title: High CO2 concentration as an inductor agent to drive production of recombinant phytotoxic antimicrobial peptides in plant biofactories.
abstract: Cationic α-helical antimicrobial peptides such as BP100 are of increasing interest for developing novel phytosanitary or therapeutic agents and products with industrial applications. Biotechnological production of these peptides in plants can be severely impaired due to the toxicity exerted on the host by high-level expression. This can be overcome by using inducible promoters with extremely low activity throughout plant development, although the yields are limited. We examined the use of modified atmospheres using the increased levels of [CO2], commonly used in the food industry, as the inductor agent to biotechnologically produce phytotoxic compounds with higher yields. Here we show that 30% [CO2] triggered a profound transcriptional response in rice leaves, including a change in the energy provision from photosynthesis to glycolysis, and the activation of stress defense mechanisms. Five genes with central roles in up-regulated pathways were initially selected and their promoters successfully used to drive the expression of phytotoxic BP100 in genetically modified (GM) rice. GM plants had a normal phenotype on development and seed production in non-induction conditions. Treatment with 30 % [CO2] led to recombinant peptide accumulation of up to 1 % total soluble protein when the Os.hb2 promoter was used. This is within the range of biotechnological production of other peptides in plants. Using BP100 as a proof-of-concept we demonstrate that very high [CO2] can be considered an economically viable strategy to drive production of recombinant phytotoxic antimicrobial peptides in plant biofactories.
authors.affiliation: Institute for Agricultural and Food Technology (INTEA), University of Girona, Campus Montilivi s/n, 17071, Girona, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Ruiz
authors.affiliation: Institute for Agricultural and Food Technology (INTEA), University of Girona, Campus Montilivi s/n, 17071, Girona, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Pla
authors.affiliation: Institute for Agricultural and Food Technology (INTEA), University of Girona, Campus Montilivi s/n, 17071, Girona, Spain.
authors.forename: Nuri
authors.initials: N
authors.lastname: Company
authors.affiliation: Institute for Agrifood Research and Technology (IRTA), Ctra. de Cabrils Km 2, 08348, Cabrils, Barcelona, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Riudavets
authors.affiliation: Institute for Agricultural and Food Technology (INTEA), University of Girona, Campus Montilivi s/n, 17071, Girona, Spain. anna.nadal@udg.edu.
authors.forename: Anna
authors.initials: A
authors.lastname: Nadal
mesh_terms: D023181:Antimicrobial Cationic Peptides / Q000235:genetics / Q000378:metabolism*; D002245:Carbon Dioxide / Q000494:pharmacology*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D020411:Oligonucleotide Array Sequence Analysis; D012275:Oryza / Q000187:drug effects* / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D060888:Real-Time Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D023181:Antimicrobial Cationic Peptides; D010940:Plant Proteins; D011994:Recombinant Proteins; D002245:Carbon Dioxide
keywords: BP100; CO2 modified atmosphere; Genetically modified plant; Inducible promoter; Phytotoxic peptide; Transcriptome