Microscopic histochemical comparison during mountain-agarwood formation
(2.National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China 100700)
(3.Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing, China 100091)
(4.Modern Research Center for Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China 100029)
(5.Alashan League Mongolian Medicine Hospital, Alxa, China 750300)
【Abstract】Mountain-agarwood plays an important role in ethnic medicine in China for its pharmaceutical value. Modern pharmacological researches demonstrated that mountain-agarwood was effective for its anti-myocardial ischemia, antibacterial, anti-inflammatory, antitumor and analgesic effects. Mountain-agarwood derives from the peeled roots, stems or twigs of Syringa pinnatifolia which belongs to Syringa genus. It often depends on the purple substance and fragrance to estimate the formation of mountain-agarwood. However, the mechanism of mountain-agarwood formation has not been reported. To observe the microcosmic change in the process during the formation of mountain-agarwood, this study described the microscopic and histochemical characteristics of mountain-agarwood formation through histochemical staining. Our results showed that a significant difference of the distribution of tyloses existed during mountain-agarwood formation. It was observed that inchoate mountain-agarwood had more starch granules and viable cells than mountain-agarwood formed with high level or low level. The amount of polysaccharide and degree of lignification were increased during the mountain-agarwood formation. The results indicated that the mountain-agarwood, which meets the quality requirements for pharmaceutical use, contained the following characteristics: a large amount of purple tyloses in heartwood; yellow-brown tyloses distributing in heartwood and sapwood which were less in the latter; lignification with high level; a few viable cells; lots of polysaccharide and few starch granules in xylem rays cell. This study is aimed to reveal the change of histochemical characteristics during mountain-agarwood formation, and lay the foundation for exploring the mechanism of mountain-agarwood formation.
【Keywords】 Syringa pinnatifolia; mountain-agarwood formation; histochemistry; microscopic observation;
 National Administration of Traditional Chinese Medicine. Chinese Materia Medica·Mongolian Medicine [M]. Shanghai: Shanghai Scientific & Technical Publishers, 2002: 173 (in Chinese).
 LI J J, GE F X, JIAO S G, et al. Pharmacological evaluation of Mongolian medicine Syringa pinnatifolia fraction I against acute myocardial ischemia in mice [J]. China Journal of Chinese Materia Medica, 2019, 44 (23): 5240 (in Chinese).
 BAO J, WANG Q, HAN S, et al. The isolation and antimicrobial activities of three monocylic sesquiterpenes from Syringa pinnatifolia [J]. Nat Prod Res, 2015, 29 (18): 1719.
 ZHANG R, FENG X, SU G, et al. Bioactive sesquiterpenoids from the peeled stems of Syringa pinnatifolia [J]. J Nat Prod, 2018, 81 (8): 1711.
 ZHANG R, FENG X, SU G, et al. Noralashinol B, a norlignan with cytotoxicity from stem barks of Syringa pinnatifolia [J]. J Asian Nat Prod Res, 2017, 19 (4): 416.
 WUKEN S N, LI J J, WANG J M, et al. Analgesic and sedative effects of Mongolian medicine Syringa pinnatifolia [J]. China Journal of Chinese Materia Medica, 2019, 44 (17): 3830 (in Chinese).
 LI H Y, FAN L, LI L. Aquilariae Lignum Resinatum Ultrafine Powder and Syringa pinnatifolia var. alashanensis Ultrafine Powder [J]. Comparison of Pharmacodynamics Between Chinese Journal of Experimental Traditional Medical Formulae, 2018, 24 (12): 92 (in Chinese).
 National Environmental Protection Agency, Institute of Botany, Chinese Academy of Sciences. 中国珍稀濒危保护植物名录 [J]. Bulletin of Biology, 1987 (7): 23 (in Chinese).
 YANG Y J. 贺兰山丁香繁殖对策的初步研究 [D]. Nanjing: Nanjing Forestry University, 2008 (in Chinese).
 LI Y P. Study on sowing and breeding techniques of Syringa pinnata [J]. Science and Technology of Qinghai Agriculture and Forestry, 2019 (1): 73 (in Chinese).
 LI L, SHI X L, GAO S F, et al. The application of microscopic histochemical localization in traditional Chinese medicine study [J]. Modern Chinese Medicine, 2014, 16 (6): 505 (in Chinese).
 PANG X S, ZHAO M S, WANG J. 蒙药山沉香的生药学研究 [J]. Journal of Medicine & Pharmacy of Chinese Minorities, 2000, 6 (S1): 59 (in Chinese).
 JIANG X M, ZHANG L F, ZHOU Y. A Study on tyloses and gums in the vessels of Chinese hardwood [J]. SCIENTIA SILVAE SINICAE, 1995, 31 (2): 155 (in Chinese).
 WANG M, ZHANG Z N. 边材与心材 [J]. Bulletin of Biology, 1998, 33 (9): 15 (in Chinese).
 Flora of China. Vol 15 [EB/OL]. [2020-01-18]. http://www.iplant.cn/foc/vol/15.
 LIVINGSTON D P, HINCHA D K, HEYER A G. Fructan and its relationship to abiotic stress tolerance in plants [J]. Cell Mol Life Sci, 2009, 66 (13): 2007.
 WEI X R, WANG G Z. The relationship between micro character of tissues and cold resistance of pear [J]. Journal of Inner Mongolia Agricultural University (Natural Science Edition), 2004, 25 (2): 73 (in Chinese).
 PLOYET R, SOLER M, CAROCHA V, et al. Long cold exposure induces transcriptional and biochemical remodelling of xylem secondary cell wall in Eucalyptus [J]. Tree Physiol, 2018, 38 (3): 409.
 ZHANG X L, LIU Y Y, CHEN H J, et al. Study on xylem structure and histochemistry in Aquilaria sinensis [J]. Journal of Shandong University (Natural Science), 2012, 47 (7): 1 (in Chinese).
 LIU P, ZHANG X, YANG Y, et al. Interxylary phloem and xylem rays are the structural foundation of agarwood resin formation in the stems of Aquilaria sinensis [J]. Trees, 2018, 33 (2): 533.
 DOLEZAL J, KLIMES A, DVORSKY M, et al. Disentangling evolutionary, environmental and morphological drivers of plant anatomical adaptations to drought and cold in Himalayan graminoids [J]. Oikos, 2019, 128 (11): 1576.
 HUANG J Q, WEI J H, ZHANG Z, et al. Historical records and modern studies on agarwood production method and overall agarwood production method [J]. China Journal of Chinese Materia Medica, 2013, 38 (3): 302 (in Chinese).
 LIU J, GAO J Q, CHEN S Y L, et al. Analysis of bacterial community structure and diversity during mountain-agarwood formation [J]. China Journal of Chinese Materia Medica, 2020, 45 (15): 3651 (in Chinese).
 YU Z X, WANG C H, CHEN D L, et al. Anti-inflammatory sesquiterpenes from agarwood produced via whole-tree agarwood-inducing technique of Aquilaria sinensis [J]. China Journal of Chinese Materia Medica, 2019, 44 (19): 4196 (in Chinese).