Functional Analysis Of La Homologues In Rice

La protein is known as RNA binding protein and ubiquitous in kinds of eukaryotic cells.By binding with the 3' termini of many newly synthesized RNAs,La protein participates in RNA processing and metabolism.RNAs bound by the La protein include all nascent transcripts made by RNA polymerase III as well as certain small RNAs synthesized by other RNA polymerases.AtLal has been demonstrated to be the bona fide La homologue in Arabidopsis as well plays an important role in embryogenesis.Knockdown of AtLal expression leads to the arrest of growth and dvelopment of shoot apical meristem.atlal mutant leads to termination of embryoic development.However there was no related study to be reported in terms of La homologues genes in rice.Our research revealed the presence of two La homologues gene in rice,Os39 and Os42.qRT-PCR and promoter-driven GUS analysis revealed that Os39 and Os42 express constitutively in rice tissues and organs,which is consistant with prediction of Genevestigator rice microarray data.Subcellular localization results show that the full-length of Os39 and Os42 are largely confined to nucleus,whereas COOH-terminally truncated(Os39 ?30 and Os42 ?30)were predominantly cytoplasmic,indicating the presence of nuclear localization signal.There is no obivious phenotype showed in Os42 over-expression transgenic lines,but CRISPR/Cas9 transgenic lines show darwfish plant architecture and adaxially rolling leaf.Consistant with this,transgenic inhibition lines of AtLal have smaller plant and rolling-deformed or needle-shaped leaf.Over-expression and CRISPR/Cas9 of Os39 transgenic lines have no obvious phenotype.According to the information above,Os42 seems to be putative La homologue in rice and may work in rice growth and development.The above experiments laid the foundation for further research work.