Effects of sucrose on starch accumulation and rate of photosynthesis in Rosa cultured in vitro

1991 ◽  
Vol 25 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Montserrat Capellades ◽  
Raoul Lemeur ◽  
Pierre Debergh
Keyword(s):  
Starch Accumulation ◽  
Rate Of Photosynthesis

scholarly journals Культура ізольованих зернівок як біотехнологічна система дорощування зиготичних зародків кукурудзи in vitro

2010 ◽  
Vol 1 (2) ◽  
pp. 49-57
Author(s):  
Е. V. Lyapustina
Keyword(s):  
Nutrient Medium ◽  
Internal State ◽  
Starch Accumulation ◽  
Globular Stage ◽  
Maize Embryo ◽  
Full Maturity

The investigation established the possibility of production of maize embryo in culture of isolated caryopsis on artificial nutrient medium in vitro conditions from a zygote / proembryo and globular stage up to the full maturity. It was determined that the cultivation of caryopsis on artificial nutrient medium provides the accumulation of starch in endosperm. The internal state of cultured caryopsis can be considered as a marker of embryo upgrowing and starch accumulation in endosperm, irrespective of the genotype. The genotype, the age of cultured caryopsis and concentration of sucrose influence on the development of endosperm, accumulation of starch in endosperm and embryo upgrowing from the zygote / proembryo and globular stage.

Heat Stress During Grain Filling in Maize: Effects on Carbohydrate Storage and Metabolism

1994 ◽  
Vol 21 (6) ◽  
pp. 829 ◽  
Author(s):  
GW Singletary ◽  
R Banisadr ◽  
PL Keeling
Keyword(s):  
Heat Stress ◽  
Seed Size ◽  
Starch Synthesis ◽  
Dry Weight ◽  
Grain Filling ◽  
Soluble Starch ◽  
Effect Of Temperature ◽  
Starch Accumulation ◽  
Maize Kernels

Heat stress during maize seed development can interfere with endosperm starch biosynthesis and reduce seed size, an important component of yield. Our objectives were to evaluate the direct influence of temperature during grain filling on kernel growth, carbohydrate accumulation, and corresponding endosperm metabolism. Kernels of maize were grown in vitro at 25�C until 15 or 16 days after pollination and then subjected to various temperatures for the remainder of their development. Mature kernel dry weight declined 45% in a linear fashion between 22 and 36�C. The rate of starch accumulation reached a maximum at approximately 32�C, and when measured at frequent intervals, declined only slightly with further temperature increase to 35�C. Reduced seed size resulted from an abbreviated duration of starch-related metabolism, which did not appear to be limited by endogenous sugars. Instead, a survey of 12 enzymes of sugar and starch metabolism indicated that ADP glucose pyrophosphorylase and soluble starch synthase were unique in displaying developmental peaks of activity which were compressed both in amount and time, similar to the effect of temperature on starch accumulation. We conclude that decreased starch synthesis in heat-stressed maize kernels results from a premature decline in the activity of these enzymes.

scholarly journals Engineering 6-phosphogluconate dehydrogenase improves grain yield in heat-stressed maize

2020 ◽  
Vol 117 (52) ◽  
pp. 33177-33185
Author(s):  
Camila Ribeiro ◽  
Tracie A. Hennen-Bierwagen ◽  
Alan M. Myers ◽  
Kenneth Cline ◽  
A. Mark Settles
Keyword(s):  
Heat Stress ◽  
Grain Yield ◽  
Fusion Proteins ◽  
Starch Synthesis ◽  
Starch Accumulation ◽  
Chloroplast Targeting ◽  
Phosphogluconate Dehydrogenase ◽  
Heat Stable ◽  
Endosperm Starch

Endosperm starch synthesis is a primary determinant of grain yield and is sensitive to high-temperature stress. The maize chloroplast-localized 6-phosphogluconate dehydrogenase (6PGDH), PGD3, is critical for endosperm starch accumulation. Maize also has two cytosolic isozymes, PGD1 and PGD2, that are not required for kernel development. We found that cytosolic PGD1 and PGD2 isozymes have heat-stable activity, while amyloplast-localized PGD3 activity is labile under heat stress conditions. We targeted heat-stable 6PGDH to endosperm amyloplasts by fusing the Waxy1 chloroplast targeting the peptide coding sequence to the Pgd1 and Pgd2 open reading frames (ORFs). These WPGD1 and WPGD2 fusion proteins import into isolated chloroplasts, demonstrating a functional targeting sequence. Transgenic maize plants expressing WPGD1 and WPGD2 with an endosperm-specific promoter increased 6PGDH activity with enhanced heat stability in vitro. WPGD1 and WPGD2 transgenes complement the pgd3-defective kernel phenotype, indicating the fusion proteins are targeted to the amyloplast. In the field, the WPGD1 and WPGD2 transgenes can mitigate grain yield losses in high–nighttime-temperature conditions by increasing kernel number. These results provide insight into the subcellular distribution of metabolic activities in the endosperm and suggest the amyloplast pentose phosphate pathway is a heat-sensitive step in maize kernel metabolism that contributes to yield loss during heat stress.

Early phases in in vitro culture of tomato cotyledons: Starch accumulation and protein pattern in relation to the hormonal treatment

PROTOPLASMA ◽  
1994 ◽  
Vol 182 (1-2) ◽  
pp. 59-64 ◽  
Author(s):  
C. Branca ◽  
A. Torelli ◽  
P. Fermi ◽  
M. M. Altamura ◽  
M. Bassi
Keyword(s):  
In Vitro Culture ◽  
Protein Pattern ◽  
Hormonal Treatment ◽  
Starch Accumulation ◽  
Early Phases

scholarly journals Cocktail Therapy of Fosthiazate and Cupric-Ammoniun Complex for Citrus Huanglongbing

2021 ◽  
Vol 12 ◽  
Author(s):  
Jingwei Duan ◽  
Xue Li ◽  
Junzhe Zhang ◽  
Baoping Cheng ◽  
Shuhan Liu ◽  
...  
Keyword(s):  
Synergistic Effects ◽  
Starch Accumulation ◽  
Bacterial Disease ◽  
Tree Roots ◽  
Tylenchulus Semipenetrans ◽  
Transmission Electron ◽  
Citrus Root ◽  
Citrus Huanglongbing ◽  
Liberibacter Asiaticus

Huanglongbing (HLB) is a destructive citrus bacterial disease caused by Candidatus Liberibacter asiaticus (Ca.Las) and cannot be cured by current pesticides. Root lesion and Tylenchulus semipenetrans juveniles were observed in HLB-affected citrus tree roots. We hypothesize that root treatment with fosthiazate (FOS) and Cupric-Ammonium Complex (CAC) will improve the root growth and inhibit HLB. CAC is a broad spectrum fungicide and can promote growth of crops. FOS kills Tylenchulus semipenetrans and protects roots from damage by harmful bacteria such as Ca.Las. After 90 days of combination treatment of FOS and CAC through root drenches, the citrus grew new roots and its leaves changed their color to green. The inhibition rate of Ca.Las reached more than 90%. During treatment process, the chlorophyll content and the root vitality increased 396 and 151%, respectively, and starch accumulation decreased by 88%. Transmission electron microscopy (TEM) and plant tissue dyeing experiments showed that more irregular swollen starch granules existed in the chloroplast thylakoid system of the HLB-infected leaves. This is due to the blocking of their secretory tissue by starch. TEM and flow cytometry experiments in vitro showed the synergistic effects of FOS and CAC. A transcriptome analysis revealed that the treatment induced the differential expression of the genes which involved 103 metabolic pathways. These results suggested that the cocktail treatment of FOS and CAC may effectively kill various pathogens including Ca.Las on citrus root and thus effectively control HLB.

Two chloroplastic PLGG1 isoforms function together to transport photorespiratory glycolate and glycerate in rice

2021 ◽  
Author(s):  
Lili Cui ◽  
Chuanling Zhang ◽  
Zhichao Li ◽  
Tuxiu Xian ◽  
Limin Wang ◽  
...  
Keyword(s):  
Rice Genome ◽  
Direct Interaction ◽  
Crop Productivity ◽  
Chloroplast Envelope ◽  
Starch Accumulation ◽  
Loss Of Function ◽  
In Planta ◽  
In Vivo Experiments

Abstract The photorespiratory pathway is highly compartmentalized. As such, metabolite shuttles between organelles are critical to ensure efficient photorespiratory carbon flux. Arabidopsis PLGG1 has been reported as a key chloroplastic glycolate/glycerate transporter. Two homologous genes OsPLGG1a and OsPLGG1b have been identified in the rice genome, although their distinct functions and relationships remain unknown. Herein, our analysis of exogenous expression in oocytes and yeast shows that both OsPLGG1a and OsPLGG1b have the ability to transport glycolate and glycerate. Furthermore, we demonstrate in planta, that the perturbation of OsPLGG1a or OsPLGG1b expression leads to extensive accumulation of photorespiratory metabolites, especially glycolate and glycerate. Under ambient CO2 conditions, loss-of-function osplgg1a or osplgg1b mutant plants exhibited significant decreases in photosynthesis efficiency, starch accumulation, plant height, and crop productivity. These morphological defects were almost entirely recovered when the mutant plants were grown under elevated CO2 conditions instead. In contrast to osplgg1a, osplgg1b mutant alleles produced a mild photorespiratory phenotype and had reduced accumulation of photorespiratory metabolites. Subcellular localization analysis showed that OsPLGG1a and OsPLGG1b are located in the inner and outer membranes of the chloroplast envelope, respectively. In vitro and in vivo experiments revealed that OsPLGG1a and OsPLGG1b have a direct interaction. Our results indicate that both OsPLGG1a and OsPLGG1b are chloroplastic glycolate/glycerate transporters required for photorespiratory metabolism and plant growth, and that they may function as a singular complex.

scholarly journals Change in Sucrose Cleavage Pattern and Rapid Starch Accumulation Govern Lily Shoot-to-Bulblet Transition in vitro

2021 ◽  
Vol 11 ◽  
Author(s):  
Yun Wu ◽  
Ziming Ren ◽  
Cong Gao ◽  
Minyi Sun ◽  
Shiqi Li ◽  
...  
Keyword(s):  
Soluble Sugars ◽  
Starch Synthesis ◽  
Underlying Mechanism ◽  
Culture Conditions ◽  
Starch Accumulation ◽  
Cleavage Pattern ◽  
Additional Support ◽  
Clear Shift ◽  
Sucrose Cleavage

In bulb crops, bulbing is a key progress in micropropagation and is the feature that most distinguishes bulbous crops from other plants. Generally, bulbing involves a shoot-to-bulblet transition; however, the underlying mechanism remains elusive. We explored this process by tracking the shoot-to-bulblet transition under different culture conditions. Rapid starch accumulation occurred at 15 days after transplanting (DAT) in the bulblet-inducing treatments as confirmed via histological observations and the significant elevation of starch synthesis related-gene transcription, including LohAGPS, LohAGPL, LohGBSS, LohSS, and LohSBE. However, for shoots that did not transition to bulblets and maintained the shoot status, much higher soluble sugars were detected. Interestingly, we observed a clear shift from invertase-catalyzed to sucrose synthase-catalyzed sucrose cleavage pattern based on the differential expression of LohCWIN and LohSuSy during the key transition stage (prior to and after bulbing at 0–15 DAT). Shoots that transitioned into bulblets showed significantly higher LohSuSy expression, especially LohSuSy4 expression, than shoots that did not transition. A symplastic phloem unloading pathway at the bulblet emergence stage (15 DAT) was verified via the 6(5)-carboxyfluorescein diacetate fluorescent tracer. We propose that starch is the fundamental compound in the shoot-to-bulblet transition and that starch synthesis is likely triggered by the switch from apoplastic to symplastic sucrose unloading, which may be related to sucrose depletion. Furthermore, this study is the first to provide a complete inventory of the genes involved in starch metabolism based on our transcriptome data. Two of these genes, LohAGPS1.2b and LohSSIIId, were verified by rapid amplification of cDNA ends cloning, and these data will provide additional support for Lilium research since whole genome is currently lacking.

Effect of changes in carbohydrate concentration on the rate of net photosynthesis in mature leaves of Abies balsamea

1973 ◽  
Vol 51 (4) ◽  
pp. 751-758 ◽  
Author(s):  
C. H. A. Little ◽  
K. Loach
Keyword(s):  
Photosynthetic Rate ◽  
Abies Balsamea ◽  
Net Photosynthesis ◽  
Total Sugar ◽  
Starch Accumulation ◽  
Carbohydrate Concentration ◽  
Normal Period ◽  
Before And After ◽  
Rate Of Photosynthesis ◽  
Foliar Concentration

The hypothesis that photosynthate accumulation within a leaf inhibits the ongoing rate of photosynthesis was investigated in 6-year-old balsam fir trees. Rates of net photosynthesis and transpiration, and concentrations of starch, total sugar, chlorophyll, and water were measured in 1-year-old or fully expanded, current needles, and leaf resistances to carbon dioxide transfer were calculated. The several-fold rise and fall in the content of carbohydrate (mostly starch) that occurs naturally in 1-year-old needles before and after budbreak was correlated positively rather than negatively with the photosynthetic rate. Shading during the normal period of starch accumulation decreased the concentrations of both starch and total sugar, but did not increase photosynthesis. Continuous cooling of the base of a branch to 2 °C to inhibit translocation of photosynthate did not affect the photosynthetic rate during a 2-week period, nor did it cause carbohydrate accumulation, as measured at the end of the experiment. Removing a ring of bark from a branch base resulted in a large increase in the foliar concentration of starch (but not total sugar) and a small decrease in photosynthesis. However, the concomitant decrease in moisture content, not the accumulation of starch, was more probably the cause of the reduced photosynthesis. We conclude that the rate of photosynthesis in fir needles, at least under normal growing conditions, is not influenced by photosynthate accumulation.

scholarly journals Histone Deacetylase Activity and Phytotoxic Effects Following Exposure of Duckweed (Lemna pausicostata L.) to Apicidin and HC-Toxin

2001 ◽  
Vol 91 (12) ◽  
pp. 1141-1148 ◽  
Author(s):  
Hamed K. Abbas ◽  
John W. Gronwald ◽  
Kathryn L. Plaisance ◽  
Rex N. Paul ◽  
Yin W. Lee
Keyword(s):  
Cell Division ◽  
Histone Deacetylase ◽  
Chlorophyll Synthesis ◽  
Effective Concentration ◽  
Starch Accumulation ◽  
Fusarium Spp ◽  
Cochliobolus Carbonum ◽  
Hc Toxin ◽  
Cyclic Tetrapeptide

The effects of two cyclic tetrapeptide fungal toxins, apicidin (from Fusarium spp.) and HC-toxin (from Cochliobolus carbonum), on duckweed (Lemna pausicostata L.) were examined. Both toxins inhibited histone deacetylase (HD) activity from duckweed plantlets; the effective concentration (EC50) for inhibition of HD was 5.6 and 1.1 μM for apicidin and HC-toxin, respectively. Approximately 65 and 85% of in vitro HD activity was inhibited by 50 μM apicidin or HC-toxin, respectively. Exposing duckweed for 72 h to apicidin or HC-toxin (25 or 50 μM) enhanced cellular leakage, impaired chlorophyll synthesis, and inhibited growth (cell division). At equivalent concentrations, the effects of HC-toxin were more pronounced than those of apicidin. In fronds, 72 h of exposure to 50 μM apicidin resulted in chloroplast deterioration indicated by loss of orientation and excess starch accumulation. In roots, a 72-h treatment with 50 μM apicidin resulted in the loss of the root cap and increased vacuolization and starch accumulation in plastids.

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