Search Results (4)

The accumulation dynamics and regulatory mechanisms of the alkylamides, the key pungent compounds in the fruits of Sichuan peppers, remain poorly understood. Using fruits of the Zanthoxylum planispinum var. dintanensis (Dintan) harvested at five key developmental stages, we comprehensively mapped the accumulation of numbering compounds and their underlying molecular drivers by integrating HPLC-based metabolite profiling and de novo transcriptomics. Total alkylamide content increased during development, with hydroxyl-α-sanshool (HαSS) being predominant. The contributions of hydroxyl-β-sanshool (HβSS) and hydroxyl-ε-sanshool (HεSS) increased in later stages. Cluster and correlation analyses identified 51 candidate genes strongly correlated (|r| ≥ 0.6) with HαSS accumulation, predominantly enriched in fatty acid and branched-chain amino acid metabolism pathways. The expression patterns of five stearoyl-CoA desaturase (SCD) genes, one long-chain acyl-CoA synthetase (ACSL/fadD), and one S-(hydroxymethyl)glutathione dehydrogenase/alcohol dehydrogenase (frmA) gene closely mirrored HαSS accumulation. In contrast, 3-oxoacyl-[acyl-carrier-protein] synthase II (fabF) and one β-ketoacyl-CoA synthase (KCS) gene exhibited a negative correlation. Accordingly, a positive regulatory network was constructed for HαSS accumulation. These findings revealed key candidate targets for deciphering the molecular basis of its unique flavor and for breeding high-pungency cultivars. Full article

The soil quality of plantations with different planting patterns and the effect of soil quality on stoichiometry provide a theoretical basis for the selection of Zanthoxylum planispinum var. dintanensis (hereafter Z. planispinum) planting patterns and nutrient management. Four mixed plantations: Z. planispinum + Prunus salicina, Z. planispinum + Sophora tonkinensis, Z. planispinum + Arachis hypogaea, and Z. planispinum + Lonicera japonica, and a monoculture Z. planispinum plantation were selected to clarify the effect of soil quality on stoichiometry. The results showed that the soil quality index (SQI) of Z. planispinum + L. japonica (1.678) was the highest, indicating that it was the preferred planting combination and that it was significantly limited by soil water content (SWC). The nutrient forms, SWC, and pH all have significant effects on processes such as nutrient transformation and cycling. The contributions of total Ca and total Mg in soil nutrients to stoichiometry were relatively high, while the effect of SQI on stoichiometry was not significant. The microbial stoichiometry ratio was mainly influenced by microbial biomass phosphorus, reflecting that microorganisms have strong internal stability. Strong interactions among soil factors occur, affecting elemental geochemical processes. The regulatory effects of different soil factors on their stoichiometry should be emphasized. Full article

Plantations with different allocation patterns significantly affect soil elements, microorganisms, extracellular enzymes, and their stoichiometric characteristics. Rather than studying them as a continuum, this study used four common allocations of plantations: Zanthoxylum planispinum var. dintanensis (hereafter Z. planispinum) + Prunus salicina, Z. planispinum + Sophora tonkinensis, Z. planispinum + Arachis hypogaea, and Z. planispinum + Lonicera japonica plantations, as well as a single-stand Z. planispinum plantation as a control. Soil samples from depths of 0–10 and 10–20 cm at the five plantations were used to analyze the element stoichiometry, microorganisms and extracellular enzymes. (1) One-way analysis of variance (ANOVA) showed that the contents of soil organic carbon (C), nitrogen (N), phosphorus (P), and potassium (K) of Z. planispinum + L. japonica plantation were high, while those of calcium (Ca) and magnesium (Mg) were low compared to the Z. planispinum pure plantation; soil microbial and enzyme activities were also relatively high. Stoichiometric analysis showed that soil quality was good and nutrient contents were high compared to the other plantations, indicating that this was the optimal plantation. (2) Two-way ANOVA showed that stoichiometry was more influenced by plantation type than soil depth and their interaction, suggesting that plantation type significantly affected the ecosystem nutrient cycle; soil microbial biomass (MB) C:MBN:MBP was not sensitive to changes in planting, indicating that MBC:MBN:MBP was more stable than soil C:N:P, which can be used to diagnose ecosystem nutrient constraints. (3) Pearson’s correlation and standardized major axis analyses showed that there was no significant correlation between soil C:N:P and MBC:MBN:MBP ratios in this study; moreover, MBN:MBP had significant and extremely significant correlations with MBC:MBN and MBC:MBP. Fitting the internal stability model equation of soil nutrient elements and soil MBC, MBN, and MBP failed (p > 0.05), and the MBC, MBN, and MBP and their stoichiometric ratios showed an absolute steady state. This showed that, in karst areas with relative nutrient deficiency, soil microorganisms resisted environmental stress and showed a more stable stoichiometric ratio. Overall stoichiometric characteristics indicated that the Z. planispinum + L. japonica plantation performed best. Full article

Understanding the relationships between carbon; nitrogen, their stable isotopes δ¹³C and δ¹⁵N, and soil stoichiometry may further our understanding of the regulatory mechanisms of the soil quality index on the equilibrium on isotopic fractionation. Four plantations of Zanthoxylum planispinum var. dintanensis (5–7, 10–12, 20–22 and 30–32 years) in the karst plateau gorge area, Guizhou Province, China, were selected to determine the variation characteristics and interactions between leaves, leaf litter, soil carbon (C), soil nitrogen (N) and their isotopes with plantation age, and to explore the relationship between soil stoichiometry and the isotopes δ¹³C and δ¹⁵N. The results were as follows: (1) the δ¹³C in leaves, litter, and soil were −28.04‰ ± 0.59‰, −26.85‰ ± 0.67‰, and −19.39‰ ± 1.37‰, respectively. The contents of δ¹⁵N were 2.01‰ ± 0.99‰, 2.91‰ ± 1.32‰, and 3.29‰ ± 0.69‰, respectively. The contents of δ¹³C and δ¹⁵N were ranked in the order, soil > litter > leaf. (2) With increasing plantation age, the soil ¹³C decreased; the leaf and the litter δ¹⁵N increased first then decreased, and the litter δ¹³C and the soil δ¹⁵N did not vary significantly. (3) The litter layer was positively correlated with soil δ¹³C and negatively correlated to δ¹⁵N. (4) Redundancy analysis showed that the soil microbial biomass carbon (MBC) and the bacteria/fungi (BAC/FUN) were the dominant factors affecting the natural abundance of C and N isotopes Full article