Screening Of Homozygous Transgenic Upland Rice And Identification Of Dwarf Line

Since abiotic stress factors such as drought and saline have become important factors affecting current crop cultivation,it is particularly important to improve the resilience of crop themselves.As a variant of rice,upland rice has its own unique advantages in some adversities,so optimizing the traits of upland rice has become a hot research direction.This thesis screened and analyzed the progeny of the upland rice transgenic lines obtained in the previous period.These lines were transferred the late embryonic developmental rich protein family LEA₃ subfamily-like protein gene in Physcomitrella patens.?Gene ID: 112289949,named LEA8981?.The main results are as follows:The candidate homozygous transgenic lines obtained by screening were subjected to Southern hybridization analysis to identify the foreign gene?LEA8981?copy number.Obtained two single copy lines,ten double copy lines and nine multiple copy lines.RT-PCR analysis was performed on 12 lines containing 1-2 copy numbers to analyze the relative expression levels of the LEA8981 gene in each low copy line.Finally,seven LEA8981 transcripts with higher transcription levels were obtained,which laid the foundation for the subsequent screening of new lines with excellent drought resistance.This study found that single copy transgenic homozygous lines 3-28 were significantly dwarfed and stably inherited compared to wild type.After TAIL-PCR,it was confirmed that the LEA8981 gene has been stably integrated into the genome of chromosome 10,and a specific insertion site was identified.To further elucidate the cause of dwarf mutations in this line,two genes in the upstream and downstream 10 KB range of the LEA8981 gene insertion site were analyzed in wild type,dwarf line 3-28,and normal plants using quantitative PCR techniques.The results showed that the expression of the downstream gene ncRNA?locus marker: OSNPB₁00351457?in the LEA8981 gene insertion site was significantly higher in the 3-28 dwarf line than in the wild line,indicating that this may be the main cause of dwarf mutation.This result provides a research direction for the subsequent study of the molecular regulation mechanisms of 3-28 dwarf mutations.