A new strategy to protect flowers from freezing stress
Liao Pan (廖攀 ), Chen Qin-Fang (陳琴芳 ),
Chye Mee-Len (蔡美蓮 )Wilson & Amelia Wong Professor in Plant Biotechnology
黃乾利辛烱僖基金教授席 ( 植物生物技術學 )
School of Biological Sciences,
The University of Hong Kong
http://pcp.oxfordjournals.org/content/early/2014/02/19/pcp.pcu0371
Significance: flowers develop into fruits and seeds (food)
Fruit crops Flowers Damaged flowersProtected Freeze-damaged
FOOD LOSS
ACYL-COA-BINDING PROTEIN6 (ACBP6)
( 醯基輔酶 A結合蛋白 6)
• A cold-inducible protein
• Expressed in both rosettes and flowers
• Rosettes = vegetative tissues
• Flowers = reproductive tissues
Chen et al., 2008, Plant Physiol 148: 304-315
Arabidopsis
Chye et al (2013) US Patent No. 8,378,172
ACBP6 overexpression in transgenic Arabidopsis (轉基因擬南芥 )
enhances freezing tolerance in rosettes
Rosettes
OE = overexpression lines; 3 OE lines were used to test reproducibility of results
Freezing treatment on Arabidopsis flowers
Flowers
Wild type (WT)
ACBP6-overexpressors
(OE)
4oC 3 days1
-7oC 1 hour2
4oC 12 hours
3
4Harvest flower samples
ACBP6-overexpressing flowers are freeze-tolerant
Transformed Arabidopsis flower
overexpressing ACBP6 (ACBP6-OE)
shows intact petals (right)
while
the control succumbs to freezing stress (left).
Liao et al. 2014, Plant & Cell Physiol
54% 86% flowers with intact petals
(-7oC 1 hour)
Why are ACBP6-OE flowers freezing tolerant?
PC increases membrane fluidity
After freezing treatment,
phosphatidylcholine (PC) (卵磷脂 )
accumulates (25-34% > WT)
increasing membrane fluidity,
enhancing freezing tolerance.
Liao et al. 2014, Plant & Cell Physiol
Liao et al., 2014, Plant & Cell Physiol
WT OE-3 OE-5
MGDG 29.6 ± 1.33 39.6 ± 0.53 36.0 ± 2.95
Plastid-specific membrane galactolipids (nmol mg-1)質體特有的光合膜半乳糖脂(納摩爾每毫克)
Why are ACBP6-OE flowers freezing tolerant?
After freezing treatment,
Monogalactosyldiacylglycerol (MGDG) ( 單半乳糖二醯甘油酯 )
accumulates [(MGDGOE-MGDGWT)/MGDGWT = 22-34% > WT]
enhancing freezing tolerance.
ACBP6 can be used to protect flowers (besides rosettes) from freezing stress
Conclusion
Potential applications
Flower protection in
• agriculture (fruits, seeds)
• floriculture (cultivated blooms)
• cold region (citrus)
http://pcp.oxfordjournals.org/content/early/2014/02/19/pcp.pcu037
P Liao, Q Chen, ML Chye (2014) Transgenic Arabidopsis Flowers Overexpressing Acyl-CoA-Binding Protein
ACBP6 are Freezing Tolerant. Plant & Cell Physiology doi:10.1093/pcp/pcu037
US Patent No. 8,378,172
Research Output