Chakrabarty Debasis, Chauhan Puneet Singh, Chauhan Abhishek Singh, Indoliya Yuvraj, Lavania Umesh Chandra, Nautiyal Chandra Shekhar
CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow 226 001, India.
Department of Botany, Lucknow University, Lucknow 226 007, India.
Sci Rep. 2015 Dec 18;5:18630. doi: 10.1038/srep18630.
Vetiver, a perennial C4 grass, has long been known for its multifarious uses in perfumery, medicine and environmental protection. Two distinct vetiver morphotypes have been identified in India, i.e., A. North Indian type characterized by thick and smooth fast growing roots that produce superior quality of laevorotatory oil; and B. South Indian type with more number of thin and hairy roots that produce inferior quality of dextrorotatory oil. The two morphotypes were targeted for transcriptome analysis to understand the contribution of genetic background on oil quality and root morphology. Sample A showed enhanced activity of flavonoid and terpenoid biosynthesis related genes, i.e. ERF, MYB, bHLH, bZIP and WRKY. Interestingly, expression analysis revealed that the genes involved in sesquiterpene biosynthesis pathway were up regulated in Sample A. Moreover, some of the genes involved in mevalonate pathway of sesquiterpene biosynthesis were unique to Sample A. Our results also demonstrated several transcripts involved in root development and hormonal regulation being up regulated in Sample A. To validate gene expression results of RNA-seq data, 20 transcripts were validated by qRT-PCR experiment. The present study provided an important start point for further discovery of genes related to root oil quality in different ecotypes of vetiver.
香根草是一种多年生C4草本植物，长期以来因其在香水制造、医药和环境保护中的多种用途而闻名。在印度已鉴定出两种不同的香根草形态类型，即：A. 北印度类型，其特点是根粗且光滑，生长迅速，可产出优质的左旋油；B. 南印度类型，根细且多毛，产出的右旋油质量较差。针对这两种形态类型进行转录组分析，以了解遗传背景对油质和根系形态的影响。样本A中类黄酮和萜类生物合成相关基因（即ERF、MYB、bHLH、bZIP和WRKY）的活性增强。有趣的是，表达分析表明，参与倍半萜生物合成途径的基因在样本A中上调。此外，参与倍半萜生物合成甲羟戊酸途径的一些基因是样本A所特有的。我们的结果还表明，样本A中一些参与根系发育和激素调节的转录本上调。为验证RNA-seq数据的基因表达结果，通过qRT-PCR实验对20个转录本进行了验证。本研究为进一步发现不同生态型香根草中与根油质量相关的基因提供了重要的起点。
