FACTORS INFLUENCIMG GENETIC TRANSFORMATION OF HYPOCOTYL PROTOPLASTS OF PHASEOLUS AUREUS (MUNG BEAN)

In this paper,we studied on factors influencing transformation of hypocotyl protoplasts of mung bean (Phaseolus aureus).The experimental result showed th t lower pH,phosphate starvation and acetosyringone could activate the expression of the vir genes of Ti-plasmid in Agrobacterium tumefaciens and promote T-DNA transfer into mung bean cells to some extent through transient expression of GUS activity in mung bean cells. Higher pH and concentration of Ca²⁺ promoted transient expression of GUS gene in PEG-mediated DNA direct transfer.The activity of GUS gene increased with the increase of foreign plasmid DNA concentration in the range of 10-100μg. The transformed calli from mung bean hypocotyl protoplasts were selected on MSO medium containing 50 mg/L chloramphanicol after the protoplasts were cocultivated with A.tumefaciens strain C₅₈C₁ (pBZ6111 ),and confirmed by analysis of nopaline synthetase (NOS) activity.