Senescence is the last phase of the plant life cycle and has an important role in plant development. The senescence process takes place in a highly regulated manner and the cell constituents are dismantled in an ordered progression. Degradation of membrane lipids is an essential process during leaf senescence. Nonetheless, little is known about the role of lipolytic enzymes in mediating specific changes in membrane lipids and how these changes affect membrane deterioration.
To address these problems, Dr JIA Yanxia from LI Weiqi’s group in Kunming Institute of Botany, comparatively analyzed the morphology, physiology, biochemistry and metabolic of membrane lipids in wiled-type and phospholipase Dδ-knockout (PLDδ-KO) Arabidopsis leaves. Lipidomic analysis based on electrospray tandem mass spectrometry (ESI-MS/MS) enabled comparative profiling of 125 molecular species of eight membrane lipid classes in wild-type Arabidopsis and Arabidopsis plant without PLDδ before and after detachment-induced and ABA-promoted senescence. Lipid profiling revealed that detachment-induced senescence had different effects on plastidic and extraplastidic lipids. The accelerated degradation of plastidic lipids during ABA-induced senescence in wile-type plants was attenuated in PLDδ-KO plants. Dramatic increases in phosphatidic acid (PA) and decreases in phosphatidylcholine (PC) during ABA-induced senescence were also suppressed in PLDδ-KO plants. The attenuation of PA formation resulting from suppression of PLDδ blocks the degradation of membrane lipids, which retards ABA-promoted senescence.
This work “Lipid Profiling Demonstrates that Suppressing Arabidopsis Phospholipase Dd Retards ABA-promoted Leaf Senescence by Attenuating Lipid Degradation” has been published in PLOS ONE (http://dx.plos.org/10.1371/journal.pone.0065687).
Hierarchal clustering analysis of lipid molecular species during detachment-induced and ABA-promoted senescence.（A. absolute levels，B. relative levels）
The effect of butanol and NAE on ABA-promoted leaf senescence
