Functional Exploration And Evolutionary Analysis Of Constitutive NcRNA SnoRNA481 And Regulatory Non-coding RNA LncRNAH30 In Cotton

Non-coding RNA(noncoding RNA,ncRNA),which lacks coding ability in the genome.Non-coding RNA can be divided into constitutive ncRNA and regulating ncRNA based on its function.Regulatory non-coding RNA can regulate the growth and development of organisms and respond to environmental stimuli,including small interfering RNA(siRNA),microRNA,and long noncoding RNA(lncRNA).Constitutive non-coding RNA mainly contains ribosomal RNA(rRNA),transport RNA(tRNA),nuclear small RNA(snRNA)and nucleolar small RNA(snoRNA).Cotton is not only the main source of natural textile materials,but also a well-evolved heterotetraploid model crop.In this paper,we employed the upload cotton as the main research object,using bioinformatics technology combined with the technology of virus-induced gene silencing(VIGS)to study the constitutive non-coding RNA and regulatory non-coding RNA.It was found that the constitutive non-coding RNA gene snoRNA481 may be involved in the regulation of plant drought tolerance.In the screening of regulatory non-coding RNA,a long noncoding RNA,H30,was found to be involved in the regulation of plant photosynthesis.The main research contents and results are as follows:(1)Using VIGS technology to screen the function of lncRNA.Our team has constructed the lncRNA library in the leaves of cotton in the previous study.According to the expression intensity,we selected the top 172 IncRNAs as candidate genes for functional screenig via VIGS.In this study,we constructed 104 VIGS constructs of lncRNA candidate genes,and finished a functional screening of 27 lncRNAs via VIGS.After repeated tests and bioinformatics analysis,two functional lncRNA genes were confirmed and selected for the further investigation,one is constitutive non-coding RNA snoRNA481,and the other is regulatory lncRNA gene H30.(2)We used a active-expressed snoRNA family in cotton leaves as an example to analyze the snoRNA in the Gossypium.We identified the snoRNAs of Gossypium hirsutum(Gh),G.arboreum(Ga)and G.raimondii(Gr)by insferal software,and characterized snoRNA in the evolution of Gossypium.SnoRNA showed the tendency of average distribution pattern between tetraploid and two progeny species.The snoRNA481 family form gene clusters on the chromosomes.We further confirmed the homologs of snoRNA 481,with 20,7 and 13 homologous sites in Gh,Ga and Gr genome respectively.(3)The regulatory lncRNA gene H30 is a unique lncRNA in polyploid cotton,which may participate in the regulation of photosynthesis and affect the growth of plants.H30 is an antisense transcript of an unknown functional coding gene NAD5L on allotetraploid genome.But the transcript does not depend on RNA polymerase Ⅱ(RNA polymerase Ⅱ,Pol Ⅱ)to express.After effectively inhibiting the expression of GhNAD5L and H30 which were transcripts of each other,cotton showed a dwarf phenotype at seedling stage,and there were physiological differences in the decrease of photosynthetic efficiency.