Lipid metabolism during plant senescence

Thompson, John E.; Froese, Carol D.; Madey, Ewa; Smith, Matthew D.; Hong, Yuwen

doi:10.1016/s0163-7827(98)00006-x

Cited by 246 publications

(212 citation statements)

References 160 publications

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“…Previous finding also revealed that UV-B pre-treatment alleviated the wilting and leaf rolling induced by PEG treatment under the same conditions (Kovács et al, 2014) could be related to the alteration detected in the fatty acid composition of leaf PG. Changes in the PE fraction may have an adaptive role in counterbalancing the membrane-rigidifying effect of increased saturation (Thompson et al, 1998). The increased proportion of unsaturated fatty acids, especially 18:3, in the MGDG, DGDG and PG fractions in the roots of UV+PEG-treated plants resulted in a substantial increase in DBI in the PG and DGDG fractions, with an even more pronounced increase in the unsaturation of DGDG compared to that recorded when PEG or UV-B were applied alone.…”

Section: Discussionmentioning

confidence: 99%

Impact of UV-B on drought- or cadmium-induced changes in the fatty acid composition of membrane lipid fractions in wheat

Gondor

Szalai

Kovács

et al. 2014

Ecotoxicology and Environmental Safety

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Several reports have demonstrated the direct and indirect effects of UV-B radiation, an integral component of sunlight, on the plant growth and metabolism of various plant species, including a range of morphological, physiological and biochemical changes (Zlatev et al., 2012). However, as well as being a damaging agent UV-B also has an important role as a regulatory signal. The perception of and responses to UV-B by plants stimulate protective mechanisms, including the accumulation of UV-absorbing phenolic compounds and the modification of the biochemical composition (Jenkins, 2008). Under natural conditions plants are often subjected to multiple stress factors, so the impact of any particular stress may be aggravated or attenuated by the simultaneous action of another stressor. In a previous study it was demonstrated that UV-B radiation may have either a positive or negative impact under the same conditions in wheat, depending on the type of secondary abiotic stress factor: Cd or drought (Kovács et al., 2014). Supplemental UV-B light prevented the wilting and leaf rolling induced by PEG treatment. In contrast, combined UV-B and Cd treatment resulted in pronounced oxidative stress, which was manifested in the further enhancement of the leaf MDA content, root antioxidant enzyme activities and also root polyamine content compared to the effect of single stress factors, Cd or UV-B radiation (Kovács et al., 2014).The ability to adjust membrane lipid fluidity by changing the level of unsaturated fatty acids is a feature of stress-tolerant plants, resulting in an environment suitable for the function of critical integral proteins. Changes have been described in the total lipid content, in the saturation of the total lipids, in the ratio of the membrane lipid fractions, and in the fatty acid composition of individual membrane fractions during single abiotic stresses, such as drought (Zhong et al., 2011;Filek et al., 2012) or heavy metal (Pál et al., 2007;Bernat et al., 2014). Nevertheless, no reports have yet been published on the combined effect of either drought or Cd treatment and UV-B radiation on the fatty acid composition of the individual membrane fractions in wheat plants. Impact of UV-B on drought-or cadmium-induced changes in the fatty acid composition of membrane lipid fractions in wheat AbstractUV-B radiation may have either a positive or negative impact under the same conditions in wheat, depending on the type of secondary abiotic stressor: Cd or drought. Supplemental UV-B prevented the wilting and leaf rolling induced by PEG treatment. In contrast, combined UV-B and Cd treatment resulted in pronounced oxidative stress. The opposite effect of UV-B radiation in the case of drought or cadmium stress may be related to the alteration induced in the fatty acid composition. UV-B caused changes in the unsaturation of leaf phosphatidylglycerol fractions, and the accumulation of flavonoid in the leaves may prevent the stress induced by subsequent drought treatment. However it resulted in pronounced injury despite ...

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Section: Discussionmentioning

confidence: 99%

Impact of UV-B on drought- or cadmium-induced changes in the fatty acid composition of membrane lipid fractions in wheat

Gondor

Szalai

Kovács

et al. 2014

Ecotoxicology and Environmental Safety

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“…During senescence, many of the SAGs regulate the catabolic events such as protein, lipid and nucleic acid degradation that ultimately lead to cell death (Thompson et al 1998). However, this programmed cell death also coincides with a remobilization of nutrients (e.g.…”

Section: Role Of Plastoglobules During Leaf Senescencementioning

confidence: 99%

A mechanism implicating plastoglobules in thylakoid disassembly during senescence and nitrogen starvation

Besagni

Kessler

2012

Planta

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Plastoglobules are lipid droplets present in all plastid types. In chloroplasts, they are connected to the thylakoid membrane by the outer lipid half-bilayer. The plastoglobule core is composed of neutral lipids most prominently the prenylquinones, triacylglycerols, fatty acid phytyl esters but likely also unknown compounds. During stress and various developmental stages such as senescence, plastoglobule size and number increase due to the accumulation of lipids. However, their role is not limited to lipid storage. Indeed, the characterization of the plastoglobule proteome revealed the presence of enzymes. Importantly it has been demonstrated that these participate in isoprenoid lipid metabolic pathways at the plastoglobule, notably in the metabolism of prenylquinones. Recently, the characterization of two phytyl ester synthases has established a firm metabolic link between PG enzymatic activity and thylakoid disassembly during chloroplast senescence and nitrogen starvation.

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“…The hexokinase-mediated sugar signaling pathway has been suggested to regulate the initiation of senescence (Dai et al, 1999). Lipid degradation also accompanies the other characteristic catabolic processes of leaf senescence (Thompson et al, 1998), and is re¯ected by an increase in the expression of a lipase (At2g42690) and Phospholipase Da (Fan et al, 1997). It is most likely that lipid degradation is not just a symptom of the senescence process but may also act in regulating the progression of age-dependent senescence .…”

Section: Carbohydrate and Lipid Metabolismmentioning

confidence: 99%

“…The downregulation of a certain set of genes on the one hand, and the upregulation of others on the other hand, re¯ect not only the transition from autotrophic to heterotrophic metabolism, but also the induction of de novo synthesis of enzymes participating in the self-destruction process that eventually causes death. Among the prominent SAGs are genes responsible for the execution of the senescence syndrome encoding degradative enzymes: proteinases (Dangl et al, 2000;Lohman et al, 1994;Thompson et al, 1998Thompson et al, , 2000, lipases (Thompson et al, 1998, nucleases (Lers et al, 2001;Rubinstein, 2000), chlorophyllases (Jacob-Wilk et al, 1999), and enzymes for nutrient recycling such as glutamate synthase (Watanabe et al, 1994). Recently, a few senescence-associated regulatory genes have been identi®ed.…”

Section: Introductionmentioning

confidence: 99%

Large‐scale identification of leaf senescence‐associated genes

et al. 2003

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SummaryLeaf senescence is a form of programmed cell death, and is believed to involve preferential expression of a speci®c set of`senescence-associated genes' (SAGs). To decipher the molecular mechanisms and the predicted complex network of regulatory pathways involved in the senescence program, we have carried out a large-scale gene identi®cation study in a reference plant, Arabidopsis thaliana. Using suppression subtractive hybridization, we isolated approximately 800 cDNA clones representing SAGs expressed in senescing leaves. Differential expression was con®rmed by Northern blot analysis for 130 non-redundant genes. Over 70 of the identi®ed genes have not previously been shown to participate in the senescence process. SAGencoded proteins are likely to participate in macromolecule degradation, detoxi®cation of oxidative metabolites, induction of defense mechanisms, and signaling and regulatory events. Temporal expression pro®les of selected genes displayed several distinct patterns, from expression at a very early stage, to the terminal phase of the senescence syndrome. Expression of some of the novel SAGs, in response to age, leaf detachment, darkness, and ethylene and cytokinin treatment was compared. The large repertoire of SAGs identi®ed here provides global insights about regulatory, biochemical and cellular events occurring during leaf senescence.

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Lipid metabolism during plant senescence

Cited by 246 publications

References 160 publications

Impact of UV-B on drought- or cadmium-induced changes in the fatty acid composition of membrane lipid fractions in wheat

Impact of UV-B on drought- or cadmium-induced changes in the fatty acid composition of membrane lipid fractions in wheat

A mechanism implicating plastoglobules in thylakoid disassembly during senescence and nitrogen starvation

Large‐scale identification of leaf senescence‐associated genes

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