Abscisic acid is required for somatic embryo initiation through mediating spatial auxin response in Arabidopsis
- PDF / 1,159,628 Bytes
- 10 Pages / 595.276 x 790.866 pts Page_size
- 111 Downloads / 209 Views
ORIGINAL PAPER
Abscisic acid is required for somatic embryo initiation through mediating spatial auxin response in Arabidopsis Ying Hua Su • Yu Xiao Su • Ying Gao Liu Xian Sheng Zhang
•
Received: 29 May 2012 / Accepted: 27 September 2012 / Published online: 5 October 2012 Ó Springer Science+Business Media Dordrecht 2012
Abstract Abscisic acid (ABA) regulates many aspects of plant development, including somatic embryo (SE) initiation. However, mechanisms of ABA functions on SE initiation have remained to be investigated. In this study, we examined the endogenous ABA contents of calli in Arabidopsis during the SE inductive process. We further found that the capacity for SE initiation was strongly impaired by treatment of fluridone, a potent inhibitor of ABA biosynthesis, as well as by mutation of ABA biosynthetic gene ABA2, suggesting that ABA is required for SE initiation. Furthermore, treatment of fluridone inhibited local auxin biosynthesis and auxin polar transport in the embryonic calli, resulting in the disturbance of auxin response pattern and the decreased regeneration frequency of SEs. However, application of exogenous ABA in the medium almost recovered patterns of auxin response and SE initiation. Thus, the results suggest that ABA functions on SE initiation through mediating both auxin biosynthesis and polar transport for establishment of auxin response pattern in callus. Our study provides new information for understanding mechanisms of SE initiation. Keywords Somatic embryo initiation ABA Auxin biosynthesis Auxin polar transport Auxin response
Ying Hua Su and Yu Xiao Su contributed equally to this work. Y. H. Su Y. X. Su Y. G. Liu X. S. Zhang (&) State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian 271018, Shandong, China e-mail: [email protected]
Introduction Somatic embryogenesis is similar to zygotic embryogenesis in multiple aspects of plant development. It has been an important way for plant production, and has also been as a model to study zygotic embryo development (Meinke 1991; Shiota et al. 1998; Birnbaum and Alvarado 2008). The original somatic embryogenesis was described in carrot (Reinert 1958; Steward et al. 1958). Somatic embryos (SEs) were initiated from cultured embryonic callus followed by removal of exogenous auxin in culture medium. Understanding the key factors required for the competence of SE initiation might provide important information for plant propagation in agriculture and zygotic embryogenesis. Abscisic acid (ABA) is a plant hormone that regulates many important physiological and developmental processes, such as embryo morphogenesis, storage protein synthesis and desiccation tolerance as well as onset and maintenance of dormancy (Koornneef and Karssen 1994; Rock and Quatrano 1995; Finkelstein et al. 2002; Nambara and Marion-Poll 2005). ABA action is associated with the major regulators LEAFY COTYLEDON1 (LEC1), LEC2, FUSCA3 (FUS3) and ABSCISIC ACID INSENSITIVE 3 (ABI
Data Loading...
