PMID- 17080619
OWN - NLM
STAT- MEDLINE
DCOM- 20061211
LR  - 20221207
IS  - 0140-7791 (Print)
IS  - 0140-7791 (Linking)
VI  - 29
IP  - 4
DP  - 2006 Apr
TI  - Tomato seed germination: regulation of different response modes by phytochrome B2 
      and phytochrome A.
PG  - 701-9
AB  - Lycopersicon esculentum seeds germinate after rehydration in complete darkness. 
      This response was inhibited by a far-red light (FR) pulse, and the inhibition was 
      reversed by a red light (R) pulse. Comparison of germination in 
      phytochrome-deficient mutants (phyA, phyB1, phyB2, phyAB1, phyB1B2 and phyAB1B2) 
      showed that phytochrome B2 (PhyB2) mediates both responses. The germination was 
      inhibited by strong continuous R (38 micromol m(-2) s(-1)), whereas weak R (28 
      nmol m(-2) s(-1)) stimulated seed germination. Hourly applied R pulses of the 
      same photon fluence partially replaced the effect of strong continuous R. This 
      response was called 'antagonistic' because it counteracts the low fluence 
      response (LFR) induced by a single R pulse. This antagonistic response might be 
      an adaptation to a situation where the seeds sit on the soil surface in full 
      sunlight (adverse for germination), while weak R might reflect that situation 
      under a layer of soil. Unexpectedly, the effects of continuous R or repeated R 
      pulses were mediated by phytochrome A (PhyA). We therefore suggest that low 
      levels of PhyA in its FR-absorbing form (Pfr) cause inhibition of seed 
      germination produced either by extended R irradiation (by degradation of 
      PhyA-Pfr) or by extended FR irradiation [keeping a low Pfr/R-absorbing form (Pr) 
      ratio].
FAU - Appenroth, Klaus J
AU  - Appenroth KJ
AD  - University of Jena, Institute of General Botany and Plant Physiology, Dornburger 
      Str. 159, 07743 Jena, Germany. Klaus.Appenroth@uni-jena.de
FAU - Lenk, Gabriele
AU  - Lenk G
FAU - Goldau, Lydia
AU  - Goldau L
FAU - Sharma, Rameshwar
AU  - Sharma R
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Plant Cell Environ
JT  - Plant, cell & environment
JID - 9309004
RN  - 0 (Phytochrome A)
RN  - 0 (Plant Proteins)
RN  - 136250-22-1 (Phytochrome B)
SB  - IM
MH  - Germination/genetics/*physiology/radiation effects
MH  - Light
MH  - Solanum lycopersicum/genetics/*growth & development/metabolism
MH  - Mutation
MH  - Phytochrome A/genetics/*physiology
MH  - Phytochrome B/genetics/*physiology
MH  - Plant Proteins/genetics/*physiology
MH  - Seeds/genetics/*growth & development/metabolism
EDAT- 2006/11/04 09:00
MHDA- 2006/12/12 09:00
CRDT- 2006/11/04 09:00
PHST- 2006/11/04 09:00 [pubmed]
PHST- 2006/12/12 09:00 [medline]
PHST- 2006/11/04 09:00 [entrez]
AID - 10.1111/j.1365-3040.2005.01455.x [doi]
PST - ppublish
SO  - Plant Cell Environ. 2006 Apr;29(4):701-9. doi: 10.1111/j.1365-3040.2005.01455.x.