An assessment of morphogenetic fluctuation during reproductive phase change in Arabidopsis.

Background And Aims: Reproductive phase change in Arabidopsis thaliana is characterized by two transitions in phytomer identity, the differentiation of the first elongate internode (bolting transition) and of the first flower (floral transition). An evaluation of the dynamics of these transitions was sought by examining the precision of the corresponding phytomer identity changes.

Methods: The length of the first elongate internode and the frequency of chimeric inflorescence structures, e.

The significance of bolting and floral transitions as indicators of reproductive phase change in Arabidopsis.

Reproductive phase change in Arabidopsis thaliana is characterized by the floral transition (initiation of the first flower) and the bolting transition (elongation of the first internode). Here, the relationship between these transitions is examined by comparing variation in cauline and total leaf numbers in wild-type plants and 49 early-flowering mutants under a wide range of photoperiods. The timing of these transitions was also evaluated by subjecting wild-type plants to photoperiodic perturbations at different developmental stages.

Diversification of photoperiodic response patterns in a collection of early-flowering mutants of Arabidopsis.

Many plant species exhibit seasonal variation of flowering time in response to daylength. Arabidopsis (Arabidopsis thaliana) flowers earlier under long days (LDs) than under short days (SDs). This quantitative response to photoperiod is characterized by two parameters, the critical photoperiod (Pc), below which there is a delay in flowering, and the ceiling photoperiod (Pce), below which there is no further delay.

Floral meristem indeterminacy depends on flower position and is facilitated by acarpellate gynoecium development in Impatiens balsamina.

* Floral meristems are generally determinate. Termination of their activity varies with species, occurring after carpel or ovule development, depending on the placentation type. In terminal flowering Impatiens balsamina (cv.

Comparison of environmental and mutational variation in flowering time in Arabidopsis.

Developmental dynamics can be influenced by external and endogenous factors in a more or less analogous manner. To compare the phenotypic effects of (i) environmental [i.e.

Extensive phenotypic variation in early flowering mutants of Arabidopsis.

Flowering time, the major regulatory transition of plant sequential development, is modulated by multiple endogenous and environmental factors. By phenotypic profiling of 80 early flowering mutants of Arabidopsis, we examine how mutational reduction of floral repression is associated with changes in phenotypic plasticity and stability. Flowering time measurements in mutants reveal deviations from the linear relationship between the number of leaves and number of days to bolting described for natural accessions and late flowering mutants.