Somatic embryogenesis and direct as well as indirect organogenesis in Lilium pumilum DC. Fisch., an endangered ornamental and medicinal plant

Abstract

Somatic embryogenesis and organogenesis in Lilium pumilum were successfully regulated by picloram, α-naphthaleneacetic acid (NAA), and 6-benzyladenine (BA). In organogenesis, the highest shoot regeneration frequency (92.5%) was obtained directly from bulb scales on Murashige and Skoog (MS) medium containing 2.0 mg L(-1) BA and 0.2 mg L(-1) NAA, while organogenic callus (OC) formed from leaves on MS medium supplemented with 1.0 mg L(-1) BA and 0.5 mg L(-1) NAA. Following subculture, 76.7% of OC regenerated shoots. In somatic embryogenesis, the combination of picloram and NAA increased the amount of embryogenic callus (EC) that formed with a maximum on 90.7% of all explants which formed 11 somatic embryos (SEs) per explant. Differences between EC and OC in cellular morphology and cell differentiation fate were easily observed. SEs initially formed via an exogenous or an endogenous origin. The appearance of a protoderm in heart-shaped SE and the bipolar shoot-root development in oval-shaped SE indicated true somatic embryogenesis. This protocol provides a new and detailed regulation and histological examination of regeneration pattern in L. pumilum.

Small RNA and Transcriptome Sequencing Reveal a Potential miRNA-Mediated Interaction Network That Functions during Somatic Embryogenesis in Lilium pumilum DC. Fisch.

“…As described previously (Zhang J. et al, 2016), there are two major stages of somatic embryo regeneration in Lilium pumilum DC. Fisch.…”

“…Protodermal factor 1 and SERK were targeted by miR399 (Table S10). Emergence of the protoderm has been noted as an indicator of SE (Raju et al, 2015; Zhang J. et al, 2016), and the accumulation of SERK is the most significant indication of the transition from somatic cells to embryogenic cells (Ma et al, 2012; Silva et al, 2014). According to our previous study examining SE in Lilium pumilum DC.…”

“…According to our previous study examining SE in Lilium pumilum DC. Fisch., the protoderm appears in HE but not in TE (Zhang J. et al, 2016), which may be explained by the accumulation of miR399, which regulates protodermal factor 1 in TE. Additionally, the accumulation of miR399 in NEC indicates that miR399 might repress the expression of SERK in NEC.…”

“…Fisch. (Zhang J. et al, 2016). Each sample represented a pool of more than 10 independent individuals.…”

Characterization of the complete chloroplast genome of an endangered ornamental and medicinal plant Lilium pumilum

“…Unfortunately, vegetative reproduction of L. pumilum is difficult and the populations of L. pumilum may have already disappeared due to overgrazing, uncontrolled overexploitation, and the effects of climate change (Zhang et al 2016). Hence, it is necessary to develop the genetic resources to protect this endangered species.…”