All living cells contain genetic material encoded in the iconic double‑helix structure of DNA. In plants, as in other eukaryotes, this DNA is safely housed within a specialized compartment called the nucleus.
DNA is composed of two sugar‑phosphate backbones linked by hydrogen‑bonded base pairs. The four bases—adenine (A), thymine (T), guanine (G) and cytosine (C)—combine to encode the amino acid sequences of proteins. Gene segments contain the specific instructions for building individual proteins.
The nucleus is a prominent, membrane‑bound organelle surrounded by a double‑layered envelope punctuated with nuclear pores. These pores are protein complexes that meticulously control the import and export of molecules, ensuring proper nuclear-cytoplasmic communication.
Genes are transcribed into messenger RNA (mRNA). Unlike DNA, mRNA is single‑stranded, contains ribose instead of deoxyribose, and substitutes uracil (U) for thymine. After transcription, mRNA is processed and ferried out of the nucleus via the pores. In the cytoplasm, ribosomes translate the mRNA sequence into functional proteins.
