454-transcriptome Sequencing Analysis Of Cotton Roots Inoculated By Verticillium Dahliae

Cotton is one of the most important economic crop in China. Verticillium wilt severely reduces cotton yield and the fiber quality, which caused by Verticillium dahliae. Due to lack of resistent germplasm in the upland cotton, so mining the potential defense related genes from sea island cotton and identifying the functions of thses genes provide the basis of molecular breeding for disease resistance in upland cotton. High-throughput sequencing technologies,454transcriptomic sequencing platforms (454-GS-FLEX Titanium) was used to sequence a mixed root RNA sample from resistant cotton(Gossypium barbadense cv.’Hai7124’) which inoculated by V. dahliae strain V991after4,12,24and48h.A total of753934reads with average length of250bp were identified after sequencing. By removing the low quality reads we stil have579532reads with high quality. Finally we have25237contigs after using assembly software. Through BLAST the genome of Verticillium dahliae and454-derived sequences, we found10genes that matched to the genome of Verticillium dahliae; About80%of contigs had BLAST hit on the NCBI redundant protein libraries, TAIR10annotated protein databases and Cotton unique sequences, respectively. What’s more,80%of the454transcriptome sequences had BLAST hit on cotton fiber gene expression database. We discovered10putative cotton receptor like protein genes by454transcriptome sequencing and find the full length of these genes through BLAST on the cotton genome D. With the homology analysis of the10putative cotton receptor like protein (RLP) genes to the receptor like proteins from Arabidopsis, the Vel gene from Tomato and Tomato related species and Ve like gene that cloned from the cotton, found that GbRLPl, GbRLP4-1, GbRLP42, GbRLP47, GbRLP4-2have homology with the Ve like gene from the cotton. The tissue expression analysis of10receptor like protein (RLP) showed the low expression quantity and the diversity of expression in each tissue above normal condition. Including GbRLP13only expressed in cotton root, which proved it is a root specific RLP gene of the cotton. These RLPs present different expression patterns after induction by Verticillium dahliae. The GbRLP4-1was down-regulated expression after induction by Verticillium dahliae; GbRLPl, GbRLP4-2, GbRLP15, GbRLP51-2were up-regulated expression induction by Verticillium dahliae. And these RLP have a different expression patterns after JA and SA induction. The result of our present experiment prove that the RLP may take participate in the resistance of cotton to the wilt fungus Verticillium dahliae. Virus mediated gene silencing (VIGS) technology is in progress in this experiment to explore the function of10RLP after inoculating by Verticillium dahliae.This study provides the data basis of exploring the cotton root specific or high-efficiency expression genes, enriching the existing cotton gene expression database which have majority of fiber genes.