A.
The cytoplasms of adjacent plant cells are connected via minute communicating channels called plasmodesmata, which span the intervening cell walls.
B.
In contrast to gap-junction channels, plasmodesmata are cytoplasmic channels lined with plasma membrane. It usually also contains a fine tubular structure, the desmotubule, derived from smooth endoplasmic reticulum.
C.
Thus in plants, the cytoplasm is, in principle, continuous from one cell to the next, allowing the passage of both small and large molecules—including some proteins and regulatory RNAs.
D.
The controlled traffic of transcription regulators and regulatory RNAs from one cell to another is important in plant development.