Programmed cell death features in apple suspension cells under low oxygen culture.
Suspension-cultured apple fruit cells (Malus pumila Mill. cv. Braeburn) were exposed to a low oxygen atmosphere to test whether programmed cell death (PCD) has a role in cell dysfunction and death under hypoxic conditions. Protoplasts were prepared at various times after low oxygen conditions were established, and viability tested by triple staining with fluorescein diacetate (FDA), propidium iodide (PI) and Hoechst33342 (HO342). DNA breakdown and phosphatidylserine exposure on the plasma membrane were observed using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), and annexin V binding. About 30% of protoplasts from cells after 48 h under low oxygen showed an increased accumulation of HO342, indicating increased membrane permeability. Positive TUNEL and annexin V results were also only obtained with protoplasts from cells under low oxygen. The results suggest that apple cell death under low oxygen is at least partially PCD mediated, and may explain tissue breakdown under controlled atmosphere (low oxygen) conditions in apple fruit.
Xu
Chang-jie
CJ
Laboratory of Fruit Molecular Physiology and Biotechnology/The State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development & Biotechnology, Zhejiang University, Hangzhou 310029, China. chjxu@zju.edu.cn
Chen
Kun-song
KS
Ferguson
Ian B
IB
D000222:Adaptation, Physiological / Q000502:physiology; D017209:Apoptosis / Q000502:physiology*; D015687:Cell Hypoxia / Q000502:physiology*; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D004249:DNA Damage / Q000502:physiology; D005638:Fruit / Q000502:physiology*; D027845:Malus / Q000502:physiology*; D010100:Oxygen / Q000378:metabolism*
D010100:Oxygen