Cloning And Function Analysis Of Phytochrome Genes In Secale Cereale

Cultivated rye(Secale cereal L.)belongs to the rye genus of the poaceae family,which is not only a valuable food and feed crop,but also an important germplasm resource for wheat improvement.It’s agronomic characters such as growth period,plant height and yield are closely related to light in the environment.Phytochromes are a class of red and far-red receptor involved in the regulation of adaptive responses such as seed germination,plant height,shade avoidance response and flowering in plants.In other crops,it has been reported to improve crops by modifying phytochromes signal transduction pathway.In agricultural production,the grain yield of rye had reduced by its lodging due to excessive plant height.Phytochromes can promote photomorphogenesis and inhibit plant height,however,there is no relevant research in rye.By studying the function of rye phytochromes,providing a reference and theoretical basis for promoting rye photomorphogenesis,inhibiting plant height and regulating growth period through phytochrome.In this study,three phytochrome genes,Sc PHYA,Sc PHYB and Sc PHYC were cloned from Weining rye.And gene structures,protein domains and phylogenetic relationship of amino acid level were analyzed.q RT-PCR was used to detected the transcriptional abundance of Sc PHYs in different tissues and different light conditions at seedling stage.Scphy C protein interaction domain was determined by yeast two-hybrid method.We observed phenotypes of Arabidopsis thaliana transgenic plants for Sc PHYC under white light,red light and long-days conditions.These results showed that the phys proteins of rye had similar domains with those of Arabidopsis thaliana,rice and wheat,and had high amino acid homology with those of wheat and rice,suggesting that they have similar function.The transcriptional abundances of Sc PHYs were highest in roots,and higher under dark and far-red light than other continuous light conditions.While the expression patterns of the three genes were slightly different in the transformation from dark to red light,far-red light,blue light and white light.In photoperiodic response,the expression patterns of the three genes were similar under long-day conditions,but different under short-day conditions.These results indicated that Sc PHYs played an important role in the photomorphogenesis of rye.Compared with Sc PHYA and Sc PHYB,Sc PHYC had higher transcription abundance under different conditions,suggesting that Sc PHYC might play a major role in photomorphogenesis of rye.The results of yeast two-hybrid experiment showed that the C-terminal domain of Scphy C was the main segment of its own interaction.We obtained transgenic lines for heterologous transformation of Sc PHYC into Arabidopsis thaliana Col-0 and phy C-2 mutants.Compared with the control group,the hypocotyl length of Sc PHYC transgenic plants was shorter under red and white light,and the chlorophyll content was increased under long-day conditions.The functional analysis of rye phytochromes is conducive to the study of phytochrome signaling mechanisms of rye,and also lays a foundation to further exploring the roles of phytochrome in improvement and molecular breeding of rye.