Abstract：
Aluminum (Al) toxcity is considered to be the primary factor limiting crop productivity in acidic soil. Many studies indicate that long non-coding RNAs (lncRNAs) fulfil a crucial role in plant growth and responses to different abiotic stress. However, identification and characterization of lncRNAs responsive to Al stress at a genome-wide level in olive tree is still lacking. Here, we performed comparative analysis on lncRNA transcriptome between Zhonglan (an Al-tolerant genotype) and Frantoio selezione (Al-sensitive) responding to Al exposure. A total of 19,498 novel lncRNAs were identified from both genotypes, and 6900 lncRNA-target pairs were identified as cis-acting and 2311 supposed to be trans-acting. Among them, 2076 lncRNAs were appraised as Al tolerance-associated lncRNAs due to their distinctly genotype-specific expression profiles under Al exposure. Target prediction and functional analyses revealed several key lncRNAs are related to genes encoding pectinesterases, xyloglucan endotransglucosylase/hydrolase, WRKY and MYB transcription factors, which mainly participate in the modification of cell wall for Al tolerance. Furthermore, gene co-expression network analysis showed 8 lncRNA-mRNA-miRNA modules participate in transcriptional regulation of downstream Al resistant genes. Our findings increased our understanding about the function of lncRNAs in responding to Al stress in olive and identified potential promising lncRNAs for further investigation.
摘要：
铝（Al）中毒被认为是限制酸性土壤中作物生产力的主要因素。许多研究表明，长链非编码RNA（lncRNA）在植物生长和对不同非生物胁迫的反应中起着至关重要的作用。然而,在橄榄树中，仍然缺乏在全基因组水平上对Al胁迫响应的lncRNAs的鉴定和表征。这里,我们对中兰（耐铝基因型）和Frantoioselezione（铝敏感）响应铝暴露的lncRNA转录组进行了比较分析。从两种基因型中总共鉴定出19,498个新的lncRNAs，6900个lncRNA-靶对被鉴定为顺式作用，2311个被认为是反式作用。其中,2076个lncRNA被评价为与Al耐受相关的lncRNA，因为它们在Al暴露下具有明显的基因型特异性表达谱。靶标预测和功能分析揭示了几个关键的lncRNAs与编码果胶酯酶的基因有关。木葡聚糖内葡萄糖基转移酶/水解酶，WRKY和MYB转录因子,其主要参与对Al耐性的细胞壁修饰。此外，基因共表达网络分析显示8个lncRNA-mRNA-miRNA模块参与下游抗Al基因的转录调控。我们的发现增加了我们对lncRNAs在橄榄中响应Al胁迫的功能的理解，并确定了潜在的有希望的lncRNAs用于进一步研究。
