Genetic modification of plants is hampered by the limited capacity of plant cells to regenerate. The current invention solves this problem by introducing or increasing the expression of a histidine kinase in a plant cell. Preferred histidine kinases are at least one of CHK2, CHK3 and CHK4. The invention therefore concerns a method for improving a cytokinin-induced regeneration capacity of a plant cell, wherein the method comprises a step of increasing or introducing the expression of a histidine kinase in the plant cell. The invention further pertains to a method for regenerating a plant, wherein the method comprises a step of introducing or increasing the expression of a histidine kinase and to a plant obtainable from such method. Moreover, the method concerns the use of at least one of CHK2, CHK3 and CHK4 for improving a cytokinin-induced regeneration capacity of a plant.

Genetic modification of plants is hampered by the limited capacity of plant cells to regenerate. The current invention solves this problem by introducing or increasing the expression of a histidine kinase in a plant cell. Preferred histidine kinases are at least one of CHK2, CHK3 and CHK4. The invention therefore concerns a method for improving a cytokinin-induced regeneration capacity of a plant cell, wherein the method comprises a step of increasing or introducing the expression of a histidine kinase in the plant cell. The invention further pertains to a method for regenerating a plant, wherein the method comprises a step of introducing or increasing the expression of a histidine kinase and to a plant obtainable from such method. Moreover, the method concerns the use of at least one of CHK2, CHK3 and CHK4 for improving a cytokinin-induced regeneration capacity of a plant.

The disclosure provides novel methods for improving the regeneration throughput and/or plugging frequency of monocot embryo explants by flotation and selective collection of viable and regenerable explants. Genetic modification or transformation of monocot plants may include preparation of seed excised embryo explants, rehydration, inoculation and co-culture, bud induction, extended bud induction, and regeneration of genetically modified plants or plant parts. To improve regeneration and plugging frequency, cultured monocot seed excised embryo explants following the bud induction or extended bud induction step are placed in a flotation medium to separate the explants into top and bottom layers or fractions, such that the top fraction can be selectively collected and advanced to regeneration media. The top fraction is shown to have a higher or similar plugging frequency than the bottom fraction and thus the flotation step reduces costs and improves transformation throughput by removing unproductive explants in the bottom fraction having a much lower regeneration and plugging frequency.