title: Alpha-momorcharin, a RIP produced by bitter melon, enhances defense response in tobacco plants against diverse plant viruses and shows antifungal activity in vitro.
abstract: Alpha-momorcharin (α-MMC) is type-1 ribosome inactivating proteins (RIPs) with molecular weight of 29 kDa and has lots of biological activity. Our recent study indicated that the α-MMC purified from seeds of Momordica charantia exhibited distinct antiviral and antifungal activity. Tobacco plants pre-treated with 0.5 mg/mL α-MMC 3 days before inoculation with various viruses showed less-severe symptom and less reactive oxygen species (ROS) accumulation compared to that inoculated with viruses only. Quantitative real-time PCR analysis revealed that the replication levels of viruses were lower in the plants treated with the α-MMC than control plants at 15 days post inoculation. Moreover, the coat protein expression of viruses was almost completely inhibited in plants which were treated with the α-MMC compared with control plants. Furthermore, the SA-responsive defense-related genes including non-expressor of pathogenesis-related genes 1 (NPR1), PR1, PR2 were up-regulated and activities of some antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) were increased after the α-MMC treatment. In addition, the α-MMC (500 μg/mL) revealed remarkable antifungal effect against phytopathogenic fungi, in the growth inhibition range 50.35-67.21 %, along with their MIC values ranging from 100 to 500 μg/mL. The α-MMC had also a strong detrimental effect on spore germination of all the tested plant pathogens along with concentration as well as time-dependent kinetic inhibition of Sclerotinia sclerotiorum. The α-MMC showed a remarkable antiviral and antifungal effect and hence could possibly be exploited in crop protection for controlling certain important plant diseases.
authors.affiliation: Ministry of Education Key Laboratory for Bio-Resource and Eco-Environment, College of Life Science, Sichuan University, Chengdu 610064, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhu
authors.forename: Ping
authors.initials: P
authors.lastname: Zhang
authors.forename: Yan-Fa
authors.initials: YF
authors.lastname: Meng
authors.forename: Fei
authors.initials: F
authors.lastname: Xu
authors.forename: Da-Wei
authors.initials: DW
authors.lastname: Zhang
authors.forename: Jian
authors.initials: J
authors.lastname: Cheng
authors.forename: Hong-Hui
authors.initials: HH
authors.lastname: Lin
authors.forename: De-Hui
authors.initials: DH
authors.lastname: Xi
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D001203:Ascomycota / Q000187:drug effects / Q000254:growth & development; D001234:Aspergillus niger / Q000187:drug effects / Q000254:growth & development; D001236:Aspergillus oryzae / Q000187:drug effects / Q000254:growth & development; D015153:Blotting, Western; D036022:Capsid Proteins / Q000235:genetics; D002374:Catalase / Q000378:metabolism; D060467:Disease Resistance / Q000187:drug effects* / Q000235:genetics; D005670:Fusarium / Q000187:drug effects / Q000254:growth & development; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D015967:Gene Expression Regulation, Viral / Q000187:drug effects; D054884:Host-Pathogen Interactions / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D029777:Momordica charantia / Q000737:chemistry; D009195:Peroxidase / Q000378:metabolism; D010935:Plant Diseases / Q000235:genetics / Q000821:virology; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000821:virology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D010942:Plant Viruses / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D054788:Ribosome Inactivating Proteins / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism* / Q000821:virology; D014779:Virus Replication / Q000187:drug effects / Q000235:genetics
chemical_list: D000935:Antifungal Agents; D036022:Capsid Proteins; D010940:Plant Proteins; D017382:Reactive Oxygen Species; C039582:MMC protein, Momordica charantia; D002374:Catalase; D009195:Peroxidase; D013482:Superoxide Dismutase; D054788:Ribosome Inactivating Proteins