DNA Synthesis and Hormonal Growth Response in Non-meristematic Tissues

Abstract

In view of the regulatory functions of hormones, much work has been done on the molecular aspects of hormonal responses. It has been demonstrated in numerous experiments that RNA and protein syntheses are essential for an optimal hormonal response. This situation is true for all hormones and plant tissues tested, except for the short term, immediate response to auxins — cell wall loosening — which takes place before any major metabolic changes can occur. Most of the evidence comes from inhibition of the hormonal response by specific inhibitors of RNA and protein synthesis. In some isolated cases information is more specific. Masuda (1965) has demonstrated the need for a GA-induced RNA in order to get a full IAA response; Matthysse and Phillips (1969) have shown that IAA interacts with the target cells’ chromatin, via a specific protein; John and Varner (1968) measured a significant increase in RNA synthesis by isolated nuclei which were treated by GA.