Higher plants hydroxylation pathways

The gibberelllns that comprise this pathway are both unique to higher plants (l.e. not present in the fungus) and widespread among higher plants. The pathway Itself has been shown to be present In maize (Zea mays) (2 12, ) and pea (Plsum sativum) (27, ). This report will consider only the early-13-hydroxylation pathway for maize. 

As previously stated, the immediate precursor common to both fungal and higher plant GAs is GAi2"ald-e yd-e The pathways that stem from this compound vary depending on the species of plant under study. They differ from each other in the extent, position, and sequence of ring hydroxylations. 

There are a number of additional gibberelllns native to higher plants with unique hydroxylation patterns (for example, hydroxylated at positions 1, 11, 12H, or 15) that fit Into no known pathways (2,3,, ). These GAs cannot be assigned to a biosynthetic pathway until radiolabeled feeding studies have been made using the plants from which the gibberelllns were Isolated. 

Evidence has also been obtained in higher plants for the operation of alternative pathways of biosynthesis for the formation of some of the substituted benzoic acids (93, 95, 97, 98 and 99) in which the required hydroxylation or methylation occurs at the stage of a Cg. Cj substrate Figure 5.9). Some attempts to establish the relative importance of the two pathways have b n made in some cases, but whether the distinctive hydroxylation patterns of the benzoic acids have been established at the cinnamic acid level... 

EARLY-3-HYDROXYLATION PATHWAY FUNGUS HIGHER PLANTS... 

EARLY-13-HYDROXYLATION PATHWAY HIGHER PLANTS ONLY... 

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