Development of a robust transient expression screening system in protoplasts of Cannabis

Transient expression systems in mesophyll protoplasts have been utilised in many plant species as an indispensable tool for gene function analysis and efficacious genome editing constructs. However, such a system has not been developed in Cannabis due to the recalcitrant nature of the plant to tissue culture as well as its illegal status for many years. In this study, young expanding leaves from aseptic in vitro Cannabis explants were used for protoplast isolation. Factorial designs were used to optimise variables in viable protoplast isolation and transient expression of GFP, with a range analyses performed to determine, and quantify, significantly impacting variables. Viable protoplast yields as high as 5.7 × 106 were achieved with 2.5% (w/v) Cellulase R-10, 0.3% (w/v) Macerozyme R-10 and 0.7 M mannitol, incubated for 16 h. As indicated by the transient expression of GFP, efficiency reached 23.2% with 30 μg plasmid, 50% PEG, 1 × 106 protoplasts and a transfection duration of 20 min. Application of the optimised protocol for protoplast isolation was successfully evaluated on three subsequent unrelated genotypes to highlight the robustness and broad applicability of the developed technique.

ISOLASI DAN KULTUR PROTOPLAS RUMPUT LAUT Kappaphycus alvarezii DI LABORATORIUM

Isolasi protoplas rumput laut K. alvarezii, telah dilakukan dalam rangka penyiapan protoplas untuk penyilangan melalui fusi protoplas. Metode yang digunakan antara lain melalui cara kimia dengan melisis tallus rumput laut dengan campuran enzim komersial, kemudian enzim yang berasal dari viscera keong mas baik yang segar maupun yang beku, dengan media kultur yang digunakan pada pemeliharaan makro algae antara lain Conwy, PES, dan air laut steril. Tallus rumput laut yang digunakan berasal dari bagian pangkal, tengah dan ujung. Protoplas yang hidup diuji menggunakan evans blue 0,1%, hormon perangsang tumbuh yang digunakan pada media pertumbuhan antara lain auxin, IAA, dan Kinetin. Pengamatan dilakukan terhadap jumlah protoplas hidup, pertumbuhan, dan sintasan. Hasil percobaan memperlihatkan bahwa enzim yang paling baik digunakan adalah campuran enzim komersial dengan media kultur Conwy dengan jumlah protoplas mencapai 19,8 x 106 sel/mL, bagian tallus yang paling baik adalah bagian pangkal berkisar antara 8,1x106 hingga 18,8 x 106 sel/ mL. Perangsang tumbuh yang paling baik adalah auxin. Filamen terbentuk setelah 5 hari dengan fotoperiod L:D=12:12.Isolation of seaweed’s protoplast Kappaphycus alvarezii had been done to provide protoplast for crossbreeding purpose by protoplast fusion. The method was chemically done by lyses of tallus used commercial enzyme mixture, enzyme from viscera of snail both fresh and frozen, culture media were Conwy (CW), PES, and sterile sea water (SSW) which were used to maintain the macro algae. Part of used tallus were upper, middle and tip of tallus. The viable protoplast was examined by using 0.1% evans blue and the growth-stimulating hormone were auxin, IAA, and Kinetin. Observation was concerned to the amount of viable protoplast, the growth, and the long live. Result showed that the best enzyme was commercial enzyme mixture with Conwy as the best culture media, provided protoplast until 19.8 x 106 cell/mL. The greatest protoplast content was in upper part of tallus, it could provide protoplast about 8.1 x 106 cell/mL until 18.8 x 106 cell/mL, and the best growth-stimulating hormone was auxin. Filament was formed after 5 days with photoperiod L: D=12:12.

SOME FACTORS AFFECTING ISOLATION OF MESOPHYLL PROTOPLASTS FROM APPLE (MALUS DOMESTICA BORKH CV. FUJI)

Experiments were conducted to investigate the factors influencing mesophyll protoplast isolation in `Fuji' apple. Half an hour pretreatment in 0.6M mannitol gave the highest protoplast yield.The enzyme solution containing 2% Cellulase Onozuka R-10 and 0.5% macrozyme R-10 with CPW 0.6M mannitol at pH 5.5 was most effective for protoplast isolation from leaf. Effective incubation time for the enzyme treatment was found to be 15-20 hrs at 25°C in the dark. Use of 1.0-2.0% PVP and 0.5mM MES was essential for higher yield and viability of protoplast. Supplementation of BA and IBA to the shoot culture media gave the higher yield of viable protoplast. From these protoplast, new cell walls were regenerated and 4 cell structures developed from one protoplast by cell division in K8P medium supplemented with 3A and NAA. Planting density higher than 10 protoplasts/ml was required for cell division from protoplast in liquid or 0.5% agarose culture.