title: Two novel antimicrobial defensins from rice identified by gene coexpression network analyses.
abstract: Defensins form an antimicrobial peptides (AMP) family, and have been widely studied in various plants because of their considerable inhibitory functions. However, their roles in rice (Oryza sativa L.) have not been characterized, even though rice is one of the most important staple crops that is susceptible to damaging infections. Additionally, a previous study identified 598 rice genes encoding cysteine-rich peptides, suggesting there are several uncharacterized AMPs in rice. We performed in silico gene expression and coexpression network analyses of all genes encoding defensin and defensin-like peptides, and determined that OsDEF7 and OsDEF8 are coexpressed with pathogen-responsive genes. Recombinant OsDEF7 and OsDEF8 could form homodimers. They inhibited the growth of the bacteria Xanthomonas oryzae pv. oryzae, X. oryzae pv. oryzicola, and Erwinia carotovora subsp. atroseptica with minimum inhibitory concentration (MIC) ranging from 0.6 to 63μg/mL. However, these OsDEFs are weakly active against the phytopathogenic fungi Helminthosporium oryzae and Fusarium oxysporum f.sp. cubense. This study describes a useful method for identifying potential plant AMPs with biological activities.
authors.affiliation: Biotechnology Program, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand; Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand. Electronic address: supaluk.tan@student.chula.ac.th.
authors.forename: Supaluk
authors.initials: S
authors.lastname: Tantong
authors.affiliation: Department of Biology, Faculty of Science, Srinakharinwirot University, Bangkok 10110, Thailand. Electronic address: onanong@swu.ac.th.
authors.forename: Onanong
authors.initials: O
authors.lastname: Pringsulaka
authors.affiliation: Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand. Electronic address: wanich_oil@hotmail.com.
authors.forename: Kamonwan
authors.initials: K
authors.lastname: Weerawanich
authors.affiliation: Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand. Electronic address: a.meeprasert@gmail.com.
authors.forename: Arthitaya
authors.initials: A
authors.lastname: Meeprasert
authors.affiliation: Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand. Electronic address: thanyada.r@chula.ac.th.
authors.forename: Thanyada
authors.initials: T
authors.lastname: Rungrotmongkol
authors.affiliation: Department of Chemistry, Faculty of Science, Mahasarakham University, Mahasarakham 44150, Thailand. Electronic address: rakrudee.s@msu.ac.th.
authors.forename: Rakrudee
authors.initials: R
authors.lastname: Sarnthima
authors.affiliation: National Center for Genetic Engineering and Biotechnology (BIOTEC), Klong Luang, Pathumthani, 12120, Thailand. Electronic address: sittiruk@biotec.or.th.
authors.forename: Sittiruk
authors.initials: S
authors.lastname: Roytrakul
authors.affiliation: Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand; Omics Sciences and Bioinformatics Center, Chulalongkorn University, Bangkok 10330, Thailand. Electronic address: supaart.s@chula.ac.th.
authors.forename: Supaart
authors.initials: S
authors.lastname: Sirikantaramas
mesh_terms: D000890:Anti-Infective Agents / Q000302:isolation & purification; D003198:Computer Simulation; D003545:Cysteine / Q000235:genetics; D023082:Defensins / Q000235:genetics* / Q000302:isolation & purification; D005670:Fusarium / Q000235:genetics / Q000472:pathogenicity; D018506:Gene Expression Regulation, Plant; D006375:Helminthosporium / Q000235:genetics / Q000472:pathogenicity; D012275:Oryza / Q000235:genetics* / Q000382:microbiology; D010455:Peptides / Q000235:genetics* / Q000302:isolation & purification; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology / Q000517:prevention & control; D014974:Xanthomonas / Q000235:genetics / Q000472:pathogenicity
chemical_list: D000890:Anti-Infective Agents; D023082:Defensins; D010455:Peptides; D003545:Cysteine
keywords: Coexpression network analysis; Defensin; Recombinant peptide production; Rice