Molecular mechanism of seed dormancy release induced by fluridone compared with cod stratification in Notopterygium incisum.

BACKGROUND: Notopterygium incisum is an important Chinese medicinal plant. Its mature seeds have underdeveloped embryos and are physiological dormant. We found the seeds with full developed embryos can germinate after treated by fluridone (FL), an inhibitor of abscisic acid (ABA). In order to understand the molecular mechanisms underlying seed dormancy release by FL, we compared the transcriptomic changes in dormancy release induced by two different methods, FL and cold stratification (CS) in N. incisum. We further analyzed the gene expression patterns involved in seed germination and dormancy using quantitative reverse-transcription PCR. RESULTS: RNA-sequence analysis revealed more dramatic changes in the transcriptomes of FL than those in CS, particularly for genes involved in the biosynthesis and regulation of gibberellins (GAs) and ABA. The down-regulation of ABA biosynthesis genes and the dramatic up-regulation of NiCYP707As, an ABA catabolic gene, contributed to the reduced ABA levels in FL. The increased GA3 levels in CS-treated seeds were due to the up-regulation of NiGA3OX. Both NiABI5 (a positive ABA regulator) and NiGAI (a negative regulator of GA) were down-regulated in FL and CS. The upregulation of strigolactones (SLs; the metabolites with the same precursor as ABA) biosynthesis and regulatory genes in both FL- and CS-treated seeds indicates that SLs contribute positively to seed dormancy release in N. incisum. CONCLUSIONS: Our results indicated that FL- and CS-seed dormancy release possibly depends on two totally different mechanisms: alleviation of the effects of ABA and potentiation of the effects of GA, respectively. However, NiABI5 and NiGAI probably function as common factors integrating the effects of ABA and GA on seed dormancy release.

Chemical constituents contained in seeds of Notopterygium franchetii / 中国中药杂志

<p><b>OBJECTIVE</b>To study the chemical constituents from the seeds of Notopterygium franchetii.</p><p><b>METHOD</b>Ethanol extracts of seeds N. franchetii were separated and purified by such methods as normal and reversed phase column chromatographies and thin-layer chromatography and structurally elucidated by MS and NMR evidences.</p><p><b>RESULT</b>Twenty nine compounds were separated, they were isoimperatorin (1), [3-sitosterol (2), phellopterin (3), bergapten (4), N-tetra, hexa, octacosanoylanthranilic acid (5-7), daucosterol (8), oxypeucedanin hydrate (9), umbelliferone (10), demethylfuropinnarin (11), (2S, 3S, 4R, 8E)-2-[(2'R)- 2'-hydroxydoco, trico, tetraco, entaco, hexaco sanosylamino] -octadecene-1, 3, 4-triol (12-16), (-)-oxypeucedanin (17), diosmetin (18), bergaptol-O-beta-D-glucopyranoside (19), nodakenin (20), 1'-O-beta-D-glucopyranosyl-(2R, 3S)-3-hydroxynodakenetin (21), uracil (22), decuroside V (23), 8-O-beta-D-glucopyranosyl-5-hydroxypsoralen (24), 8-O-beta-D-glucopyranosyl-5-methoxylpsoralen (25), diosmin (26), alaschanioside C (27), kynurenic acid (28) and mannitol (29).</p><p><b>CONCLUSION</b>All of these compounds were separated from the seeds of N. franchetii for the first time. Of them, 18, 22, 26 and 29 were firstly obtained from genus Notopterygium.</p>

Studies on chemical constituents from fruits of Forsythia suspense / 中国中药杂志

Twenty-four compounds in the fruits of Forsythia suspensa were isolated and purified by column chromatography and preparative TLC. On the basis of comprehensive spectroscopic methods including IR, ESI-MS/MS, 1D and 2D NMR, these compounds were identified as ten ceremides (1-10), six triterpenes (11-16), one steroids (17), three flavonoids (18-20), two C6-C2 alcohols (21-22) and two lignans (23-24). Compounds 1-10 were reported from F. suspense for the first time, among which 1, 2, 4 and 5 were new ones.

Studies on habitats suitability of endangered medicinal plant Notopterygium incisum / 中国中药杂志

<p><b>OBJECTIVE</b>To assess the suitability of origin habitats of Notopterygium incisum, and provide theoretical basis of screening suitable areas for its large-scale cultivation.</p><p><b>METHOD</b>Detailed field survey of N. incisum, spatial databases, and GIS technology were used for the habitats suitability assessment.</p><p><b>RESULT</b>More than 142 073 km2 in 118 counties of Sichuan, Tibetan, Qinghai and Gansu are the most suitable habitats for N. incisum in which more than 47% of the area is located in sichuan, and more than of 377 000 km2 in 266 counties are relative suitable for N. incisum in Sichuan, Tibetan, Qinghai, Gansu, Yunnan, Xinjiang, etc and 32% of the area is located in Sichuan.</p><p><b>CONCLUSION</b>Almost all the most suitable habitats are appropriate for germplasm conservation, wild population protection and regeneration due to the shortage of arable land, fragmentation of these alpine and subalpine ecosystems and sensitiveness of the environment changes. Therefore, large-scale cultivation of N. incisum could be developed in those relative suitable areas abundant in arable lands and labors, especially in moutainous regions with high elevation in the west of Sichuan province, and Qinghai Tibet plateau in the northwest of Sichuan, Southeast of Qinghai and Gansu province.</p>

Comparative studies on photosynthetic characteristics of Notopterygium incisum and N. forbesii / 中国中药杂志

<p><b>OBJECTIVE</b>To compare the photosynthetic characteristics of Notopterygium incisum and N. forbesii in order to provide basic data for introduction and cultivation of the two wild medicinal species.</p><p><b>METHOD</b>The light-response, CO2-response and Chlorophy II fluorescence parameters of leaves at the booting stages between N. incisum and N. forbesii, were analyzed in situ by Li-6400 Portable Photosynthesis system under natural conditions.</p><p><b>RESULT</b>1) The light saturation point (LSP) was 1539 micromol x m(-2) x s(-1) for N. incisum and 1464 micromol x m(-2) x s(-1) for N. forbesii, the maximum net photosynthetic rate (Pmax) was 22.95 micromol x m(-2) x s(-1) for N. incisum and 19.65 micromol x m(-2) x s(-1) for N. forbesii, the apparent quantum yield (AQY) was 0.0509 for N. incisum and 0.0470 for N. forbesii, LSP, AQY and Pmax of N. incisum were significantly higher than those of N. forbesii; the light compensation point (LCP) was 17.92 micromol x m(-2) x s(-1) for N. incisum and 26.69 micromol x m(-2) x s(-1) for N. forbesii, LCP of N. incisum was significantly lower than that of N. forbesii. 2) The carbondioxide compensation point (CCP) were 33.41 micromol x mol(-1) for N. incisum and 37.82 micromol x mol(-1) for N. forbesii, the carbon dioxide saturation point (CSP) were 988 micromol x mol(-1) for N. incisum and 1150 micromol x mol(-1) for N. forbesii, CCP and CSP of N. incisum were significantly lower than N. forbesii; the carboxylation efficiency (CE) were 0.0591 for N. incisum and 0.0459 for N. forbesii; the maximum rate of RuBP regeneration (Jmax) were 28.18 micromol x m(-2) x s(-1) for N. incisum and 25.32 micromol x m(-2) x s(-1) for N. forbesii; the light respiration rate (Rd) were 1.971 micromol x m(-2) x s(-1) for N. incisum and 1.736 micromol x m(-2) x s(-1) for N. forbesii, CE, Jmax and Rd of N. incisum were higher than those of N. forbesii. 3) The primary light energy conversion of PS II (Fv/Fm) was 0.8213 for N. incisum and 0.8257 for N. forbesii, wihich didn't showed significant difference, between N. incisum and N. forbesii there was no photoinhibition.</p><p><b>CONCLUSION</b>Both N. incisum and N. forbesii were C3 type plant, could perfectly acclimate to light condition. However, the weak light of N. incisum was absorbed significantly higher than that of N. forbesii, strong photosynthesis ability causes assimilation products accumulation of N. incisum obviously to be higher than that of N. forbesii.</p>