| Zea mays has different light sensitivity among genotypes.Phytochrome played a decisive role in the photosensitivity of different types of maize germplasm.It is response to changes in red(R)and far red(FR)and involved in seed germination,leaf extension and stem elongation,flowering induction,seedling de-etiolation and other developmental stage.In this study,PhyA1,PhyA2,PhyBl,PhyB2 and PhyCl,PhyC2 gene sequences of six different light and temperature sensitive maize were obtained according to the primers of maize B73 Phytochrome gene sequences,analyze its phytochrome gene encoding the amino acid sequence and structure of the domain,and with some other plants phytochrome gene sequence alignment and analysis the homologous relationship between them;Using the real-time PCR technology to analyze the expression pattern of phytochrome gene,clarify its expression mode,which response to light,dark and supplement light.It is important for the study of the reasons for the different light and temperature sensitivity of different mature varieties.The main results are as follows:(1)There was no large fragment insert or deletion of the phytochrome gene sequence of two types of different light sensitive maize varieties.A small number of SNP(single nucleotide polymorphisms)sites were found for their encoded amino acid sequence alignment.Phytochrome protein in plants can be divided into N-terminal photosensitive region and C-terminal light transfer region.Compared with the sequenced B73 amino acid sequence,where the PhyAl sequence has a SNP site falling into the 5 species C-terminal light transfer region.There were 6 amino acid differences in CML288 that occurred in the N-terminal photosensitive region of PhyB1.There are two differences in PhyC1 that fall within the N-terminall photosensitive region of CML288 and Huang zao 4.(2)Across to analysis of the amino acid sequence of phytochrome genes of Zea mays with Sorghum bicolor,Oryza sativa,Arabidopsis thaliana,Setaria italica and Linum usitatissimum and their genetic phylogenetic tree analysis.The results showed that the phytochrome of monocotyledonous and dicotyledon were obviously divided into two categories,and the genetic relationship between maize and sorghum was relatively close,and the genetic distance between Zea mays and sorghum bicolor was higher than that of Zea mays Between the genetic distance.The phytochrome of maize are relatively far homologous to the Oryza sativa and Setaria italica.(3)The expression of phytochrome in CML288 and Huangcao 4 leaves was analyzed under different conditions of light and dark.The expression of PhyA in Huangshao 4 was significantly higher than that in B73 and CML288 under light conditions,and under dark conditions,And the expression of PhyBl in Huangcao 4 and CML288 was almost not expressed in the dark condition.However,the expression of PhyBl in Huangshao 4 was significantly increased after 24 hours of supplementation.PhyB2 was significantly increased in CML288 have a greater degree of recovery.The expression level of PhyC in the light condition was higher than that in the dark condition.Indicating that the PhyC gene will be mutated in different latitude,and this variation will affect the maturity and sensitivity of light and temperature.The expression level of CML288 was significantly higher than that of light and dark treatment after 24 hours.There was no significant difference in the expression level of the phytochrome gene between the leaf and the expression level of the root tissue.PhyA,PhyB and PhyC is mainly expressed under light conditions.The expression level of PhyAl and PhyCl in light condition was higher than that in dark condition,and the expression level of PhyA1 and PhyC1 was higher than that of other tested cultivars.PhyB1 is mainly expressed in CML288 and has a certain effect on its de-etiolation effect.There was no significant difference in the expression level of photosynthetic pigment gene between leaf and root.The expression levels of the phytochrome genes in different light-sensitive maize varieties in different light and dark conditions are different,which is related to the small SNP point mutations in different amino acid sequences in their protein structure analysis.Can this explain the different varieties Corn has different light sensitivity reasons need further study. |
