Growth regulators are chemicals that alter the growth and development of plants. They may be natural or artificial, and typically they are active at very low concentrations. The most important plant growth regulators are the hormones, auxin, gibberellin, ethylene, cytokinin, and abscisic acid. Other growth regulators often act by modifying the action of the natural hormones. For example, naphth...

It is 60 years since Went and Thimann (1937) published their classic book Phytohormones. At that time, the term phytohormone was synonymous with auxin, although the existente of other phytohormones, such as cell division factors, was anticipated on the basis of physiological experiments. It is impressive that aside from some confusion about the structure of auxin, many of the basic phenomena of...

Plant hormones are the key regulators of adaptive stress response. Abiotic stresses such as drought and salt are known to affect the growth and productivity of plants. It is well known that the levels of plant hormones such as zeatin (ZA), abscisic acid (ABA), salicylic acid (SA), jasmonic acid (JA), and brassinolide (BR) fluctuate upon abiotic stress exposure. At present, there is not any sing...

Abstract Global warming has great impacts on plant growth and development, as well ecological distribution. Plants constantly perceive environmental temperatures adjust their development programs accordingly to cope with the environment under non-lethal warm temperature conditions. Plant hormones are endogenous bioactive chemicals that play central roles in growth, developmental, responses biot...