Growth Of Seedlings Research Articles

Glycine betaine seed priming to induce salt stress tolerance in durum wheat (Triticum durum Desf.)

Salinity stress is an important environmental factor that limits plant growth and productivity in the world. The effect of seed priming with glycine betaine (GB) on the germination of four durum wheat varieties (Salim, Maâli, Monastir and Carioca) under salt stress conditions induced by sodium chloride (NaCl) were investigated. Three concentrations of GB (0, 50 and 100 mM) were tested under three levels of salt stress (0, 100 and 200 mM). The main results obtained showed significant effects of treatments and varieties on most studied traits. Salt stress had a negative effect on the germination and growth of wheat seedlings. However, seed priming with GB significantly improved seed germination under both no stress and salt stress conditions. Under severe salt stress conditions (200 mM NaCl), the highest values of germination percentage (65.5%), mean daily germination (0.825), vigor index (119.566), shoot length (0.568 cm) and root length (3.05 cm) were obtained using 50 mM GB. Consequently, the results of this study indicate that GB seed priming at 50 mM can to help durum wheat grow in salt-stress conditions.

Identification of salt-tolerant cultivars and plant traits in wheat during germination and seedling emergence stages

Identification of salt-tolerant cultivars and plant traits in wheat during germination and seedling emergence stages

Integrative analyses of morpho-physiological, biochemical, and transcriptomic reveal the seedling growth response of Pinus yunnanensis to nitrogen and phosphorus fertilization

Appropriate nitrogen (N) and phosphorus (P) fertilization is critical for plant growth and production. Pinus yunnanensis, a silvicultural tree in southwestern China, faces economic and ecological limitations due to nutrient deficiency in the soils in its distribution areas. The slow growth of this species during the seedling stage exacerbates these problems. Therefore, it is important to realize the regulating effects of N and P proportioning fertilization on seedling growth to enhance nutrient-use efficiency. In this study, variations in morphological, physiological, and biochemical characteristics of seedlings were analyzed under nine treatments of NP proportioning in an open nursery using a regression design. Growth in height and basal diameter increased and showed an approximate tendency in all treatments. The maximum biomass accumulation was observed at 480 d after treatment in roots of T5 (14.714 g) (application N 0.4 g·per−1 and P 3 g·per−1), stems of T5 (12.654 g), leaves of T9 (24.261 g) (application N 0.8 g·per−1 and P 6 g·per−1), aboveground parts of T9 (35.402 g) and individuals of T5 (49 g). The total chlorophyll content peaked in the leaves at 120 d and was correlated with the peak levels of N, P, and K in leaves. The content and reserves of nutrient elements in the organs of seedlings subjected to NP proportioning were significantly higher than those in unfertilized seedlings. Analysis of nutrient utilization efficiency revealed that T5 demonstrated superior seedling growth performance. Appropriate fertilization dosage of N and P for P. yunnanensis seedlings in this study was 0.32 g·per−1–0.58 g·per−1 and 3.02 g·per−1–4.95 g·per−1 respectively, using path analysis and regression equation. Transcriptomic sequencing revealed that there were 2,301 DEGs between T5 and T1 (control), which were involved in the uptake and assimilation of nutrients, biosynthesis of phytohormones and secondary metabolites, and photosynthesis. Additionally, the abundance of genes involved in cell division and proliferation, cellulose biosynthesis, and cell wall extension were dramatically upregulated, which potentially correlated with enhanced seedling growth. In conclusion, this study provides comprehensive information on the response of seedlings to varying proportions of N and P and may promote the growth of P. yunnanensis seedlings by optimizing the proportion of N and P in fertilizers.

Salt Overly Sensitive Components Differentially Regulate Seed Germination and Seedling Growth under Saline Conditions in Arabidopsis

Salt Overly Sensitive Components Differentially Regulate Seed Germination and Seedling Growth under Saline Conditions in Arabidopsis

Soil Microbial Mechanisms to Improve Pear Seedling Growth by Applying Bacillus and Trichoderma-Amended Biofertilizers.

Bacillus velezensis SQR9 or Trichoderma harzianum NJAU4742-amended bioorganic fertilizers might significantly improve the soil microbial community and crop yields. However, the mechanisms these microorganisms act are far away from distinctness. We combined amplicon sequencing with culturable approaches to investigate the effects of these microorganisms on pear tree growth, rhizosphere nutrients and microbial mechanisms. The SQR9 and T4742 treatments increased the total biomass of pear trees by 68% and 84%, respectively, compared to the conventional organic fertilizer treatment (CK). SQR9 tends to increase soil organic matter and available phosphorus, while T4742 more effectively enhances nitrogen, potassium, iron and zinc levels. These effects were primarily linked to changes in the microbial community. T4742 treatment enriched twice as many differential microbes as SQR9. SQR9 significantly enriched Urebacillus, Streptomyces and Mycobacterium, while T4742 increased the abundance of Pseudomonas, Aspergillus and Penicillium. In vitro experiments revealed that secondary metabolites secreted by B. velezensis SQR9 and T. harzianum NJAU4742 stimulate the growth of key probiotics associated with their respective treatments, enhancing soil fertility and plant biomass. The study revealed the specific roles of these bioorganic fertilizers in agricultural applications, providing new insights for developing effective and targeted bioorganic fertilizer products and promoting sustainable agriculture.

Exogenous selenium enhances cadmium stress tolerance by improving physiological characteristics of Artemisia argyi seedlings

The contamination of Chinese medicinal materials with cadmium (Cd) is a pressing global issue that poses significant risks to human health. The beneficial effects of selenium (Se) have been established in improving plant growth and reducing Cd accumulation in plant under Cd stress. This study employed soil cultivation experiments to investigate the remediation effects of exogenous Se (0, 0.5, 1, and 2 mg kg⁻1) under varying levels of Cd stress (0, 0.6 and 4 mg kg⁻1). The findings revealed that Cd stress markedly impaired seedling growth, biomass, and physiological characteristics in Artemisia argyi. Regardless of Cd levels, exogenous Se significantly enhanced seedling biomass, improved antioxidant enzyme activity, and increased the plant’s antioxidant capacity, thereby mitigating Cd stress. Additionally, exogenous Se promoted A. argyi plant growth, decreased malondialdehyde (MDA) content in the shoots, and under two Cd stress environments of 0.6 and 4 mg kg⁻1, the application of 1 mg kg⁻1 Se reduced the Cd content in the aboveground parts of seedlings by 31.99 and 82.21%, respectively. We conclude 1 mg kg⁻1 Se could represent a promising strategy to contribute to the development and sustainability of crop production on soils contaminated with Cd at a concentration of up to 0.6 and 4 mg kg⁻1. These results indicate that exogenous Se activates physiological and biochemical defense mechanisms in A. argyi seedlings against Cd stress, offering a foundation for cultivating high-yield, high-quality A. argyi in Cd-contaminated soils.

Effect of Growing Media Composition and Watering Intervals on the growth of Gmelina arborea Roxb seedlings

Gmelina arborea Roxb is one type of forestry plant that has the potential to be cultivated. This is because in addition to having a high economic value, Gmelina arborea Roxb is a plant that is able to grow in critical areas and has a short life cycle. In addition, Gmelina arborea Roxb is one type of wood that has high productivity, high economic value, has a wide natural distribution, has a large genetic variation, can be bred easily, easy to master cultivation techniques, and is resistant to pests and diseases. The purpose of this study was the effect of planting media composition and watering interval on the growth of Gmelina arborea Roxb seedlings. The study used a complete randomised design (RCD) factorial pattern consisting of two factors: The first factor: the composition of planting media, the second factor: watering interval. The results showed that the treatment of media composition and watering intensity treatment and the combination of treatments had a significant effect on the growth of gmelina seedlings. The treatment with the composition of 750 g soil and 250 g cocopeat with watering intensity once a day gave the best results for the growth of gmelina seedlings.

Biochar Nanoparticles Reduce Ciprofloxacin Accumulation and Restore Growth and Hormonal Balance in Rice Seedlings

Ciprofloxacin (CIP), a widely used fluoroquinolone antibiotic, poses a growing environmental concern due to its persistence in agricultural soils and potential adverse effects on crop production. While previous studies have documented CIP’s negative impacts on plant growth, effective strategies to protect crops from antibiotic stress remain limited. Biochar-based approaches show promise, but their application at the nanoscale for antibiotic stress management is largely unexplored. This study demonstrates how biochar nanoparticles (BNPs) effectively mitigate CIP-induced stress in rice seedlings through adsorption mechanisms. Rice seedlings were treated with 5 and 10 mg L−1 CIP, with and without 0.2 g L−1 BNPs. Results showed that CIP significantly disrupted plant growth, decreasing shoot length by 20.5% and root length by 45.2%, along with reduced biomass. Application of BNPs effectively reduced CIP bioavailability by over 80%, leading to a decreased CIP accumulation of 49.7% in shoots and 33.1% in roots. The addition of BNPs mitigated these growth impacts by restoring shoot length to 98.2% of control levels at 5 mg L−1 CIP and improving root growth and biomass accumulation. BNPs also mitigated CIP-induced hormone imbalance, evidenced by a recovery in IAA levels by 8.9%, an increase in 6-BA by 152.6%, and an enhancement in SA levels by 12.7–13.6%. These findings demonstrate the significant potential of nanoscale biochar in reducing antibiotic stress in agricultural systems and provide insights into plant responses under these conditions. This research offers a promising strategy for enhancing crop resilience in areas affected by pharmaceutical pollutants.

Abscisic Acid Can Improve the Salt Tolerance and Yield of Rice by Improving Its Physiological Characteristics

Salt stress exerts a notable influence on rice’s normal growth and development process. It causes a decline in rice yield, and in certain extreme cases can lead to the complete failure of rice crops. Abscisic acid, also known as S-ABA, may play an important role in regulating rice plant responses to various stressors and promoting crop growth against adversity. In this research, the impact of externally applied S-ABA (0.03% S-ABA, diluted 100 times) on the growth and yield of rice was explored. The experiment made use of the traditional rice variety Huanghuazhan as the test material. The study focused on how S-ABA affected rice at various growth phases under salt-stress conditions. The effects of S-ABA sprayed once (three-leaf/one-heart stage) and twice (three-leaf/one-heart stage, break stage) on the photosynthetic characteristics, antioxidant metabolism, membrane lipid peroxidation products, osmotic regulation, and yield of rice under 0.4% NaCl were studied. The experimental outcomes indicated that the presence of salt stress had a restraining effect on the growth of rice. There was a notable decline in the net photosynthetic rate; moreover, the yield was diminished by 26.90%. Salt-induced stress clearly imposed negative impacts on these aspects of rice’s physiological functions and productivity. The exogenous application of S-ABA was highly effective in mitigating the inhibitory influence of salt stress on the growth of rice. When S-ABA was sprayed on two occasions, there was a notable increase in the total chlorophyll content within the rice leaves, ranging from 7.40% to 80.99%. This led to an enhancement in the photosynthetic ability of the plants. Additionally, the growth of rice seedlings was significantly promoted. The activity of antioxidant enzymes also witnessed an upward trend, and the content of soluble protein increased by 0.87–2.60%. The content of malondialdehyde and hydrogen peroxide were decreased by 4.18–12.49% and 13.71–52.18%, respectively, the damage to membrane lipid peroxidation was alleviated, and rice yield was increased by 14.84% and 29.29% after spraying S-ABA once or twice under salt stress, respectively. In conclusion, salt stress inhibits the growth and development of rice during grouting and destroys the antioxidant system of the rice plant, thus reducing its yield. Leaf spraying with S-ABA can alleviate the degradation of chlorophyll, enhance the photosynthesis, antioxidant system, and osmotic regulation ability of rice, reduce salt-stress damage, and thus alleviate the yield loss under salt stress to a certain extent. In addition, the regulation effect of two sprayings of S-ABA is better than that of one spraying. The results of this study revealed the physiological regulation mechanism of S-ABA at different growth stages of rice under salt stress, and provided theoretical support for the reduction of salt-stress damage to rice. This suggests that S-ABA has potential applications in the improvement of salt tolerance in rice.

24-epibrassinolide regulates oxytetracycline-induced phytotoxicity and its detoxification mechanism.

Oxytetracycline (OTC), a crop-absorbable antibiotic, poses a health risk to humans through the food chain. Conversely, 24-epibrassinolide (EBL), a plant growth hormone, mitigates the toxic effects of various pollutants on plants. However, the mechanism by which exogenous EBL affects the growth of rape seedlings exposed to OTC remains largely unknown. In this study, we found that environmental OTC concentrations significantly inhibited plant growth and metabolism, whereas exogenous EBL could restore plant growth characteristics. Exogenous EBL significantly decreased reactive oxygen species (ROS) accumulation, alleviating OTC-induced cell membrane lipid peroxidation. This was achieved by increasing the antioxidant capacity and secondary metabolism levels. Notably, our findings suggested that EBL stimulated glutathione S-transferase (GST) and glutathione reductase (GR) activities, enhancing reduced glutathione synthesis and participating in plant OTC detoxification. OTC residues in EBL + OTC-treated seedlings at 21 d were significantly reduced by 29 % compared with OTC alone. Further transcriptomic and metabolomic analyses revealed that the differentially expressed genes and metabolites in the EBL and OTC alone or combined treatment groups were primarily involved in the regulation of phenylpropanoid biosynthesis, glutathione metabolism, and lant hormone signal transduction pathways in response to phytotoxic effects and detoxification mechanisms, as compared to the control group.

Amazonian Microorganism Strains Improve Physiological Performance to Oil Palm Seedlings Growth Promote

Amazonian Microorganism Strains Improve Physiological Performance to Oil Palm Seedlings Growth Promote

Effect of Growing Media on Seed Germination and Seedling Growth of Chili (Capsicum Annuum L.)

Suitable growing media is considered a basic requirement to get the maximum germination and growth. So, the present investigation was carried out at Mominpur Farmers Hub (name of model), Rangpur Sadar Upazila during February-March, 2023 to investigate the effect of growing media on germination percentage, germination emergence percentage, shoot length, shoot fresh weight, root length, root fresh weight, leaf number, shoot length vigor index, root shoot ratio of chili under open field condition. The experiment was sequenced according to Completely Randomized Design in three replicates. Five different growing media namely soil + sand, cocopeat, soil + sand + cocopeat, vermicompost + cocopeat, and vermicompost + soil + sand was used in the experiment. The results obtained from this study showed that the maximum germination percentage (94%), shoot length (9.62 cm), shoot fresh weight (7.16 g), root length (3.09 cm), root fresh weight (1.93 g), leaf number (7.02) and shoot length vigor index (1194.74%) were recorded when the seed was growing in the cocopeat. The findings of this study recommend the use of cocopeat as a growth media for raising nurseries by farmers as it had a significant positive effect on seed germination and plant growth parameters of seedlings that lead to increased production of chili. SAARC J. Agric., 22(2): 289-301 (2024)

Mechanisms by Which Soil Solution Fe2+ Affects Seedling Growth of Rice Under Rice Straw Return

Rice straw return plays an important role in sustainable agricultural development, but the impact of rice straw return on rice growth remains inconclusive. In this experiment, we employed a combination of soil and water cultivation experiments to investigate the impact of rice straw return on seedling growth of rice in Northeast China. This study demonstrated that rice straw return inhibited rice plant growth within 37 days but was no longer significant after 37 days. Rice straw return resulted in an increase in iron(II) (Fe2+) concentration of soil solution. The hydroponic test demonstrated that a high concentration of Fe2+ significantly increased the uptake of Fe, reduced the H2O2 content in root, facilitated the formation of root iron plaque, and inhibited the dry weight at the rice seedling stage, in comparison to a nutrient solution with a normal Fe2+ concentration. The increased Fe2+ concentration of soil solution under rice straw return may be a significant factor in the inhibition of rice seedling growth. Moreover, in field management, this study also linked the amount of rice straw returned and soil solution Fe2+ to provide a clear quantitative guide without affecting plant growth.

Anti-TMV activity based flavonol derivatives containing piperazine sulfonyl: Design, synthesis and mechanism study.

A series of flavonoid derivatives containing piperazine sulfonate were designed and synthesized. The results of antiviral experiments in vivo showed that some target compounds had good inhibitory effect on tobacco mosaic virus (TMV). The EC50 values of S15 and S19 curative activity were 174.5 and 110.4μg/mL, respectively, which were better than 253.7μg/mL of Ningnanmycin (NNM). The EC50 values of S4 and S19 protection activity were 140.3 and 116.1μg/mL, respectively, better than that of NNM (247.1μg/mL). Microscale thermophoresis (MST) and molecular docking experiments showed that S19 had a good molecular binding force with TMV. Transmission electron microscopy (TEM) results show that S19 can fracture TMV particles and affect self-assembly. S19 treatment had almost no effect on the growth of seeds and seedlings, and can change the content of chlorophyll malondialdehyde (MDA) and superoxide dismutase (SOD) in tobacco to a certain extent, and improve the disease resistance of tobacco.

Regulation of photosynthetic characteristics carbon and nitrogen metabolism and growth of maize seedlings by graphene oxide coating

Maize seedlings in cold regions and high latitude often face abiotic stress. As a result, weak seedlings affect maize production, The commonly used seed coating agents in production are mainly to prevent biological stress of pests and diseases, and have little effect on seedling vigor and abiotic resistance. In this experiment, the combination of graphene oxide (GO) and seed coating agent can effectively prevent pests and diseases and increase the growth of seedlings.The effects of different concentrations of composite GO seed coating agent on photosynthetic carbon and nitrogen metabolism activity of maize were verified by pot experiments. It provides a reference for the application of nanomaterials in maize seed adjuvant technology and the improvement of maize seedling quality. Using maize as a model plant, the study evaluates, 22 g/L(T1), 44 g/L(T2), 66 g/L(T3), and 88 g/L(T4), GO were add respectively. Commercial seed coating agent as control (Con). Under the conditions of this experiment, GO thickened the stem by regulating the nutrients absorption of the roots in maize seedlings. The leaf thickness and vascular bundle area were increased, the photosynthetic efficiency of leaves were improved. Finally, it promoted the carbon and nitrogen metabolism of maize seedling leaves. Therefore, 44 g/L GO is the most suitable concentration as a coating agent in this experiment.

The Physiological Mechanism of Exogenous Melatonin Regulating Salt Tolerance in Eggplant Seedlings

There is little study on melatonin’s ability to prevent salt damage in eggplants, despite the fact that it is a strong antioxidant in plants that has been found to help mitigate a variety of adverse challenges. In this study, we used “Anhui Eggplant No.8” as the test material and simulated salt stress by irrigating the roots with 150 mmol·L NaCl solution. Subsequently, we treated the eggplants with different concentrations of exogenous melatonin (0, 50, 100, 150, 200, 250 μmol·L) and assessed the plant traits and an array of physiological and biochemical indices following melatonin application to observe the impact of salt stress. Our study results indicate that exogenous melatonin at a concentration of 200 μmol·L can significantly alleviate the inhibition of eggplant photosynthesis under salt stress by increasing the content of chlorophyll in leaves and the activity of antioxidant enzymes. This leads to a notable increase in the levels of non-enzyme antioxidants and osmotic regulatory substances. As a result, the antioxidant capacity of the eggplants is enhanced, the degree of membrane lipid peroxidation is reduced, and the growth of eggplant seedlings under salt stress is effectively promoted, thereby strengthening the salt tolerance of eggplant seedlings. Fluorescence quantitative data analysis indicates that SmCAT4 is indeed a gene that positively regulates salt stress. However, in the SmPPO family, we did not find any genes that respond to salt stress. This research provides a theoretical foundation for improving the yield productivity and quality of eggplants under protected farming by clarifying the physiological mechanism by which melatonin controls the salt tolerance of eggplant seedlings.

The splicing auxiliary factor OsU2AF35a enhances thermotolerance via protein separation and promoting proper splicing of OsHSA32 pre-mRNA in rice.

Heat stress significantly impacts global rice production, highlighting the critical need to understand the genetic basis of heat resistance in rice. U2AF (U2 snRNP auxiliary factor) is an essential splicing complex with critical roles in recognizing the 3'-splice site of precursor messenger RNAs (pre-mRNAs). The U2AF small subunit (U2AF35) can bind to the 3'-AG intron border and promote U2 snRNP binding to the branch-point sequences of introns through interaction with the U2AF large subunit (U2AF65). However, the functions of U2AF35 in plants are poorly understood. In this study, we discovered that the OsU2AF35a gene was vigorously induced by heat stress and could positively regulate rice thermotolerance during both the seedling and reproductive growth stages. OsU2AF35a interacts with OsU2AF65a within the nucleus, and both of them can form condensates through liquid-liquid phase separation (LLPS) following heat stress. The intrinsically disordered regions (IDR) are accountable for their LLPS. OsU2AF35a condensation is indispensable for thermotolerance. RNA-seq analysis disclosed that, subsequent to heat treatment, the expression levels of several genes associated with water deficiency and oxidative stress in osu2af35a-1 were markedly lower than those in ZH11. In accordance with this, OsU2AF35a is capable of positively regulating the oxidative stress resistance of rice. The pre-mRNAs of a considerable number of genes in the osu2af35a-1 mutant exhibited defective splicing, among which was the OsHSA32 gene. Knocking out OsHSA32 significantly reduced the thermotolerance of rice, while overexpressing OsHSA32 could partially rescue the heat sensitivity of osu2af35a-1. Together, our findings uncovered the essential role of OsU2AF35a in rice heat stress response through protein separation and regulating alternative pre-mRNA splicing.

Connotation of Plant Growth Regulators on Seed Germination

Seed germination is a complex physiological process influenced by various internal and external factors. The initial requirements for seed germination include suitable temperature (depending on the seed type), moisture, and oxygen. The endosperm serves as a reservoir of food and contains hormones that initiate seed germination. Both endogenous (produced within the seed) and exogenous (externally applied) hormones play a crucial role in germination and the early growth of seedlings. Plant growth activators enhance seed germination and promote growth, while retardants inhibit both germination and growth processes and may induce dormancy. Growth inhibitors, therefore, can be strategically applied to prolong seed viability during storage. Furthermore, various exogenous chemicals are employed to regulate seed and plant growth processes. These hormones and chemicals not only influence germination but also help to determine the seed's chemistry, providing insights into its physiology and predicting its behavior under different conditions.

Effects of humic acid on the growth and cadmium accumulation of maize (Zea mays L.) seedlings

The increasing prevalence of cadmium (Cd)-contaminated agricultural soils threatens the safe production of maize (Zea mays L.). To decrease the Cd accumulation in maize, a pot experiment was conducted to study the effects of humic acid on the growth and Cd uptake of maize seedlings. Cd treatment led to a decrease in biomass and photosynthetic pigment content in maize seedlings, as well as an increase in the activities of antioxidant enzymes. Under Cd stress, the application of humic acid resulted in an increase in biomass, photosynthetic pigment content, and antioxidant enzyme activity in maize seedlings. Additionally, the application of humic acid led to a decrease in root Cd content and an increase in shoot Cd content and translocation factor in maize seedlings under Cd stress. Compared to Cd treatment, humic acid reduced root Cd content by 14.63% and increased shoot Cd content by 12.81%. Furthermore, the carotenoid content, translocation factor, chlorophyll a + b content, and chlorophyll a content were strongly associated with shoot Cd content under Cd stress. Therefore, the application of humic acid can enhance growth, inhibit Cd uptake in roots, and promote Cd translocation from roots to shoots of maize seedlings under Cd stress.

Cocultivos de microorganismos endófitos: Estrategia para la producción de bioestimulantes y compuestos de valor agregado

Cocultures between algae and bacteria aim to harness the metabolic capabilities of both microorganisms for biotechnological purposes. However, establishing a successful coculture is challenging because of their different nutritional and environmental requirements. This work proposes the establishment of a coculture between the plant growth-promoting bacterium Methylobacterium oryzae and the unicellular green alga Coccomyxa simplex, both endophytes of Vachellia farnesiana, with the aim of using their metabolic capacities to produce value-added compounds. To achieve this, the conditions to obtain a stable alga-bacteria coculture were defined, and the effect of the coculture and the initial nutrient concentration on lipid and pigment production, as well as plant growth stimulation were evaluated. A stable coculture was successfully established enabling the growth of both microorganisms even in the absence of carbon and nitrogen sources. The coculture stimulated lipid production (up to 43%) and pigment production (by 2.5 to 4.8 times). Additionally, the coculture's supernatant improved the growth of radish seedlings, suggesting that the coculture promotes the production of biostimulant compounds with potential to enhance crop yields and reduce the use of chemical fertilizers.