The Effect Of Circadian Clock-relate Gene LHY,CCA1 And GI On Vegetative Phase Change In Arabidopsis Thaliana

The growth and development of higher plants is a continuous process in the whole life cycle,including embryonic development and post-embryonic development.Post-embryonic development can also be divided into the vegetative growth stage and the reproductive stage.Only through the juvenile phase and adult phase,composed to the vegetative growth period,the vegetative phase change(VPC)can be finished.VPC is an important physiological process in the growth and development of higher plants.Only through this shift,a plant can enter into reproductive growth,blossom and bear fruit.In the growth and development of higher plants,the changes of phenotype,shoot apical meristem and gene expressed in molecular level and so on,all have an intimate contact with vegetative phase change.The first onset of adaxial trichomes on rosette leaf has in juvenile phase of Arabidopsis can be used as morphological markers of vegetative phase change.The shoot apical meristem(SAM)plays an important role in the growth and development of high plants,and it is an important pathway during the development of plants.miR156 and its target gene SPL3,belonging to the genes SPLs(SQUAMOSA PROMOTER BINDING PROTEIN LIKE),play a key role in the regulation of VPC.Plants go through an internal "clock" to achieve the purpose of regulating the response to the night long or short.Under the certain conditions,the plant can maintain every day 24 h rhythms,the internal mechanism of this kind of rhythm called biothythm clock(circadian clock).The vegetative phase change is closely related to the circadian rhythms.However,the role of circadian clock genes in the vegetative phase change is still not clear.From the morphological characteristics,anatomical structure and the expression of miR156 and SPL3 in molecular level controlled by VPC and so on,we analyze the characteristics from various aspects of circadian clock related mutants lhy,cca1,gi during the VPC in Arabidopsis thaliana.The results showed that the mutants of lhy,cca1 growth cycle and wild type Col-0 were similar,but the growth period of gi is longer than wild type.By observing its morphological changes of leaves,length-width ratio of rosettes leaves,trichome distribution and the changes of the shoot apical meristem,the circadian clock related mutants of lhy,cca1,gi showed a delated VPC in Arabidopsis thaliana.Moreover,through the detection of RT-PCR and Q-PCR for the expression of mainly regulating genes of miR156 and SPL3 controlled by VPC,the results also indicated a delated VPC in lhy,cca1,gi.