Orobanche infection is a major constraint to tomato production because the parasite acts as a strong physiological and nutritional sink, impairing host growth, photosynthesis, and metabolism. To test whether elevated atmospheric CO 2 can alleviate these adverse effects, this 10-week study evaluated host photosynthesis, amino-acid and polyamine metabolism, and rhizosphere polyphenols across four combinations of ambient or eCO 2 with and without parasite infection. Orobanche infection reduced plant growth and photosynthetic performance, whereas eCO 2 substantially alleviated these effects. Compared with infected plants under ambient CO 2 , eCO 2 increased biomass accumulation by approximately 45 percent (P < 0.05) and reduced tubercle biomass by approximately 30 percent (P < 0.05), whereas tubercle number per plant remained unaffected. eCO 2 was also associated with increased concentrations of several amino acids, particularly glutamic acid, alanine, and glycine, together with enhanced activities of polyamine-related enzymes, including arginine decarboxylase (ADC), spermine synthase, and diamine oxidase (DAO). These changes were accompanied by increased polyamine accumulation and higher levels of soil polyphenols. Collectively, the findings indicate that eCO 2 is associated with coordinated adjustments in photosynthetic performance, primary amino-acid metabolism, polyamine metabolism, and rhizosphere-associated biochemical responses during Orobanche infection. This integrated response could contribute to improved tomato performance under parasitic stress and highlights the potential of eCO 2 conditions to support climate-resilient tomato production.
Macadamia, a fruit tree prized for its premium edible kernels, suffers severe fruit abscission during early fruit development, yet its physiological and molecular basis remains unclear. In this study, the husk tissues of fruits collected from the infructescence with a thick rachis (IT) and the infructescence with a slender rachis (IS) were analyzed via comparative transcriptome and targeted hormone metabolome at different developmental stages. Compared with IS husks, IT husks exhibited significantly elevated levels of several hormones, including the free auxin IAA, its metabolites Me-IAA and IAN, active and conjugated cytokinins (tZ, tZR, tZRMP, tZOG, tZ9G, IPR, DHZROG), jasmonates (JA-Val, Me-JA), and GA8, GA19, whereas ABA, GA3, IP, IPRMP, TRP and JA-ACC significantly decreased. However, these differences were largely stage-dependent, and notably OPDA, JA, and JA-ILE showed opposite patterns between the earlier and later stages. Transcriptome analysis identified 53 differentially expressed genes involved in hormone biosynthesis, metabolism, and signal transduction, which were associated with fruit abscission. RT-qPCR further supported the RNA-seq expression patterns for selected genes. Collectively, these findings provide insights into hormone-related molecular changes associated with fruit abscission in macadamia husks, offering a basis for further functional investigation.
Orobanche infection is a major constraint to tomato production because the parasite acts as a strong physiological and nutritional sink, impairing host growth, photosynthesis, and metabolism. To test whether elevated atmospheric CO2 can alleviate these adverse effects, this 10-week study evaluated host photosynthesis, amino-acid and polyamine metabolism, and rhizosphere polyphenols across four combinations of ambient or eCO2 with and without parasite infection. Orobanche infection reduced plant growth and photosynthetic performance, whereas eCO2 substantially alleviated these effects. Compared with infected plants under ambient CO2, eCO2 increased biomass accumulation by approximately 45 percent (P < 0.05) and reduced tubercle biomass by approximately 30 percent (P < 0.05), whereas tubercle number per plant remained unaffected. eCO2 was also associated with increased concentrations of several amino acids, particularly glutamic acid, alanine, and glycine, together with enhanced activities of polyamine-related enzymes, including arginine decarboxylase (ADC), spermine synthase, and diamine oxidase (DAO). These changes were accompanied by increased polyamine accumulation and higher levels of soil polyphenols. Collectively, the findings indicate that eCO2 is associated with coordinated adjustments in photosynthetic performance, primary amino-acid metabolism, polyamine metabolism, and rhizosphere-associated biochemical responses during Orobanche infection. This integrated response could contribute to improved tomato performance under parasitic stress and highlights the potential of eCO2 conditions to support climate-resilient tomato production.
This study evaluated the effects of seasons (summer and winter) and shade levels (30% and 15% incident-PPFD transmittance) on the growth and flowering of two Oncidesa Gower Ramsey cultivars, ‘Honey Angel’ (HA) and ‘Golden Star’ (GS). The results showed that summer was associated with greater leaf growth and earlier flowering, whereas winter was associated with higher flower quality. Both cultivars showed reduced performance under high summer temperatures; HA plants in particular performed more poorly than GS plants under the combined conditions of high temperature and high PPFD (30% incident-PPFD transmittance) in summer, although no formal temperature × light interaction was tested. Superior pseudobulb width and thickness were observed during winter, whereas pseudobulb length was significantly greater in summer. Although higher accumulated light in summer facilitated leaf expansion, flowering quality was significantly superior in winter as evidenced by increased floret number (FN) and branch number (FB), while inflorescence length (FL) depended jointly on light intensity and season rather than on season alone. Conversely, the summer season significantly shortened the number of days to flowering (FD). Within winter, FL, FB, and FN were numerically higher under 30% PPFD than under 15% PPFD (Figs. 3A–C), although this comparison reflects two non-replicated, single net-house environments rather than a replicated light-intensity treatment effect and should be interpreted accordingly. In addition, GS plants significantly outperformed HA plants in pseudobulb length and width, leaf thickness and width, and FN, whereas HA plants required significantly fewer days to flowering (FD) than GS. In conclusion, both season and PPFD significantly influenced the growth and flowering of these two Oncidesa cultivars under the studied production conditions, providing reference data for optimizing cultivation management and cut-flower quality in this system.
Strawberry ( Fragaria x ananassa ) , is one of the most cultivated berry crops globally, esteemed for its intense aroma, pleasant taste, and bright red colour. Current genetic improvement objectives include increasing marketable yield, plant vigour, and fruit quality, particularly sweetness and aroma. Additionally, enhancing nutritional value and addressing challenges associated with pathogens, pests, and environmental stressors are imperative. To date, several different classical breeding programmes have enhanced the adaptation of this species to diverse environmental conditions, increased tolerance to some biotic and abiotic stresses, and improved specific traits too meet consumer preferences. However, significant challenges remain in increasing fruit yield and improving fruit quality while ensuring adaptation to changing environmental conditions and reducing dependence on external inputs. Biotechnological techniques such as those based on recombinant DNA technology offer promising approaches to introduce desired traits into existing varieties faster and more precisely than traditional methods. This review provides an analysis of the biotechnological approaches employed to obtain genetically modified plants and highlights recent discoveries in strawberry genetics that are instrumental in improving varieties through genetic engineering.
