Li Xiaofei, Fang Xiaoying, Cui Zhiyi, Hong Zhou, Liu Xiaojin, Li Gaiyun, Hu Houzhen, Xu Daping
Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou, Guangdong, China.
College of Landscape Architecture, Nanjing Forestry University, Nanjing, Jiangsu, China.
Front Plant Sci. 2024 Mar 25;15:1320226. doi: 10.3389/fpls.2024.1320226. eCollection 2024.
Recently, some new Qi-Nan clones of (Lour.) Spreng which intensively produces high-quality agarwood have been identified and propagated through grafting techniques. Previous studies have primarily focused on ordinary and the differences in composition when compared to Qi-Nan and ordinary . There are few studies on the formation mechanism of Qi-Nan agarwood and the dynamic changes in components and endophytic fungi during the induction process. In this paper, the characteristics, chemical composition, and changes in endophytic fungi of Qi-Nan agarwood induced after 1 year, 2 years, and 3 years were studied, and Qi-Nan white wood was used as the control. The results showed that the yield of Qi-Nan agarwood continued to increase with the induction time over a period of 3 years, while the content of alcohol extract from Qi-Nan agarwood reached its peak at two years. During the formation of agarwood, starch and soluble sugars in xylem rays and interxylary phloem are consumed and reduced. Most of the oily substances in agarwood were filled in xylem ray cells and interxylary phloem, and a small amount was filled in xylem vessels. The main components of Qi-Nan agarwood are also chromones and sesquiterpenes. With an increasing induction time, the content of sesquiterpenes increased, while the content of chromones decreased. The most abundant chromones in Qi-Nan agarwood were 2-(2-Phenethyl) chromone, 2-[2-(3-Methoxy-4-hydroxyphenyl) ethyl] chromone, and2-[2-(4-Methoxyphenyl) ethyl] chromone. Significant differences were observed in the species of the endophytic fungi found in Qi-Nan agarwood at different induction times. A total of 4 phyla, 73 orders, and 448 genera were found in Qi-Nan agarwood dominated by and . Different induction times had a significant effect on the diversity of the endophytic fungal community in Qi-Nan. After the induction of agarwood formation, the diversity of Qi-Nan endophytic fungi decreased. Correlation analysis showed that there was a significant positive correlation between endophytic fungi and the yield, alcohol extract content, sesquiterpene content, and chromone content of Qi-Nan agarwood, which indicated that endophytic fungi play a role in promoting the formation of Qi-Nan agarwood. Qi-Nan agarwood produced at different induction times exhibited strong antioxidant capacity. DPPH free radical scavenging activity and reactive oxygen species clearance activity were significantly positively correlated with the content of sesquiterpenes and chromones in Qi-Nan agarwood.
最近，一些新的奇楠沉香母株被鉴定出来，这些母株能大量产出高品质沉香，并通过嫁接技术进行繁殖。以往的研究主要集中在普通沉香以及与奇楠沉香和普通沉香相比的成分差异上。关于奇楠沉香的形成机制以及诱导过程中成分和内生真菌的动态变化的研究较少。本文研究了诱导1年、2年和3年后奇楠沉香的特征、化学成分和内生真菌的变化，并以奇楠白木作为对照。结果表明，奇楠沉香的产量在3年的诱导期内随着诱导时间的延长而持续增加，而奇楠沉香的醇提取物含量在两年时达到峰值。在沉香形成过程中，木射线和木间韧皮部中的淀粉和可溶性糖被消耗并减少。沉香中的油性物质大多填充在木射线细胞和木间韧皮部中，少量填充在木质部导管中。奇楠沉香的主要成分也是色酮和倍半萜。随着诱导时间的增加，倍半萜的含量增加，而色酮含量降低。奇楠沉香中含量最多的色酮是2-(2-苯乙基)色酮、2-[2-(3-甲氧基-4-羟基苯基)乙基]色酮和2-[2-(4-甲氧基苯基)乙基]色酮。在不同诱导时间的奇楠沉香中发现的内生真菌种类存在显著差异。在奇楠沉香中共发现4个门、73个目和448个属，以子囊菌门和担子菌门为主。不同的诱导时间对奇楠内生真菌群落的多样性有显著影响。沉香形成诱导后，奇楠内生真菌的多样性降低。相关性分析表明，内生真菌与奇楠沉香的产量、醇提取物含量、倍半萜含量和色酮含量之间存在显著正相关，这表明内生真菌在促进奇楠沉香的形成中发挥作用。不同诱导时间产生的奇楠沉香表现出较强的抗氧化能力。DPPH自由基清除活性和活性氧清除活性与奇楠沉香中倍半萜和色酮的含量显著正相关。
