Rapid induction of somatic embryogenesis by 2,4-D in leaf base cultures of wheat (Triticum aestivum L.)

Abstract

Wheat leaf base segments treated with 2,4-D (10μM) for 24h developed somatic embryos without an intervening callus when cultured on basal Murashige and Skoog's medium for less than 2 weeks. This response is auxin specific and genotype independent. In fact, vacuum infiltration of 2,4-D, although at a higher concentration (50μM), in the basal leaf segments for 1 min, followed by culture on the basal medium, was sufficient to evoke the embryogenic response. In comparison to indirect somatic embryogenesis, this highly efficient system for direct embryogenesis not only curtails the time span for somatic embryogenesis by 15-20 days, it also obviates any secondary changes that may occur during dedifferentiation. The rapid induction of somatic embryogenesis in wheat leaf bases, under easily manipulable culture conditions, thus provides a unique opportunity to monitor the molecular events associated with auxin-mediated induction of somatic embryogenesis and also to study the associated developmental events.