Transcriptome Analysis Under Drought Stress And TIFY Gene Family Analysis Of Setaria Italica

Foxtail millet(Setaria italica(L.)P.Beauv.)is an important cereal crop in the north of China.It has good quality of resistance to barren and drought.In recent years,drought has a great impact on the yield and quality of global crops.The growth and development of foxtail millet and its yield are also seriously restricted by drought.At present,there are more and more researches on drought resistance of plants.The researches on drought stress of foxtail millet can promote the exploration of drought resistance genes and drought resistance mechanism of plants.In this study,AN-04,YG-1 and QH-2 were selected as the research materials.Among these materials,AN-04 is the drought sensitive variety.High throughput sequencing was used to analyze the transcriptome of the leaves under seedling stage of these three foxtail millet varieties under drought stress,and weighted gene coexpression network analysis(WGCNA)was used to dig drought resistant candidate genes under drought stress,and TIFY family of foxtail millet was analyzed.The main results are as follows:1.Transcriptome analysis of foxtail millet leaves under drought stress at seedling stageTranscriptome analysis of three foxtail millet varieties under drought stress,the results showed that the number of differentially expressed genes in control and rehabilitation of drought-resistant varieties were much more than that of drought-sensitive variety under middle day and pre-dawn;at the same time,there were also differences in genes responding to drought within varieties when there was middle day and pre-dawn,including genes responding to both light in the middle day and at pre-dawn,and genes responding to drought stress only when there was in the middle day or at pre-dawn.Moreover,the genes of drought-resistant varieties were enriched by GO for differentially expressed genes in the three varieties of foxtail millet under middle day and pre-dawn between control and treatment;the GO terms enriched by the three foxtail millet varieties mainly include hormone signaling pathway,photosynthesis,metabolism,and so on.8 genes randomly selected from the differential genes were verified by q RT-PCR.The results showed that the expression levels of these genes were basically consistent with the transcriptome sequencing results.2.Analysis of drought stress related genes in foxtail millet by WGCNAWe carry out WGCNA by using the transcriptomes of three foxtail millet varieties under drought stress.As a result,we get darkgrey and lightcyan modules related to drought stress.GO functional enrichment analysis was performed for the genes within the two modules,and chlorophyll,metabolism,photosynthesis and other items were mainly enriched in both modules.Using cytoscape software to construct a co-expression network map for the two modules,nine drought core candidate genes were excavated.Among 9 genes,two genes belong to AP2-like family and b ZIP family.3.Identification of TIFY gene family and analysis of drought resistance in foxtail millet24 TIFY family genes were identified from foxtail millet,and 24 genes were distributed on eight chromosomes.By constructing phylogenetic tree,structure analysis,cis-acting elements and collinearity analysis,the results showed that the TIFY family genes of foxtail millet were more closely related to rice genes,and most of them contained cis-acting elements such as stress resistance response,light response,hormone response and circadian rhythm regulation response acting element,and so on,TIFY family genes of foxtail millet are mainly expressed in plant leaves,and the expression of TIFY family genes of foxtail millet under drought stress is more specific in drought-resistant varieties than in drought-sensitive varieties.In conclusion,the number of genes expressed in different varieties of foxtail millet with distinct drought sensitivity in drought stress is diverse,which indicates that different varieties of foxtail millet have unlike drought resistance mechanisms.In this study,genes involved in drought resistance of foxtail millet were obtained through transcriptome analysis and WGCNA analysis.TIFY family gene analysis enriches the research ideas of drought resistance genes of foxtail millet,and lays a foundation for the exploration and identification of drought resistance genes in foxtail millet.