Limits...
Characterisation of Lipid Changes in Ethylene-Promoted Senescence and Its Retardation by Suppression of Phospholipase Dδ in Arabidopsis Leaves.

Jia Y, Li W - Front Plant Sci (2015)

Bottom Line: Lipid profiling revealed that ethylene caused a decrease in all lipids levels, except phosphatidic acid (PA), caused increases in the ratios of digalactosyl diglyceride/monogalactosyl diglyceride (MGDG) and phosphatidylcholine (PC)/phosphatidylethanolamine (PE), and caused degradation of plastidic lipids before that of extraplastidic lipids in wild-type plants.The accelerated degradation of plastidic lipids during ethylene-promoted senescence in wild-type plants was attenuated in PLDδ-KO plants.The integrity of the cell membrane in PLDδ-KO plants facilitated maintenance of the membrane function and of the proteins associated with the membrane.

View Article: PubMed Central - PubMed

Affiliation: Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences Kunming, China.

ABSTRACT
Ethylene and abscisic acid (ABA) both accelerate senescence of detached Arabidopsis leaves. We previously showed that suppression of Phospholipase Dδ (PLDδ) retarded ABA-promoted senescence. Here, we report that ethylene-promoted senescence is retarded in detached leaves lacking PLDδ. We further used lipidomics to comparatively profile the molecular species of membrane lipids between wild-type and PLDδ-knockout (PLDδ-KO) Arabidopsis during ethylene-promoted senescence. Lipid profiling revealed that ethylene caused a decrease in all lipids levels, except phosphatidic acid (PA), caused increases in the ratios of digalactosyl diglyceride/monogalactosyl diglyceride (MGDG) and phosphatidylcholine (PC)/phosphatidylethanolamine (PE), and caused degradation of plastidic lipids before that of extraplastidic lipids in wild-type plants. The accelerated degradation of plastidic lipids during ethylene-promoted senescence in wild-type plants was attenuated in PLDδ-KO plants. No obvious differences in substrate and product of PLDδ-catalyzed phospholipid hydrolysis were detected between wild-type and PLDδ-KO plants, which indicated that the retardation of ethylene-promoted senescence by suppressing PLDδ might not be related to the role of PLDδ in catalyzing phospholipid degradation. In contrast, higher plastidic lipid content, especially of MGDG, in PLDδ-KO plants was crucial for maintaining photosynthetic activity. The lower relative content of PA and higher PC/PE ratio in PLDδ-KO plants might contribute to maintaining cell membrane integrity. The integrity of the cell membrane in PLDδ-KO plants facilitated maintenance of the membrane function and of the proteins associated with the membrane. Taking these findings together, higher plastidic lipid content and the integrity of the cell membrane in PLDδ-KO plants might contribute to the retardation of ethylene-promoted senescence by the suppression of PLDδ.

No MeSH data available.


Related in: MedlinePlus

Hierarchical clustering analysis of lipid molecular species during ethylene-promoted senescence. Absolute (nmol/mg dry weight) (left) and relative levels (mol%) of lipid molecular species (right). The color of each bar represents the abundance of the corresponding lipid species. Expression is shown as the relative change from the mean center of each lipid species. Lipid species in the indicated lipid classes were organized using class (as indicated), total acyl carbons (in ascending order within a class), and total double bonds (in ascending order within a class and number of total acyl carbons). Annotation: data of “#” column is from Jia et al. (2013).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4663248&req=5

Figure 2: Hierarchical clustering analysis of lipid molecular species during ethylene-promoted senescence. Absolute (nmol/mg dry weight) (left) and relative levels (mol%) of lipid molecular species (right). The color of each bar represents the abundance of the corresponding lipid species. Expression is shown as the relative change from the mean center of each lipid species. Lipid species in the indicated lipid classes were organized using class (as indicated), total acyl carbons (in ascending order within a class), and total double bonds (in ascending order within a class and number of total acyl carbons). Annotation: data of “#” column is from Jia et al. (2013).

Mentions: As an overview, most lipid species changed dramatically in terms of both their level (absolute value; Figure 2, left) and the composition (relative value; Figure 2, right) during ethylene-promoted senescence in the leaves of both genotypes of Arabidopsis. The levels of most lipids declined in both WS and PLDδ-KO leaves, although there were some differences in the profiles of membrane lipids between plants of the two genotypes during ethylene-promoted senescence (Figure 2). Clustering of the lipid contents of leaves in ethylene-promoted senescence suggested that the ethylene treatment was the main factor inducing the degradation of membrane lipids. The differences between WS and PLDδ-KO leaves subjected to ethylene treatment were greater than those between WS and PLDδ-KO leaves without such treatment (Figure 2). These results suggest that ethylene treatment affected lipid degradation, and that PLDδ participated in this lipid degradation during ethylene-promoted senescence.


Characterisation of Lipid Changes in Ethylene-Promoted Senescence and Its Retardation by Suppression of Phospholipase Dδ in Arabidopsis Leaves.

Jia Y, Li W - Front Plant Sci (2015)

Hierarchical clustering analysis of lipid molecular species during ethylene-promoted senescence. Absolute (nmol/mg dry weight) (left) and relative levels (mol%) of lipid molecular species (right). The color of each bar represents the abundance of the corresponding lipid species. Expression is shown as the relative change from the mean center of each lipid species. Lipid species in the indicated lipid classes were organized using class (as indicated), total acyl carbons (in ascending order within a class), and total double bonds (in ascending order within a class and number of total acyl carbons). Annotation: data of “#” column is from Jia et al. (2013).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4663248&req=5

Figure 2: Hierarchical clustering analysis of lipid molecular species during ethylene-promoted senescence. Absolute (nmol/mg dry weight) (left) and relative levels (mol%) of lipid molecular species (right). The color of each bar represents the abundance of the corresponding lipid species. Expression is shown as the relative change from the mean center of each lipid species. Lipid species in the indicated lipid classes were organized using class (as indicated), total acyl carbons (in ascending order within a class), and total double bonds (in ascending order within a class and number of total acyl carbons). Annotation: data of “#” column is from Jia et al. (2013).
Mentions: As an overview, most lipid species changed dramatically in terms of both their level (absolute value; Figure 2, left) and the composition (relative value; Figure 2, right) during ethylene-promoted senescence in the leaves of both genotypes of Arabidopsis. The levels of most lipids declined in both WS and PLDδ-KO leaves, although there were some differences in the profiles of membrane lipids between plants of the two genotypes during ethylene-promoted senescence (Figure 2). Clustering of the lipid contents of leaves in ethylene-promoted senescence suggested that the ethylene treatment was the main factor inducing the degradation of membrane lipids. The differences between WS and PLDδ-KO leaves subjected to ethylene treatment were greater than those between WS and PLDδ-KO leaves without such treatment (Figure 2). These results suggest that ethylene treatment affected lipid degradation, and that PLDδ participated in this lipid degradation during ethylene-promoted senescence.

Bottom Line: Lipid profiling revealed that ethylene caused a decrease in all lipids levels, except phosphatidic acid (PA), caused increases in the ratios of digalactosyl diglyceride/monogalactosyl diglyceride (MGDG) and phosphatidylcholine (PC)/phosphatidylethanolamine (PE), and caused degradation of plastidic lipids before that of extraplastidic lipids in wild-type plants.The accelerated degradation of plastidic lipids during ethylene-promoted senescence in wild-type plants was attenuated in PLDδ-KO plants.The integrity of the cell membrane in PLDδ-KO plants facilitated maintenance of the membrane function and of the proteins associated with the membrane.

View Article: PubMed Central - PubMed

Affiliation: Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences Kunming, China.

ABSTRACT
Ethylene and abscisic acid (ABA) both accelerate senescence of detached Arabidopsis leaves. We previously showed that suppression of Phospholipase Dδ (PLDδ) retarded ABA-promoted senescence. Here, we report that ethylene-promoted senescence is retarded in detached leaves lacking PLDδ. We further used lipidomics to comparatively profile the molecular species of membrane lipids between wild-type and PLDδ-knockout (PLDδ-KO) Arabidopsis during ethylene-promoted senescence. Lipid profiling revealed that ethylene caused a decrease in all lipids levels, except phosphatidic acid (PA), caused increases in the ratios of digalactosyl diglyceride/monogalactosyl diglyceride (MGDG) and phosphatidylcholine (PC)/phosphatidylethanolamine (PE), and caused degradation of plastidic lipids before that of extraplastidic lipids in wild-type plants. The accelerated degradation of plastidic lipids during ethylene-promoted senescence in wild-type plants was attenuated in PLDδ-KO plants. No obvious differences in substrate and product of PLDδ-catalyzed phospholipid hydrolysis were detected between wild-type and PLDδ-KO plants, which indicated that the retardation of ethylene-promoted senescence by suppressing PLDδ might not be related to the role of PLDδ in catalyzing phospholipid degradation. In contrast, higher plastidic lipid content, especially of MGDG, in PLDδ-KO plants was crucial for maintaining photosynthetic activity. The lower relative content of PA and higher PC/PE ratio in PLDδ-KO plants might contribute to maintaining cell membrane integrity. The integrity of the cell membrane in PLDδ-KO plants facilitated maintenance of the membrane function and of the proteins associated with the membrane. Taking these findings together, higher plastidic lipid content and the integrity of the cell membrane in PLDδ-KO plants might contribute to the retardation of ethylene-promoted senescence by the suppression of PLDδ.

No MeSH data available.


Related in: MedlinePlus