Dissecting the Concept of the Thin Cell Layer: Theoretical Basis and Practical Application of the Plant Growth Correction Factor to Apple, Cymbidium and Chrysanthemum

Recent advances and novelties in the thin cell layer-based plant biotechnology – a mini-review

“…This result fortifies the notion that the outcome or variation in in vitro productivity may depend on the timing of sampling (Teixeira da Silva and Dobránszki, 2013b). Earlier studies related to the productivity of apple leaf tTCLs, and the effect of sampling time, had already been proven (Teixeira da Silva and Dobránszki, 2013bDobránszki, , 2014. However, we also reported that the effect of timing of sampling depended on the genotype, position of the source explant, and the choice of PGRs used in the regeneration medium.…”

“…Three examples include 5 mm sections from leaves in apple (Malus × domestica Borkh. ), 5 mm wide protocorm-like bodies (half-PLBs) from hybrid Cymbidium, or 8 mm internode sections from chrysanthemum (Dendranthema grandiflora Kitamura) (Teixeira da Silva and Dobránszki, 2014). Unlike conventional explants, the TCL technology requires the use of thin or ultrathin sections, typically 0.1-2 mm in thickness (Nhut et al 2003;Teixeira da Silva and Dobránszki, 2014).…”

“…), 5 mm wide protocorm-like bodies (half-PLBs) from hybrid Cymbidium, or 8 mm internode sections from chrysanthemum (Dendranthema grandiflora Kitamura) (Teixeira da Silva and Dobránszki, 2014). Unlike conventional explants, the TCL technology requires the use of thin or ultrathin sections, typically 0.1-2 mm in thickness (Nhut et al 2003;Teixeira da Silva and Dobránszki, 2014). Preparation of these explants requires stability of hand and thus intensive labor is necessary that does not currently allow the technique to be mechanized, thereby restricting its use across a wide range of plant species (Teixeira da Silva and Tanaka, 2011).…”

“…Therein lies the practical importance of TCLs. Experiments conducted with apple (Malus × domestica), an orchid (Cymbidium ), and an ornamental plant (chrysanthemum) showed that when considering productivity (number of shoots or desired regenerating organs) per unit area of an explant, TCLs produced many more regenerants than conventional explants (Teixeira da Silva and Dobránszki, 2014). For example, in apple "Freedom", five shoots formed per leaf (conventional explant), but once a growth correction factor was applied that took into account the area, size, shape, and volume of TCLs relative to regular explants, leaf tTCLs produced 65 shoots per leaf (for "Gala" apple, the values were 24 and 286, respectively).…”

The Untapped Potential Of Plant Thin Cell Layers

“…In addition, the secret to the developmental success of a TCL in vitro lies, not only in the tissue types it might incorporate, either by cutting transversally or longitudinally, but also in the area and volume of the explant itself. Using three horticultural crops (Cymbidium, apple, and chrysanthemum), the plant growth correction factor was used to extrapolate the productivity of a TCL relative to a conventional explant, indicating that even though the face-value organogenic outcome was less in TCLs than in conventional explants, once the size, shape, and volume of the explant were factored in, the productivity of the TCL was, in fact, several fold higher than a conventional explant (Teixeira da Silva & Dobránszki 2014). This little known fact by many plant scientists, together with the smallest of developmental treasures, the TCLs, would serve the plant science community well, if applied more widely to a greater range of plant species.…”