EFFECT OF PLANT HORMONES ON INVERTASE ACTIVITY AND ON PETAL GROWTH OF CUT ROSE

Abstract

Cell expansion caused by water influx in petal cells is an important mechanism responsible for the flower opening process. It is believed that carbohydrates are key factors as an osmolite to draw water into cells. To clarify the mechanism of flower opening and to improve cut flower quality, we investigated sucrose metabolism in rose petals using attached and cut flowers. We have been probing into possibility that the quality of cut rose flowers can be improved by controlling the invertase activity in postharvest condition. In this present study, we tried to clarify the effect of plant hormones on invertase activity and on the petal growth of cut roses. First we used petal discs of Rosa 'FEbesa' for plant hormone (IAA, ABA, GA 3 , and JA) treatment. The results showed that IAA and GA 3 could increase the activity of cell-wall bound invertase, and IAA, GA 3 , and ABA increase that of vacuolar invertase. For applied experiments with plant hormones, we used a scent rose Rosa 'Meivildo', which has a short vase life. We found some of the plant hormones (IAA and JA) in vase solution affected the petal growth of cut rose. For example, flower opening was promoted by NAA treatment and delayed by JA treatment compared with control. We are now investigating about sugar metabolism including invertase activity in rose petal on each treatment.