Exogenous GA3 delays walnut fruit maturation and alters kernel fatty acid composition by modulating genes and hormones during development.

Changes in Morphological Characteristics, Endogenous Hormones, Soluble Sugars, and Anthocyanin Content During Fruit Development in Eggplant (Solanum melongena L.)

Understanding the coordinated regulation of growth and metabolism during fruit development is essential for improving crop quality and harvest management. This study investigated changes in morphological traits, endogenous phytohormones, soluble sugars, anthocyanins, and water-soluble vitamins in eggplant (Solanum melongena L.) fruit from 3 to 15 days after anthesis (DAA). Fruit length, diameter, and fresh weight increased significantly, with fresh weight increasing 16.6-fold. Cellular analysis showed that fruit enlargement was driven predominantly by cell expansion. Total soluble sugars increased 2.8-fold, with glucose and fructose as the predominant sugars. Delphinidin-based anthocyanins increased sharply during mid-development (9–12 DAA) and then declined slightly, whereas water-soluble vitamins decreased progressively. Based on integrated data, fruit development was classified into three phases: early (3 DAA, initiation and defense), mid (6–9 DAA, rapid growth and pigmentation), and late (12–15 DAA, functional maturation). Notably, 15 DAA was identified as a critical candidate stage with maximum sugar content, high anthocyanin levels, and completed seed development, suggesting its utility as a potential indicator of optimal harvest timing under the present conditions. These results provide an integrated understanding of developmental and metabolic processes in eggplant fruit and offer practical insights for optimizing harvest strategies.

GA₃ and NAA foliar application enhances fruit set, quality, and storage performance in 'Fengtang' plum by regulating endogenous hormonal balance.

The development of the high-value 'Fengtang' plum industry in Guizhou Province is constrained by a low fruit set rate and inconsistent fruit quality. This study investigated the efficacy of exogenous plant growth regulators (PGRs)-gibberellic acid (GA3) and naphthaleneacetic acid (NAA), applied individually or in combination at flowering-on improving fruit set, yield, growth dynamics, quality, and storage characteristics. Treatments included foliar sprays of 100 mg L- 1 GA3, 30 mg L- 1 NAA, 100 mg L- 1 GA3 + 30 mg L- 1 NAA, and a distilled water control (CL). Results demonstrated that the 100 mg L- 1 GA3 treatment significantly increased the [GA3 + IAA + tZ (trans-zeatin, a natural endogenous cytokinin)]/ABA ratio in pistils, achieving a fruit set rate of 4.13% (2.32 times that of CL) and boosting yield by 48.65% compared with CL. This treatment also significantly enhanced fruit weight (increased by 27.98 g), vertical diameter (increased by 9.42 mm), fruit shape index (increased by 0.14), and fruit firmness (increased by 1.68 N cm- 2) at maturity. Furthermore, GA3 application significantly elevated key quality parameters, including vitamin C (2.49 mg 100 g- 1), total phenols (0.52 mg g- 1), and total flavonoids (0.36 mg g- 1). During storage, GA3-treated fruit exhibited a delayed decline in firmness (1.35 times that of CL) and maintained higher levels of soluble sugars (1.15 times that of CL) and soluble solids content (SSC, 1.17 times that of CL). While the NAA treatment improved fruit weight (increased by 28.19 g) and vertical diameter (increased by 8.39 mm), its overall effect was inferior to that of GA3. The combined GA3 + NAA treatment showed no significant improvement over GA3 alone for most parameters. In conclusion, foliar application of 100 mg L- 1 GA3 at flowering effectively regulates endogenous hormonal balance, significantly enhances fruit set, yield, quality, and storage characteristics in 'Fengtang' plum, establishing it as the optimal PGR protocol for high-quality and high-yield cultivation.

Forchlorfenuron (CPPU) suppresses fruitlet abscission in Areca catechu by modulating carbohydrate allocation, hormonal dynamics, and lignin biosynthesis

Effect of Drought Application on Flower, Yield and Leaf Mineral Content of Durian (cv. Monthong) in Cambodia

While synthetic plant growth regulators (PGRs) like paclobutrazol and chlorate compounds are conventionally used to suppress gibberellic acid and induce flowering, their chronic application results in chemical residues, strict export phytosanitary violations, and tree dieback. Water deficit (water stress) presents a sustainable alternative by naturally mimicking chemical retardants to trigger reproductive shifts. However, the exact physiological mechanisms underlying this transition remain incomplete. This study addresses this gap by investigating the dynamic fluctuations of critical macronutrient (N, P, and K) alongside leaf-tissue carbon balances during water deficit to induced flowering. the duration of induced drought stress significantly regulates both the reproductive performance and internal foliar nutrient dynamics of the crop. Prolonged moisture deficit over 28 days markedly optimizes reproductive phenology, driving a significant increase in floral density (P = 0.012), which directly enhancements in fruit-set (P < 0.001) and harvested fruit count (P < 0.001). Consequently, total crop yield per tree significantly increased by roughly 30.7%, without altering individual fruit weight or fruit drop percentages. Physiologically, these reproductive advancements are accompanied by significant alterations in leave macronutrient status; as drought duration extends to 28 days, leaf nitrogen and phosphorus concentrations significantly decline to minimum thresholds of 1.69% (P = 0.006) and 0.146% (P = 0.009), respectively, whereas potassium and total carbon levels remain unaffected. This drives a significant upregulation of the leaf C/N ratio from 25.78 to 30.13 (P = 0.007), identifying this physiological carbon-nitrogen balance as a critical operational mechanism underlying drought (water deficit) mediated floral induction and enhanced yield productivity.

Physiological, transcriptomic, and metabolomic insights into divergent responses to gibberellin and paclobutrazol in walnut (Juglans regia) leaves.

Gibberellins (GA) and paclobutrazol (PP) are plant growth regulators with contrasting effects on plant development, but their regulatory associations in perennial tree crops like walnut (Juglans regia) remain incompletely understood. In this study, 'Lvling' walnut trees were foliar-sprayed with 50 mg L-1 GA and 1000 mg·L-1 PP at 30 days after flowering.Physiological, transcriptomic, and metabolomic analyses were then performed to clarify the mechanisms by which these two growth regulators affect the growth and development of walnut leaves. GA treatment decreased abscisic acid (ABA) and indole-3-acetic acid (IAA) and increased zeatin riboside, isopentenyladenine, chlorophyll, soluble sugars, and proteins; by contrast, PP increased ABA and IAA but reduced chlorophyll, soluble sugars, and starch, thereby delaying growth. Transcriptome analysis showed that GA upregulated GA signalling and starch metabolism genes (GID1, SLY1, AGPase, SUS), while PP activated ABA signalling (NCED3, ABF2) and stress-resistance genes (LOX2, PR1). Kyoto Encyclopedia of Genes and Genomes enrichment analysis indicated that GA mainly influenced carotenoid and starch-sucrose metabolism, whereas PP regulated α-linolenic acid metabolism and anthocyanin biosynthesis. Metabolomics further revealed that GA promoted the accumulation of flavonoids and jasmonic acid, while PP increased the abundance of osmotic adjustment compounds such as proline and glutathione. Overall, these results suggest that GA and PP induce divergent regulatory patterns in walnut leaves, with GA favoring growth-related hormone signaling and carbon metabolism, and PP favoring stress- and defense-related metabolic reprogramming. This study provides candidate genes and metabolic pathways for optimizing the application of growth regulators in walnut cultivation.

Floral Phenology and Changes in Economic Traits During Different Stages of Fruit Growth and Development in Seven Avocado Accessions