Heat-Resistant Inbred Lines Coordinate the Heat Response Genes Expression Remarkably in Maize

High temperature is increasingly becoming one of the prominent environmental factors affecting the growth and development of maize (Zea mays L.). Therefore, it is critical to identify key genes and pathways related to heat stress (HS) tolerance in maize. Here, we identified a heat-resistant (Z58D) and heat-sensitive (AF171) maize inbred lines at seedling stage. Transcriptomic analysis identified 3,006 differentially expressed genes (DEGs) in AF171 and 4,273 DEGs in Z58D under HS treatments, respectively. Subsequently, GO enrichment analysis showed that shared upregulated genes in AF171 and Z58D involved in response to HS, protein folding, abiotic and temperature stimulus pathway. Moreover, the comparison between the two inbred lines under HS showed that response to heat and response to temperature stimulus significantly overrepresented for the 1,234 upregulated genes. Furthermore, commonly upregulated genes in Z58D and AF171 had higher expression level in Z58D than AF171. In addition, maize inbred CIMBL55 had been verified to be more tolerant than B73 and commonly upregulated genes had higher expression level in CIMBL55 than B73 under HS. The consistent results indicated that heat-resistant inbred lines may coordinate the remarkable expression of genes in order to recover from HS. Additionally, 35 DEGs were conserved among 5 inbred lines by a comparative transcriptomic analysis. Most of them were more pronounced in Z58D than AF171 at expression level. Those candidate genes may confer thermotolerance in maize. Overall design: Sequencing data of leaf of heat-sensitive and heat-resistant line under normalcondition and heat stress condition

高温日益成为影响玉米（Zea mays L.）生长发育的主要环境胁迫因子之一。因此，鉴定与玉米耐热胁迫（heat stress, HS）相关的关键基因及调控通路至关重要。本研究在苗期筛选得到耐热玉米自交系Z58D与热敏感自交系AF171。转录组分析结果显示，热胁迫处理后，AF171中鉴定出3006个差异表达基因（differentially expressed genes, DEGs），Z58D中则鉴定出4273个差异表达基因。后续GO富集分析表明，AF171与Z58D中共有的上调基因显著富集于热胁迫响应、蛋白质折叠、非生物胁迫及温度刺激响应通路。进一步比较两个自交系在热胁迫下的基因表达谱发现，1234个上调基因显著富集于热响应与温度刺激响应通路。此外，Z58D与AF171的共有上调基因在Z58D中的表达水平高于AF171。另外，本研究验证了玉米自交系CIMBL55的耐热性优于B73，且其共上调基因在热胁迫下的表达水平同样高于B73。上述一致结果表明，耐热自交系可通过协调关键基因的高效表达以应对热胁迫损伤。此外，通过比较转录组分析，在5个自交系中鉴定出35个保守的差异表达基因，其中多数在Z58D中的表达水平较AF171更为显著。上述候选基因可能赋予玉米耐热性。整体实验设计：热敏感与耐热玉米自交系在正常培养条件与热胁迫条件下的叶片转录组测序数据。