Phenotype And Genetic Analysis Of Arabidopsis Lightperiod Sensitive Pleiotropic Mutant Ldd1

Lightperiod as one of the most important environment signals generate endogenous circadian rhythm and affect many aspects of plant development. We isolated an Arabidopsis lightperiod sensitive pleiotropic T-DNA insertion mutant lightperiod-dependant dwarf 1 (ldd1) by change of the lightperiod condition. In general, lddl shows reduced height, shortened internodes, increased branches, changed leaf shape, uncertain flowering time and slower grown of vegetative organs compared with WT. Under 24hours light condition, lddl has seriously changed shape of young leaves and pavement cells, dramatically shortened internodes between silique and cauline branches, later flowering time, and also prolonged life cycle. But when the lightperiod condition recovered to long-day or short-day, all of these abnormities disappeared, alleviated or even reversed, indicated the appearance of these phenotypes are lightperiod sensitive and dependant.24hours light condition could seriesly strength these mutant phenotypes. Genetic studies showed no phenotypical segregation in lddl selfcross progeny. When back crossed to WT, F1 progeny display a WT phenotype, and about 1/4 F2 progeny kept lddl's phenptypes, suggested lddl is a recessive, single gene or closely linkaged multiple genes mutant.