Evaluation of thermal-stress on the accumulation of podophyllotoxin in shoot in vitro cultures of Linum persicum

Abstract

<em>Linum persicum</em> is an endangered plant native to Iran, from Linaceae family. Phytochemical analysis has shown that <em>L. persicum in vitro </em>cultures contain podophyllotoxin (PTOX), the pharmacological precursor for anticancer drugs such as etoposide, etopophos, and teniposide. Shoot culture of <em>L. persicum</em> was established from callus cultures in MS medium containing GA₃. A study was designed to investigate the effects of thermal-stress treatments (TST) on the shoot growth pattern of <em>L. persicum</em> along with the accumulation of PTOX. Shoots were heat-stressed at 37, 40, 45, 50, and 55 °C for 3 h, and then transferred back to the growth room. In each thermal group after 2, 3, and 4 weeks, 4 flasks were extracted for PTOX analysis. HPLC analysis (<em>p</em><span style="text-decoration: underline;"><</span>0.05) revealed that shoots which had experienced 37 °C of TST after 4 weeks showed the highest amount of growth as well as PTOX production, 1.62±0.21% dry weight.