Plant Stem Cell (CMC) and Callus (DDC) are Fundamentally Different Cells

Callus (A.K.A Dedifferentiated Cell, DDCs) is dedifferentiated tissue composed by a variety of heterogeneous cells from dozens of dedifferentiated cells obtained by dedifferentiation process on differentiated plant organs (such as leaves). 

On the other hand, The CMCs developed by PIPSCI team are innately undifferentiated cells that has never been differentiated nor dedifferentiated, and CMCs are strictly homologous homogeneous cells.

Therefore, Plant stem cell (CMC) and callus (DDC) are fundamentally different from each other. Plant stem cell (CMC) and callus (DDC) show significant differences in cell morphology, gene expression, cell growth rate and stability, as well as plant active component synthesis due to their different origins. 

CMCs (left) • Cells are arranged closely with uniform color, and separate from callus naturally • Composed of one type of cell	DDCs (right) • Cells are arranged loosely with different colors, form a irregular cluster • Composed of various types of cells

CMCs (left) • Cells are alive without aging after long term subculture	DDCs (right) • Cells are aging or dead after long term subculture

CMCs (left) • Cells are suspended within small cell cluster	DDCs (right) • Cells are highly aggregated and form different sizes of clusters.

CMCs (left) • Numerous small vacuoles in the cell	DDCs (right) • Single huge vacuoles in the cell

CMCs (left) • Numerous, active and diverse shapes of mitochondria in the cell	DDCs (right) • A few mitochondria in the cell

CMCs (left) • Faster decomposition of hydrogen peroxide into oxygen due to strong anti-oxidants in CMCs	DDCs (right) • Slower decomposition of hydrogen peroxide into oxygen due to weaker anti-oxidants in DDCs

Needle DDCs (left) • DDCs from the yew tree leave have lower paclitaxel yield than CMCs	Embryo DDCs (middle) • DDCs from the yew tree embryo have lower paclitaxel yield than CMCs	CMCs (right) • Highest paclitaxel yield

	Callus (DDC)	Plant Stem Cell (CMC)
Cell composition	Heterogeneous cell types	Homogeneous cell type
Genetic variations	Yes	No
Vacuoles	Single  large vacuole	Numerous and small
Cell aggregation	Big cell clusters	Single or small cell clusters
Shear stress damage	Sensitive	Resistance
Cell viability	Low	High
Growth rate	Slow and  unstable	Fast and stable
NP biosynthesis	Decrease or loss	Stable and high