Answer:
Plant growth hormones will influence the growth, development and regeneration of Plants from the somatic cells and also helps in differentiation of cells.
carbenicillin are used to kill the A. tumefaciens, not for selection purpose.
Kanamycin is used as a selection marker. As kanamycin resistance gene is present in the expression vector containing foreign gene (TDNA ). so use of kanamycin antibiotic will allow the growth of only those plant cells which have incorporated the T DNA(containing gene of interest ) in their genome as they will have kanamycin resistance gene.
So if you left out the kanamycin, it will be difficult for you to select the plant cells that have taken up DNA. so further expression studies will be difficult.
means selection will be impossible.
