Roles and regulation of cytokinins in tomato fruit development.

Cytokinins (CKs) are thought to play important roles in fruit development, especially cell division. However, the mechanisms and regulation of CK activity have not been well investigated. This study analysed CK concentrations and expression of genes involved in CK metabolism in developing tomato (Solanum lycopersicum) ovaries.

An unusual spliced variant of DELLA protein, a negative regulator of gibberellin signaling, in lettuce.

DELLA proteins are negative regulators of the signaling of gibberellin (GA), a phytohormone regulating plant growth. DELLA degradation is triggered by its interaction with GID1, a soluble GA receptor, in the presence of bioactive GA. We isolated cDNA from a spliced variant of LsDELLA1 mRNA in lettuce, and named it LsDELLA1sv.

Isolation and functional characterization of the FLOWERING LOCUS T homolog, the LsFT gene, in lettuce.

High temperature-induced bolting of lettuce is undesirable agriculturally, making it important to find the mechanism governing the transition from vegetative to reproductive growth. FLOWERING LOCUS T (FT) genes play important roles in the induction of flowering in several plant species. To clarify floral induction in lettuce, we isolated the FT gene (LsFT) from lettuce.

The endogenous level of GA(1) is upregulated by high temperature during stem elongation in lettuce through LsGA3ox1 expression.

Bolting of lettuce is promoted by high temperatures. Gibberellins (GAs) play an important role in the bolting of several plant species, and it has been reported that exogenous GAs induce bolting and early flowering in lettuce. To clarify the role of GAs in this process, we examined the expression of genes involved in GA metabolism (LsGA20ox-1 and -2, LsGA3ox-1 and -2, and LsGA2ox-1 and -2) and endogenous GAs in lettuce stems.