Effect of irradiance during acclimatization on content of proline and phytohormones in micropropagated Ulmus minor

Abstract

This study aimed to investigate the effects of irradiance on plant growth and content of proline and phytohormones during ex vitro acclimatization of micropropagated Ulmus minor plants. In vitro rooted plants were acclimatized to ex vitro conditions in a climate chamber with two irradiances, 200 mu mol m(-2) s(-1) (high irradiance, HI) and 100 mu mol m(-2) s(-1) (low irradiance, LI) for 40 d. Immediately after the ex vitro transfer, the plants experienced a water deficit [wilting leaves with the reduced relative water content (RWC)], but following the experiment, the recovery of the RWC was more pronounced in the HI treatment. Also, the content of proline, ABA, and JA-Ile were higher in HI treatment. Growth analyses revealed that HI improved growth and biomass production.