Identification And Expression Profiling Of CCA1Genes In Barley

Flowering is a key period for the plant, and it is the cue to ensure proper timing of the switchfrom vegetative to reproductive growth. The plant coordinates biological processes with dailyand seasonal changes that in the environments by an endogenous mechanism which is calledcircadian clock. The circadian cycles take place over the course of approximately24-hday-night.CCA1is a MYB-domain transcription factor that functions in or close to the centraloscillator in Arabidopsis. The mutant has a phenotype of short period rhythm. We get theinformation about CCA1gene in barley by the Genbank through the homologues genes fromArabidopsis and rice. By the method of RT-PCR,we identificated a CCA1gene in barley,analyzed the phylogenetic relationship with rice、maize and Arabidopsis, and examined itsexpression in different conditions in barely seedling, in order to give some in clues for thebarley photoperiods. The results as follows:(1) By RT-PCR, the cDNA sequence of CCA1gene was isolated from barley inbredZong3and named BaCCA1. The results showed that the full length coding sequence ofBaCCA1was2157bp and was predicted to encode a protein with718aa.(2) The phylogenetic analysis showed that BaCCA1had the least relationship withArabidopsis which shared39.9%identity in protein sequence，and have69.4%and72%identities to maize and oryza sativa CCA1. It suggests what we cloned may be a CCA1horologes.(3) We found the transcript stability of CCA1is regulated by light.CCA1has differerntexpression in different conditions by real-time PCR.(4) The plant body is through this kind of internal regulation mechanism to feel lightcycle and adapting to climate change, so as to maintain their normal life activities. In addition,the expression of the other components in the circadian clock core oscillator such as GI andthe downstream gene CAB are changed rhythmic indicated that are required for thefunctioning of the core oscillator.