Phytochromes are a family of related chromoproteins that regulate photomorphogenesis in plants. Ectopic overexpression of the phytochrome A in several plant species has pleiotropic effects, including substantial dwarfing, increased pigmentation, and delayed leaf senescence. We show here that the dwarf response is related to a reduction in active gibberellins (GAs) in tobacco (Nicotiana tabacum)...

To explore the effects of altering the level of Activator (Ac) transposase (TPase) expression, a series of plasmids was constructed in which heterologous promoters were fused to the TPase gene. Promoters for the cauliflower mosaic virus (CaMV) 35S transcript and the octopine synthase (ocs) and nopaline synthase (nos) genes were tested. These fusions, and constructs expressing TPase from the wil...

Zinc (Zn), an essential nutrient in cells, plays a vital role in controlling cellular processes such as growth, development, and differentiation. Although the mechanisms of Zn translocation in rice plants (Oryza sativa) are not fully understood, it has recently received increased interest. OsZIP4 is a Zn transporter that localizes to apical cells. Transgenic rice plants overexpressing the OsZIP...

The Activator (Ac) element of maize is active at a low frequency in Arabidopsis. To determine whether this is due to poor expression of the Ac transposase gene, we obtained and studied 19 Arabidopsis transformants containing fusions of the octopine synthase (ocs), nopaline synthase (nos), cauliflower mosaic virus (CaMV) 35S, or Ac promoters to the transposase open reading frame. These transform...

The ubiquitin/proteasome pathway plays a crucial role in many biological processes. Here we report a novel role for the Arabidopsis 19S proteasome subunit RPT2a in regulating gene activity at the transcriptional level via DNA methylation. Knockout mutation of the RPT2a gene did not alter global protein levels; however, the transcriptional activities of reporter transgenes were severely reduced ...

Glutamine synthetase (GS) catalyzes the ATP-dependent condensation of NH4+ with glutanate to yield glutamine. Gene constructs consisting of the cauliflower mosaic virus (CaMV) 35S promoter driving a cytosolic isoform of GS (GS1) gene have been introduced into alfalfa (Medicago sativa). Although transcripts for the transgene were shown to accumulate to high levels in the leaves, they were undete...

The genome of the geminivirus tomato golden mosaic virus (TGMV) consists of two circular DNA molecules designated as components A and B. We have constructed Nicotiana benthamiana plants that are transgenic for the three overlapping open reading frames, AL1, AL2, and AL3, from the left side of TGMV A. In the transgenic plants, the AL open reading frames are under the control of the cauliflower m...

A full-length DNA copy of the M-RNA of cowpea mosaic virus (CPMV), supplied with either the 35S promoter from cauliflower mosaic virus (CaMV) or the nopaline synthase promoter from Agrobacterium tumefaciens, was introduced into the T-DNA region of a Ti-plasmid-derived gene vector and transferred to cowpea Vigna unguiculata cells. Southern blot analysis of the transformed callus tissue obtained ...

A series of chimeric promoters for higher-level expression of foreign genes in plants was constructed as fusions of a gene for beta-glucuronidase (GUS) with the terminator of a gene for nopaline synthase (nos) or of the cauliflower mosaic virus (CaMV) 35S transcript, and the strength of these promoters was assayed in transient and stable expression systems in tobacco and rice. As parts of these...