Morphological and transcriptome analyses reveal mechanism for efficient regeneration of adventitious buds from in vitro leaves of Rhododendron delavayi regulated by exogenous TDZ

Direct regeneration and morpho-histological study of de novo shoot development from leaf explants of Rhododendron mucronulatum Turcz.

“…In R. delavayi, another scenario of TDZ-induced morphogenesis from partly incised leaf lamina was shown. The regeneration of adventitious shoots started from the swelling cells at the site of wounding leaf blade what can be identi ed as dedifferentiation stage, and then redifferentiation and acquisition of regeneration competence by the swelled cells resulted in the formation of protrusions and further development of meristematic cell clusters (Peng et al 2022). Moreover, the epidermal cells in petiole and the base of the leaf blade of R. delavayi were found not to able to regenerate de novo shoots.…”

“…So, the tissue a liation of these formations has not been fully clari ed still and yet to be studied. It has been found that the сells of these protuberances were arranged neatly and stained deeply, indicating they harbored pluripotency (Peng et al 2022). Besides, there has been reported that high TDZ concentrations initiate somatic embryogenesis, and low -de novo organogenesis in African violet (Lo et al 1997).…”

“…Grandi orum showed the formation of embryo-like strictures and revealed the connection of its vascular system with vascular system of leaf explant and the lack of a root apex (Zaytseva et al 2016). The histological analysis of TDZ-induced regeneration from leaf explants of evergreen R. delavay showed that the direct morphogenesis was also accompanied by the formation of globular structures connected with explant by jointed vascular system (Peng et al 2022). Thus, although these de novo structures looked like somatic embryos under the stereo microscope, histological examination revealed only direct regeneration of adventitious shoots.…”

“…Rhododendrons were known to include evergreen, semi-deciduous and deciduous plants, but successful standardized protocols based on triggering TDZ-induced morphogenesis from leaf explants were developed mainly for evergreen varieties (Pavingerová 2009, Eeckhaut 2010, Jesionek et al 2016Peng et al 2022). Moreover, it was found that morphogenic pathways of TDZ-induced shoot regeneration from leaf explants are of differences among the evergreen and semi-evergreen members of Rhododendron genus (Zaytseva et al 2016).…”

Variations of soil metal content, soil enzyme activity and soil bacterial community in Rhododendron delavayi natural shrub forest at different elevations

“…It can not only promote local economic development as an ornamental plant, but also prevent ecological degradation 18 . At present, the research on R. delavayi has mainly focused on ower color formation 19 , reproduction and breeding 20,21 , the community structure and diversity 11 , and changes in the structure of rhizosphere microbial 22 and so on. However, little research has been done on how changes in soil bacterial communities help R. delavayi adapt to different elevation environment.…”