As far as I know, mannitol as a carbohydrate sources for initiation somatic embryos. Also, mannitol induce somatic embryogenesis with create osmotic stress. PEG enforce water stress and also endogenous ABA content in explants. The positive effect of ABA on Somatic embryogenesis can be attribute to ABA role on ascorbic acid and nitrogen metabolism, polyamin synthesis and nucleotid biosynthesis.

Thank you Reza Ghahremani

please let me know whether ABA/PEG is used with PGR or not.

Abscisic acid can affect somatic embryogenesis without PGR. Of course, it depends on the type of plant being studied.

Dear Swati,

Please take a look at these 2 interesting papers attached. I hope it will be useful for the discussion.

Polyethylene glycol and abscisic acid improve maturation and regeneration of Panax ginseng somatic embryos

Light Inhibition of Shoot Regeneration Is Regulated by Endogenous Abscisic Acid Level in Calli Derived from Immature Barley Embryos

Best regards,

Jean

Swati Sharan I fully agree with Jean Carlos Bettoni.

PEG and Mannitol create dehydration stress and help in the maturation of SEs.

Thank you so much for valuable inputs Mahipal Shekhawat @ Jean Carlos Bettoni@