RID1 , encoding a Cys2/His2-type zinc finger transcription factor, acts as a master switch from vegetative to floral development in rice

Abstract

Transition from the vegetative phase to reproductive phase is a crucial process in the life cycle of higher plants. Although the molecular mechanisms of flowering regulation have been extensively characterized in a number of plant species, little is known regarding how the transition process initiates. Here, we show that the Rice Indeterminate 1 (RID1) gene acts as the master switch for the transition from the vegetative to reproductive phase. RID1 encodes a Cys-2/His-2-type zinc finger transcription factor that does not have an ortholog in Arabidopsis spp. A RID1 knockout (rid1), mutated by T-DNA insertion, never headed after growing for >500 days under a range of growth conditions and is thus referred to as a never-flowering phenotype. This mutation-suppressed expression of the genes is known to be involved in flowering regulation, especially in the Ehd1/Hd3a pathway and a series of RFT homologs. RID1 seems to be independent of the circadian clock. A model was proposed to place RID1 in the molecular pathways of flowering regulation in rice, for which there are two indispensable elements. In the first, RID1 is controlling the phase transition and initiation of floral induction. In the other, the

DTH8 Suppresses Flowering in Rice, Influencing Plant Height and Yield Potential Simultaneously

“…In LD conditions, the expression of Hd3a is suppressed by Hd1 (Hayama et al, 2003), and Ehd1 and Hd3a are also suppressed by Ghd7 (Xue et al, 2008), which accounts for the late flowering in rice. Additionally, RID1/OsID1/Ehd2 promotes flowering under both SD and LD conditions by up-regulating Ehd1 (Matsubara et al, 2008;Park et al, 2008;Wu et al, 2008). In this study, DTH8 was found to delay rice flowering time by negatively influencing the expression of Ehd1 and Hd3a in LD conditions ( Fig.…”

“…More genes for plant height in rice have been identified (Ashikari et al, 1999;Yamamuroa et al, 2000;Sasaki et al, 2002Sasaki et al, , 2003Honga et al, 2003;Itoh et al, 2004;Tanabe et al, 2005). The molecular genetic pathway for flowering time has been under elucidation in rice since the isolation of many correlative genes or QTLs (Yano et al, 2000;Kojima et al, 2002;Doi et al, 2004;Kim et al, 2007;Wu et al, 2008). Although there are close correlations among yield, plant height, and flowering time, most of these genes were reported to be regulating only one of the three traits.…”

“…S7), suggesting that DTH8 is a flowering suppressor by down-regulating the expression of Ehd1 and Hd3a under LD conditions. There are many studies to have reported that Ehd1 locates in the upstream of Hd3a and could promote its expression (Doi et al, 2004;Kim et al, 2007;Matsubara et al, 2008;Park et al, 2008;Wu et al, 2008). At the same time, some other reports show that the flowering suppressor could repress Hd3a expression by down-regulating Ehd1 and then inhibits flowering (Xue et al, 2008).…”

“…By contrast, Hd1 represses flowering by down-regulating Hd3a expression under LD conditions (Kojima et al, 2002). Additionally, RID1/OsID1/ Ehd2, which is homologous to maize (Zea mays) Indeterminate1 (ID1), promotes flowering in both SD and LD conditions by up-regulating Ehd1 (Matsubara et al, 2008;Park et al, 2008;Wu et al, 2008). Ghd7, encoding a CCT domain protein, has been proven to have major effects on an array of traits in rice, including number of grains per panicle, plant height, and flowering time (Xue et al, 2008); it represses Ehd1 and Hd3a expression and then delays flowering in LD conditions.…”

A long noncoding RNA regulates photoperiod-sensitive male sterility, an essential component of hybrid rice

“…It has been known for centuries that flowering of plants is regulated by day length (2). In recent years, many genes for photoperiod-controlled flowering have been identified in a number of plants, leading to characterization of pathways in flowering regulation (3)(4)(5)(6)(7)(8)(9). However, photoperiod regulation of other developmental processes has been studied in far less detail than flowering.…”