In 1996, a molecular phylogenetic study of the rbcL gene showed that Agapanthus was misplaced in Alliaceae, and the authors excluded it from the family.
Our carbon-based life originates from a carbonation reaction that is most often catalysed by the enzyme RuBisCO.
A rise in leaf temperatures may alter ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCo) relationship with carbon dioxide and oxygen which will also affect the plants' photosynthesis capabilities.
Studies to find their evolutionary relationship using chloroplast (RuBisCO gene) or mitochondrial DNA (intergenic spacer) sequence markers have been inconclusive.
Many grasses are C4 plants that concentrate CO2 levels in their bundle sheaths to increase the efficiency of RuBisCO, the enzyme responsible for photosynthesis, while Junipers are C3 plants that rely on (and may benefit from) the natural CO2 concentrations of the environment, although they are less efficient at fixing CO2 in general.
The monophyly of Euphorbiaceae had long been held in doubt by some, but the first strong evidence of its polyphyly came in 1993 with the first maximum parsimony analysis of DNA sequences of the gene rbcL from a large number of seed plants.
The term "RuBisCO" was coined humorously in 1979, by David Eisenberg at a seminar honouring the retirement of the early, prominent RuBisCO researcher, Sam Wildman, and also alluded to the snack food trade name "Nabisco" in reference to Wildman's attempts to create edible tobacco leaves.
RuBisCO |