Generation Of Transgenic Lines Carrying One Of SPL-family Genes Under The Control Of Their Own Promoters

Rice is one of the most important crop,which production is related to the food security.It is very urgent to cultivate new stress-tolerant rice varieties with high yield and high quality.Transcription factors can activate or inhibit gene expression by binding to specific sequences of cis-acting elements of target genes,and then regulate many important agronomic traits and stress tolerance of plants.Therefore,it is important to study the regulatory network of transcription factors to analysis the biological mechanism for improving rice quality and stress resistance.A family of SPLs transcription factors play an important role in the regulation of plant growth,resistance to biotic and abiotic stresses and signal transduction.SPL transcription factors have been identified in many plant species by whole genome analysis,such as rice,Arabidopsis thaliana,upland cotton,corn,soybean and so on.There are 19 members in rice SPL family.The expression of rice OsSPLs gene is regulated by various regulatory factors,among which micro RNAs(mi RNAs)play an important role in this process.mi RNAs can regulate the expression of target genes by cleavage or translation at the post transcription level or translation level.At present,the regulatory functions of some rice OsSPLs transcription factors have been known.For example,Ideal Plant Architecture 1(IPA1)encodes Os SPL14,which makes rice thicker with almost no ineffective tillers and more grains per panicle.In addition,overexpression of IPA1 can improve the resistance of rice to Pyricularia grisea.OsSPLs genes have the phenomenon of functional redundancy.For example both SPL3 and SPL12 regulate the root development of rice and SPL7,SPL13 and SPL14 regulate the panicle development of rice.In this study,we have obtained transgenic lines carrying one of SPL-family genes with tag under the control of their own promoter,and completed DNA extraction of 1350 rice samples from 59 lines,and identified 512 transgenic plants with SPLs genes and FLAG tag.By RNA extraction and reverse transcription,63 plants with expressed transgene were identified.Then,the 63 positive transgenic plants were used to detect whether OsSPLs protein have been expressed.We identified 12 positive plants with expressed OsSPLs proteins,which belonged to five OsSPLs family members,namely Os SPL3,Os SPL8,Os SPL9,Os SPL11 and Os SPL12.We observed the growth phenotype of transgenic rice plants carrying OsSPLs gene detected at protein level,and did not find significant phenotypic difference in germination rate,plant height,root development and so on between wild type and transgenic lines.Among the members of OsSPLs transcription factor family identified in transgenic rice with tag protein,there is only Os SPL3 which has been studied about the binding sites and regulation of physiological stage.There are no reports on the genome-wide binding sites and the screening of target genes of other four transcription factors.Therefore,based on the obtained transgenic lines carrying OsSPLs gene with tag,we laid a foundation for the subsequent genome-wide identification of transcription factor binding sites,screening of transcription factor regulatory target genes and gene function research,which results can provide a theoretical basis for breeding stress-tolerant rice varieties with high yield and high quality.