A simple high efficiency and low cost in vitro growth system for phenotypic characterization and seed propagation of Arabidopsis thaliana

Background Arabidopsis research relies extensively on the use of in vitro growth for phenotypic analysis of the seedlings and characterization of plant responses to intrinsic and extrinsic cues. For this purpose, stress-free optimal growth conditions should be set up and used as a reference especially in studies aimed at characterizing the plant responses to abiotic and biotic stresses. Currently used standard in vitro protocols for growth and characterization of Arabidopsis thaliana plants often suffer from sub-optimal composition due to an excessively high nutritional content which represents a stress per se and an experimental bias.

Results We describe a simple protocol for in vitro growth of Arabidopsis plants in which the phenotypic analysis is based on an optimized and nutritionally balanced culture medium. We show that the protocol is robustly applicable for growth of several Arabidopsis mutants, including mutants lacking the root system. This protocol enables rapid high scale seed production in vitro avoiding soil usage while saving space and time. The optimized in vitro protocol aims at: 1) making in vitro growth as close as possible to natural soil conditions by optimizing nutrient balance in the medium; 2) simplifying phenotypic and molecular investigation of individual plants by standardizing all steps of plant growth; 3) enabling seeds formation also in genotypes with severe defect in the root system; 4) minimizing the amount of waste and space for plant growth by avoiding soil usage.

Conclusions Here we report an optimized protocol for optimal growth of Arabidopsis thaliana plants to avoid biases in phenotypic observation of abiotic/biotic stress experiments. The protocol also enables the completion of the whole life cycle in vitro within 40-45 days and a satisfactory seed set for further propagation with no need for facilities for plant growth in soil and seed sterilisation.