scholarly journals Stem Vacuole-targeted Sucrose Isomerase Enhances Sugar Accumulation in Sorghum

Author(s):  
Guoquan Liu ◽  
Yan Zhang ◽  
Hao Gong ◽  
Shan Li ◽  
Yunrong Pan ◽  
...  

Abstract Background: Sugar accumulation is critically important in determining sugar crop productivity. However, improvement in sugar content has been stagnant among sugar crops for decades. Sorghum, especially sweet sorghum with high biomass, has shown great potential for biofuel. In this study, sorghum was investigated as a C4 diploid model for crops with more complicated genomes such as maize and sugarcane. To enhance sugar accumulation, the sucrose isomerase (SI) gene, driven by stem-specific promoters (A2 or LSG) with a vacuole-targeted signal peptide, was transformed into the sorghum inbred line (Tx430).Results: The study demonstrated that transgenic lines of grain sorghum, containing 50-60% isomaltulose, accumulated sevenfold (804 mM) more total sugar than the control Tx430 did (118 mM) in stalks. Subsequently, the elite engineered lines (A5, and LSG9) were crossed with sweet sorghum (R9188, and Rio). Total sugar contents (over 750 mM), were significantly higher in F1, and F2 progenies than the control Rio (480 mM). The sugar contents of the engineered lines (over 750 mM), including T0, T1, F1, and F2, are higher than that of the field-grown sugarcane (normal range 600-700 mmol/L). Additionally, physiological characterization demonstrated that the superior progenies had notably higher rates of photosynthesis, sucrose transport, and sink strength than the controls.Conclusions: The genetic engineering approach has significantly enhanced total sugar content in grain sorghum (T0, and T1) and hybrid sorghum (F1, and F2), demonstrating that sorghum can accumulate sugar contents as high or higher than sugarcane. This research puts sorghum in the spotlight and frontier as a biofuel crop, particularly as it is a shorter duration crop. The substantial increase in sugar content would lead to enormous financial benefits for industrial utilization. This study could have a substantial impact on renewable bioenergy. More importantly, our results demonstrated that the phenotype of high sugar accumulation is inheritable and shed light on improvement for other sugar crops.

2020 ◽  
Author(s):  
Guoquan Liu ◽  
Yan Zhang ◽  
Yunrong Pan ◽  
Christopher Eric Davis ◽  
Hai-Chun Jing ◽  
...  

Abstract Background: Sugar accumulation is critically important in determining sugar crop productivity. Sorghum, especially high biomass sweet sorghum has shown great potential for biofuel. However, improvement in sugar content has been stagnant among sugar crops for decades. In this study, sorghum was investigated as a C4 diploid model for more complicated genomes such as maize and sugarcane. To promote sugar accumulation in sorghum, the sucrose isomerase (SI) gene, driven by stem-specific promoters A1 (A) or LSG2 (L) with a signal peptide, was designed to target the stem vacuole in grain sorghum inbred line (Tx430).Results: The study demonstrated that transgenic lines of grain sorghum can accumulate isomaltulose which accounted for 50-60% of total sugar (up to 1012 mM) in stalks. While the average sugar content is 118 mM in the control Tx430. Subsequently, the best-engineered line (L9) was crossed with an elite sweet sorghum variety (Rio). The total sugar contents were significantly higher in both F1 (up to 763 mM) and F2 (up to 821 mM) progenies than the sweet sorghum Rio (485 mM), representing 57% and 69% increase respectively. Those total sugar contents in those engineered sorghum lines are higher than in the field-grown sugarcane (600-700 mM). Physiological characterization demonstrated that the superior progenies of F2 hybrids had notably higher rates of photosynthesis, sucrose transport, and sink strength than controls.Conclusion: The genetic engineering approach has significantly enhanced total sugar content in grain sorghum and hybrids of (sweet X grain) sorghum. This research has put sorghum in the spotlight and frontier as a biofuel crop. More importantly, our results prove that the phenotype of high sugar content is heritable in the grain sorghum as well as hybrids. The massive increase in sugar accumulation would lead to enormous financial benefits for industrial and biofuel use. This study would have a substantial impact on renewable energy due to the supreme capacity of total sugar accumulation in transgenic sorghum.


2019 ◽  
Author(s):  
Guoquan Liu ◽  
Yan Zhang ◽  
Yunrong Pan ◽  
Christopher Eric Davis ◽  
Hai-Chun Jing ◽  
...  

Abstract Background: Sugar accumulation is critically important in determining sugar crop productivity. Sorghum, especially high biomass sweet sorghum has shown great potential for biofuel. However, improvement in sugar content has been stagnant among sugar crops for decades. In this study, sorghum was investigated as a C4 diploid model for more complicated genomes such as maize and sugarcane. To promote sugar accumulation in sorghum, the sucrose isomerase (SI) gene, driven by stem-specific promoters (A2 or LSG) with a signal peptide, was designed to target the stem vacuole in grain sorghum inbred line (Tx430) and sweet x grain hybrids (Rio x Tx430). Results: The study demonstrated that transgenic lines of grain sorghum, containing 50-60% isomaltulose, accumulated sevenfold (804 mmol/L) more total sugar than the control Tx430 did (118 mmol/L) in stalks. Subsequently, the best-engineered line (LSG9) was crossed with an elite sweet sorghum variety (Rio). The total sugar concentrations (over 800 mmol/L) measured by HPLC (high-performance liquid chromatography), were significantly higher in both F1 and F2 progenies than the sweet sorghum Rio, representing a 57% and 69% increase respectively. Those total sugar contents in engineered sorghum lines are higher than in the field-grown sugarcane (normal range 600-700 mmol/L). Physiological characterization demonstrated that the superior progenies had notably increased rates of photosynthesis, sucrose transport, and sink strength. Conclusion: The genetic engineering approach has significantly enhanced total sugar concentration in grain sorghum and hybrids of (grain x sweet) sorghum. This research has put sorghum in the spotlight and frontier as a biofuel crop. More importantly, our results prove that the phenotype of high sugar accumulation is inheritable in the grain sorghum as well as hybrids. The massive increase in sugar accumulation would lead to enormous financial benefits for industrial and biofuel use. This study would have a substantial impact on renewable energy due to the supreme capacity of total sugar accumulation in sorghum.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Guoquan Liu ◽  
Yan Zhang ◽  
Hao Gong ◽  
Shan Li ◽  
Yunrong Pan ◽  
...  

Abstract Background Sugar content is critically important in determining sugar crop productivity. However, improvement in sugar content has been stagnant among sugar crops for decades. Sorghum, especially sweet sorghum with high biomass, shown great potential for biofuel, has lower sugar content than sugarcane. To enhance sugar content, the sucrose isomerase (SI) gene, driven by stem-specific promoters (A2 or LSG) with a vacuole-targetted signal peptide, was transformed into the sorghum inbred line (T×430). Results The study demonstrated that transgenic lines of grain sorghum, containing 50–60% isomaltulose, accumulated up to eightfold (1000 mM) more total sugar than the control T×430 did (118 mM) in stalks of T0 generation. Subsequently, the elite engineered lines (A5, and LSG9) were crossed with sweet sorghum (Rio, and R9188). Total sugar contents (over 750 mM), were notably higher in F1, and F2 progenies than the control Rio (480 mM). The sugar contents of the engineered lines (over 750 mM), including T0, T1, F1, and F2, are surprisingly higher than that of the field-grown sugarcane (normal range 600–700 mmol/L). Additionally, analysis of physiological characterization demonstrated that the superior progenies had notably higher rates of photosynthesis, sucrose transportation, and sink strength than the controls. Conclusions The genetic engineering approach has dramatically enhanced total sugar content in grain sorghum (T0, and T1) and hybrid sorghum (F1, and F2), demonstrating that sorghum can accumulate as high or higher sugar content than sugarcane. This research illustrates that the SI gene has enormous potential on improvement of sugar content in sorghum, particularly in hybirds and sweet sorghum. The substantial increase on sugar content would lead to significant financial benefits for industrial utilization. This study could have a substantial impact on renewable bioenergy. More importantly, our results demonstrated that the phenotype of high sugar content is inheritable and shed light on improvement for other sugar crops.


HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 420C-420
Author(s):  
Gene Lester ◽  
Luis Saucedo Arias ◽  
Miguel Gomez-Lim

Muskmelon [Cucumis melo L. (Reticulatus Group)] fruit sugar content is the single most important consumer preference attribute. During fruit ripening, sucrose accumulates when soluble acid invertase (AI) activity is less then sucrose phosphate synthase (SPS) activity. To genetically heighten fruit sugar content, knowledge of sugar accumulation during fruit development in conjunction with AI and SPS enzyme activities and their peptide immunodetection profiles is needed. Two netted muskmelon cultivars [`Valley Gold' (VG), a high sugar accumulator, and `North Star' (NS), a low sugar accumulator] with similar maturity indices were assayed for fruit sugars, AI, and SPS activity and immunodetection of AI and SPS polypeptides following 2, 5, 10, 15, 20, 25, 30, 35, and 40 (abscission) days after anthesis (DAA). Both cultivars, grown in spring and fall, showed similar total sugar accumulation profiles. Total sugars increased 1.5 fold, from 2 through 5 DAA and then remained unchanged until 30 DAA. From 30 DAA until abscission, total sugar content increased, with VG accumulating significantly more sugar then NS. In both cultivars, during both seasons, sucrose was detected at 2 DAA, which coincided with higher SPS activity than AI activity. At 5 through 25 DAA, SPS activity was less then AI activity resulting in little or no sucrose detection. It was not until 30 DAA that SPS activity was greater than AI activity resulting in increased sucrose accumulation. VG at abscission had higher total sugar content and SPS activity and lower AI activity than NS. Total polypeptides from both cultivars 2 through 40 DAA, were immunodetected with antibodies: anti-AI and anti-SPS. NS had Al isoforms bands at 75, 52, 38, and 25 kDa that generally decreased wtih DAA. One isoform at 52 kDa remained detectable up to anthesis (40 DAA) VG had the same four Al isoforms, all decreased with DAA and became undetectable by 20 DAA. It is unclear if one or all AI isoforms correspond with detected enzyme activity. VG and NS had one SPS band at 58 kDa that increased with DAA and concomitantly with SPS activity. VG had a more intense SPS polypeptide band at abscission then did NS. Thus, netted muskmelon sugar accumulation may be increased by selecting for cultivars with a specific number of AI isoforms, which are down-regulated, and with high SPS activity during fruit ripening.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 497e-497
Author(s):  
Lili Zhou ◽  
David Christopher ◽  
Robert E. Paull

The source size and sink strength were modified by continual defoliation and fruit removal in `Sunset' papaya. Flower and fruit set, mature fruit mass, and TSS was recorded weekly. Fruit at four different stages of development were harvested at the end of the experiment. Fruit mass, respiration, sugar content, and sucrose phosphate synthase (SPS), sucrose synthase (SS), and invertase enzyme activities were compared. Continual defoliation resulted in lower new fruit set (25% of control), smaller fruit size (77% of control), and lower TSS (85% of control) in the 24-week experimental period. In contrast, there were 52% and 100% more new fruit when fruit were removed than in the control within the first 8 weeks and 24 weeks, respectively. Larger fruit size, earlier fruit development, lower respiration, and higher sugar contents were observed when fruit were removed at 140, 154, and 175 days from anthesis. No significant difference was found in TSS level in the mature fruit compared to the control. Fruit removal plus defoliation gave the same number and mass of new fruit as the control and slightly lower TSS in mature fruit than in the control. Fruit sugar was higher with increased fruit invertase activity and fruit age. Data confirmed that source–sink balance was critical for fruit set, development, and sugar accumulation in papaya.


2014 ◽  
Vol 32 (3) ◽  
pp. 307-314 ◽  
Author(s):  
Jaime Humberto Bernal ◽  
Gustavo A. Ligarreto M. ◽  
Ruby Stella Hernández

Sugar production in sweet sorghums is affected by the environment. Therefore, in this study on the effects of the genotype x environment interaction on sugar accumulation, plant traits associated with the sugar content in the stem were evaluated in ten sorghum genotypes grown in six contrasting environments. The results indicated that the stem dry weight, juice sugar concentration (°Brix), stem sugar content and juice volume were controlled by the genetic constitution of the genotype, with a large environmental contribution to their expression. The results allowed for the identification of the sweet sorghum genotypes that have a high potential for the biofuel agroindustry due to their high sugar contents in the environmental conditions of Palmira, Espinal, Cerete and Codazzi. Humid tropical environments such as Gaitan and Villavicencio were less favorable for the competitive production of sweet sorghums for bioethanol due to their low levels of solar radiation and soil fertility.


2016 ◽  
pp. 765-769
Author(s):  
Martijn Leijdekkers

Since 2013, the glucose content of all beet samples from beet reception and field trials is routinely analyzed in The Netherlands using a biosensor which is integrated into the automatic beet laboratory system. The invert sugar content is subsequently calculated from the glucose content using a linear conversion factor. This additional information helps to identify beet deliveries with a questionable beet quality at an early stage and provides valuable information on various agronomic factors that increase invert sugar accumulation in the beet. Based on results obtained during the past years, different factors are highlighted that affect the invert sugar content in the beet. Among these factors, beet deterioration following frost damage and the presence of root rot due to infestation by pests and diseases have shown to increase the invert sugar content dramatically. In addition, unfavorable storage conditions and bad harvesting quality had a substantial impact on invert sugar accumulation. Growth conditions and beet variety also influenced the invert sugar content markedly, although to a much lesser extent. Using the obtained data, the most important control measures that enable growers to prevent undesired invert sugar formation and consequent sugar losses in their beet are discussed.


2016 ◽  
Vol 54 (4) ◽  
pp. 526
Author(s):  
Dinh Thi Thanh Tra ◽  
Igarashi Yasuo ◽  
Xiao Hua ◽  
Luo Feng ◽  
Xu Chang Zheng ◽  
...  

Sweet sorghum has become a candidate species for combining phytoremediation with biofuel production due to heavy metal resistance, great biomass and sugar enrichment in stem. However, the influence of heavy metals on sugar accumulation in sweet sorghum is still unknown. In this study, Cd induced modification of sugar storage and translocation in stem was monitored using two sweet sorghum cultivars Keller (KE) and E-tian (ET). Brix degree, which represents sugar content in stem juice, displays significant reduction in response to exogenous Cd treatment in both lines. The sugar enrichment is more obviously repressed in the lower internodes while it is hardly affected in the top internodes. Excessive Cd results in drastically enhanced Cd accumulation, preferentially in the lower internodes. More interestingly, negative correlation between Cd and sugar content is detected along internodes, indicating antagonistic translocation between Cd and sugar along stem of sweet sorghum. The preferential compartmentation of Cd and sugar in different regions of stem provides novel insights into understanding and application of sweet sorghum for combining biofuel production with phytoremediation of heavy metal in soil.


2009 ◽  
pp. 51-56
Author(s):  
Éva Erdei ◽  
Pál Pepó ◽  
János Csapó ◽  
Szilárd Tóth ◽  
Béla Szabó

Sweet sorghum can be utilized for bioethanol production because it has high sugar content (14-17%). We determined the most important nutritional values of 5 silo type sorghum lines in waxy and full maturation. The examined restorer lines were: RL 4, RL 9, RL 15, RL 18, K 1. The following nutritional parameters were examined: dry material content, refractometric total sugar content, reducing sugar content. In waxy maturation 73.85-87.37% of dry matter in stalk juice makes the total sugar. Dry  material content, total and reducing sugar content of stalkdecreases from waxy mature to full maturation.There are differences between lines in dry matter (SzD5%=0.76), total sugar (SzD5%=0.79), reducing sugar content (SzD5%=0.30). RL 4 performed a decrease in total sugar content from 10.07% to 10.02% during this period, reducing sugar also decreased from 4.01% to 2.47%. RL 9 performed a decrease in total sugar content from 11.76% to 11.08% during this period. Reducing sugar also decreased from 3.17% to 2.01% in the waxymaturation. RL 15 showed a total sugar content decrease from 15.43 % to 15.36%. The reducing sugar also decreased from  3.23% to 1.71% in waxy maturation. In RL 18 total mean sugar content during waxy maturation was 13.78% which dropped to 13.26% approaching full maturation. Reducing sugar also decreased from 4.11% to 2.23% in waxy mature. K 1 performed a decrease in total sugar content from 9.35% to 6.15% during this period, while reducing sugar also decreased from 1.52% to 0.77%. These lines upcoming for experiments are perspectives since having excellent stalk juice nutritional parameters they are of great or very great height and their stalks are thick-very thick, stalk medullas are wet.


2001 ◽  
Vol 126 (1) ◽  
pp. 33-36 ◽  
Author(s):  
Gene E. Lester ◽  
Luis Saucedo Arias ◽  
Miguel Gomez-Lim

Muskmelon [Cucumis melo L. (Reticulatus Group)] fruit sugar content is the single most important consumer preference attribute. During fruit ripening, sucrose accumulates when soluble acid invertase (AI) activity is less then sucrose phosphate synthase (SPS) activity. To genetically heighten fruit sugar content, knowledge of sugar accumulation during fruit development in conjunction with AI and SPS enzyme activities and their peptide immunodetection profiles, is needed. Two netted muskmelon cultivars, Valley Gold a high sugar accumulator, and North Star a low sugar accumulator, with identical maturity indices were assayed for fruit sugars, AI and SPS activity, and immunodetection of AI and SPS polypeptides 2, 5, 10, 15, 20, 25, 30, 35, or 40 (abscission) days after anthesis (DAA). Both cultivars, grown in the Fall, 1998 and Spring, 1999, showed similar total sugar accumulation profiles. Total sugars increased 1.5 fold, from 2 through 5 DAA, then remained unchanged until 30 DAA. From 30 DAA until abscission, total sugar content increased, with `Valley Gold' accumulating significantly more than `North Star'. During both seasons, sucrose was detected at 2 DAA, which coincided with SPS activity higher than AI activity, at 5 through 25 DAA, no sucrose was detected which coincided with SPS activity less than AI activity. At 30 DAA when SPS activity was greater than AI activity, increased sucrose accumulation occurred. `Valley Gold' at abscission had higher total sugar content and SPS activity, and lower AI activity than `North Star'. `North Star' had AI isoforms at 75, 52, 38, and 25 kDa (ku) that generally decreased with maturation, although the isoform at 52 ku remained detectable up to anthesis (40 DAA). `Valley Gold' had the same four AI isoforms, all decreased with maturation and became undetectable by 20 DAA. Both `Valley Gold' and `North Star' had one SPS band at 58 ku that increased with DAA, and coincided with SPS activity. `Valley Gold' had a more intense SPS polypeptide band at abscission than `North Star'. Thus, netted muskmelon fruit sugar accumulation may be increased, either by genetic manipulation or by selecting for cultivars with a specific number of down-regulated AI isoforms, and higher SPS activity during fruit ripening.


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