菌根共生参与基因对不同品种小麦菌根侵染的响应

Responses of genes involved in mycorrhizal symbiosis to arbuscular mycorrhizal colonization in different wheat cultivars

为研究不同小麦品种之间丛枝菌根(Arbuscular mycorrhiza,AM)侵染率差异的分子机制,于2017~2019年进行了两个生长季的盆栽试验,使用Claroideoglomus etunicatum、Rhizophagus intraradices、Funneliformis mosseae,Acaulospora delicate 4种菌剂混合接种,测定菌根侵染率并筛选出极端菌根侵染差异品种小红麦(低侵染)和扬麦14(高侵染),后通过转录组分析比较了两个品种中菌根共生参与基因(转录因子、转运蛋白、酶类和其他基因)对菌根侵染的响应,旨在探究小麦菌根侵染率基因型差异的分子机制。研究结果表明,扬麦14的菌根侵染率显著高于小红麦,二者差异可达7倍以上。共检测到GRAS、AP2和MYB共3类转录因子家族基因,其中的绝大多数被菌根侵染上调表达,仅有2个MYB转录因子基因在两个品种小麦中对菌根侵染的响应明显不同;检测到编码ABC转运蛋白、磷酸盐转运蛋白、蔗糖转运蛋白和铵转运蛋白的基因响应菌根侵染,其中19个ABC转运蛋白基因对菌根侵染的响应最为强烈,且其中的多数基因在两个小麦品种中对菌根侵染的响应均有较大差异;检测到12类酶编码基因响应菌根侵染,其中24个基因的表达差异倍数在16倍以上,3个E3泛素连接酶基因、1个枯草杆菌蛋白酶家族基因、6个细胞色素P450家族基因以及2个丝氨酸羧肽酶编码基因在两个小麦品种中对菌根侵染的响应有较大差异;此外,检测到5类106个其它菌根共生参与基因也显著响应菌根侵染,其中3个F-box家族基因在两个小麦品种中对菌根侵染的响应有较大差异。本研究共鉴定到57个在两个小麦品种中对菌根侵染响应明显差异的基因,这些基因可能在影响小麦菌根侵染率基因型差异的过程中发挥关键作用。

In order to study mechanism of the differences of arbuscular mycorrhizal(AM)colonization rates among wheat genotypes,a pot experiment was conducted in two growing seasons from 2017 to 2019.Claroideoglomus etunicatum,Rhizophagus intraradices,Funneliformis mosseae,Acaulospora delicata were used for mixed inoculation,and the AM colonization was measured.Two wheat cultivars(YM14 and XHM)with contrast AM colonization were screened out and used for transcriptome analysis.The response of four types of genes(transcription factors,transporters,enzymes and other genes)that previously reported to be involved in AM symbiosis formation to AM colonization were focused.The study aimed to explore the molecular mechanisms of the genotypic differences of wheat in AM colonization.The results showed that the AM colonization rate of the cultivar YM14 was significantly higher than that of XHM,and the difference was more than 7times.Three types of transcription factor family genes such as GRAS,AP2 and MYB were detected,most of which were upregulated by AM colonization,but only 2 MYB transcription factor genes had distinct different responses to AM colonization between the two cultivars;Four types of transporter genes,including ABC transporter gene,phosphate transporter,sucrose transporter and ammonium transporter gene,were detected to respond to AM colonization.Among them,19 ABC transporter genes responded most strongly to AM colonization,and most of them had different responses to AM colonization between the two wheat cultivars;12 types of enzyme-encoding genes were detected to respond to AM colonization,of which 24 genes had differential expression more than 16 times,3 E3 ubiquitin ligase genes,1 subtilisin-like protease genes,6cytochrome P450 family genes,and 2 serine carboxypeptidase genes had different responses to AM colonization between the two wheat cultivars;in addition,five other gene types involved in mycorrhizal symbiosis were detected,and 106 genes significantly responded to AM colonization,of which 3 F-box family genes had different responses to AM colonization between the two wheat varieties.In this study,57 genes with significant differences in response to AM colonization in the two wheat cultivars were identified,and may play key roles in affecting the genotypic differences of wheat in AM colonization.