Wang Guang-Long, Huang Ying, Zhang Xin-Yue, Xu Zhi-Sheng, Wang Feng, Xiong Ai-Sheng
State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.
Plant Cell Rep. 2016 Aug;35(8):1743-55. doi: 10.1007/s00299-016-1992-0. Epub 2016 May 9.
Carrot root development associates lignin deposition and regulation. Carrot is consumed worldwide and is a good source of nutrients. However, excess lignin deposition may reduce the taste and quality of carrot root. Molecular mechanisms underlying lignin accumulation in carrot are still lacking. To address this problem, we collected taproots of wild and cultivated carrots at five developmental stages and analyzed the lignin content and characterized the lignin distribution using histochemical staining and autofluorescence microscopy. Genes involved in lignin biosynthesis were identified, and their expression profiles were determined. Results showed that lignin was mostly deposited in xylem vessels of carrot root. In addition, lignin content continuously decreased during root development, which was achieved possibly by reducing the expression of the genes involved in lignin biosynthesis. Carrot root may also prevent cell lignification to meet the demands of taproot growth. Our results will serve as reference for lignin biosynthesis in carrot and may also assist biologists to improve carrot quality.
胡萝卜根的发育与木质素沉积及调控相关。胡萝卜在全球范围内被食用，是营养的良好来源。然而，过量的木质素沉积可能会降低胡萝卜根的口感和品质。目前仍缺乏关于胡萝卜中木质素积累的分子机制。为了解决这个问题，我们在五个发育阶段收集了野生胡萝卜和栽培胡萝卜的主根，分析了木质素含量，并使用组织化学染色和自发荧光显微镜对木质素分布进行了表征。鉴定了参与木质素生物合成的基因，并确定了它们的表达谱。结果表明，木质素主要沉积在胡萝卜根的木质部导管中。此外，在根发育过程中木质素含量持续下降，这可能是通过降低参与木质素生物合成的基因的表达来实现的。胡萝卜根也可能通过防止细胞木质化来满足主根生长的需求。我们的结果将为胡萝卜中木质素的生物合成提供参考，也可能有助于生物学家改善胡萝卜品质。
