Hormones-regulated In Vitro Shoot Regeneration Of Arabidopsis

Organ regeneration in vitro is affected by many factors, but little is done to analyze systematically these factors. In this study, a one-step adventitious shoot regeneration method was developed using roots of Arabidopsis as explants. Compared with the traditional method, this method is efficient, simple and rapid. So it provides a good system to research the shoot regeneration in vitro. Basing on the system, we analyzed the effects of several factors, such as ecotype, explant, hormone type and hormone concentration, on the shoot regeneration The results are as follows:1) Different kinds of auxin result in different callus morphology. The formation of calli is more efficient on medium containing NAA or 2,4-D.2) For different hormones, the concentration that is suitable for the shoot regeneration in vitro is relatively fixed. The concentration rage of ZT, one kind of cytokinin, and its upper limit is higher than 6-BA. The concentration ranges of auxins suitable for shoot regeneration are relatively stable. The suitable concentration ranges of IAA, NAA, 2,4-D are 10.0-20.0μM,1.0-10.0μM,0.1μM, respectively. In a word, the concentration range of hormones is enssential to shoot regeneration.3) The frequencies of shoot regeneration from different ecotypes of Arabidopsis are different. The shoot regeneration from explants of Ws (Wassilewskija, Ws) ecotype is more efficient, more normal than that from explants of Col (Columbia, Col) ecotype.4) Different organ resources have little influence on the frequency of shoot regeneration, but the number of regeneration shoot in each callus decrease a bit with increased cytokinin concentration.5) Specific medium is necessary for shoot regeneration. Under the some hormone induction, Calli and shoots can not be induced on MS medium instead of B5 medium.