Final answer:
The triplet AUG codes for the amino acid methionine in plants, just as it does in bacteria. This is because the genetic code is universal across different organisms. AUG also serves as the initiation codon in protein synthesis.
Step-by-step explanation:
The question asks if the triplet AUG codes for methionine in bacteria, what does it code for in plants? The answer is that AUG also codes for methionine in plants. The genetic code is considered to be universal, which means AUG would specify methionine in nearly all organisms, including both prokaryotes like bacteria and eukaryotes such as plants. Methionine is also typically the initiation codon signaling the start of protein synthesis, and other processes like the establishment of the reading frame for mRNA translation are also initiated by this codon.
It is important to note that in addition to coding for methionine during the elongation of the polypeptide chain, the first methionine in a newly synthesized polypeptide is usually enzymatically removed before the chain is completed. Therefore, the vast majority of polypeptides do not actually begin with methionine, despite it being the initial amino acid incorporated during translation.