陆地棉粉花花蕾与黄花花蕾的比较转录组分析

Comparison of the transcriptomes between pink flower buds and yellow flower buds in upland cotton

【目的】挖掘影响棉花花色多态性的代谢物质和候选基因。【方法】以陆地棉黄色花品种中棉所24和粉色花品系中遗红为研究材料,取花瓣变色前后的花蕾进行花色苷含量测定和转录组测序分析。【结果】在开花前,中棉所24和中遗红的花蕾颜色已表现出差异,随着花蕾的发育,花色差异逐渐增大,其中天竺葵素-3-O-葡萄糖苷、矢车菊素-3-O-半乳糖苷、矢车菊素-3-O-葡萄糖苷和矢车菊素-3-O-(6''-O-丙二酰)-葡萄糖苷在中遗红花蕾中特异性积累。对中棉所24和中遗红花蕾中差异表达基因(differentially expressed gene,DEG)进行联合分析,共获得8790个上调表达基因和8521个下调表达基因,它们在液泡质子ATP酶(V型ATP酶)复合体、类黄酮生物合成过程等通路富集。进一步分析发现,花色苷合成相关的基因在2个材料中的表达水平并无明显差异,而调控花色苷合成、转运以及液泡酸碱平衡的基因Gh_A07G083500、bHLH基因Gh_D11G130400、GST基因Gh_A07G079800和V型ATP酶基因Gh_A09G123000、Gh_A08G012100和Gh_D09G115200在中遗红中高水平表达。【结论】本研究构建了粉花花色形成的调控通路,鉴定了与棉花花色相关的候选基因,为棉花育种提供基因资源。

[Objective]This study aims to detect the metabolites and candidate genes which affect the polymorphsim of cotton flower color.[Method]Before and after petal color was changed,the flower buds of yellow flower cotton variety CCRI 24 and pink flower cotton line Zhongyihong were extracted to perform anthocyanin content detection and RNA-seq analysis.[Result]Before flowering,the color of CCRI 24 buds and Zhongyihong buds was different,and the difference was gradually increased with the development of buds.Among them,pelargonidin-3-O-glucoside,cyanidin-3-O-galactoside,cyanidin-3-O-glucoside(Kuromanin)and cyanidin-3-O-(6''-O-malonyl)-glucoside were specifically accumulated in Zhongyihong buds.A total of 8790 up-regulated and 8521 down-regulated genes were obtained by differentially expressed gene(DEG)analysis between CCRI 24 and Zhongyihong,which were enriched in pathways such as proton-transporting V-type ATPase complex and flavonoid biosynthesis.Further analysis showed that there was no significant difference in the expression of genes related to anthocyanin synthesis between the two materials,while Gh_A07G083500,bHLH gene Gh_D11G130400,GST gene Gh_A07G079800,and V-type ATPase genes Gh_A09G123000,Gh_A08G012100,and Gh_D09G115200 involved in regulating anthocyanin synthesis,transporting and vacuolar acid-base balance were highly expressed in CCRI 24.[Conclusion]This study demonstrated the gene expression pathway of pink flower formation,and identified several candidate genes related to the flower color of cotton,which provide genetic resources for cotton breeding.