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Background The agronomic quality of cutting-propagated strawberry seedlings is a critical determinant of subsequent field performance and economic returns in the annual production of fresh-market strawberries. Although far-red light (FR) has been well established as a key regulator of plant architecture and productivity in many horticultural crops, its specific physiological roles during the strawberry seedling establishment stage remain poorly understood. Thus, investigating whether end-of-day far red (EOD-FR) light treatment can effectively enhance the growth vigor and overall development of strawberry runners addresses a significant knowledge gap, with direct implications for commercial seedling production systems. Methods The experiment investigated the effects of 0 (CK), 3 h, 6 h, and 9 h EOD-FR durations on strawberry cuttings ( Fragaria × ananassa Duch. cv. Benihoppe). The 60-d period experiment was conducted in a solar greenhouse, employing a completely randomized block design. The sampling was carried at 30 d and 60 d to assess physiological and morphological responses of strawberry seedlings. Results Compared with the control (CK), 6 h EOD-FR supplementation markedly enhanced seedling growth, including increases in height, leaf area, petiole diameter and length, biomass accumulation, root development and vigor index. In addition, anatomical observations revealed that while prolonged EOD-FR exposure led to reduction in leaf thickness, the 6 h EOD-FR increased the number of vascular bundles in petioles and accelerated floral bud differentiation. The physiological analysis showed that 6 h EOD-FR supplementation enhanced net photosynthetic rate and stomatal conductance, and water use efficiency. This was observed alongside increased activities of antioxidant enzyme and greater accumulation of osmolytes, including free amino acids, soluble sugars, and proteins. Hormonal profiling indicated that 6 h EOD-FR increased the IAA, Brassinosteroids, and ABA levels in leaves and petioles. However, the marked increase of ABA content and reduce of GA₃ content were only found in shoot apices. Based on membership function values and principal component analysis, the order of treatment performance (6 h > 3 h > CK > 9 h) was consistent across both 30-d and 60-d experimental durations. Conclusion In summary, supplementation with 6 h EOD-FR optimizes photosynthetic performance, strengthens antioxidant capacity, regulates hormone balance, and promotes nutrient accumulation in strawberry seedlings, ultimately leading to enhanced growth and stimulated floral induction.

The effects of cadmium stress on the growth and physiological characteristics of Sassafras tzumu Hemsl . were studied in pot experiments. Five Cd levels were tested [CT(Control Treatment) : 0 mg/kg, Cd5: 5 mg/kg, Cd20: 20 mg/kg, Cd50: 50 mg/kg, and Cd100: 100 mg/kg]. The growth and physiological characteristics of the sassafras seedlings in each level were measured. The results showed that soil Cd had negative influences on sassafras growth and reduced the net growth of plant height and the biomass of leaf, branch and root. Significant reductions were recorded in root biomass by 18.18%(Cd5), 27.35%(Cd20), 27.57%(Cd50) and 28.95%(Cd100). The contents of hydrogen peroxide decreased first then increased while malondialdehyde showed the opposite trend with increasing cadmium concentration. Decreases were found in hydrogen peroxide contents by 10.96%(Cd5), 11.82%(Cd20) and 7.02%(Cd50); increases were found in malondialdehyde contents by 15.47%(Cd5), 16.07%(Cd20) and 7.85%(Cd50), indicating that cadmium stress had a certain effect on the peroxidation of the inner cell membranes in the seedlings that resulted in damage to the cell membrane structure. Superoxide dismutase activity decreased among treatments by 17.05%(Cd5), 10,68%(Cd20), 20.85%(Cd50) and 8.91%(Cd100), while peroxidase activity increased steadily with increasing cadmium concentration; these results suggest that peroxidase is likely the main protective enzyme involved in the reactive oxygen removal system in sassafras seedlings. Upward trends were observed in proline content by 90.76%(Cd5), 74.36%(Cd20), 99.73%(Cd50) and 126.01%(Cd100). The increase in proline content with increasing cadmium concentration indicated that cadmium stress induced proline synthesis to resist osmotic stress in the seedlings. Compared to that in CT, the soluble sugar content declined under the different treatments by 32.84%(Cd5), 5.85%(Cd20), 25.55%(Cd50) and 38.69%(Cd100). Increases were observed in the soluble protein content by 2.34%(Cd5), 21.36%(Cd20), 53.15%(Cd50) and 24.22%(Cd100). At different levels of cadmium stress, the chlorophyll content in the seedlings first increased and then decreased, and it was higher in the Cd5 and Cd20 treatments than that in the CT treatment. These results reflected that cadmium had photosynthesis-promoting effects at low concentrations and photosynthesis-suppressing effects at high concentrations. The photosynthetic gas exchange parameters and photosynthetic light-response parameters showed downward trends with increasing cadmium concentration compared with those in CT; these results reflected the negative effects of cadmium stress on photosynthesis in sassafras seedlings.

Background Drought is one of the major factors limiting global maize production. Exposure to long-term drought conditions inhibits growth and leads to yield losses. Although several drought-responsive genes have been identified and functionally analyzed, the mechanisms underlying responses to drought and water recovery treatments have not been fully elucidated. To characterize how maize seedling respond to drought stress at the transcriptional level, we analyzed physiological responses and differentially expressed genes (DEGs) in the inbred line B73 under water deficit and recovery conditions. Results The data for relative leaf water content, leaf size, and photosynthesis-related parameters indicated that drought stress significantly repressed maize seedling growth. Further RNA sequencing analysis revealed that 6107 DEGs were responsive to drought stress and water recovery, with more down-regulated than up-regulated genes. Among the DEGs, the photosynthesis- and hormone-related genes were enriched in responses to drought stress and re-watering. Additionally, transcription factor genes from 37 families were differentially expressed among the three analyzed time-points. Gene ontology enrichment analyses of the DEGs indicated that 50 GO terms, including those related to photosynthesis, carbohydrate metabolism, oxidoreductase activities, nutrient metabolism and other drought-responsive pathways, were over-represented in the drought-treated seedlings. The content of gibberellin in drought treatment seedlings was decreased compared to that of control seedlings, while abscisic acid showed accumulated in the drought treated plants. The deep analysis of DEGs related to cell wall development indicated that these genes were prone to be down-regulated at drought treatment stage. Conclusions Many genes that are differentially expressed in responses to drought stress and water recovery conditions affect photosynthetic systems and hormone biosynthesis. The identified DEGs, especially those encoding transcription factors, represent potential targets for developing drought-tolerant maize lines.

Auxin transport, which is mediated by specialized influx and efflux carriers, plays a major role in many aspects of plant growth and development. AUXIN1 (AUX1) has been demonstrated to encode a high-affinity auxin influx carrier. In Arabidopsis thaliana, AUX1 belongs to a small multigene family comprising four highly conserved genes (i.e., AUX1 and LIKE AUX1 [LAX] genes LAX1, LAX2, and LAX3). We report that all four members of this AUX/LAX family display auxin uptake functions. Despite the conservation of their biochemical function, AUX1, LAX1, and LAX3 have been described to regulate distinct auxin-dependent developmental processes. Here, we report that LAX2 regulates vascular patterning in cotyledons. We also describe how regulatory and coding sequences of AUX/LAX genes have undergone subfunctionalization based on their distinct patterns of spatial expression and the inability of LAX sequences to rescue aux1 mutant phenotypes, respectively. Despite their high sequence similarity at the protein level, transgenic studies reveal that LAX proteins are not correctly targeted in the AUX1 expression domain. Domain swapping studies suggest that the N-terminal half of AUX1 is essential for correct LAX localization. We conclude that Arabidopsis AUX/LAX genes encode a family of auxin influx transporters that perform distinct developmental functions and have evolved distinct regulatory mechanisms.

Seeds germination and seedlings growth are crucial factors in ensuring effective rice grain productivity. However, the mechanisms for maintaining seed vigor remains largely unknown. The seed aging phenomenon that occurs during storage poses a significant challenge to crop production, as it can lead to reduced germination rates and impaired seed vitality. The current study explored the underlying mechanisms that enable rice seeds to maintain high germination rates and seedling vigor after long - term storage. We employed transcriptomic and metabolomic techniques to identify metabolic changes and key genes associated with the aging of rice seeds during long - term storage. We utilized indicators such as imbibition rate (IR), germination rate (GR), mean germination time (MGT), germination coefficient (GC), germination index (GI), and germination potential (GP) to comprehensively assess germination activity. Traits including seedling emergence rate, seedling strength index, photosynthetic parameters, carbohydrate accumulation, and enzyme activity related to carbon metabolism were used to determine the impact of seed storage duration on seedling growth. Our research findings revealed significant differences in gene expression patterns and metabolic characteristics among seeds stored for different duration. Notably, IAA levels, the IAA/ABA ratio, and linoleic acid metabolism were identified as key factors affecting germination and seedling development. Results indicated that with the extension of storage duration, the germination potential and seedling development significantly declined. Current study provided a comprehensive understanding of the physiological and molecular mechanisms behind the germination and morphogenesis of rice seeds under different storage years. The insights gained from this study could be utilized to improve the storage and quality control of rice seeds, thereby ultimately enhancing agricultural productivity.

Plants are very vulnerable to pathogen attacks and environmental stress as they are exposed to harsh environments in natural conditions. However, they have evolved a self-defense system whereby reactive oxygen and nitrogen species (RONS) act as double-edged swords by imposing (at higher concentration) and mitigating (at lower concentration) environmental stress. Cold plasma is emerging as a feasible option to produce a variety of RONS in a controlled manner when amalgamate with water. Cold plasma activated/treated water (PAW) contains a variety of RONS at concentrations, which may help to activate the plant’s defense system components. In the present study, we examine the effect of cold atmospheric-air jet plasma exposure (15 min, 30 min, and 60 min) on the water’s RONS level, as well as the impact of PAW irrigation, (assigned as 15PAW, 30PAW, and 60PAW) on tomato seedlings growth and defense response. We found that PAW irrigation (priming) upregulate seedlings growth, endogenous RONS, defense hormone (salicylic acid and jasmonic acid), and expression of key pathogenesis related (PR) gene. 30 min PAW contains RONS at concentrations which can induce non-toxic signaling. The present study suggests that PAW irrigation can be beneficial for agriculture as it modulates plant growth as well as immune response components.

Responses of Opuntia streptacantha seedlings under combined water and light treatments at 15, 30 and 45 days. a) osmotic potential (MPa) and, b) titratable acidity (mmol equiv. Delgado-Sánchez P, Yáñez-Espinosa L, Jiménez-Bremont JF, Chapa-Vargas L, Flores J (2013) Ecophysiological and Anatomical Mechanisms behind the Nurse Effect: Which Are More Important? A Multivariate Approach for Cactus Seedlings.

Main conclusion Silicon application at a concentration of 2 mM induced sugarcane resistance to Nigrospora oryzae by upregulating pathogen recognition and defense genes, thus increasing plant metabolic activities and productivity. Sugarcane is an important global food and industrial crop, but numerous pathogens threaten its productivity. Our team recently identified the fungus Nigrospora oryzae as a pathogen affecting sugarcane’s growth and productivity. Although silicon supplementation is active against most fungi, it remains unclear if it would enhance the resilience of sugarcane to N. oryzae , and molecular mechanisms underlying this process are yet to be explored. In this study, we explored the effects of four silicon concentrations (control, 1 mM, 2 mM, and 4 mM) on the growth and disease resistance of seedlings of the sugarcane variety ROC22 under fungal stress. Employing an integrative approach combining detailed phenotypic analysis with transcriptomic and metabolomic profiling, we elucidated the underlying molecular mechanisms of silicon’s protective effects. Results indicated that optimal concentrations (2 mM) of silicon enhanced disease resistance and significantly improved plant height, root characteristics, and enzymatic activities. Transcriptomic analysis revealed an upregulation of genes (826) involved in pathogen recognition and defensive response, while metabolomic analysis highlighted alterations in metabolic pathways pertinent to stress response. These findings suggest that silicon supplementation could effectively bolster sugarcane’s defense against fungal diseases, offering new insights into its role in plant pathology and paving the way for developing more resilient crop varieties. Graphical abstract