Auxin is a plant growth regulator involved in diverse fundamental developmental responses. Much is now known about auxin transport, via influx and efflux carriers, and about auxin perception and its role in gene regulation. Many developmental processes are dependent on peaks of auxin concentration and, to date, attention has been directed at the role of polar auxin transport in generating and maintaining auxin gradients. However, surprisingly little attention has focussed on the role and significance of auxin biosynthesis, which should be (...) expected to contribute to active auxin pools. Recent reports on the function of the YUCCA flavin monooxygenases and a tryptophan aminotransferase in Arabidopsis have caused us to look again at the importance of local biosynthesis in developmental processes. Many alternative and redundant pathways of auxin synthesis exist in many plants and it is emerging that they may function in response to environmental cues. (shrink)

Most Liberals hold that public policies ought always be justifiable by reference to public reasons; that citizens should also refrain from advocacy in the absence of such reasons; and that exclusively religious reasons cannot be public reasons. This is challenged by Paul Weithman and Christopher Eberle. Both argue that basic liberal principles permit citizens in some circumstances to advance exclusively religious reasons, and in particular that Rawls's notions of reasonableness (Weithman) and the strains of commitment (Eberle) can be used in (...) defence of this position. I argue that neither makes out his case, and that no plausible case has been made against the standard Liberal view. (shrink)