Somatic embryogenesis and two embryo specific proteins (38 and 33 kD) in Catharanthus roseus

Abstract

In the present study, the regeneration pathway, especially the different events of somatic embryogenesis (SE) have been studied morphologically and biochemically in Catharanthus roseus. Firstly, the calluses were induced from different explant sources (hypocotyl, epicotyl and root) by using various auxins. Embryogenic and non-embryogenic calluses were identified based on their morphology, colour and dry weight. Embryogenic callus was later cultivated on MS added with 0.45 μM 2,4-D, 6.62 μM BAP and 1.44 μM GA3 for obtaining various developmental stages of embryos. Different stages of embryos have been assayed for the establishment of marker based embryogenesis, particularly on embryo specific proteins whose presence or absence will ensure a rapid and efficient production of embryos that has a special application to clonal biotechnology. Two embryo specific proteins (38 and 33 kD) have been identified for the first time in C. roseus during torpedo stage of embryogenesis. Besides, multiple shoot formation from in vitro raised emblings was also attempted to examine the role of BAP and kinetin for shoot proliferation. The shoots were rooted with 5.37 μM NAA and 5.71 μM IAA before transplantation.