Avena phytochrome a overexpressed in transgenic tobacco seedlings differentially affects red/far-red reversible and very-low-fluence responses (cotyledon unfolding) during de-etiolation

Casal, Jorge J.; Sánchez, Rodolfo A.; Vierstra, Richard D.

doi:10.1007/bf00198564

Cited by 20 publications

(12 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…6). In dicotyledonous plants, a similar effect of phyA overexpression has been interpreted as the result of an exacerbated HIR in light-grown seedlings, impairing the response to changes in R/FR caused by supplementary FR (McCormac et al 1991;Casal and Sfinchez 1994). Third, rice transgenics were able to respond to canopy shade light.…”

Section: Jj Casal Et Al: Phytochrome a And Hir In Grassesmentioning

confidence: 92%

See 1 more Smart Citation

High-irradiance responses induced by far-red light in grass seedlings of the wild type or overexpressing phytochrome A

Casal

Clough

Vierstra

1996

Planta

View full text Add to dashboard Cite

Abstract. The occurrence of phytochrome-mediated highirradiance responses (HIR), previously characterised largely in dicotyledonous plants, was investigated in Triticum aestivum L., Zea mays L., Lolium muhiflorumLam. and in both wild-type Oryza sativa L. and in transgenic plants overexpressing oat phytochrome A under the control of a 35S promoter. Coleoptile growth was promoted (maize, ryegrass) or inhibited (wild-type rice) by continuous far-red light (FRc). However, at equal fluences, hourly pulses of far-red light (FRp) were equally effective, indicating that the growth responses to FRc were not true HIR. In contrast, in maize and rice, FRc increased anthocyanin content in the coleoptile in a fluence-rate dependent manner. This response was a true HIR as FRp had reduced effects. In maize, anthocyanin levels were significantly higher under FRc than under continuous red light. In rice, overexpression of phytochrome A increased the inhibition of coleoptile growth and the levels of anthocyanin under FRc but not under FRp or under continuous red light. The effect of FRc was fluence-rate dependent. In light-grown rice, overexpression of phytochrome A reduced leaf-sheath length, impaired the response to supplementary far-red light, but did not affect the response to canopy shade-light. In grasses, typical HIR, i.e. fluence-rate dependent responses showing reciprocity failure, can be induced by FRc. Under FRc, overexpressed phytochrome A operates through this action mode in transgenic rice.

show abstract

Section: Jj Casal Et Al: Phytochrome a And Hir In Grassesmentioning

confidence: 92%

“…Third, rice transgenics were able to respond to canopy shade light. Light-grown tobacco plants overexpressing phyA respond to natural shade light and other experimental reductions in R/FR ratio unless caused by supplementary FR (Casal and Sfinchez 1994).…”

Section: Jj Casal Et Al: Phytochrome a And Hir In Grassesmentioning

confidence: 99%

High-irradiance responses induced by far-red light in grass seedlings of the wild type or overexpressing phytochrome A

Casal

Clough

Vierstra

1996

Planta

View full text Add to dashboard Cite

show abstract

“…Work by Nagy et al (1993) and Casal et al (1994) can be interpreted to indicate that phyA is the phytochrome that entrains the circadian oscillator. A very-low-fluence response can phase shift the circadian cycling of Lhcb mRNA in T .…”

Section: Discussionmentioning

confidence: 99%

Genetic Regulation of Development in Sorghum bicolor (X. Greatly Attenuated Photoperiod Sensitivity in a Phytochrome-Deficient Sorghum Possessing a Biological Clock but Lacking a Red Light-High Irradiance Response)

Childs

Mullet

et al. 1995

Plant Physiol.

View full text Add to dashboard Cite

“…Thus, under Re or Rp, the mode of action of phyA can be defined as 'multiple VLFR'. There are other systems, such as cotyledon unfolding in etiolated tobacco (Casal, Sanchez & Vierstra 1994), mesocotyl growth in rice (Clough et al 1995) and seed germination in Arabidopsis (Botto et al 1996), where phyA (overexpressed or endogenous) selectively induces VLFR. Therefore, phyA operates via two different action modes: HIR (under FRc) and VLFR.…”

Section: Phytochrome a Mediates Very Low Fluence Responses Under Contmentioning

confidence: 99%

Dual effect of phytochrome A on hypocotyl growth under continuous red light

Mazzella

Magliano

Casal

1997

Plant Cell & Environment

View full text Add to dashboard Cite

Tbe role of pbytocbrome A in tbe control of bypocotyl growtb under continuous red ligbt (Re) was investigated using phyA and phyB mutants of Arabidopsis thaliana, wbicb lack pbytochrome A (pbyA) or pbytocbrome B (pbyB), respeetively, and transgenie seedlings of Nicotiana tabacum overexpressing Avena pbyA, compared to tbe corresponding wild type (WT). In WT seedlings of A. thaliana, hypocotyl growtb inhibition showed a biphasic response to the fluence rate of Re, with a brake at 10 /imol m s . At equal total fluence rate, hourly pulses of red light caused slightly more inhibition than Re. The response to very low fluences of eontinuous or pulsed red light was absent in the phyA and phyA phyB mutants and present in the phyB mutant. The second part of the response was steeper in the phyA mutant than in the WT but was absent in the phyB mutant. In WT tobacco the response to Re was biphasic. Overexpression of Avena phyA enhanced the response only at very low fluence rates of Re (< 10"^ ;UmoI m~^ s"'). In both species, the effect of hourly pulses of far-red light was similar to the maximum inhibition observed in the first phase of the response to Re. Using reciprocity failure (i.e. higher inhibition under continuous than pulsed light) as the operational criterion, a 'true' high-irradianee reaction occurred under continuous far-red light but not under Re or red plus far-red light mixtures. Native and overexpressed phyA are proposed to mediate very low fluence responses under Re. In WT A. thaliana, this effeet is eounteraeted by a negative action of phyA on phyB-mediated low-fluenee responses.

show abstract

Avena phytochrome a overexpressed in transgenic tobacco seedlings differentially affects red/far-red reversible and very-low-fluence responses (cotyledon unfolding) during de-etiolation

Cited by 20 publications

References 25 publications

High-irradiance responses induced by far-red light in grass seedlings of the wild type or overexpressing phytochrome A

High-irradiance responses induced by far-red light in grass seedlings of the wild type or overexpressing phytochrome A

Genetic Regulation of Development in Sorghum bicolor (X. Greatly Attenuated Photoperiod Sensitivity in a Phytochrome-Deficient Sorghum Possessing a Biological Clock but Lacking a Red Light-High Irradiance Response)

Dual effect of phytochrome A on hypocotyl growth under continuous red light

Contact Info

Product

Resources

About