High impact information on LD

• FPA is expressed most strongly in developing tissues, similar to the expression of FCA and LUMINIDEPENDENS, two components of the autonomous pathway previously identified [1].
• The levels of FLC mRNA are regulated positively by FRI and negatively by LUMINIDEPENDENS [2].
• The predicted amino acid sequence of the LD protein contains 953 residues and includes two putative bipartite nuclear localization signals and a glutamine-rich region [3].
• The early-flowering phenotype in 35S::LMADS3 transgenic Arabidopsis plants was correlated with the up-regulation of flowering time genes FT, SUPPRESSOR OF OVEREXPRESSION OF CO 1, LUMINIDEPENDENS, and flower meristem identity genes LEAFY and APETALA1 [4].
• (Arabidopsis) confer a late-flowering phenotype, indicating that LD normally functions to promote the floral transition [5].

Biological context of LD

• RNA and protein blot analyses, along with the analysis of transgenic plants containing a fusion between a genomic fragment of LD and the reporter gene uidA (GUS), indicate that LD is expressed primarily ipical proliferative regions of the shoot and root, including the shoot apical meristem and leaf primordia [5].
• The Arabidopsis flowering-time gene LUMINIDEPENDENS is expressed primarily in regions of cell proliferation and encodes a nuclear protein that regulates LEAFY expression [5].
• Overexpression of AGL28 caused precocious flowering via the upregulation of the expression of FCA and LUMINIDEPENDENS (LD), both floral promoters within the autonomous pathway [6].

Regulatory relationships of LD

• In Ler, the late-flowering phenotype of FRIGIDA and mutations in LUMINIDEPENDENS is suppressed by the Ler allele of FLC [7].

Other interactions of LD

• These data are consistent with the idea that at least one function of LD is to participate in the regulation of LFY [5].
• These effects were not influenced markedly by the activities of the Arabidopsis LD or FLC genes [8].

References