Sucrose transport and metabolism control carbon partitioning between stem and grain in rice

2021 ◽  
Author(s):  
Jyotirmaya Mathan ◽  
Anuradha Singh ◽  
Aashish Ranjan
Keyword(s):  
Grain Yield ◽  
Wild Rice ◽  
Grain Filling ◽  
Invertase Activity ◽  
Cultivated Rice ◽  
Sucrose Transport ◽  
Unit Leaf ◽  
In The Wild ◽  
Source Sink ◽  
Oryza Australiensis

Abstract The source-sink relationship is key to overall crop performance. Detailed understanding of the factors that determine source-sink dynamics is imperative for the balance of biomass and grain yield in crop plants. We investigated the differences in the source-sink relationship between a cultivated rice Oryza sativa cv. Nipponbare and a wild rice Oryza australiensis that show striking differences in biomass and grain yield. Oryza australiensis, accumulating higher biomass, not only showed higher photosynthesis per unit leaf area but also exported more sucrose from leaves than Nipponbare. However, grain features and sugar levels suggested limited sucrose mobilization to the grains in the wild rice due to vasculature and sucrose transporter functions. Low cell wall invertase activity and high sucrose synthase cleavage activity followed by higher expression of cellulose synthase genes in Oryza australiensis stem utilized photosynthates preferentially for the synthesis of structural carbohydrates, resulting in high biomass. In contrast, the source-sink relationship favored high grain yield in Nipponbare via accumulation of transitory starch in the stem, due to higher expression of starch biosynthetic genes, which is mobilized to panicles at the grain filling stage. Thus, vascular features, sucrose transport, and functions of sugar metabolic enzymes explained the differences in the source-sink relationship between Nipponbare and Oryza australiensis.

scholarly journals Sucrose transport and Sucrose Synthase activity control the source-sink relationship for biomass and grain yield in rice

2020 ◽  
Author(s):  
Jyotirmaya Mathan ◽  
Anuradha Singh ◽  
Aashish Ranjan
Keyword(s):  
Grain Yield ◽  
Wild Rice ◽  
Sucrose Synthase ◽  
Grain Filling ◽  
Cultivated Rice ◽  
Sucrose Transport ◽  
Cleavage Activity ◽  
In The Wild ◽  
Source Sink ◽  
Grain Filling Stage

AbstractThe source-sink relationship is key to overall crop performance. Detailed understanding of the factors that determine source-sink dynamics is imperative for the balance of biomass and grain yield in a crop plant. We investigated the differences in the source-sink relationship between a cultivated rice Oryza sativa cv. Nipponbare and a wild rice Oryza australiensis that show striking differences in biomass and grain yield. The wild rice, accumulating higher biomass, was not only photosynthetically efficient but also had efficient sucrose export from leaves. However, sucrose mobilization to the grains was limited due to impaired vasculature and sucrose transporter functions at the reproductive tissues of the wild rice. High cleavage activity of Sucrose Synthase followed by higher expression of Cellulose Synthase genes in the wild rice stem efficiently utilized photosynthates for the synthesis of structural carbohydrates, resulting in high biomass. In contrast, the source-sink relationship favored high grain yield in Nipponbare via accumulation of transitory starch in the stem, due to higher expression of starch biosynthetic genes, which is mobilized to panicles at the grain filling stage. Thus, sucrose transport along with functions of key sugar metabolic enzymes explained the differences in the source-sink relationship between the selected cultivated and wild rice.

scholarly journals Photosynthetic traits of Australian wild rice (Oryza australiensis) confer tolerance to extreme daytime temperatures

2022 ◽  
Author(s):  
Aaron L. Phillips ◽  
Andrew P. Scafaro ◽  
Brian J. Atwell
Keyword(s):  
Wild Rice ◽  
Soluble Sugar ◽  
Rubisco Activase ◽  
Shoot Biomass ◽  
Cultivated Rice ◽  
Differential Heat ◽  
In The Wild ◽  
Leaf Tissues ◽  
Oryza Australiensis ◽  
Carbon Economy

Abstract Key message A wild relative of rice from the Australian savannah was compared with cultivated rice, revealing thermotolerance in growth and photosynthetic processes and a more robust carbon economy in extreme heat. Abstract Above ~ 32 °C, impaired photosynthesis compromises the productivity of rice. We compared leaf tissues from heat-tolerant wild rice (Oryza australiensis) with temperate-adapted O. sativa after sustained exposure to heat, as well as diurnal heat shock. Leaf elongation and shoot biomass in O. australiensis were unimpaired at 45 °C, and soluble sugar concentrations trebled during 10 h of a 45 °C shock treatment. By contrast, 45 °C slowed growth strongly in O. sativa. Chloroplastic CO2 concentrations eliminated CO2 supply to chloroplasts as the basis of differential heat tolerance. This directed our attention to carboxylation and the abundance of the heat-sensitive chaperone Rubisco activase (Rca) in each species. Surprisingly, O. australiensis leaves at 45 °C had 50% less Rca per unit Rubisco, even though CO2 assimilation was faster than at 30 °C. By contrast, Rca per unit Rubisco doubled in O. sativa at 45 °C while CO2 assimilation was slower, reflecting its inferior Rca thermostability. Plants grown at 45 °C were simultaneously exposed to 700 ppm CO2 to enhance the CO2 supply to Rubisco. Growth at 45 °C responded to CO2 enrichment in O. australiensis but not O. sativa, reflecting more robust carboxylation capacity and thermal tolerance in the wild rice relative.

Source - sink effects on grain weight of bread wheat, durum wheat, and triticale at different locations

2006 ◽  
Vol 57 (2) ◽  
pp. 227 ◽  
Author(s):  
Daniel F. Calderini ◽  
M. P. Reynolds ◽  
G. A. Slafer
Keyword(s):  
Grain Yield ◽  
Durum Wheat ◽  
Bread Wheat ◽  
Grain Filling ◽  
Grain Weight ◽  
The Other ◽  
Field Conditions ◽  
Breeding Strategies ◽  
Source Sink ◽  
Source Limitation

Source limitation during grain filling is important for both management and breeding strategies of grain crops. There is little information on the sensitivity of grain weight of temperate cereals to variations in source–sink ratios, and no studies are available on the comparative behaviour of temperate cereals growing together in the same experiment. The objective of the current study was to evaluate, under field conditions, the response of grain weight to different source–sink ratios during grain filling in high-yielding cultivars of bread wheat, durum wheat, and triticale at 2 contrasting locations. Two experiments were carried out at C. Obregon and El Batan in Mexico. In each location, 6 genotypes (2 bread wheat, 2 durum wheat, 2 triticale) were evaluated. A week after anthesis, 2 source–sink (control and halved spikes) treatments were imposed. Location and genotype significantly (P < 0.01) affected grain yield and components. Significant grain weight increases (P < 0.05) were found only in 2 cases in El Batan. The highest response of 17% was found in triticale, with less than 10% in most of the other genotypes. The effect of genotype and location is discussed.

scholarly journals Trehalose 6-phosphate signalling and impact on crop yield

2020 ◽  
Vol 48 (5) ◽  
pp. 2127-2137
Author(s):  
Matthew J. Paul ◽  
Amy Watson ◽  
Cara A. Griffiths
Keyword(s):  
Resource Allocation ◽  
Grain Yield ◽  
Green Revolution ◽  
Regulatory System ◽  
Grain Filling ◽  
Stem Height ◽  
Grain Number ◽  
Plant Resource ◽  
Whole Plant ◽  
Source Sink

The domestication and breeding of crops has been a major achievement for mankind enabling the development of stable societies and civilisation. Crops have become more productive per unit area of cultivated land over the course of domestication supporting a current global population of 7.8 billion. Food security crops such as wheat and maize have seen large changes compared with early progenitors. Amongst processes that have been altered in these crops, is the allocation of carbon resources to support larger grain yield (grain number and size). In wheat, reduction in stem height has enabled diversion of resources from stems to ears. This has freed up carbon to support greater grain yield. Green revolution genes responsible for reductions in stem height are known, but a unifying mechanism for the active regulation of carbon resource allocation towards and within sinks has however been lacking. The trehalose 6-phosphate (T6P) signalling system has emerged as a mechanism of resource allocation and has been implicated in several crop traits including assimilate partitioning and improvement of yield in different environments. Understanding the mode of action of T6P through the SnRK1 protein kinase regulatory system is providing a basis for a unifying mechanism controlling whole-plant resource allocation and source-sink interactions in crops. Latest results show it is likely that the T6P/SnRK1 pathway can be harnessed for further improvements such as grain number and grain filling traits and abiotic stress resilience through targeted gene editing, breeding and chemical approaches.

Source - sink balance and manipulating sink - source relations of wheat indicate that the yield potential of wheat is sink-limited in high-rainfall zones

2010 ◽  
Vol 61 (10) ◽  
pp. 852 ◽  
Author(s):  
Heping Zhang ◽  
Neil C. Turner ◽  
Michael L. Poole
Keyword(s):  
Grain Yield ◽  
Western Australia ◽  
Unit Area ◽  
Grain Filling ◽  
Yield Potential ◽  
Limiting Factor ◽  
Wheat Cultivars ◽  
High Rainfall ◽  
Sink Size ◽  
Source Sink

Grain yield depends on the number of grains per unit area (sink) and the availability of assimilates (source) to fill these grains. The aim of the current work was to determine whether wheat yield in the high-rainfall zone of south-western Australia is limited in current cultivars by the size of the sink or by the assimilates available for grain filling. Three wheat cultivars (Calingiri, Chara and Wyalkatchem) and two breeding lines (HRZ216 and HRZ203) were grown in four replicates in the field from 2005 to 2007. Dry matter and water soluble carbohydrates (WSC) at anthesis and maturity were measured and used to determine the source and sink balance of the crop. In 2007, three further treatments were applied to manipulate the sink–source relationships: (i) spikelets were removed on main stems to increase the source : sink ratio; (ii) incoming solar radiation was reduced by 40% by shading after anthesis to reduce the availability of assimilates to grains; and (iii) supplemental irrigation was used to maintain the capacity for photosynthesis by an improved water supply during grain filling. The source–sink balance of the crops showed that the potential source was 25% greater than the actual grain yield in average and above-average seasons (2005 and 2007), suggesting that sink size, represented by the number of grain per unit area, was a limiting factor to yield potential. However, the source may have become a limiting factor in a drought season (2006). The grain yield increased with increased number of grains/m2 and kernel weight remained relatively stable even when grain number increased from 7000 to 16 000 per m2. The removal of half of the spikelets on the main stem did not increase kernel mass of the remaining grains and an additional 33 mm of irrigation water did not increase grain yield, but significantly (P < 0.05) increased WSC left in stems and leaf sheaths at maturity. Shading after anthesis did not significantly reduce grain yield of the current cultivars Calingiri and Wyalkatchem, but it reduced grain yield by 23–25% (P < 0.05) in Chara and HRZ203. The source–sink balance over three seasons and three independent experiments in 2007 suggested that the yield of the current wheat cultivars is more sink- than source-limited and that breeding wheat with a larger sink size than in the current cultivars may lift the yield potential of wheat in the high-rainfall zone of south-western Australia.

Grain physical characteristic of the Australian wild rices

2016 ◽  
Vol 15 (5) ◽  
pp. 409-420 ◽  
Author(s):  
Tiparat Tikapunya ◽  
Glen Fox ◽  
Agnelo Furtado ◽  
Robert Henry
Keyword(s):  
Wild Rice ◽  
Paddy Rice ◽  
Rice Gene ◽  
Cultivated Rice ◽  
Wild Rices ◽  
A Genome ◽  
In The Wild ◽  
Processing Techniques ◽  
Grain Colour ◽  
Limited Genetic Diversity

AbstractRice yield improvement is required to support increasing global rice demand. However, the limited genetic diversity within the cultivated rice gene pool may be a major obstacle. Australian wild rice which has been largely genetically isolated from cultivated rice might be a new source of genetic variation for use in improving rice production. The physical properties of Oryza australiensis and of the two perennial Australian Wild rice taxa-belonging to the A genome wild rice were evaluated. Seeds collected from rice in the wild were generally smaller than those from domesticated rice. The wild rice A genome collections were classified as extra-long paddy rice with grains that were long or medium, while O. australiensis was categorized as long paddy rice with a short grain. However, these wild rices were slender compared with domesticated rice. The grain colour of these wild rices varied from light red brown to dark brown compared with domesticated rice which is brighter, with less redness and more yellowness than the wild rice. The physical characteristics of the grains of the Australian wild rice indicate that these rice grains may be successfully processed using current rice processing techniques and may be a useful novel food especially in the coloured rice market.

scholarly journals Rapid Accumulation of Proline Enhances Salinity Tolerance in Australian Wild Rice Oryza australiensis Domin

Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2044
Author(s):  
Ha Thi Thuy Nguyen ◽  
Sudipta Das Bhowmik ◽  
Hao Long ◽  
Yen Cheng ◽  
Sagadevan Mundree ◽  
...  
Keyword(s):  
Salinity Stress ◽  
Wild Rice ◽  
Oryza Sativa L ◽  
Early Stage ◽  
Membrane Integrity ◽  
Free Proline ◽  
Cultivated Rice ◽  
Cell Membrane Integrity ◽  
Rapid Accumulation ◽  
Oryza Australiensis

Proline has been reported to play an important role in helping plants cope with several stresses, including salinity. This study investigates the relationship between proline accumulation and salt tolerance in an accession of Australian wild rice Oryza australiensis Domin using morphological, physiological, and molecular assessments. Seedlings of O. australiensis wild rice accession JC 2304 and two other cultivated rice Oryza sativa L. cultivars, Nipponbare (salt-sensitive), and Pokkali (salt-tolerant), were screened at 150 mM NaCl for 14 days. The results showed that O. australiensis was able to rapidly accumulate free proline and lower osmotic potential at a very early stage of salt stress compared to cultivated rice. The qRT-PCR result revealed that O. australiensis wild rice JC 2304 activated proline synthesis genes OsP5CS1, OsP5CS2, and OsP5CR and depressed the expression of proline degradation gene OsProDH as early as 1 h after exposure to salinity stress. Wild rice O. australiensis and Pokkali maintained their relative water content and cell membrane integrity during exposure to salinity stress, while the salt-sensitive Nipponbare failed to do so. An analysis of the sodium and potassium contents suggested that O. australiensis wild rice JC 2304 adapted to ionic stress caused by salinity by maintaining a low Na+ content and low Na+/K+ ratio in the shoots and roots. This demonstrates that O. australiensis wild rice may use a rapid accumulation of free proline as a strategy to cope with salinity stress.

scholarly journals Abscisic acid synergizes with sucrose to enhance grain yield and quality of rice by improving the source-sink relationship

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Tingting Chen ◽  
Guangyan Li ◽  
Mohammad Rezaul Islam ◽  
Weimeng Fu ◽  
Baohua Feng ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Grain Yield ◽  
Indica Rice ◽  
Starch Synthesis ◽  
Dry Matter Accumulation ◽  
Sucrose Transport ◽  
Yield And Quality ◽  
Grain Yield And Quality ◽  
Source Sink

Abstract Background Abscisic acid (ABA) and sucrose act as molecular signals in response to abiotic stress. However, how their synergy regulates the source-sink relationship has rarely been studied. This study aimed to reveal the mechanism underlying the synergy between ABA and sucrose on assimilates allocation to improve grain yield and quality of rice. The early indica rice cultivar Zhefu802 was selected and planted in an artificial climate chamber at 32/24 °C (day/night) under natural sunlight conditions. Sucrose and ABA were exogenously sprayed (either alone or in combination) onto rice plants at flowering and 10 days after flowering. Results ABA plus sucrose significantly improved both the grain yield and quality of rice, which was mainly a result of the higher proportion of dry matter accumulation and non-structural carbohydrates in panicles. These results were mainly ascribed to the large improvement in sucrose transport in the sheath-stems in response to the ABA plus sucrose treatment. In this process, ABA plus sucrose significantly enhanced the contents of starch, gibberellic acids, and zeatin ribosides as well as the activities and gene expression of enzymes involved in starch synthesis in grains. Additionally, remarkable increases in trehalose content and expression levels of trehalose-6-phosphate synthase1, trehalose-6-phosphate phosphatase7, and sucrose non-fermenting related protein kinase 1A were also found in grains treated with ABA plus sucrose. Conclusion The synergy between ABA and sucrose increased grain yield and quality by improving the source-sink relationship through sucrose and trehalose metabolism in grains.

Source–sink relations and effects of post-anthesis canopy defoliation in wheat at low latitudes

1990 ◽  
Vol 114 (1) ◽  
pp. 93-99 ◽  
Author(s):  
P. K. Aggarwal ◽  
R. A. Fischer ◽  
S. P. Liboon
Keyword(s):  
Grain Yield ◽  
Flag Leaf ◽  
Dry Weight ◽  
Grain Filling ◽  
The Philippines ◽  
New Delhi ◽  
Dry Matter Accumulation ◽  
Area Index ◽  
Grain Nitrogen ◽  
Source Sink

SUMMARYSource–sink balance was studied by imposing different canopy defoliation treatments on wheat crops grown in Los Banos (Philippines) in 1985/86 and 1986/87, Sonora (Mexico) in 1972/73 and 1974/75 and New Delhi (India) in 1987/88. The crops were grown in replicated trials with optimum cultural management. Six defoliation treatments were imposed at anthesis on all shoots in the canopy in an area ranging between 1·65 and 3·0 m2. Defoliation reduced dry weight in proportion to the reduction in percentage light interception. The number of grains per unit land area was reduced slightly, and in most cases not significantly, except when all leaves were removed. Despite reduction of leaf lamina area index to as low as 0·5, the decrease in grain yield was small. In particular, flag leaf removal led to a remarkably small reduction in grain yield. Grain nitrogen content in defoliated crops decreased much less than expected from the amount of N removed by defoliation. The slope of the relation between reduction in grain yield with defoliation and reduction in post-anthesis dry matter accumulation was 0·56, indicating moderate source limitation for grain filling. The crops at the hottest site, in the Philippines, were less limited by source than the other crops. It is suggested that selection for smaller flag leaves may be worthwhile for high-input wheat crops.

Chloroplast DNA variability in wild and cultivated rice (Oryza spp.) revealed by polymorphic chloroplast simple sequence repeats

Genome ◽  
1997 ◽  
Vol 40 (1) ◽  
pp. 104-110 ◽  
Author(s):  
J. Provan ◽  
G. Corbett ◽  
W. Powell ◽  
J. W. McNicol
Keyword(s):  
Simple Sequence Repeats ◽  
Wild Rice ◽  
Simple Sequence Repeat ◽  
Sequence Repeat ◽  
Cultivated Rice ◽  
Chloroplast Markers ◽  
Chloroplast Genomes ◽  
In The Wild ◽  
Wild Accessions ◽  
Simple Sequence

Short mononucleotide repeats analogous to nuclear microsatellites or simple sequence repeats (SSRs) have been identified in chloroplast genomes. Primers flanking mononucleotide repeats in the fully sequenced rice chloroplast genome have been used in conjunction with PCR to amplify genomic DNA from 42 wild rice accessions. The amplification products exhibited length polymorphism, which allowed the levels of chloroplast variability detected to be quantified. Seven primer pairs that amplified products from different regions of the rice chloroplast were used, five of which also amplified polymorphic products in cultivated rice (Oryza sativa). Diversity values ranged from 0.5224 ± 0.0845 (SE) to 0.8298 ± 0.0085 in the wild accessions, which was higher than that detected in the O. sativa accessions. Both intra- and inter-specific polymorphism was detected, and the extent of chloroplast genomic differentiation based on chloroplast simple sequence repeat (cpSSR) assays was quantified using the RST statistic. Primers designed to amplify cpSSRs in O. sativa can also be used to generate polymorphic chloroplast markers in related taxa. The potential of using cpSSR to trace the origin of rice polyploid species is discussed.Key words: rice, chloroplast, simple sequence repeat, microsatellites.

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