Growth and genetic stimulation of Cattleya-91 plantlets enriched with oxygenated ultrafine bubbles in vitro under aseptic conditions

ABSTRACT Effective Cattleya micropropagation enables achieving enhanced seedling quality and production. Ultrafine bubbles (UFBs) represent a recent technological breakthrough that is expected to improve the growth and development of orchid plantlets. The objective of this research was to reveal the effects of oxygenated UFB (O-UFB) at different liquid nutrition strengths on the morpho-physiology and gene expression of Cattleya plantlets grown in vitro under septic conditions. Uniform plantlets were planted on granular vermiculite-perlite (VP) (1:1) with full-Murashige Skoog (MS), –-MS, ½-MS, and full-Hougland (HG) liquid media enriched with oxygenated UFB (O-UFB), and full-MS-0 was used as control. A lower ionic strength (–-MS) medium with the presence of O-UFB improved Cattleya plantlet growth both morphologically and physiologically. Nutrition strength also induced the overexpression of SUT2 and PEPCK genes during the in vitro septic culture, leading to a physiological transition from heterotrophic to autotrophic micropropagation. Therefore, O-UFB supplementation during Cattleya plantlet growth and development can improve its quality and productivity.