Apical dominance and shoot branching. Divergent opinions or divergent mechanisms?

摘要

Various hypotheses of shoot branching are discussed: classical hypothesis (i.e. auxin acts to regulate shoot branching in conjunction with secondary messengers, such as cytokinin), auxin transport hypothesis (i.e. regulatory control is exerted by auxin movement in the auxin transport stream, as opposed to the actual level of auxin), and bud transition hypothesis (i.e. the bud enters different developmental stages that have varying degrees of sensitivity or responses to long-distance signals, including auxin)..