金铁锁扦插苗与组培苗低温胁迫应答转录组比较

Comparison Between Responsive Transcriptome of Cutting and Tissue Cultural Seedlings of Psammosilene tunicoides Under Low Temperature Stress

【目的】了解金铁锁扦插苗与组培苗在环境胁迫应答方面的基因表达差异,为研究其组培苗生理特性及其抗逆机制提供参考。【方法】对金铁锁扦插苗与组培苗及其低温胁迫下的叶片进行转录组测序,并比较分析其基因表达与调控通路。【结果】从金铁锁扦插苗及其低温胁迫、组培苗及其低温胁迫4个样本中共获得118 097条单基因(unigene),其中,81 271条单基因在Nr、Nt、SwissProt、KEGG、COG、Pfam和GO数据库中获得注释,分别注释78 422条、61 476条、59 294条、60 749条、61 926条、59 653条和55 061条。扦插苗和组培苗分别识别15 493个和27 649个低温应答基因,扦插苗中低温诱导表达7 235个基因、低温抑制表达8 258个基因,组培苗中低温诱导表达12 580个基因,低温抑制表达15 069个基因,低温胁迫下扦插苗和组培苗共同应答的基因有6 818个。在低温应答基因中,发现多个CBF转导途径的基因成员,其中,一些DREB/CBF基因在植株受到低温胁迫2 h内出现差异表达。除CBF外,多个已知或假定编码转录因子的其他低温应答基因也被诱导表达。【结论】金铁锁低温应答过程可能与次生代谢物的生物合成、碳代谢、淀粉和蔗糖代谢、核糖体和过氧化物酶体等过程有关。

【Objective】The difference in gene expression between cutting and tissue culture seedlings under low temperature stress was known to provide a reference for studying physiological property and stress-resistance mechanism of tissue culture seedlings of Psammosilene tunicoides.【Method】The leaf transcriptomes of cutting and tissue culture seedlings,and cutting and tissue culture seedlings under low temperature stress were sequenced and then the gene expression and regulatory pathway were analyzed and compared.【Result】118097 unigenes were obtained from 4 samples of cutting seedlings under low temperature stress and tissue culture seedlings under low temperature in P.tunicoides.81271 unigenes were annotated in Nr,Nt,SwissProt,KEGG,COG,Pfam and GO database,which were 78422,61476,59294,60749,61926,59653 and 55061 respectively.15493 and 27649 cold-responsive genes were identified in cutting and tissue culture seedlings separately.7235 genes with cold inducible expression and 8258 genes with cold suppression expression were identified in P.tunicoides cutting seedlings.12580 genes with cold inducible expression and 15069 genes with cold suppression expression were identified in P.tunicoides tissue culture seedlings.There were 6818 responsive genes identified both in cutting and tissue culture P.tunicoides seedlings under low temperature stress.Many gene members of CBF transduction pathway were found in cold-responsive genes and some DREB/CBF genes of P.tunicoides seedlings appeared differential expression within 2 hours under low temperature stress.The cold-responsive genes of more known or assumed coding transcription factors were inductively expressed except for CBF.【Conclusion】The cold responsive process may be correlated with biosynthesis of secondary metabolite,carbon metabolism,starch and sucrose metabolism,ribosome and peroxisome in P.tunicoides.