The Regulatory Role of Ethylene on Cell Differentiation and Growth of Mustard Plants In Vitro

Abstract

The relation of ethylene to in vitro shoot organogenesis and growth and development of mustard plants (Brassica juncea (L.) Czern & Coss) was investigated. Ethylene production by cultured leaf discs reduced by 70-80% in the presence of aminoethoxyvinylglycine (AVG), whereas AgNO3 enhanced ethylene production by 5-6-fold. However, both ethylene inhibitors (EI) were equally effective in promoting in vitro shoot organogenesis from leaf discs, which were otherwise recalcitrant. The presence of AVG did not affect growth and development of in vitro-grown plants, although endogenous 1-aminocyclopropane-1-carboxylic acid (ACC) synthase activity, ACC and ethylene levels of four week-old plants were greatly reduced. In contrast, plant growth and development were inhibited by AgN03, which resulted in an increase of endogenous ACC synthase activity, ACC and ethylene production. Leaf discs derived from EI-grown plants were highly regenerative in the absence of EI, but AgNO3 was inhibitory to regeneration from explants originating from AgN03-grown plants.