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Translocation of phospholipase A2α to apoplasts is modulated by developmental stages and bacterial infection in Arabidopsis.

Jung J, Kumar K, Lee HY, Park YI, Cho HT, Ryu SB - Front Plant Sci (2012)

Bottom Line: The present study shows that PLA(2)α possesses unique characteristics in terms of spatiotemporal subcellular localization, as compared with the other paralogs that remain in the ER and/or Golgi apparatus during secretory processes.When Pseudomonas syringae pv.~tomato DC3000 carrying the avirulent factor avrRpm1 infects the apoplasts of host plants, PLA(2)α rapidly translocates to the apoplasts where bacteria attempt to become established.It would be interesting to investigate if PLA(2)α functions in plant defense responses at apoplasts where secreted PLA(2)α confronts with invading pathogens.

View Article: PubMed Central - PubMed

Affiliation: Environmental Biotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea.

ABSTRACT
Phospholipase A(2) (PLA(2)) hydrolyzes phospholipids at the sn-2 position to yield lysophospholipids and free fatty acids. Of the four paralogs expressed in Arabidopsis, the cellular functions of PLA(2)α in planta are poorly understood. The present study shows that PLA(2)α possesses unique characteristics in terms of spatiotemporal subcellular localization, as compared with the other paralogs that remain in the ER and/or Golgi apparatus during secretory processes. Only PLA(2)α is secreted out to extracellular spaces, and its secretion to apoplasts is modulated according to the developmental stages of plant tissues. Observation of PLA(2)α-RFP transgenic plants suggests that PLA(2)α localizes mostly at the Golgi bodies in actively growing leaf tissues, but is gradually translocated to apoplasts as the leaves become mature. When Pseudomonas syringae pv.~tomato DC3000 carrying the avirulent factor avrRpm1 infects the apoplasts of host plants, PLA(2)α rapidly translocates to the apoplasts where bacteria attempt to become established. PLA(2)α promoter::GUS assays show that PLA(2)α gene expression is controlled in a developmental stage- and tissue-specific manner. It would be interesting to investigate if PLA(2)α functions in plant defense responses at apoplasts where secreted PLA(2)α confronts with invading pathogens.

No MeSH data available.


Related in: MedlinePlus

Translocation of PLA2α to apoplasts was enhanced by the inoculation of bacteria, Pst-avrRpm1, in pre-mature young leaves.(A–C) Images showing increased fluorescence intensity and vesicle sizes followed by the translocation of PLA2α to apoplasts at 3 h post-inoculation of Pst-avrRpm1 (C) compared to the no-treatment control (A) and 0.015% Silwet/10 mM MgCl2-treated mock (B) in pre-mature young leaves where PLA2α is normally localized primarily in Golgi bodies. Fluorescent (top), bright field (middle), and merged images (bottom) are presented. Bars = 20 μm.
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Figure 4: Translocation of PLA2α to apoplasts was enhanced by the inoculation of bacteria, Pst-avrRpm1, in pre-mature young leaves.(A–C) Images showing increased fluorescence intensity and vesicle sizes followed by the translocation of PLA2α to apoplasts at 3 h post-inoculation of Pst-avrRpm1 (C) compared to the no-treatment control (A) and 0.015% Silwet/10 mM MgCl2-treated mock (B) in pre-mature young leaves where PLA2α is normally localized primarily in Golgi bodies. Fluorescent (top), bright field (middle), and merged images (bottom) are presented. Bars = 20 μm.

Mentions: As leaves become mature, PLA2α is secreted into the apoplast, where it generates its lipid products, lysophospholipids and free fatty acids. The lipid products have been suggested to function as bio-active molecules that mediate a variety of cellular processes. Apoplasts are an important site for the interaction of plant cell defense mechanisms with invading bacteria, which attempt to become established in the apoplasts. If PLA2α positively participates in defense responses to pathogen attack, we hypothesized that its translocation to the apoplasts would be enhanced when pathogens are inoculated. As speculated, the translocation of PLA2α to the apoplasts was enhanced at 3 h post-inoculation of avirulent bacteria, Pst-avrRpm1, in young leaves (Figure 4C) and in close-to-mature leaves (Figure 5C), as compared to non-treated controls (NT) and 0.015% Silwet/10 mM MgCl2-treated mocks (Figures 4A,B and 5A,B).


Translocation of phospholipase A2α to apoplasts is modulated by developmental stages and bacterial infection in Arabidopsis.

Jung J, Kumar K, Lee HY, Park YI, Cho HT, Ryu SB - Front Plant Sci (2012)

Translocation of PLA2α to apoplasts was enhanced by the inoculation of bacteria, Pst-avrRpm1, in pre-mature young leaves.(A–C) Images showing increased fluorescence intensity and vesicle sizes followed by the translocation of PLA2α to apoplasts at 3 h post-inoculation of Pst-avrRpm1 (C) compared to the no-treatment control (A) and 0.015% Silwet/10 mM MgCl2-treated mock (B) in pre-mature young leaves where PLA2α is normally localized primarily in Golgi bodies. Fluorescent (top), bright field (middle), and merged images (bottom) are presented. Bars = 20 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3376726&req=5

Figure 4: Translocation of PLA2α to apoplasts was enhanced by the inoculation of bacteria, Pst-avrRpm1, in pre-mature young leaves.(A–C) Images showing increased fluorescence intensity and vesicle sizes followed by the translocation of PLA2α to apoplasts at 3 h post-inoculation of Pst-avrRpm1 (C) compared to the no-treatment control (A) and 0.015% Silwet/10 mM MgCl2-treated mock (B) in pre-mature young leaves where PLA2α is normally localized primarily in Golgi bodies. Fluorescent (top), bright field (middle), and merged images (bottom) are presented. Bars = 20 μm.
Mentions: As leaves become mature, PLA2α is secreted into the apoplast, where it generates its lipid products, lysophospholipids and free fatty acids. The lipid products have been suggested to function as bio-active molecules that mediate a variety of cellular processes. Apoplasts are an important site for the interaction of plant cell defense mechanisms with invading bacteria, which attempt to become established in the apoplasts. If PLA2α positively participates in defense responses to pathogen attack, we hypothesized that its translocation to the apoplasts would be enhanced when pathogens are inoculated. As speculated, the translocation of PLA2α to the apoplasts was enhanced at 3 h post-inoculation of avirulent bacteria, Pst-avrRpm1, in young leaves (Figure 4C) and in close-to-mature leaves (Figure 5C), as compared to non-treated controls (NT) and 0.015% Silwet/10 mM MgCl2-treated mocks (Figures 4A,B and 5A,B).

Bottom Line: The present study shows that PLA(2)α possesses unique characteristics in terms of spatiotemporal subcellular localization, as compared with the other paralogs that remain in the ER and/or Golgi apparatus during secretory processes.When Pseudomonas syringae pv.~tomato DC3000 carrying the avirulent factor avrRpm1 infects the apoplasts of host plants, PLA(2)α rapidly translocates to the apoplasts where bacteria attempt to become established.It would be interesting to investigate if PLA(2)α functions in plant defense responses at apoplasts where secreted PLA(2)α confronts with invading pathogens.

View Article: PubMed Central - PubMed

Affiliation: Environmental Biotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea.

ABSTRACT
Phospholipase A(2) (PLA(2)) hydrolyzes phospholipids at the sn-2 position to yield lysophospholipids and free fatty acids. Of the four paralogs expressed in Arabidopsis, the cellular functions of PLA(2)α in planta are poorly understood. The present study shows that PLA(2)α possesses unique characteristics in terms of spatiotemporal subcellular localization, as compared with the other paralogs that remain in the ER and/or Golgi apparatus during secretory processes. Only PLA(2)α is secreted out to extracellular spaces, and its secretion to apoplasts is modulated according to the developmental stages of plant tissues. Observation of PLA(2)α-RFP transgenic plants suggests that PLA(2)α localizes mostly at the Golgi bodies in actively growing leaf tissues, but is gradually translocated to apoplasts as the leaves become mature. When Pseudomonas syringae pv.~tomato DC3000 carrying the avirulent factor avrRpm1 infects the apoplasts of host plants, PLA(2)α rapidly translocates to the apoplasts where bacteria attempt to become established. PLA(2)α promoter::GUS assays show that PLA(2)α gene expression is controlled in a developmental stage- and tissue-specific manner. It would be interesting to investigate if PLA(2)α functions in plant defense responses at apoplasts where secreted PLA(2)α confronts with invading pathogens.

No MeSH data available.


Related in: MedlinePlus