Response Of Serine/Arginine-rich And Heterogeneous Nuclear RNP Gene Family In Maize Seedlings To Drought Stress

As an important regulatory mode of gene expression for higher eukaryotes,alternative splicing(AS) plays vital roles on the composition and relative abundanceof transcriptome.，in which serine/arginine-rich proteins (SR proteins) and hnRNP(heterogeneous nuclear RNP) act as key regulators. We research the characteristics ofmolecular biology and evolutionary relationships of Splicing factors bybioinformatics method. We conclude that Splicing factor are the significant role inregulating the gene transcription to resist the drought damage in maize. The briefresults are as follows:1. We studied forty-two members of hnRNP protein family, which are unevendistributed in ten chromosomes, where four members located on chromosome1and8,the chromosome2,3and4have six members, the chromosome5have five membersand there are three members distributed in chromosome6, each with one member ofthe distribution of the rest of the chromosomes. The molecular mass of the proteinsencoded by this gene family are between15427-88734, the length of those aminoacids are between155aa-794aa., and the rest of gene members encode acidic protein.2. Establishing the phylogenetic tree for the hnRNP protein family members thatwe researched based on RRM conserved domain, because the N-terminal of six fromthe42members don’t have RRM recognition motif, so we used the first RRMdomain located on the N-terminal to analyze the phylogenetic tree. The36membersof hnRNP gene family were divided into five subgroups in Zea mays.3. We analyzed the promoter regions of the selected42members from hnRNPprotein family, and the results showed that the promoter regions of hnRNP proteingenes contained3-8cis-regulatory elements which were concerned with development,plant hormones and stress response besides the core promoter elements (CAAT-Box,TATA-Box). 4. According to the expression profiles analysis, the hnRNP protein genes weredown-regulated in H21, while were up-regulated in Ye478on the whole underdrought stress.5. The relative water content of leaves was measured with three geneticmaterials Zheng58， Chang7-2and Zhengdan-958. The results show that,Zhengdan-958had the smallest change on RWC under drought stress, whichindicated that Zhengdan-958had a strong tolerance to drought stress; In contrast, thewater content of Chang7-2changed a lot under drought stress, which confirming thatit had higher sensitivity to water stress.6. The analysis on difference expression profiles of SR protein family genesindicated that the overall expression pattern of SR gene family has continuity ofregulation, strong genotype dependence and tissue-specific. The overall SR proteingenes were down-regulated in root under drought stress, while were up-regulated inshoots. The overall expression patterns of SR protein gene family with the treatmentof rewatering primarily were down-regulated. Additionally, the own alternativesplicing was widespread existed.