水稻幼穗与Ustilaginoidea virens互作早期的转录组分析

Transcriptomic analysis of early interaction between rice young spikelets and Ustilaginoidea virens

由子囊菌门真菌稻绿核菌Ustilaginoidea virens引起的稻曲病是世界范围内水稻生产上的重要病害之一。但是,对水稻抗稻曲病的抗性机制仍不清楚。为初步探明水稻与稻曲病菌之间互作早期的分子调控机制,本研究采用比较转录组测序技术对稻曲病菌接种抗病品种‘IR28’和感病品种‘两优培九’(LYP9) 6 h的测序数据进行了分析,试图初步阐明水稻抗病分子机制。分析发现,在抗病和感病品种中均差异表达基因有1 005个共表达,在这些基因中,抗病品种中表达上调基因(697个)多于感病品种中表达上调的基因(626个),下调的基因(308个)少于感病品种中下调表达的基因(379个);随后通过GO富集和KEGG代谢途径分析,发现苯丙烷类代谢途径和双萜植保素合成途径相关的基因、几丁质酶、β-1,3-葡聚糖酶、糖基水解酶和过氧化物酶等基因在抗病品种中被显著诱导上调表达,而在感病品种中基因表达低于抗病品种或下调表达,推测这些基因很可能在水稻与稻曲病菌识别早期发挥重要的抗病作用。该研究结果可为水稻抗稻曲病基因克隆及抗稻曲病分子育种提供理论基础。

Rice false smut,caused by Ustilaginoidea virens,is a major threat to rice production worldwide,but the mechanisms underlying rice resistance to U.virens remain elusive.To understand molecular bases underlying the initial interaction between rice and U.virens,transcriptional changes associated with the early stage of U.virens infection in the resistant‘IR28’and susceptible‘LYP9’rice cultivars were analyzed using the transcriptome analyses.The results demonstrated that 1 005 differentially expressed genes(DEGs)were common to‘IR28’and‘LYP9’,Among common DEGs shared in both cultivars with the isolate P1 at 6h post inoculation.More genes were up-regulated in‘IR28’(697)than in‘LYP9’(626)while fewer DEGs(308)in‘IR28’were down-regulated than those(379)in‘LYP9’.GO enrichment and KEGG metabolic pathway analysis revealed that phenylpropanoid biosynthesis,diterpene phytoalexin biosynthetic genes,chitinase beta-1,3-glucan,glycosyl hydrolase and peroxidase genes were specifically induced in the resistant variety,while these DEGs were down-regulated or less induced in the susceptible cultivar,implying that these genes may play an important role in disease resistance at the early stage of U.virens infection.Our results provide a theoretical basis for further exploitation of rice resistance genes and for molecular breeding of false smut-resistance rice.