◽  
Iman Lohraseb ◽  
Nicholas C. Collins
Keyword(s):  
Triticum Aestivum ◽  
Grain Size ◽  
Heat Stress ◽  
Heat Waves ◽  
Flag Leaf ◽  
Grain Filling ◽  
Water Soluble ◽  
Grain Weight ◽  
Soluble Carbohydrates ◽  
Stem Reserves

Short heat waves during grain filling can reduce grain size and consequently yield in wheat (Triticum aestivum L.). Grain weight responses to heat represent the net outcome of reduced photosynthesis, increased mobilisation of stem reserves (water-soluble carbohydrates, WSC) and accelerated senescence in the grain. To compare their relative roles in grain weight responses under heat, these characteristics were monitored in nine wheat genotypes subjected to a brief heat stress at early grain filling (37°C maximum for 3 days at 10 days after anthesis). Compared with the five tolerant varieties, the four susceptible varieties showed greater heat-triggered reductions in final grain weight, grain filling duration, flag leaf chla and chlb content, stem WSC and PSII functionality (Fv/Fm). Despite the potential for reductions in sugar supply to the developing grains, there was little effect of heat on grain filling rate, suggesting that grain size effects of heat may have instead been driven by premature senescence in the grain. Extreme senescence responses potentially masked stem WSC contributions to grain weight stability. Based on these findings, limiting heat-triggered senescence in the grain may provide an appropriate focus for improving heat tolerance in wheat.

scholarly journals Grain filling patterns of barley as affected by high temperature stress

2017 ◽  
Vol 15 (2) ◽  
pp. 174-181
Author(s):  
Md Rasel Rana ◽  
Md Masudul Karim ◽  
Md Juiceball Hassan ◽  
Md Alamgir Hossain ◽  
Md Ashraful Haque
Keyword(s):  
Heat Stress ◽  
Grain Yield ◽  
Grain Filling ◽  
High Temperature Stress ◽  
Water Soluble ◽  
Grain Weight ◽  
Soluble Carbohydrates ◽  
Barley Cultivars ◽  
The Mean ◽  
Grain Filling Period

Grain filling determines the grain weight, a major component of grain yield in cereals. Grain filling in barley depends on current assimilation and culm reserves (mainly water-soluble carbohydrates). Nowadays barley is facing heat stress problem which is mostly responsible to reduce the yield of barley. A field experiment was conducted at the Field Lab, Department of Crop Botany, BangladeshAgriculturalUniversity, Mymensingh during November 2015 to March 2016 to study the grain filling patterns and the contributions of culm reserves to grain yield under heat stress. The experiment consisted of two factors—barley cultivars and heat stress. The heat stress was imposed by late sowing. The tillers were sampled once a week during grain filling period to determine the changes in dry weights of different parts, viz., leaves, culm with sheath, spikes, and grains; and to examine the contribution of culm reserves to grain yield. The results in the experiment revealed that the grain yield was reduced by 22-28% due to the stress. The grain yield varied from 52 to 150 g m−2 with the mean of 102 g m−2 under control while it varied from 37 to 116 g m−2 with the mean of 75 g m−2 under heat stress. Among the cultivars studied BARI Barley5, BARI Barley2 and BARI Barley1, seemed as high yielders while BARI Barley3, BARI Barley4, BARI Barley6 as the low yielders under heat stress treatment. The reduction in grain yield was attributable mainly to lighter grain weight due to the stress. Heat stress drastically reduced the grain filling duration by 45–50%. However, the stress increased the grain filling rate by 6–53%. The amount of reserves remobilized to grain varied among the cultivars ranging from 4.8 to 12.77 mg spike−1 in control and from 1.73 to 6.25 mg spike−1 in stressed plants. The stressed barley plants exhibited lower accumulation of reserves in culm but they showed almost its complete remobilization to the grain. The contribution of culm reserves to grain yield varied from 1.13 to 19.52%, and 1.09 to 2.11% in control and in stressed plants, respectively. In conclusion, culm reserve is the important attributes in grain yield in Bangladeshi barley cultivars but the contribution remains almost unaffected due the post-anthesis heat stress.J. Bangladesh Agril. Univ. 15(2): 174-181, December 2017

Carbohydrate Storage and Mobilisation by the Culm of Wheat Between Heading and Grain Maturity: the Relation to Sucrose Synthase and Sucrose-Phosphate Synthase

1994 ◽  
Vol 21 (3) ◽  
pp. 255 ◽  
Author(s):  
IF Wardlaw ◽  
J Willenbrink
Keyword(s):  
Sucrose Synthase ◽  
Flag Leaf ◽  
Sucrose Phosphate Synthase ◽  
Leaf Sheath ◽  
Water Soluble ◽  
Soluble Carbohydrates ◽  
Carbohydrate Storage ◽  
Stem Reserves ◽  
Sucrose Phosphate ◽  
Phosphate Synthase

Wheat plants grown under non-stress conditions at a dayhight temperature of 18/13�C under glasshouse conditions from head emergence to maturity showed a maximum accumulation of water-soluble, non-structural carbohydrates 20-25 days after anthesis. This storage was largely as fructans with the timing and amount of storage and mobilisation varying between cultivars, although the maximum concentration (fructose equivalents per unit stem fresh weight) was similar in all cultivars. The main storage in the culm was located in the lower part of the peduncle enclosed by the flag leaf sheath, in the penultimate internode and for one cultivar also in the flag leaf sheath. 14CO2 pulse-chase studies showed that there was a considerable delay in the incorporation of flag leaf assimilates into stem fructans, a delay probably associated with transfer and metabolic processes in the stem itself. At anthesis, when soluble carbohydrates were rapidly accumulating in the culm, the level of activity of sucrose synthase (SS) in the penultimate internode was much greater than that of sucrose phosphate synthase (SPS). The activity of SS declined rapidly as active storage ceased. This pattern was the reverse of that found in the leaf where SPS, rather than SS, was initially high and declined towards maturity. These changes are discussed in relation to the possible role of sucrose synthesising enzymes, particularly SS, in the accumulation and mobilisation of stem reserves in wheat.

scholarly journals Effects of Favorable Alleles for Water-Soluble Carbohydrates at Grain Filling on Grain Weight under Drought and Heat Stresses in Wheat

PLoS ONE ◽  
2014 ◽  
Vol 9 (7) ◽  
pp. e102917 ◽  
Author(s):  
Bin Zhang ◽  
Weiyu Li ◽  
Xiaoping Chang ◽  
Runzhi Li ◽  
Ruilian Jing
Keyword(s):  
Grain Filling ◽  
Water Soluble ◽  
Grain Weight ◽  
Soluble Carbohydrates ◽  
Favorable Alleles ◽  
Water Soluble Carbohydrates

scholarly journals Carbohydrate and Amino Acid Dynamics during Grain Growth in Four Temperate Cereals under Well-Watered and Water-Limited Regimes

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1516
Author(s):  
Ana María Méndez-Espinoza ◽  
Miguel Garriga ◽  
Sinda Ben Mariem ◽  
David Soba ◽  
Iker Aranjuelo ◽  
...  
Keyword(s):  
Durum Wheat ◽  
Flag Leaf ◽  
Water Soluble ◽  
Grain Weight ◽  
The Other ◽  
Soluble Carbohydrates ◽  
Grain Development ◽  
Grain Number ◽  
Cereal Species ◽  
The Impact

Grain development in cereals depends on synthesis and remobilisation compounds such as water-soluble carbohydrates (WSCs), amino acids (AAs), minerals and environmental conditions during pre- and post-anthesis. This study analyses the impact of water stress on metabolite (WSCs, AAs and nitrogen) dynamics between the source (leaves and stems) and sink (grain) organs in triticale, bread wheat, durum wheat and barley. Plants were grown in glasshouse conditions under well-watered (WW) and water-limited (WL) regimes (from flag leaf fully expanded until maturity). The results showed that the stem WSC content and the apparent mobilisation of WSC to the grain were much higher in triticale and were associated with its larger grain size and grain number. In the four cereals, grain weight and the number of kernels per spike were positively associated with stem WSC mobilisation. After anthesis, the AA concentration in leaves was much lower than in the grain. In grain, the main AAs in terms of concentration were Asn, Pro and Gln in triticale, bread, and durum wheat, and Asn, Pro and Val in barley. The water-limited regime reduced grain weight per plant in the four cereal species, but it had no clear effects on WSC content and AAs in leaves and grain. In general, triticale was less affected by WL than the other cereals.

scholarly journals Effect of stem reserve mobilization on grain filling under drought stress conditions in recombinant inbred population of wheat

2017 ◽  
Vol 9 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Ashutosh Srivastava ◽  
Puja Srivastava ◽  
Achla Sharma ◽  
R. S. Sarlach ◽  
N. S. Bains
Keyword(s):  
Flag Leaf ◽  
Carbon Assimilation ◽  
Grain Filling ◽  
Grain Weight ◽  
Adaptation Mechanism ◽  
Rainfed Condition ◽  
Reserve Mobilization ◽  
Rainfed Conditions ◽  
Stem Reserves ◽  
1000 Grain Weight

Pre-anthesis carbon assimilation of stem reserves is considered as an important source for grain filling during post anthesis drought stresses that inhibit photosynthesis. 175 RILs from cross (C518/2*PBW343) along with check cultivars were evaluated for stem reserve mobilization under irrigated and rainfed conditions. These two cultivars belonging to distinct adaptation mechanism, offer several morpho -physiological and biochemical con-trasts. C 518 is tall and adapted to low input rainfed conditions whereas PBW 343 is semi -dwarf and input re-sponsive. Further C 518 is known for better stem reserves on account of larger peduncle and strong commitment to grain filling due to effective stem reserve mobilization. The parents and the RIL population was tested for stem reserve mobilization by defoliation of flag leaf and second leaf at anthesis under irrigated and rainfed environments. Evaluated entries differed significantly (p<0.001) for reduction in 1000 grain weight under defoliation (TGWL). Percent reduction in 1000 grain weight ranged from 4.4 % to 39.6 % under irrigated environment and 3.2 % to 35.0 under rainfed condition. A significant positive correlation (r = +0.357) between stem reserve mobilization and peduncle length was observed under rainfed condition. Tested RILs vary individually for stem reserve mobilization when subjected to removal of flag leaf and second leaf inhibiting the photosynthesis. The genotypes with better stem reserve mobilization based on 1000 grain weight in the absence of photosynthesis may also provide relative tolerance to drought.

scholarly journals Transcriptomic and Physiological Response of Durum Wheat Grain to Short-Term Heat Stress during Early Grain Filling

2021 ◽  
Author(s):  
Anita Arenas-M ◽  
Francisca M. Castillo ◽  
Diego Godoy ◽  
Javier Canales ◽  
Daniel F. Calderini
Keyword(s):  
Heat Stress ◽  
Durum Wheat ◽  
Grain Quality ◽  
Heat Waves ◽  
Grain Filling ◽  
Grain Weight ◽  
Extreme Weather Events ◽  
Climate Extreme ◽  
Short Term ◽  
Wheat Grains

In a changing climate, extreme weather events such as heat waves will be more frequent and could affect grain weight and the quality of crops such as wheat, one of the most significant crops in terms of global food security. In this work, we characterized the response of Triticum turgidum spp. durum wheat to a short-term heat-stress (HS) treatment at transcriptomic and physiological levels during early grain filling in glasshouse experiments. We found a significant reduction in grain weight and size from HS treatment. Grain quality was also affected, showing a decrease in starch content in addition to increments in grain protein levels. Moreover, an RNA-seq analysis of durum wheat grains allowed us to identify 1590 differentially expressed genes related to photosynthesis, response to heat, and carbohydrate metabolic process. A gene regulatory network analysis of HS-responsive genes uncovered novel transcription factors (TFs) controlling the expression of genes involved in abiotic stress response and grain quality, such as a member of the DOF family predicted to regulate glycogen and starch biosynthetic processes in response to HS in grains. In summary, our results provide new insights into the extensive transcriptome reprogramming that occurs during short-term HS in durum wheat grains.

scholarly journals Screening of barley genotypes for drought tolerance based on culm reserves contribution to grain yield

2018 ◽  
Vol 16 (1) ◽  
pp. 62-66
Author(s):  
Md Masudul Karim ◽  
Md Amirul Islam ◽  
Md Rasel Rana ◽  
Md Alamgir Hossain ◽  
Md Abdul Kader
Keyword(s):  
Drought Stress ◽  
Grain Yield ◽  
Grain Filling ◽  
Water Soluble ◽  
Grain Weight ◽  
Soluble Carbohydrates ◽  
Barley Cultivars ◽  
Two Factors ◽  
Grain Filling Period ◽  
Ripe Stage

Grain filling determines the grain weight, a major component of grain yield in cereals. Grain filling in barley depends on current assimilation and culm reserves. A pot experiment was conducted at the Grilled House, Department of Crop Botany, Bangladesh Agricultural University, Mymensingh during October 2015–May 2016 to study the grain filling patterns and the contributions of culm reserves to grain yield under drought stress. The experiment consisted of two factors—barley cultivars (six cultivars) and drought stress treatments (control and drought stress). Drought stress was imposed by limiting the irrigation during grain filling period. The tillers were sampled at anthesis, milk-ripe and maturity to determine the changes in dry weights of different parts, viz., leaf lamina, culm with sheath, spikes, and grains; and to examine the contribution of culm reserves to grain yield. The result in this experiment revealed that the grain yield was reduced by 5–25% due to drought stress. The reduction in grain yield was attributable to reduce number of grains per spike and lighter grain weight due to the stress. Drought stress drastically reduced the grain filling duration by about 30% and the stress induced early leaf senescence. Photosynthesis rate and leaf greenness were also reduced in stress. The stress altered the contribution of culm reserves, water soluble carbohydrates (WSCs) in culms to grains. At milk ripe stage, accumulation reached its peak. It accumulated 29.0 to 70.0 mg and from 15.8 to 40.6 mg culm−1 in control and stressed plants, respectively. The residual culm WSCs ranged from 3.5 to 11.2 mg and 1.0 to 3.5 mg culm−1 under control and stress conditions, respectively. The highest contribution of culm WSCs to grain yield was observed in BARI barley2 and the lowest was in BARI barley5 both in control and stress condition. Among the cultivars studied, BARI barley2 produced higher yield with the higher contribution of culm reserves to grain yield under the drought stress.J. Bangladesh Agril. Univ. 16(1): 62-66, April 2018

scholarly journals Effect of Heat Stress on Inter-relationship of Physiological and Biochemical Traits with Grain Yield in Wheat (Triticum aestivum L.)

2020 ◽  
pp. 19-29
Author(s):  
Amrita Kumari ◽  
R. D. Ranjan ◽  
Chandan Roy ◽  
Awadesh Kumar Pal ◽  
S. Kumar
Keyword(s):  
Heat Stress ◽  
Grain Yield ◽  
Flag Leaf ◽  
Grain Filling ◽  
Triticum Aestivum L ◽  
Seedling Stage ◽  
Biochemical Traits ◽  
Highly Correlated ◽  
Complex Phenomena ◽  
Physiological And Biochemical

Heat stress, particularly the stress appears at the time of flowering to grain filling stages causing severe yield loss in wheat. Heat tolerance is complex phenomena that include adjustment in morphological, physiological and biochemical traits of the crop. Present investigation was carried out to understand the effect of terminal heat stress on different traits of wheat. The experiment was conducted in three dates of sowing as timely sown, late sown and very late sown to expose the crop to heat stress at later stages of the crop growth. Significant genetic variations for all the traits evaluated under three conditions indicated the presence of variability for the traits. Trait association analysis revealed that flag leaf chlorophyll content and MSI at seedling stage; MDA at reproductive stage had direct relationship with grain yield. While under very late sown condition MDA and RWC at seedling stages were found to be highly correlated with grain yield. It indicates that MDA, RWC at seedling stage and days to booting, days to milking plays important role in very late sown condition that can be used as selection criteria in breeding programme.

Postanthesis green area duration in a semidwarf and a standard-height wheat cultivar as affected by sink strength

1994 ◽  
Vol 45 (7) ◽  
pp. 1337 ◽  
Author(s):  
GA Slafer ◽  
R Savin
Keyword(s):  
Grain Growth ◽  
Seedling Emergence ◽  
Grain Filling ◽  
Grain Weight ◽  
Soluble Carbohydrates ◽  
Sink Strength ◽  
Green Area ◽  
Ca 50 ◽  
Source Sink ◽  
The University

Postanthesis green area duration (GAD) has been associated frequently with yield. The senescence pattern of green organs is a major component of GAD. It has been proposed that delayed or accelerated senescence is strongly controlled by environmental conditions and the level of source or sink limitation on grain growth. In particular, it has been generally reported that the removal of reproductive structures delays the senescence process. However, results reporting this effect in wheat are not conclusive. A field experiment was conducted at the experimental station of The University of Melbourne comprising a factorial combination of a semidwarf and a standard-height wheat, and two levels of sink strength. At anthesis, 20 main shoots were tagged and detillered. Ten days after anthesis all the spikelets from one side of 10 tagged ears were removed by hand. The experiment was performed under natural, and 3 h-extended photoperiods from seedling emergence to heading. The photoperiod treatments induced differing grain filling environments and differing plant characteristics at onset of grain filling. Green area senescence was similar for both sink size treatments at any combination of cultivar and grain filling condition, indicating that the dynamics of plant senescence was insensitive to a severe reduction in number of grains per spike. Therefore, GAD was not significantly affected by the reduction in sink strength. The number of grains per spike were reduced to ca. 50% due to trimming. Therefore, source-sink ratio was doubled, but no significant changes in individual grain weight were found. There was no relationship between GAD and individual grain weight, confirming that grain growth in field-grown wheat is not limited by the strength of the source. Alternatively, our results confirmed that field-grown wheat is sink-limited during grain filling and that the likely accumulation of soluble carbohydrates in leaves does not affect the onset or rate of senescence.

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