Comparative Transcriptome Analysis Reveals Different Mechanisms of Adaptation to Environment among Three Species of Saussurea DC.

Abstract

Saussurea medusa, Saussurea hypsipeta and Saussurea obvallata are typical alpine snowline plants growing in the Qinghai-Tibet plateau. They are characterized by a specialized morphology. S. medusa and S. hypsipeta have very dense trichomes on whole plant, whereas S. obvallata has transparent bracts covered inflorescences. The different forms reflect their adaptation to cold environments. To investigate the different mechanisms of adaptation of these species to cold temperatures, transcriptome sequencing was performed in three species of Saussurea DC. A total of 116394 137237 and 113879 Unigenes were identified from S. medusa, S. hypsipeta and S. obvallata, respectively. Of these, 55909 (48.03%), 65519 (47.74%) and 51889 (45.56%) Unigenes were matched in public databases. GO analysis identified that most of annotated Unigenes in the three species of plants were related to cellular, metabolic, and single−organism processes, and binding and catalytic activities. The differential expression of 37 genes related to environmental adaptation were discovered by pairwise comparisons. Of these, two candidate genes (Interaptin-like and CSLB3) related to trichome development were identified only in S. medusa and S. hypsipeta, which was consistent with their distinct morphology. Our data can provide a valuable resource for the further studies on the adaptive mechanisms of molecular and functional ecology in Saussurea DC.

Analysis and Verification of the Conserved MYB Binding Element in the <i>DFR</i> Promoter in Compositae

“…Comparative transcriptome analysis reveals mechanisms of adaptation to extreme environments among Three Species of Compositae [16]. The regulation pathway through which the MYB protein of subgroup 6 promotes DFR expression has been verified in an increasing number of Asteraceae plants, suggesting that such a pathway is highly conserved in Compositae (Table 1).…”