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Direct Observation and Automated Measurement of Stomatal Responses to Pseudomonas syringae pv. tomato DC3000 in Arabidopsis thaliana
Published on: February 9, 2024
Programmed cell death occurs asymmetrically during abscission in tomato.
Tal Bar-Dror1, Marina Dermastia, Ales Kladnik
1Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250, Israel.
The Plant Cell
|December 1, 2011
Summary
Programmed cell death (PCD) is essential for plant abscission, occurring asymmetrically within the abscission zone (AZ). The LX ribonuclease plays a key role in this PCD process, influencing the timing of leaf and flower drop.
Area of Science:
- Plant Biology
- Molecular Biology
- Developmental Biology
Background:
- Abscission is a natural developmental process in plants occurring in the abscission zone (AZ).
- Previous research indicated a delay in tomato leaf abscission when LX ribonuclease (LX) was inhibited.
- LX's known association with programmed cell death (PCD) suggested PCD's involvement in abscission.
Purpose of the Study:
- To identify hallmarks of PCD in tomato leaf and flower AZs during abscission.
- To investigate the role of PCD and LX in the abscission process.
- To examine the spatial expression patterns of PCD-related genes and their asymmetry within the AZ.
Main Methods:
- Observation of PCD hallmarks (cell viability, nuclear morphology, DNA fragmentation, ROS, enzyme activity, gene expression) in tomato AZs.
- Overexpression of antiapoptotic proteins to assess their effect on abscission.
- Visualization of PCD, LX, and nuclease gene expression in AZ tissues.
- Analysis of asymmetric gene expression related to cell wall hydrolysis and ethylene biosynthesis.
Main Results:
- Hallmarks of PCD were identified in tomato leaf and flower AZs during abscission.
- Overexpression of antiapoptotic proteins retarded abscission, confirming PCD's requirement.
- PCD, LX, and nuclease gene expression showed asymmetric localization within the AZ, primarily in distal tissues.
- Genes involved in cell wall hydrolysis and ethylene biosynthesis also exhibited asymmetric expression patterns.
Conclusions:
- Programmed cell death (PCD) is a critical, asymmetric mechanism during normal plant abscission.
- The LX ribonuclease is important for PCD during abscission.
- Differential gene expression between proximal and distal AZ sides contributes to asymmetric abscission processes.
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