Abstract:

The aims are to study the transcriptome expression characteristics of Anoectochilus roxburghii (Wall.) Lindl. under heat stress and to analyze its heat shock response mechanism. A. roxburghii (NYJ2) under normal culture and high temperature stress (45^oC) were used as materials and sequenced by using Illumina HiSeq^TM2000 platform, and De novo assembly was performed by Trinity software. As a result, a total of 75,688 unigenes were obtained, and 28,323 unigenes were annotated in Nr, KOG, KEGG and Swisspro database, with an annotation rate of 37.42%. Among them, 17,532 unigenes were annotated into 25 functional categories of KOG database; 10,108 unigenes were annotated into 128 metabolic pathways by the KEGG databases; and 17,485 unigenes were annotated in the GO database, which were divided into 47 functional categories through biological process, molecular function and cell composition. There were 777 differentially expressed unigenes before and after heat stress, of which 362 unigenes were up-regulated and 415 unigenes were down-regulated after stress. 24 genes were found in response to heat stress, including 1 heat shock protein gene, 15 genes related to PS Ⅰ and PS Ⅱ, 3 chloroplast rbcL genes, 2 PLD genes, 1 CAT-coding gene, 1 GAPDH gene and 1 CYP-coding gene. This research analyzed the response of A. roxburghii to heat stress at transcriptome level. These data will lay a foundation for identification of functional genes, and provide a reference basis for the cultivation of A. roxburghii heat-resistant strains.

Key words: Anoectochilus roxburghii (Wall.) Lindl., heat stress, transcriptome sequencing, gene annotation, differentially expressed genes