Plant Responses to Sugar Starvation

Morkunas, Iwona; Borek, Sławomir; Formela, Magda; Ratajczak, Lech

doi:10.5772/51569

Cited by 24 publications

(34 citation statements)

References 172 publications

(253 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Many amino acids involved in gluconeogenesis are glucogenous, in particular, aspartic and glutamic acids, which are directly converted to α‐ketoglutarate and oxalacetate, respectively. Gluconeogenesis as a dominant sugar synthesis pathway from noncarbohydrate carbon substances is well documented during seed germination, when storage lipids or storage proteins are converted into sugars . This is a multistep process involving several cell compartments and consisting of a series of enzyme‐catalysed reactions (Figure ), moreover the pathway of these process dependents on the substrate being used.…”

Section: Introductionmentioning

confidence: 99%

Melatonin redirects carbohydrates metabolism during sugar starvation in plant cells

Kobylińska

Borek²,

Posmyk

2018

Journal of Pineal Research

View full text Add to dashboard Cite

Recent studies have shown that melatonin is an important molecule in plant physiology. It seems that the most important is that melatonin efficacy eliminates oxidative stress (direct and indirect antioxidant) and moreover induce plant stress reaction and switch on different defence strategies (preventively and interventively actions). In this report, the impact of exogenous melatonin on carbohydrate metabolism in Nicotiana tabacum L. line Bright Yellow 2 (BY-2) suspension cells during sugar starvation was examined. We analysed starch concentration, α-amylase and PEPCK activity as well as proteolytic activity in culture media. It has been shown that BY-2 cell treatment with 200 nM of melatonin improved viability of sugar-starved cells. It was correlated with higher starch content and phosphoenolpyruvate carboxykinase (PEPCK) activity. The obtained results revealed that exogenous melatonin under specific conditions (stress) can play regulatory role in sugar metabolism, and it may modulate carbohydrate concentration in etiolated BY-2 cells. Moreover, our results confirmed the hypothesis that if the starch is synthesised even in sugar-starved cells, it is highly probable that melatonin shifts the BY-2 cell metabolism on gluconeogenesis pathway and allows for synthesis of carbohydrates from nonsugar precursors, that is amino acids. These points to another defence strategy that was induced by exogenous melatonin applied in plants to overcome adverse environmental conditions.

show abstract

Section: Introductionmentioning

confidence: 99%

Melatonin redirects carbohydrates metabolism during sugar starvation in plant cells

Kobylińska

Borek²,

Posmyk

2018

Journal of Pineal Research

View full text Add to dashboard Cite

show abstract

“…Published data indicate that senescence can be induced by sugar deficit or excess [60][61][62]. It was previously shown that glucose (and fructose) was accumulated and the SAG12 (SENESCENCE-ASSOCIATED GENE12) senescence marker was strongly induced in A. thaliana leaves during senescence (yellowing).…”

Section: Introductionmentioning

confidence: 99%

Regulatory roles of sugars in plant growth and development

Ciereszko

2018

Acta Soc Bot Pol

View full text Add to dashboard Cite

In recent years, several studies have focused on the factors and mechanisms that regulate plant growth and development, as well as the functioning of signaling pathways in plant cells, unraveling the involvement of sugars in the processes regulating such growth and development. Saccharides play an important role in the life of plants: they are structural and storage substances, respiratory substrates, and intermediate metabolites of many biochemical processes. Sucrose is the major transport form of assimilates in plants. Sugars can also play an important role in the defense reactions of plants. However, it has been shown that glucose, sucrose, or trehalose-6-phosphate (Tre6P) can regulate a number of growth and metabolic processes, acting independently of the basal functions; they can also act as signaling molecules. Changes in the concentration, qualitative composition, and transport of sugars occur continuously in plant tissues, during the day and night, as well as during subsequent developmental stages. Plants have developed an efficient system of perception and transmission of signals induced by lower or higher sugar availability. Changes in their concentration affect cell division, germination, vegetative growth, flowering, and aging processes, often independently of the metabolic functions. Currently, the mechanisms of growth regulation in plants, dependent on the access to sugars, are being increasingly recognized. The plant growth stimulating system includes hexokinase (as a glucose sensor), trehalose-6-phosphate, and TOR protein kinase; the lack of Tre6P or TOR kinase inhibits the growth of plants and their transition to the generative phase. It is believed that the plant growth inhibition system consists of SnRK1 protein kinases and C/S1 bZIP transcription factors. The signal transduction routes induced by sugars interact with other pathways in plant tissues (for example, hormonal pathways) creating a complex communication and signaling network in plants that precisely controls plant growth and development.

show abstract

“…Hence, metabolite accumulation at the first moments of exposure to darkness (24 h) could indicate a decline in the metabolic rate, which is typical of the acclimation phase (Morkunas et al . ). For example, the respiratory activity in the embryonic axis of Lupinus luteus is reduced under carbon starvation conditions (Borek et al .…”

Section: Discussionmentioning

confidence: 97%

Regulation of reserve mobilisation in sunflower during late seedling establishment in continuous darkness

et al. 2017

View full text Add to dashboard Cite

Reserve mobilisation, metabolite partitioning and reserve-degrading enzyme activity were studied in sunflower seedlings cultivated in vitro under a 12-h photoperiod or in the dark to investigate the involvement of source-sink relation and carbon starvation in the regulation of reserve mobilisation under continuous darkness. Reserves, metabolites and enzyme activity were determined with standard spectrophotometric methods. At the first 24 h of treatment (acclimation phase), darkness did not affect growth, but restricted carbon and nitrogen use, as indicated by sugar and amino acid accumulation in the different seedling parts. After 5 days of treatment (survival phase), extended darkness limited growth and retarded storage lipid mobilisation due to carbon starvation, as evidenced by the depletion of carbohydrates in cotyledons and hypocotyl, as well as the consumption of amino acids in hypocotyls and roots. Alterations in the source-sink relationship might have been a response to prolonged darkness, instead of a mechanism used to regulate reserve mobilisation, as these alterations cannot be associated with negative feedback mediated by metabolite accumulation. Storage lipid degradation depends, at least in part, on mechanisms that co-ordinately regulate the activities of lipases and isocitrate lyase. Taking these results together, it is possible that reserve mobilisation in sunflower seedlings cultivated in the dark might be regulated by mechanisms that perceive the absence of light and predict carbon starvation, adjusting reserve use according to future energy demands to allow, at least in the short term, seedling survival.

show abstract

Plant Responses to Sugar Starvation

Cited by 24 publications

References 172 publications

Melatonin redirects carbohydrates metabolism during sugar starvation in plant cells

Melatonin redirects carbohydrates metabolism during sugar starvation in plant cells

Regulatory roles of sugars in plant growth and development

Regulation of reserve mobilisation in sunflower during late seedling establishment in continuous darkness

Contact Info

Product

Resources

About