Postharvest softening limits the shelf life and commercial value of blackberries; however, the molecular correlates underlying firmness variation among cultivars remains unclear. Here, soft-fruited ‘Kiowa’ was compared with firm-fruited ‘Navaho’ and ‘Arapaho’ using transcriptomics and metabolomics. At the ripe stage, fruit firmness was highest in ‘Navaho’ (3.48 N) and lowest in ‘Kiowa’ (1.88 N). PG activity and protopectin degradation were significantly higher in ‘Kiowa’ than in the firm cultivars. Conversely, CAD enzyme activity and lignin content were significantly higher in the firm cultivars. Five core PG genes (RuPG1, RuPG2, RuPG3, RuPG5, and RuPG6) were expressed at significantly lower levels in the firm cultivars, whereas all three CAD genes (RuCAD1, RuCAD2, and RuCAD3) showed higher expression. Metabolomics revealed that the firm cultivars accumulated distinct phenolic acids, intermediates of the lignin pathway: ‘Arapaho’ accumulated ferulic acid (correlating with RuCAD1), whereas ‘Navaho’ accumulated sinapic acid (correlating with RuCAD2/3). Correlation analysis showed that fruit firmness, pectin content, CAD activity, and lignin content were negatively correlated with RuPG1/2 expression and positively correlated with RuCAD2/3 expression, whereas PG, PME, and PL activities exhibited the opposite patterns. Collectively, firm-fruited cultivars display reduced pectin degradation (associated with lower PG expression) and higher lignin content (associated with higher CAD expression).These results provide key molecular targets for breeding high-firmness blackberry.
Strong light fluctuations, along with changes in light ratio and wavelength, can cause stress in plants, which can be minimized by using humic materials. These materials have biostimulant activity, altering photosynthetic activity. However, it is unclear whether responses to humic materials are light-dependent. Thus, in this study, Cajanus cajan (L.) Millspaugh was used to investigate the dependence of HA effects on photosynthetically active radiation (PAR) levels and to evaluate the impact of shading on HA action in this species. To this end, a humic acid concentration–response trial was conducted (0, 1, 2, 4, and 8 mM C L−1), with root morphology being analyzed. Based on the highest concentration obtained, another trial was conducted with HA at different irradiance levels (100
Ecosystem services require robust quantification to support effective environmental management, particularly in urban landscapes increasingly shaped by anthropogenic disturbance. Novel ecosystems (NE) are common in cities but remain underrepresented in ecosystem services assessments. In this study, we quantified and compared carbon storage and sequestration provided by urban forest fragments, including two novel ecosystems (NE1 and NE2), and a conserved rural Atlantic Forest fragment in Southeastern Brazil. Phytosociological data from standardized forest inventories (10 plots of 20 × 20 m per fragment) were analyzed using the i-Tree Eco v.6.1 model to estimate carbon stocks, annual sequestration, and associated economic valuation. Our results show that fragment NE1 had the lowest carbon stock (96 t CO2 Equivalent/ha) and sequestration (16.52 t CO2 Equiv./ha/year), while NE2, had the highest stock (388.75 t CO2 Equiv./ha) and sequestration (42.45 t CO2 Equiv./ha/year) among the NE. The native forest fragment had a carbon stock of 681.25 t/ha of CO2 Equiv. and a sequestration of annual sequestration of 44.50 t CO2 Equiv./ha/year. Differences between novel ecosystems were strongly associated with land-use history, species dominance, and successional trajectories, with NE1 reflecting ecological homogenization following landfill and monoculture planting of Eremanthus erythropappus (DC.) MacLeish, whereas NE2 benefited from long-term natural regeneration despite dominance by Pinus elliottii Engelm. Our findings demonstrate that established novel urban ecosystems can provide carbon-related ecosystem services comparable to conserved forests, highlighting their potential role as complementary components of urban green infrastructure. However, these benefits should be interpreted cautiously, as carbon gains may coexist with ecological tradeoffs not captured by single-service assessments.
This study examines species divergence time and phylogenetic relationships across 195 plant taxa using two widely used chloroplast molecular markers, rbcL and matK, analysed through Bayesian Inference in MrBayes under relaxed molecular clocks. Divergence time estimation was calibrated against seven fossil constraints, including Palaeonitella cranii (≥ 410 Ma), Rhyniophyta/Cooksonia (420–430 Ma), and Archaefructus sinensis (125–130 Ma). Three datasets, rbcL, matK, and the concatenated rbcL+matK dataset, were analysed under the GTR + G + I substitution model to evaluate marker performance. The concatenated rbcL+matK dataset produced the deepest and most precisely constrained divergence estimates, dating land plant origin to 457.6 MYA, seed plant emergence to approximately 330 MYA, crown angiosperm radiation to 138.7 MYA, and the monocot–eudicot split to 125.0 MYA, all consistent with established fossil benchmarks. Sequence statistics revealed contrasting levels of nucleotide diversity between the two markers. Tajima’s D values differed among datasets, but because sampling was interspecific rather than population-based, we interpreted these statistics descriptively rather than as direct evidence of specific selective or demographic processes. The combined dataset displayed intermediate diversity (π = 0.1758) alongside narrower highest posterior density (HPD) intervals, reflecting improved estimation precision. The resulting time-calibrated phylogeny resolved 13 major clades spanning charophyte outgroups (447.60 MYA) through gymnosperms (412.25 MYA), pteridophytes, bryophytes, and monocots (395.08 MYA), to all eudicot superclades, providing a broad temporal framework across major geological intervals. Single-gene analyses revealed systematic limitations: rbcL underestimated deep divergence times, while matK generated wider HPD intervals at shallow nodes. The concatenated dataset generally showed stronger node support, fewer apparent polytomies, and narrower 95
