Optimisation strategies for sustainable molecular farming

Molecular farming is a rapidly developing field of modern plant biotechnology that can provide industrial-scale support of biologically active therapeutics for medicine and veterinary. The review aimed to identify the main strategies for improvement of the efficiency of therapeutic protein production in plants. To achieve the aim, analyses of Scopus and PubMed databases, generalisation, and critical evaluation of data regarding to strategies enhancing the efficiency of therapeutic protein production in plants were conducted. Key criteria that should be covered in selection of a vector for transformation were identified. Super-binary or tertiary vectors are recommended to optimise the genetic transformation of recalcitrant species. For transient transformation, magnICON systems and geminivirus-based vectors were proposed. The ways to overcome plant recalcitrance to the in vitro culture and to the genetic transformation were reviewed. Methods such as overexpression of morphogenic genes (WOX, BBM) that increase the efficiency of regeneration were mentioned. The newest gene delivery systems for precise and accurate gene insertion were reviewed. Tissue-specific, inducible, or active at certain stages of plant development, promoters are recommended to increase the expression of target proteins. The study determined that protein stability can be increased by its targeting to cell compartments or co-expression with protease inhibitors. The study also established that correction of protein post-translational modifications can improve its biological activity. Reduction in toxic secondary metabolites of the host is also among the goals. The conclusions can be used to develop new strategies for optimisation of plant transformation, increasing the yield of recombinant protein, and improving its therapeutic efficacy