Rhamnolipids induce oxidative stress responses in cherry tomato fruit to Alternaria alternata.
BACKGROUND
Rhamnolipids showed an antimicrobial activity applicable to a variety of pathogenic microorganisms, but mechanisms were mostly focused on their direct inhibitory effect.


RESULTS
This study showed that disease incidence obviously decreased when cherry tomatoes were treated with rhamnolipids, whether before or after Alternaria alternata inoculation. The activities of antioxidant enzymes, including superoxide dismutase and catalase, were increased in rhamnolipid-pretreated cherry tomato inoculated with A. alternata within 12 h, while contents of reactive oxygen species decreased. Moreover, resistant response of cherry tomato treated with rhamnolipids and A. alternata was also attributed to activity stimulation of ascorbate peroxidase and glutathione reductase, accompanied with an increase in reduced glutathione, which is beneficial for scavenging excessive H2 O2 .


CONCLUSIONS
Results indicated that rhamnolipids could effectively reduce fungal disease of harvested cherry tomato by inducing fruit resistance and mechanisms involved in elicitation of antioxidative reactions such as the ability to scavenge excess reactive oxygen species. © 2015 Society of Chemical Industry.
Department of Food Science and Nutrition, Zhejiang University, Hangzhou, China.|Zhejiang Key Laboratory for Agro-food Processing, Zhejiang University, Hangzhou, China.|Fuli Institute of Food Science, Zhejiang University, Hangzhou, China.
Fujie
F
Yan
Department of Food Science and Nutrition, Zhejiang University, Hangzhou, China.|Zhejiang Key Laboratory for Agro-food Processing, Zhejiang University, Hangzhou, China.|Fuli Institute of Food Science, Zhejiang University, Hangzhou, China.
Hao
H
Hu
Department of Food Science and Nutrition, Zhejiang University, Hangzhou, China.|Zhejiang Key Laboratory for Agro-food Processing, Zhejiang University, Hangzhou, China.|Fuli Institute of Food Science, Zhejiang University, Hangzhou, China.
Laifeng
L
Lu
Department of Food Science and Nutrition, Zhejiang University, Hangzhou, China.|Zhejiang Key Laboratory for Agro-food Processing, Zhejiang University, Hangzhou, China.|Fuli Institute of Food Science, Zhejiang University, Hangzhou, China.
Xiaodong
X
Zheng
D000528:Alternaria / Q000254:growth & development*; D005516:Food Microbiology; D005638:Fruit / Q000378:metabolism / Q000382:microbiology; D005659:Fungicides, Industrial; D006017:Glycolipids; D006861:Hydrogen Peroxide / Q000378:metabolism; D018551:Solanum lycopersicum / Q000378:metabolism / Q000382:microbiology*; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000378:metabolism
D005659:Fungicides, Industrial; D006017:Glycolipids; D017382:Reactive Oxygen Species; C418382:rhamnolipid; D006861:Hydrogen Peroxide
Alternaria alternata; cherry tomatoes; post-harvest control; resistant responses; rhamnolipids