早春短生植物鸢尾蒜在干热和湿润环境下的比较转录组研究

Comparative Transcriptomic Analysis of Spring Ephemeral Ixiolirion tataricum in Dry and Hot Habitat and Under-Canopy Humid Habitat

本研究对新疆干旱区早春短生植物鸢尾蒜进行转录组测序,通过比较转录组分析,揭示干热生境和林下湿润生境中鸢尾蒜个体基因表达的差异,探讨鸢尾蒜适应新疆干热环境的分子机理.转录组测序共得到150702个同基因,检测到两种生境间显著差异表达基因1929个,其中827个上调,1102个下调.差异基因共富集到49个GO条目,下调基因功能主要包括代谢过程、生物合成、生物调节、细胞、细胞器、催化活性、结合活性等,上调基因功能包括繁殖、繁殖过程、信号、转导活性等.KEGG代谢通路富集发现下调基因显著富集到光合作用、碳代谢、氨基酸代谢和蛋白质加工等通路中,而上调基因显著富集到与细胞渗透压调节、抗氧化活性相关的次生代谢产物合成代谢及信号转导通路中.干热环境可能通过降低光合作用抑制鸢尾蒜的生长,植株通过激活信号转导、提高渗透调节物质和抗氧化活性以维持细胞的内稳态和正常功能;此外,发育过程和繁殖过程的促进保障了个体在干热环境中快速完成生活周期.研究结果为揭示新疆短生植物适应干热环境的分子调控机制以及适应性进化提供了基础.

Transcriptome sequencing was performed on individuals of spring ephemeral plant Ixiolirion tataricum from two different habitats:dry and hot habitat and under canopy humid habitat in arid Xinjiang.We investigated the difference of gene expression between the two habitats by comparative transcriptomic analysis,aiming to discuss the adaptive mechanism of I.tataricum to the hot and dry environment in Xinjiang.A total of 150702 unigenes were assembled from the raw reads.A total of 1929 significantly differential expressed genes(DEGs)were detected between the two habitats,of which 827 were up-regulated and 1102 down-regulated.DEGs were enriched into 49 gene ontology(GO)items.Down-regulated gene were mainly enriched in function groups metabolic processes,biosynthesis,biological regulation,cells,organelles,catalytic activity,binding activity,etc.,while up-regulated genes in reproduction,reproduction process,signal,transduction activity,etc..KEGG metabolic pathway enrichment found that down-regulated genes were significantly enriched in photosynthesis,carbon metabolism,amino acid metabolism and protein processing,while up-regulated genes in secondary metabolites synthesis related to cell osmotic pressure regulation and antioxidant activity,and signal transduction pathways.The dry and hot environ-ment inhibited the growth of I.tataricum by reducing photosynthesis and related biological processes.I.tataricum maintained the homeostasis and normal functions of cells by activating signal transduction,increasing osmotic reg-ulation substances and antioxidant activities.In addition,it was enabled that I.tataricum complete the life cycle timely by promotion of the development process and reproduction process in dry and hot environment.This study will provide basic knowledge for revealing the molecular regulation and adaptive evolution of ephemeral plants in dry and hot environment.