THE DARK-ADAPTATION RESPONSE OF THE DEETIOLATED PEA MUTANT LIP1 IS MODULATED BY EXTERNAL SIGNALS AND ENDOGENOUS PROGRAMS

Citation
S. Frances et Wf. Thompson, THE DARK-ADAPTATION RESPONSE OF THE DEETIOLATED PEA MUTANT LIP1 IS MODULATED BY EXTERNAL SIGNALS AND ENDOGENOUS PROGRAMS, Plant physiology, 115(1), 1997, pp. 23-28
Citations number
24
Categorie Soggetti
Plant Sciences
Journal title
ISSN journal
00320889
Volume
115
Issue
1
Year of publication
1997
Pages
23 - 28
Database
ISI
SICI code
0032-0889(1997)115:1<23:TDROTD>2.0.ZU;2-K
Abstract
The lip1 mutant of pea (Pisom sativum L.) exhibits a de-etiolated phen otype. When grown in darkness, lip1 plants have several characteristic s normally associated only with light-grown plants. Young wild-type (W T) seedlings accumulate high levels of transcripts from plastid-relate d genes (such as those encoding chlorophyll a/b-binding proteins, ferr edoxin, and the small subunit of Rubisco) only in the light. In contra st, regardless of the light conditions under which the plants are grow n, young mutant seedlings accumulate transcript levels equal to or gre ater than those seen in light-grown WT seedlings of the same age. Unde r some conditions, light-grown lip1 seedlings failed to respond to dar k treatment. The largest response to darkness observed in the mutant o ccurred when older seedlings were first grown under low-light conditio ns before transfer to darkness. The mutant's inability to respond to d arkness is not due to a gross disturbance in the circadian clock. We c onclude that environmental signals (light) and endogenous programs (de velopmental and circadian) regulate gene expression in both WT and mut ant plants. However, mutant seedlings exhibit a developmentally regula ted and exaggerated response to light. In addition, the effect of the mutation may be greatest during a brief period early in development.