Effects Of BR On The Development And Differentiation Of Cotton Fibber And The Transformation Of Bzr1 Via Particle Bombardment

Brassinosteroides(BRS) are a special class of plant hormone that have wide distribution throughout the plant kingdom.They plays an important role in the growth and development of plants, involved in the processes of cells division, differentiation, expantion; stem elongation; pollen tube germination and the light-harvesting. Also they can help plants to relieve or overcome environmental stress. By the method of cultivating cotton ovules in vitro, we investigate the effects of BR to the development of cotton fibber cells. Also we transformed the bzrl~CFPgene into cotton ovules via particle bombardment and investigate the usage of CFP~a mutant of GFP in the study of cotton fibber as a reporter gene. The following results were obtained.(1) Adding BR into BT medium , the concentration were different :0, 0. 005, 0.05, 0. 5, 5, 50MM. The cotton fibber grew longer as the concentration of BR goes up until the BR concentration was 0.5)41, then decreased. Cotton fibber cant' t grow in the BT medium with 50MM of BR. Compared with the CK, we know BR play strong activity in cotton fibber elongation.Also we cultivated the Idpa and - Idpa cotton ovules in the six di fferent BT medium. The results showed that fibber can grow from the Idpa cotton ovules, but failed from the - Idpa ones. Through the observation (if the surface of ovules with SEM, we know the surl'ace cells of Idpaovules have developed into fibber cells and get into the stage of elongation. But the - Idpa ones haven' t. Then we concluded though BR can stimulate the elongation of cotton fibber, but it has no effect on the differentiation of fibber cells.(2) When BR(0. 5MM) and GA(5HM) were added into the BT medium at the same time and cultivated the Idpa cotton ovules. The fibber grew longer than any other ones: T0(CK), TB,,(0. 5MM BR) and T(;,(5nM GA). Thus we know BR and GA work in coordination in cotton fibber elongation.(3)We transformed the bzrl~CFP gene into cotton ovules via particle bombardment and then cultivated them in the BT medium with 0. SUM BR. Bright cyan fluorescence is visualized by fluorescence microscopy after 7 days, but then disappeared. This show the expression was transient. But we can see the fluorescence of CFP within 7 days, this means CFP can be used in the study of cotton fibber as a new reporter gene.