Factors affecting flowering seasonality

Abstract

Environmental regulation of flowering seasonality and set seed is critical for this survival as it allows seeds to develop in the most favourable conditions. Recent genetic and molecular approaches provide a basis for understanding how plants use seasonal changes in natural daylight duration and temperature to achieve reproducible timing of flowering. Recent studies have led to the identification of members of the FLOWERING LOCUS T (FT) in Arabidopsis, and its orthologs in several plant species act as florigen. In addition to the floral inducer florigen, the systemic floral inhibitor anti-florigen, anti-florigenic FT/TFL1 family protein (AFT), has been identified from a wild chrysanthemum and plays a predominant role in the obligate photoperiodic response. In Arabidopsis, the molecular basis for vernalization process has been revealed. The key factor in the vernalization pathway is a repressor of flowering, FLOWERING LOCUS C (FLC). In temperate cereals that require vernalization to flower, three genes possibly participate in a regulatory loop to control the timing of flowering, namely, VRN1, VRN2, and VRN3. VRN2 is a key factor for flowering repression in winter varieties.