Altitudinal Variation of Metabolites, Mineral Elements and Antioxidant Activities of Rhodiola crenulata (Hook.f. & Thomson) H.Ohba

Microscopical Observation and Transcriptome Analysis Reveal the Effects of High-Altitude Ecosystem in the Qualities of Different Genetic Varieties Brassica napus Resources

Improving the biomass and nutritional quality of Brassica napus is important for its breeding and resource conservation, but there are few studies on the effects of high altitude on its biomass and quality. In this study, 27 varieties of Brassica napus were cultivated both at 1600 m and 150 m altitudes to investigate the effect of different altitudes in the biomass and quality traits of B. napus. At high altitude, all B. napus varieties exhibited decreased picking period, reduced fresh and dry weights, diminished stem length and diameter, as well as lowered nitrogen (N), phosphorus (P), and kalium (K) contents. The soluble sugar and cellulose contents of some varieties decreased, while ascorbic acid and protein increased by 74% and 85%, respectively. Furthermore, histology microscopical observation showed cell size increased and cell density decreased in the shoot apical meristem (SAM) after bolting and at high altitude, compared to those cells before bolting and at low altitude. Transcriptome analysis showed that sucrose phosphate synthase (SPS), sucrose synthase (SUS), fructose-1,6-bisphosphate aldolase (FBA1), and alpha-galactosidase (AGAL2) genes were significantly up-regulated during the after-bolting period at different altitude. This study will be helpful to further understand the influence of high altitude ecosystem on biomass and quality for Brassica napus resource and evolution.

Urban Flora Riches: Unraveling Metabolic Variation Along Altitudinal Gradients in Two Spontaneous Plant Species

Using resilient, self-sustaining plants in urban green spaces enhances environmental and cultural benefits and reduces management costs. We assessed two spontaneous plant species, Linaria vulgaris Mill. and Cichorium intybus L., in four sites from the surrounding urban areas, ranging in altitude from 78 to 1040 m. Protection against UV-B radiation is crucial for plants at higher altitudes, guiding our focus on UV-visible absorption spectra, fluorometric emission spectra, secondary metabolite accumulation, and pigment dynamics in leaves. Our findings revealed a slight increase in UV-absorbing compounds with altitude and species-specific changes in visible spectra. The UV-emission of fluorochromes decreased, while red emission increased with altitude but only in chicory. Polyphenols and flavonoids showed a slight upward trend with altitude. Divergent trends were observed in condensed tannin accumulation, with L. vulgaris decreasing and C. intybus increasing with altitude. Additionally, chicory leaves from higher altitudes (792 and 1040 m) contained significantly lower triterpene concentrations. In L. vulgaris, chlorophyll pigments and carotenoids varied with sites, contrasting with UV absorbance variations. For C. intybus, pigment variation was similar to absorbance changes in the UV and VIS range, except at the highest altitude. These observations provide valuable insights into species-specific strategies for adapting to diverse environmental contexts.