Water and sucrose regulate canola embryo development

Johnson, Robert W.; Asokanthan, Ponita S.; Griffith, Marilyn

doi:10.1111/j.1399-3054.1997.tb01009.x

Cited by 22 publications

(20 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In many species, decreased stomatal conductance has been suggested as the main regulatory factor of carbon assimilation in response to abiotic stress (Hsiao 1973). Johnson et al (1997) reported that sucrose plays multiple roles in plants, including those of carbon and energy sources, but that it also exerts osmotic activity. Sucrose in the culture medium induces osmotic stress above certain concentrations and can lead to decreased growth (Kim and Kim 2002;Javed and Ikram 2008).…”

Section: Discussionmentioning

confidence: 99%

Metabolic profiling of photoautotrophic and photomixotrophic potato plantlets (Solanum tuberosum) provides new insights into acclimatization

Badr

Angers

Desjardins

2011

Plant Cell Tiss Organ Cult

View full text Add to dashboard Cite

Conventional photomixotrophic micropropagation systems are inefficient due to the high rates of mortality upon the transfer of plantlets from in vitro to ex vitro conditions. Exogenous medium sugar has been suggested to be the major cause of this problem. The aim of this study was to investigate the role of sucrose supply on the metabolic profile of in vitro-grown potato plantlets subjected to different tissue culture conditions consisting of Murashige and Skoog medium and without sucrose [photoautotrophic (PAT) condition] or with 3% sucrose [photomixotrophic (PMT) condition]. Using gas chromatography-mass spectrometry, we identified a set of 51 different metabolites in leaf tissues during the rooting phase. Most growth parameters, such as shoot length, leaf fresh weight, leaf number, and leaf area/plant, were significantly lower under PMT than under PAT conditions. Moreover, photosynthesis was inhibited due to partial stomatal closure under PMT conditions. The metabolomic profiles along with principal component analysis and hierarchical cluster analysis revealed that the two treatments were characterized by distinct metabolic signatures. PAT leaves were characterized by the accumulation of urea and erythritol. In comparison, PMT leaves were characterized by the accumulation of metabolites belonging to the primary metabolism and catecholamines as well as compounds related to abiotic stress conditions, such as proline, hydroxyproline, asparagine, c-aminobutyric acid (GABA), soluble sugars, and myo-inositol.

show abstract

Section: Discussionmentioning

confidence: 99%

Metabolic profiling of photoautotrophic and photomixotrophic potato plantlets (Solanum tuberosum) provides new insights into acclimatization

Badr

Angers

Desjardins

2011

Plant Cell Tiss Organ Cult

View full text Add to dashboard Cite

show abstract

“…As a consequence, it may not only be efficient but also essential for the developing oilseed embryo to conduct refixation or export of CO 2 . B. napus embryos have green chloroplasts with the capability of photosynthetic carbon fixation (Eastmond et al, 1996;Asokanthan et al, 1997;Eastmond and Rawsthorne, 1998;King et al, 1998). Measured rates of oxygen evolution of developing B. napus embryos (Eastmond et al, 1996;King et al, 1998) as well as Rubisco activity (King et al, 1998) are at least theoretically sufficient to refix the CO 2 that is produced by maximal oil synthesis.…”

Section: Discussionmentioning

confidence: 99%

“…In addition to the nutrient composition, the total osmotic pressure of the growth medium is an important factor influencing embryo development (Johnson et al, 1997). High osmotic pressure must be maintained to prevent precocious germination (Finkelstein and Crouch, 1986;Johnson et al, 1997).…”

Section: Influence Of Osmotic Pressure On Growthmentioning

confidence: 99%

“…High osmotic pressure must be maintained to prevent precocious germination (Finkelstein and Crouch, 1986;Johnson et al, 1997). Johnson et al (1997) defined a minimum osmotic pressure of Ϫ14 atm, which will inhibit precocious germination in 100% of B. napus embryos and enabled continuous growth in embryonic mode. To maintain such a high osmotic pressure in liquid growth media, polyols (without nutritional effect) such as sorbitol or mannitol have been used in liquid culture of B. napus embryos.…”

Section: Influence Of Osmotic Pressure On Growthmentioning

confidence: 99%

See 1 more Smart Citation

Probing in Vivo Metabolism by Stable Isotope Labeling of Storage Lipids and Proteins in Developing Brassica napusEmbryos

2002

View full text Add to dashboard Cite

Developing embryos of Brassica napus accumulate both triacylglycerols and proteins as major storage reserves. To evaluate metabolic fluxes during embryo development, we have established conditions for stable isotope labeling of cultured embryos under steady-state conditions. Sucrose supplied via the endosperm is considered to be the main carbon and energy source for seed metabolism. However, in addition to 220 to 270 mm carbohydrates (sucrose, glucose, and fructose), analysis of endosperm liquid revealed up to 70 mm amino acids as well as 6 to 15 mm malic acid. Therefore, a labeling approach with multiple carbon sources is a precondition to quantitatively reflect fluxes of central carbon metabolism in developing embryos. Mid-cotyledon stage B. napus embryos were dissected from plants and cultured for 15 d on a complex liquid medium containing 13 C-labeled carbohydrates. The 13 C enrichment of fatty acids and amino acids (after hydrolysis of the seed proteins) was determined by gas chromatography/mass spectrometry. Analysis of 13 C isotope isomers of labeled fatty acids and plastid-derived amino acids indicated that direct glycolysis provides at least 90% of precursors of plastid acetyl-coenzyme A (CoA). Unlabeled amino acids, when added to the growth medium, did not reduce incorporation of 13 C label into plastid-formed fatty acids, but substantially diluted 13 C label in seed protein. Approximately 30% of carbon in seed protein was derived from exogenous amino acids and as a consequence, the use of amino acids as a carbon source may have significant influence on the total carbon and energy balance in seed metabolism. 13 C label in the terminal acetate units of C 20 and C 22 fatty acids that derive from cytosolic acetyl-CoA was also significantly diluted by unlabeled amino acids. We conclude that cytosolic acetyl-CoA has a more complex biogenetic origin than plastidic acetyl-CoA. Malic acid in the growth medium did not dilute 13 C label incorporation into fatty acids or proteins and can be ruled out as a source of carbon for the major storage components of B. napus embryos.Plant oils represent the largest renewable resource of highly reduced carbon chains and there is interest in increasing their production by oilseed crops. Brassica napus (canola, oilseed rape) is a major oil crop and a multitude of literature focuses on the biochemistry and physiology of oil accumulation in developing seeds of B. napus (see Singal et al., 1987;Murphy and Cummis, 1989;Kang and Rawsthorne, 1994;Eastmond and Rawsthorne, 1998;King et al., 1998). Although the biochemical pathways leading from Suc to oil storage are largely understood, a number of questions remain regarding, for example, the subcellular organization of reactions, and the origin of acetyl-CoA, reducing power, and ATP for fatty acid synthesis. These questions are particularly difficult to address using standard in vitro or organellar biochemical analyses that often result in loss of key activities. In addition, due to several reasons including dilution of isotopes by ...

show abstract

“…It is believed that carbohydrates are involved in transport and storage processes, providing energy and carbon skeletons and regulation of gene expression (Carrier et al 1997;Johnson et al 1997). Total soluble sugar content was higher on the inoculation day.…”

Section: Biochemical Analysesmentioning

confidence: 99%

Growth curve, biochemical profile and phytochemical analyses in calli obtained from the procambium segments of Bacupari

Filho

Santos

Barbosa

et al. 2014

Braz. arch. biol. technol.

View full text Add to dashboard Cite

show abstract

Water and sucrose regulate canola embryo development

Cited by 22 publications

References 16 publications

Metabolic profiling of photoautotrophic and photomixotrophic potato plantlets (Solanum tuberosum) provides new insights into acclimatization

Metabolic profiling of photoautotrophic and photomixotrophic potato plantlets (Solanum tuberosum) provides new insights into acclimatization

Probing in Vivo Metabolism by Stable Isotope Labeling of Storage Lipids and Proteins in Developing Brassica napusEmbryos

Growth curve, biochemical profile and phytochemical analyses in calli obtained from the procambium segments of Bacupari

Contact Info

Product

Resources

About