GIBBERELLIN RESPONSE AND SIGNAL TRANSDUCTION

摘要

GAs are a large family of tetracyclic diterpenoid plant growth regulators and have been reported to be associated with a number of plant growth and development processes such as seed germination, stem elongation, flowering and fruit development (Reid1993; Hooley 1994; Ross et al. 1997). GA-related mutants in plants show dwarf or elongated phenotypes, and these mutants are crucial for elucidating the regulatory mechanisms governing the GA biosynthetic and signal transduction pathways. Because dwarf characteristics are favored in plant breeding, the study of these characteristics has applications not only for understanding basic plant biology but also for molecular breeding. Many GA-related mutants have been isolated from numerous plant species (Reid1993; Hooley 1994; Ross et al. 1997) and can be roughly classified into 2 categories: GA-sensitive and GA-insensitive. A GA-sensitive mutant responds to exogenous GA because it cannot produce GA, or it produces insufficient GA due to a deficiency in genes encoding GA catalytic enzymes. On the other hand, a GA-insensitive mutant does not respond to exogenous GA, and gene related to GA-insensitivity may be associated with GA signal transduction (Hedden and Phillips 2000; Olszewski et al. 2002). Here shows the rice GA insensitive mutants and their gene functions.