Cytophysiological Features of the Cereal-Based Experimental System “Embryo In Vivo–Callus In Vitro”

Morpho‐histology of co‐occurrence of somatic embryos, shoots, and inflorescences within a callus of Limonium ‘Misty Blue’

“…This approach is an important tool for understanding structural changes at the cellular level during genetic reprogramming for organogenesis and somatic embryogenesis. This study also revealed the dedifferentiation process in competent cells of highly differentiated mature tissues, identified the zone within the callus from which the acquisition of pluripotency or totipotency occurs, and, most importantly, revealed the spatial and temporal development of vegetative shoots, floral organs, and somatic embryos (Kruglova et al, 2023). Moreover, anatomical studies during the regeneration process will explain the role of programmed cell death (PCD) and polyphenol accumulation during the origination and pattern formation of shoot buds and somatic embryos.…”

“…(Awal et al, 2013) and Arabidopsis thaliana (Cheng et al, 2010), but no one has previously reported co‐occurrence of shoot, flower, and somatic embryo differentiation from a single piece of callus in any plant system. The simultaneous differentiation of vegetative and reproductive organs, together with somatic embryogenesis, depends on differential genetic reprogramming of existing somatic cells of the callus and the acquisition of either cellular totipotency or pluripotency from the stem cell niche (Kruglova et al, 2023). To learn the tangible facts, it is pertinent to study the ontogeny of the redifferentiation process based on sequential histological observations.…”

Histological Approach to the Study of Morphogenesis in Callus Cultures In Vitro: A Review

“…The morphological characteristics of calli that have appeared on the surfaces of various explants and are capable of morphogenesis during further in vitro culturation are quite similar in many plants; they are compact nodular structures [29][30][31][32] (Figure 1(1)). 2) data; developed primary morphogenic callus according to morphological (3) and histological (4) data; shoots (buds) in the morphogenic callus according to morphological (5) and histological (6) data; roots in the morphogenic callus according to morphological (7) and histological (8) data; gemmorhizogenic structures in the morphogenic callus according to morphological (9) and histological (10) data; somatic embryos in the morphogenic callus according to morphological (11) and histological (12) According to histological data, for example, the primary morphogenic callus obtained from the wheat embryo, in the initial stages of development, is represented by a system of meristematic cells of similar size [33] (Figure 1(2)). However, these histological features do not correspond to all such calli.…”

“…Various morphogenesis pathways were revealed in calli in the subsequent stages of in vitro cultivation (Figure 1(4-11)): organogenesis (gemmogenesis-type or caulogenesistype, consisting of the formation and development of the shoot; rhizogenesis-type, consisting of the formation and development of the root; or gemmorhizogenesis-type, consisting of the formation and development of the gemmorhizogenic structure that combines both the shoot and the root) and somatic embryogenesis (consisting of the formation and development of somatic embryos) (reviews [15,16,21,33]). Thus, reprogrammed callus cells exhibit the properties of pluripotency and totipotence under adequate in vitro conditions.…”