Salt-tolerance and proline accumulation: a comparative study in salt-tolerant and wild type cultured cells of eggplant.

A NaCl-tolerant cell line of eggplant has been isolated, as a spontaneous variant, on agar solidified medium supplemented with 1% NaCl (Electrical conductivity -17.5 m mho/cm), a concentration lethal to the wild type cells. The stability of the altered response of the selected clone was confirmed by growing it on normal medium for 3 months and then bringing back to the stress medium. This cell line not only grew well on media containing upto 1% NaCl but also required 0.25% NaCl for its optimal growth. It is interesting to note that there is a certain concentration of NaCl (Critical point) above which the proline content of the cells rises sharply. A relationship between the NaCl stress and proline content has been found. The critical point in the wild type cultured cells (0.75% NaCl) lies below to that of the selected salt-tolerant variant (1.0% NaCl).