Chen Yicun, Yin Hengfu, Gao Ming, Zhu Huiping, Zhang Qiyan, Wang Yangdong
State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry Bejing, China.
Front Plant Sci. 2016 Dec 27;7:1974. doi: 10.3389/fpls.2016.01974. eCollection 2016.
(tung oil tree) is a promising industrial crop. Unfortunately, the devastating wilt disease has caused its great losses, while its sister species () is remarkably resistant to this pathogen. However, the genetic mechanisms underlying this difference remain largely unknown. We here generated comparative transcriptomic atlases for different stages of infected root. The transcriptomes of and were assembled and contained 258,430 and 245,240 non-redundant transcripts with N50 values of 1776 and 2452, respectively. A total of 44,310 pairs of putative one-to-one orthologous genes were identified in species. Overall, the vast majority of orthologous genes shared a remarkably similar expression mode. The expression patterns of a small set of genes were further validated by quantitative real-time PCR. Moreover, 157 unigenes whose expression significantly correlated between the two species were defined, and gene set enrichment analysis indicated roles in increased defense response and in jasmonic and salicylic acid signaling responses during pathogen attack. Co-expression network analysis further identified the 17 hub unigenes, such as the serine/threonine protein kinase D6PK, leucine-rich repeat receptor-like kinase (LRR-RLK), and EREBP transcription factor, which play essential roles in plant pathogen resistance. Intriguingly, the expression of most hub genes differed significantly between and . Based on our results, we propose a model to describe the major molecular reactions that underlie the defense responses of resistant to . These data represent a crucial step toward breeding more pathogen-resistant .
油桐是一种很有前景的经济作物。不幸的是，毁灭性的枯萎病已使其遭受巨大损失，而其近缘物种对这种病原体具有显著抗性。然而，这种差异背后的遗传机制在很大程度上仍不清楚。我们在此生成了油桐感染根不同阶段的比较转录组图谱。油桐和近缘物种的转录组被组装，分别包含258,430和245,240个非冗余转录本，N50值分别为1776和2452。在这两个物种中总共鉴定出44,310对假定的直系同源基因。总体而言，绝大多数直系同源基因共享非常相似的表达模式。一小部分基因的表达模式通过定量实时PCR进一步验证。此外，定义了157个在两个物种间表达显著相关的单基因，基因集富集分析表明它们在病原体攻击期间增强防御反应以及茉莉酸和水杨酸信号反应中发挥作用。共表达网络分析进一步鉴定出17个核心单基因，如丝氨酸/苏氨酸蛋白激酶D6PK、富含亮氨酸重复序列的类受体激酶（LRR-RLK）和EREBP转录因子，它们在植物病原体抗性中起关键作用。有趣的是，大多数核心基因在油桐和近缘物种之间的表达存在显著差异。基于我们的结果，我们提出了一个模型来描述抗性近缘物种对油桐防御反应的主要分子反应。这些数据代表了培育更多抗病原体油桐品种的关键一步。
