Hypsizygus marmoreus is valued for its nutrition and medicinal properties, yet the pigment basis of its white and brown cultivars remains unclear. This study compared the white strain BYG and brown strain XWG using metabolomics and transcriptomics to elucidate color-determining compounds and their formation mechanisms. We identified 265 differentially accumulated metabolites (DAMs). KEGG annotation linked five pathways—tyrosine metabolism, phenylpropanoid biosynthesis (two routes), flavonoid biosynthesis, and phenylalanine/tyrosine/tryptophan biosynthesis—to melanin and proanthocyanidin production. Among these, three precursors (3-dehydroshikimic acid, phenylpyruvic acid, coumaric acid) were down-regulated, while (+)-catechin and (−)-epicatechin were up-regulated in XWG. A total of 17,117 differentially expressed genes (DEGs) were detected. KEGG enriched two relevant pathways, involving 51 DEGs encoding 11 enzymes. Prephenate dehydratase (TyrA) and aspartate aminotransferase (AST) were significantly up-regulated in XWG. Integrated analysis revealed that the phenylalanine, tyrosine, and tryptophan biosynthetic pathway was significantly down-regulated in XWG. These findings suggest that melanin and proanthocyanidins are the primary determinants of the color difference between BYG and XWG, and that the upregulated expression of TyrA and AST in XWG contributes to their elevated accumulation. Quantification confirmed that both melanin and proanthocyanidin contents in XWG were significantly higher than in BYG. Melanin was characterized as eumelanin, and proanthocyanidins were identified as B1 and B2—the first report in H. marmoreus.Eumelanin and proanthocyanidins, regulated via the phenylalanine/tyrosine/tryptophan pathway, are the primary determinants of color difference between BYG and XWG. These findings aid consumer strain selection and guide future breeding for improved color and quality.
The productivity and fruit quality of strawberries (Fragaria × ananassa Duch.) are closely linked to leaf photosynthesis, redox homeostasis, and carbohydrate metabolism. Developing efficient micronutrient-management strategies to improve these processes is important for sustainable strawberry production. However, it remains unclear how the physiological response of strawberries to foliar spraying with nano-molybdenum (nano-Mo) varies across growth stages. In this study, strawberry plants at the five-leaf stage received a single foliar application of nano-Mo at 0, 0.10, 0.25, 0.50, 0.75, or 1.00 mg L⁻¹. Plant physiological responses were monitored across eight developmental stages, and fruit yield and quality were evaluated at maturity. Among the treatments, 0.50 mg L⁻¹ nano-Mo (Mo3) produced the most favorable overall response. Compared with the control, Mo3 increased the net photosynthetic rate (Pn) by 9.9–29.8% during main developmental stages. This response was accompanied by increased stomatal conductance (Gs), improved maximum photochemical efficiency of PSII (Fv/Fm), enhanced Rubisco activity, and reduced malondialdehyde (MDA) accumulation, indicating coordinated changes in stomatal and non-stomatal components of photosynthesis. Mo3 treatment was also associated with the activities of key enzymes in the ascorbate-glutathione cycle, including monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), ascorbate peroxidase (APX), and ascorbate oxidase (AAO), together with lower H₂O₂ accumulation. In addition, increased activities of pyruvate kinase and acid invertase coincided with enhanced sugar accumulation and improved fruit quality. Compared to the control, the Mo3 treatment increased yield per plant by 23.8%, single fruit weight by 36.7%, and marketable fruit rate by 14.7%. It also improved the sugar-to-acid ratio and increased phenolics and anthocyanins contents. Overall, a single foliar application of nano-Mo at appropriate concentration was associated with improved strawberry productivity and fruit quality by improved photosynthesis, antioxidant capacity, and sugar metabolism. These findings provide evidence for the potential use of nano-enabled micronutrient management in high-value horticultural production. However, further studies comparing nano-Mo with conventional Mo fertilizers at equivalent Mo doses are required to distinguish nano-specific effects from general Mo nutritional effects.
This article evaluates the physiological, quality, and economic performance of three commercial almond cultivars (Guara, Marta, and Lauranne) subjected to regulated and sustained deficit irrigation strategies in two orchards with contrasting agroeconomic conditions. Moving beyond conventional agronomic assessments, the study integrates physiological indicators commonly used in precision irrigation scheduling, including leaf water potential and stomatal conductance, to interpret cultivar-specific responses and assess these strategies within a data-informed irrigation management framework. Results indicate that deficit irrigation can enhance resource-use efficiency by achieving water savings greater than the proportional reduction in yield, without compromising kernel quality and even improving attributes linked to sensory quality and potential market value. These gains in quality and efficiency improve irrigation water productivity and profitability, providing a mechanism to ensure economic performance at the orchard level and supporting deficit irrigation as a viable precision-irrigation strategy under water scarcity conditions.
Understanding how deficit irrigation regulates soil–plant water relations and agronomic performance is critical for optimizing water management in drought-prone subtropical orchards. This study aimed to elucidate how different irrigation deficit levels regulate soil water distribution, root-system responses, plant water-uptake strategies, and ultimately fruit yield and quality in a Nanfeng tangerine orchard.We investigated the effects of three irrigation regimes—severe deficit (W1), mild deficit (W2), and full irrigation (W3)—by integrating soil moisture monitoring, root trait analysis, dual stable isotope techniques (δ²H and δ¹⁸O), and the MixSIAR Bayesian mixing model to characterize soil–plant water interactions and water-source partitioning across the 0–200 cm soil profile.Mild deficit irrigation (W2) consistently maintained higher soil water availability within the 0–120 cm active root zone while effectively preventing deep percolation. Water-source partitioning revealed that W2 promoted progressively increasing reliance on shallow soil water (up to 93 %), whereas full irrigation induced greater late-season dependence on deep soil water. These physiological and hydrological responses translated into significant agronomic benefits: W2 achieved the highest fruit yield (166.6 kg·plant⁻¹), increasing yield by 162.36 % and 28.95 % compared with W1 and W3, respectively. Furthermore, W2 significantly improved fruit quality attributes, including soluble sugars (86.28 mg·g⁻¹), total soluble solids (14.9 %), titratable acidity (0.58 %), and vitamin C content (190.81 μg·g⁻¹).Mild deficit irrigation fostered the most stable and physiologically adaptive water uptake strategy by reducing deep percolation losses and enhancing water use efficiency, thereby improving both yield and fruit quality. These findings demonstrate that mild deficit irrigation represents an effective water-saving strategy for red soil citrus orchards prone to seasonal drought.
