Relationship of carbohydrate metabolism with lipid biosynthesis in developing sunflower (Helianthus annuus L.) seeds

Luthra, Rajesh; Munshi, S. K.; Sukhija, P. S.

doi:10.1016/s0176-1617(11)80137-9

Cited by 13 publications

(15 citation statements)

References 43 publications

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“…Embryo maturation involves the deposition of storage reserves that are used during germination and seedling growth (Lai and McKersie ). Starch is the major form of storage carbon and is a substrate for biosynthesis of lipids and free sugars such as sucrose (Leprince et al , Luthra et al ). As the main form of transported carbon and temporary storage in plants, sucrose can readily be converted to starch through the enzymes, sucrose synthase (EC 2.4.1.13), ADP glucose pyrophosphorylase (AGPase) (EC 2.7.7.27) and starch synthase (EC 2.4.1.21) (Geigenberger and Stitt , Fernie et al ).…”

Section: Discussionmentioning

confidence: 99%

The effect of carbohydrates and osmoticum on storage reserve accumulation and germination of Norway spruce somatic embryos

Businge

Bygdell

Wingsle

et al. 2013

Physiologia Plantarum

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Somatic embryogenesis (SE) represents a useful experimental system for studying the regulatory mechanisms of embryo development. In this study, the effect of carbohydrates and osmoticum on storage reserve accumulation and germination of Norway spruce [Picea abies (L.) Karst] somatic embryos were investigated. Using time lapse photography, we monitored development from proliferation of proembryogenic masses (PEMs) to maturation of somatic embryos in two P. abies cell lines cultured on two maturation treatments. A combination of sugar assays, metabolic and proteomic analyses were used to quantify storage reserves in the mature somatic embryos. The maturation treatment containing a nonpermeating osmoticum, polyethylene glycol (PEG, 7.5%) and maltose (3%) as the carbohydrate gave significantly high maturation and low germination frequencies of somatic embryos compared to the treatment with only 3% sucrose. Somatic embryos treated with 3% sucrose contained high levels of sucrose, raffinose and late embryogenesis abundant (LEA) proteins. These compounds are known to be involved in the acquisition of desiccation tolerance during seed development and maturation. In addition the sucrose treatment significantly increased the content of starch in the somatic embryos while the maltose and PEG treatment resulted in somatic embryos with a high content of storage proteins. The high levels of sucrose, raffinose and LEA proteins in the embryos treated with 3% sucrose suggest that sucrose may improve the germination of somatic embryos by promoting the acquisition of desiccation tolerance.

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Section: Discussionmentioning

confidence: 99%

The effect of carbohydrates and osmoticum on storage reserve accumulation and germination of Norway spruce somatic embryos

Businge

Bygdell

Wingsle

et al. 2013

Physiologia Plantarum

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“…The mean oxygen concentration displayed a clear developmental pattern, with the lowest levels occurring between 10 d and 25 d after flowering (Rolletschek et al ., 2007). This timing corresponds to the periods of maximal oil accumulation rate (Luthra et al ., 1991). Sunflower seeds accumulate large amounts of oil within the embryo.…”

Section: High‐resolution Mapping Of Oxygen Distribution In the Dementioning

confidence: 99%

The oxygen status of the developing seed

2009

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SummaryRecent applications of oxygen-sensitive microsensors have demonstrated steep oxygen gradients in developing seeds of various crops. Here, we present an overview on oxygen distribution, major determinants of the oxygen status in the developing seed and implications for seed physiology. The steady-state oxygen concentration in different seed tissues depends on developmental parameters, and is determined to a large extent by environmental factors. Photosynthetic activity of the seed significantly diminishes hypoxic constraints, and can even cause transient, local hyperoxia. Changes in oxygen availability cause rapid adjustments in mitochondrial respiration and global metabolism. We argue that nitric oxide (NO) is a key player in the oxygen balancing process in seeds, avoiding fermentation and anoxia in vivo. Molecular approaches aiming to increase oxygen availability within the seed are discussed.Abbreviations: At, Arabidopsis thaliana; AOX, alternative oxidase; COX, cytochrome C oxidase; HIF1, hypoxia-inducible factor; NO, nitric oxide; ROS, reactive oxygen species. I. IntroductionThe modern atmosphere contains approx. 21 kPa oxygen. However, over the course of the past 550 million yr (Phanerozoic time), during which time the vascular plants invaded the land surface, plants have adapted to levels of atmospheric oxygen ranging from 13 to 51 kPa (Raven, 1991). This variation has been a major driver of plant evolution, and has led to the tuning New Phytologist (2009) 182: 17-30 doi: 10.1111/j. 1469-8137.2008.02752.x Key words: hypoxia, nitric oxide (NO), oxygen diffusion, oxygen sensing, seed development, seed photosynthesis, storage metabolism. Tansley review Review 18New Phytologist ( of plant architecture/ultrastructure and metabolism to tolerate both low and high oxygen supply (Berner, 1999). Although over a shorter time-scale the atmospheric oxygen level may appear stable, plants must be able to adapt to variation in oxygen provision imposed by the local environment. For example, little oxygen is available to the plant root in a temporarily waterlogged soil, so plants have developed a number of strategies for acclimatization, avoidance and escape (Armstrong et al., 1994; Crawford & Brändle, 1996; Drew, 1997;Vartapetian et al., 2008). The diffusion of gas is 10 000 fold slower through a liquid medium than through air, so waterlogging rapidly leads to hypoxic and eventually even to anoxic conditions. Under hypoxia, the concentration of oxygen limits mitochondrial ATP production (oxidative phosphorylation), whereas under anoxia there is essentially no oxygen available for mitochondrial respiration. A restricted capacity for oxygen diffusion, in conjunction with a high rate of cellular metabolism, can generate hypoxia even in aerial organs such as the fruit (Ke et al., 1995), certain vascular tissues (Kimmers & Stringer, 1988), the pollen grain (Leprince & Hoekstra, 1998) and the seed (Rolletschek et al., 2002). From a historical perspective, seed germination and subsequent seedling growth has been one of...

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“…Photoassimilate transport depends on the physiological activity and the competition of these sinks, both changing in the course of ontogeny. Photoassimilate distribution in the capitulum was studied during the preanthesis (Hernandez & Palmer, 1992) and postanthesis stages (Goffner et al ., 1988; Luthra et al ., 1991), whereas the period between floret opening of outer whorls and seed filling has not been as intensively investigated. Therefore, the second objective of the present study was to analyse photoassimilate distribution in the capitulum during anthesis and seed filling.…”

Section: Introductionmentioning

confidence: 99%

Evidence for sectorial photoassimilate supply in the capitulum of sunflower (Helianthus annuus)

2002

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Summary• Photoassimilate transport from source leaves to the capitulum was investigated in sunflower ( Helianthus annuus ) during anthesis and seed filling.• Following foliar application of a 13/14 CO 2 -pulse, labelled photoassimilates were detected using mass spectrometry, phosphorimaging, HPTLC and HPLC.• The upper 10 (to 15) leaves exported photoassimilates into the capitulum. Photoassimilate distribution patterns were sectorial: each leaf supplied a defined 2/8 -3/8 sector of the capitulum. Photoassimilates exported via the midvein accumulated in a 1/8 sector, which aligned exactly with the insertion site of the leaf. The two main lateral veins of the leaf exported photoassimilates into the two adjacent 1/8 sectors of the capitulum. During early and late stages of anthesis, strong sinks were staminate florets and young achenes, respectively. During seed filling, an import maximum and minimum appeared in the intermediate and central whorls, respectively. Sucrose was established as the only phloem transport sugar. Raffinose, although also 14 C-labelled in the path, is not transported in sunflower.• It is concluded that a single floret is typically connected with the leaves of three neighbouring ortostichies in sunflower. Photoassimilate distribution patterns demonstrated here generally may reflect the functional relationships between the phyllotaxy of source leaves and the position of sinks in developing inflorescences like those of Asteraceae.

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Relationship of carbohydrate metabolism with lipid biosynthesis in developing sunflower (Helianthus annuus L.) seeds

Cited by 13 publications

References 43 publications

The effect of carbohydrates and osmoticum on storage reserve accumulation and germination of Norway spruce somatic embryos

The effect of carbohydrates and osmoticum on storage reserve accumulation and germination of Norway spruce somatic embryos

The oxygen status of the developing seed

Evidence for sectorial photoassimilate supply in the capitulum of sunflower (Helianthus annuus)

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