Insights into the plateau adaptation of Salvia castanea by comparative genomic and WGCNA analyses

第一作者：Ling Xua

第一单位：浙江理工大学

通讯作者：Ake Liu

 Abstarct 

背景回顾：Salvia castanea, a wild plant species is adapted to extreme Qinghai-Tibetan plateau (QTP) environments. It is also used for medicinal purposes due to high ingredient of tanshinone IIA (T-IIA). Despite its importance to Chinese medicinal industry, the mechanisms associated with secondary metabolites accumulation (i.e. T-IIA and rosmarinic acid (RA)) in this species have not been characterized. Also, the role of special underground tissues in QTP adaptation of S. castanea is still unknown. 

栗色鼠尾草（Salvia castanea）是一种适应青藏高原极端环境的野生植物。由于其丹参酮-IIA（T-IIA）成分含量较高，因此常被用于医疗领域。尽管其对中国的医药工业很重要，但栗色鼠尾草中与T-IIA和迷迭香酸（RA）等次生代谢物积累相关的机制研究还欠缺。此外，栗色鼠尾草特殊地下组织在其对青藏高原极端环境的适应中的作用尚不清楚。

研究目的：We explored the phenomenon of periderm-like structure in underground stem center of S. castanea with an aim to unravel the molecular evolutionary mechanisms of QTP adaptation in this species. 

本文中，作者研究了栗色鼠尾草地下茎中的类周皮结构，旨在揭示该物种适应青藏高原极端环境的演化机制。

方法：Morphologic observation and full-length transcriptome of S. castanea plants were conducted. Comparative genomic analyses of S. castanea with other 14 representative species were used to reveal its phylogenetic position and molecular evolutionary mechanisms. RNA-seq and WGCNA analyses were applied to understand the mechanisms of high accumulations of T-IIA and RA in S. castanea tissues. 

作者对栗色鼠尾草进行了形态学数据和全长转录组的分析。通过对栗色鼠尾草和其他14个代表种的比较基因组分析揭示了栗色鼠尾草的系统发育地位以及分子演化机制。作者通过RNA-seq和WGCNA分析揭示栗色鼠尾草组织中T-IIA和RA的高水平积累机制。

结果：Based on anatomical observations, we proposed a “trunk-branches” developmental model to explain periderm-like structure in the center of underground stem of S. castanea. Our study suggested that S. castanea branched off from cultivated Danshen around 16 million years ago. During the evolutionary process, significantly expanded orthologous gene groups, 24 species-specific and 64 positively selected genes contributed to morphogenesis and QTP adaptation in S. castanea. RNA-seq and WGCNA analyses unraveled underlying mechanisms of high accumulations of T-IIA and RA in S. castanea and identified NAC29 and TGA22 as key transcription factors. 

基于解剖学的观察，作者提出了一个“树干-分枝”的发育模型，用来解释地下茎中心的类周皮结构。本文的研究显示栗色鼠尾草是一千六百万年前从丹参栽培种分化出来形成的一支。在栗色鼠尾草的演化历程中，有一些显著扩增的基因家族、24个物种特异性的基因，以及64个受到正选择基因，这些基因共同作用于栗色鼠尾草的形态发生以及对青藏高原极端环境的适应。RNA-seq和WGCNA分析揭示了栗色鼠尾草高水平积累T-IIA和RA的潜在机制，鉴定了NAC29和TGA22两个转录因子发挥关键作用。

结论：We proposed a “trunk-branches” developmental model for the underground stem in S. castanea. Adaptations to extreme QTP environment in S. castanea are associated with accumulations of high secondary metabolites in this species.

作者提出了一个“树干-分枝”的发育模型，用于解释栗色鼠尾草的地下茎。栗色鼠尾草适应青藏高原极端环境与高水平的次生代谢积累相关。

** 刘阿克 **

doi: https://doi.org/10.1016/j.jare.2022.02.004

Journal: Journal of Advanced Research

Published date: February 14, 2022