Wang Yan, Liu Kaitai, Zhou Yunyun, Chen Yong, Jin Chenzhong, Hu Yihong
College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi 417000, China.
Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, State Key Laboratory of Chemo/Biosensing and Chemometrics, National Center of Technology Innovation for Saline-Alkali Tolerant Rice, College of Biology, Hunan University, Changsha 410082, China.
Plants (Basel). 2023 Feb 19;12(4):943. doi: 10.3390/plants12040943.
(Mill.) Druce is an essential Chinese herb, but continuous cropping (CC) often results in a serious root rot disease, reducing the yield and quality. Phenolic acids, released through plant root exudation, are typical autotoxic substances that easily cause root rot in CC. To better understand the phenolic acid biosynthesis of roots in response to CC, this study performed a combined microRNA (miRNA)-seq and RNA-seq analysis. The phenolic acid contents of the first cropping (FC) soil and CC soil were determined by HPLC analysis. The results showed that CC soils contained significantly higher levels of -coumaric acid, phenylacetate, and caffeic acid than FC soil, except for cinnamic acid and sinapic acid. Transcriptome identification and miRNA sequencing revealed 15,788 differentially expressed genes (DEGs) and 142 differentially expressed miRNAs (DEMs) in roots from FC and CC plants. Among them, 28 DEGs and eight DEMs were involved in phenolic acid biosynthesis. Meanwhile, comparative transcriptome and microRNA-seq analysis demonstrated that eight miRNAs corresponding to five target DEGs related to phenolic acid synthesis were screened. Among them, ath-miR172a, ath-miR172c, novel_130, sbi-miR172f, and tcc-miR172d contributed to phenylalanine synthesis. Osa-miR528-5p and mtr-miR2673a were key miRNAs that regulate syringyl lignin biosynthesis. Nta-miR156f was closely related to the shikimate pathway. These results indicated that the key DEGs and DEMs involved in phenolic acid anabolism might play vital roles in phenolic acid secretion from roots of under the CC system. As a result of the study, we may have a better understanding of phenolic acid biosynthesis during CC of roots of .
（米尔.）德鲁斯是一种重要的中药材，但连作往往会导致严重的根腐病，降低产量和品质。通过植物根系分泌释放的酚酸是典型的自毒物质，容易在连作中引发根腐病。为了更好地了解根系对连作的酚酸生物合成响应，本研究进行了联合微RNA（miRNA）测序和RNA测序分析。通过高效液相色谱（HPLC）分析测定了头茬（FC）土壤和连作土壤中的酚酸含量。结果表明，除肉桂酸和芥子酸外，连作土壤中香豆酸、苯乙酸和咖啡酸的含量显著高于头茬土壤。转录组鉴定和miRNA测序揭示了FC和连作植物根系中15788个差异表达基因（DEG）和142个差异表达miRNA（DEM）。其中，28个DEG和8个DEM参与酚酸生物合成。同时，比较转录组和微RNA测序分析表明，筛选出了与5个酚酸合成相关靶标DEG对应的8个miRNA。其中，ath-miR172a、ath-miR172c、novel_130、sbi-miR172f和tcc-miR172d有助于苯丙氨酸合成。Osa-miR528-5p和mtr-miR2673a是调节紫丁香基木质素生物合成的关键miRNA。Nta-miR156f与莽草酸途径密切相关。这些结果表明，参与酚酸合成代谢的关键DEG和DEM可能在连作体系下植物根系酚酸分泌中发挥重要作用。作为该研究的结果，我们可能对植物根系连作过程中的酚酸生物合成有更好的理解。
