Shoot Growth Research Articles

Growth of shoots, ear and yield structure of winter wheat under drought

Aim. The aim of the work was to study the growth of shoots, ears and the structure of the yield of bread winter wheat (Triticum aestivum L.) under drought. Methods. Wheat plants cultivars Chigyrynka and Jamala were grown under optimal conditions until the earing-flowering phase, after that the experimental plants were transferred to drought regime for 8 days. Optimal water supply was restored to the end of vegetation. During the experiment, shoot growth and ear weight were measured during the experiment. Ripened plants were analyzed the yield structure. Results. It was established that the water deficit in the soil during the critical phase of the ontogeny of earing-flowering delayed the growth of shoots, decreased the weight of the ear grain productivity in both cultivars of plants. Restoration of irrigation stimulated growth of shoots and ears, but did not compensate for the loss of yield. Conclusions. Water deficit in soil in critical earing-flowering phase decreased shoots length, ears weight and productivity of winter wheat plants.

Effect of Plant Growth Substances on Rhizogenesis of Stem Cuttings in Pointed Gourd (Trichosanthes dioica Roxb.)

An experiment was conducted to know the influence of growth regulators IBA, NAA and salicylic acid with different concentrations on rooting of stem cuttings in pointed gourd (Trichosanthes dioica Roxb.) in College of Horticulture, Venkataramannagudem, during the year 2023-2024. The experiment was laid out by following Factorial Randomized Block Design (FRBD) with twenty treatment combinations which consists of two factors, Factor-1: types of cuttings (male and female) and Factor-2: growth substances (10). By adopting standard methodology, observations on root and shoot growth were recorded and statistically analyzed. Studies on the effects of various growth substances on the formation of roots in cuttings of pointed gourd vines showed that IBA at 150 ppm recorded highest percentage of rooting, the longest root, the number of roots per cutting the number of leaves per cutting, the length of the shoot and the percentage of establishment in main field among various growth substances. In comparison to female cuttings, male cuttings showed a considerably higher percentage of rooting, as well as more roots per cutting, longest root, longest shoot, more leaves per cutting and a higher percentage of establishment in the main field. IBA 150 ppm + male cuttings recorded considerably more roots per cutting and the longest root than the other combinations, according to the interaction between growth substance and type of cutting.

Harnessing the Phytochemistry Through Pesticidal Potential of Diverse Elsholtzia Species: A Path to Sustainable Agriculture.

This study investigates the phytochemical profiles and pesticidal activities of various Elsholtzia species, including E. ciliata, E. flava, E. fruticosa, and E. eriostachya, to discover their bioactive potential for sustainable pest management. Through comparative phytochemical analysis using GC-MS technique, key compounds in the essential oils were identified. The major components were thymoquinone (44.97%) in E. ciliata, shisofuran (28.66%) in E. flava, perillene (50.88%) in E. fruticosa, and pinocarvone (42.41%) in E. eriostachya. Despite variability in chemical composition, all species primarily contained oxygenated monoterpenes. The bioactivity of the oils was evaluated for their nematicidal and herbicidal bioassays. E. ciliata showed the highest egg hatching inhibition and juvenile mortality of M. incognita, while E. flava exhibited the lowest activity. For herbicidal activity, E. eriostachya achieved 96.70% seed germination inhibition, 100% root growth inhibition, and 95.56% shoot growth inhibition. E. flava showed the lowest inhibition in germination, root length, and shoot length at 66.70%, 81.56%, and 85.28%, respectively. The findings revealed significant variations in phytochemical composition and pesticidal efficacy, emphasizing the importance of species selection for pest management. This research highlights the bioactive potential of Elsholtzia species in sustainable pest management strategies.

Boron toxicity in plants: understanding mechanisms and developing coping strategies; a review.

Boron is essential for plants, but excess can induce toxicity. Boron (B) is a vital micronutrient for plants, but excess B can induce toxicity symptoms and reduce crop yields. B bioavailability depends on soil properties, including clay type, pH, and organic matter content. Symptoms of B toxicity include reduced shoot and root growth, leaf chlorosis and necrosis, impaired photosynthesis, and disrupted pollen development. This review paper examines the current knowledge on B toxicity mechanisms, tolerance strategies, and management approaches in plants. This review covers (1) factors affecting B bioavailability; (2) toxicity symptoms in plants; (3) uptake, transport, and detoxification mechanisms; and (4) strategies. To mitigate toxicity, plants reduce B uptake, activate efflux transporters, compartmentalize B, and enhance antioxidant systems. On the basis of this review, future research should focus on identifying novel tolerance mechanisms, exploring genetic strategies for improved B management, and developing innovative agronomic interventions. These insights will facilitate the breeding and management of crops for enhanced productivity under B toxicity stress.

Growth, Photosynthesis and Yield Responses of Common Wheat to Foliar Application of Methylobacterium symbioticum under Decreasing Chemical Nitrogen Fertilization

Current agriculture intensifies crop cultivation to meet food demand, leading to unsustainable use of chemical fertilizers. This study investigates a few physiological and agronomic responses of common wheat following the inoculation with plant growth-promoting bacteria to reduce nitrogen inputs. A field trial was conducted in 2022–2023, in Legnago (Verona, Italy) on Triticum aestivum var. LG-Auriga comparing full (180 kg ha−1) and reduced (130 kg ha−1) N doses, both with and without foliar application at end tillering of the N-fixing bacterium Methylobacterium symbioticum. Biofertilization did not improve shoot growth, while it seldom increased the root length density in the arable layer. It delayed leaf senescence, prolonged photosynthetic activity, and amplified stomatal conductance and PSII efficiency under the reduced N dose. Appreciable ACC-deaminase activity of such bacterium disclosed augmented nitrogen retrieval and reduced ethylene production, explaining the ameliorated stay-green. Yield and test weight were unaffected by biofertilization, while both glutenin-to-gliadin and HMW-to-LMW ratios increased together with dough tenacity. It is concluded that Methylobacterium symbioticum can amplify nitrogen metabolism at a reduced nitrogen dose, offering a viable approach to reduce chemical fertilization under suboptimal growing conditions for achieving a more sustainable agriculture. Further research over multiple growing seasons and soil types is necessary to corroborate these preliminary observations.

Plant biotechnology for the conservation of Argania spinosa (Skeels L): optimising propagation and sustainable valorisation

ABSTRACT Argania spinosa, an endangered species from southwestern Morocco, is studied for preservation through plant biotechnology. The research aims to optimise argan tree propagation to boost production, preserve heritage, and use residual species. In vitro seedlings are transferred to a modified Murashige and Skoog medium with various phytohormones. Six combinations of auxins and cytokinins are tested for germination. Results show that a liquid medium with activated charcoal from argan shells promotes stem elongation. Meta-topoline at 0.5 mg L−1, combined with naphthalene acetic acid (NAA) at 0.2 mg L−1, enhances shoot growth, leaf formation, and callogenesis. Adding benzylaminopurine (BAP) at 0.1 mg L−1 and indole-3-butyric acid (IBA) at 0.02 mg L−1 to the medium elongates stems by 4.3 cm after 21 days. A 2000 ppm IBA concentration is key for a 90% rooting rate. These findings underscore plant biotechnology’s role in preserving and propagating argan trees, improving resource management, and supporting sustainability.

Physio-Morphological Traits Contributing to Genotypic Differences in Nitrogen Use Efficiency of Leafy Vegetable Species under Low N Stress

Soil fertility is declining in low-input agriculture due to insufficient fertilizer application by small-scale farmers. On the other hand, concerns are rising regarding the environmental pollution of both air and water in high-input agriculture due to the excessive use of N fertilizers in short growing seasons for vegetable crops, which is directly linked to the health of human beings and environmental safety. This study aimed to determine genotypic differences in the Nitrogen Use Efficiency (NUE) levels of different leafy vegetable species (Arugula, Spinach, Cress, Parsley, and Dill) grown hydroponically under two different N rates, low N (0.3 mM) and high N (3.0 mM), and to identify the plant traits that are contributing to NUE. A nutrient solution experiment was conducted between March and April 2024 by using an aerated Deep-Water Culture (DWC) technique in a fully automated climate room with a completely randomized block design (CRBD) with three replications for five weeks. The results indicated that shoot growth, as well as root morphological and leaf physiological responses, was significantly (p < 0.001) affected by genotype, the N rate, and genotype–N rate interactions. Shoot growth in some vegetable species (Arugula, Spinach, and Cress) was significantly higher under a low N than a high N rate, illustrating that they have a great capability for NUE under low N stress conditions. Similar results were also recorded for the root growth of the N-efficient species under low N rates. The NUE levels of these species were closely associated with leaf physiological (leaf area, leaf chlorophyll index (SPAD), photosynthesis, and total leaf chlorophyll (a + b) and carotenoids) and root morphological (root length, root volume, and average root diameter) characteristics. These plant traits could be useful indicators for the selection and breeding of ‘N-efficient’ leafy vegetable species for sustainable low-input agriculture systems in the future. However, further investigation should be carried out at the field level to confirm their commercial production viability.

N-Acetylcysteine Mitigates Oxidative Stress Induced by Transplanting Lettuce Seedlings into a DFT Hydroponic System

Oxidative stress results from an imbalance between the production and accumulation of reactive oxygen species (ROS), which can impede plant growth under various environmental stresses. While waterlogging is a well-known inducer of oxidative stress, the effects of oxidative stress on plant roots grown using the deep flow technique (DFT) hydroponic system remain poorly understood. In this study, we demonstrate that N-acetylcysteine (NAC) enhances the growth of lettuce seedlings transplanted into a DFT system. NAC application significantly improved both shoot and root growth, with the most pronounced effects observed at a concentration of 0.3 mM. Moreover, NAC mitigated the accumulation of hydrogen peroxide in roots following transplantation. It also reduced a temporary increase in lipid peroxidation and total phenolic content in both roots and shoots. These results suggest that NAC functions as an antioxidant, alleviating oxidative stress by scavenging hydrogen peroxide in the roots. Importantly, NAC’s protective effects may extend to other hydroponically grown crops, offering broader potential for reducing oxidative stress across various cultivation systems.

The effects of humic substances application on the phytohormone profile in Lactuca sativa L.

AbstractHumic substances (HS) are commonly employed as plant biostimulants to enhance crop yields. However, the HS mechanisms of action, as well as the differences between radicular and foliar modes of application, remain unclear. Here, we explored the changes in phytohormonal balance as possible mechanism of HS to enhance lettuce (Lactuca sativa L.) growth, and the difference between both modes of application. For this purpose, BLACKJAK®, a HS‐based product was applied as radicular (R) and foliar (F) at the concentrations (mL/L): 0.20 (R1), 0.40 (R2), 0.60 (R3), 0.80 (R4), 5.00 (F1), 7.50 (F2), 10.00 (F3), and 12.50 (F4). The experiment was performed in pots filled with vermiculite:perlite (3:1) and HS were applied three times with a periodicity of 10 days. Shoot and root growth parameters were measured. In addition, the phythormones indole‐3‐acetic acid (IAA), gibberellins (GAs), trans‐zeatine (tZ), isopentenyl adenine (iP), 1‐aminocyclopropane‐1‐carboxylic acid (ACC), abscisic acid (ABA), jasmonic acid (JA), and salicylic acid (SA), were analysed by U‐HPLC‐MS. BLACKJAK® application resulted in higher shoot growth at doses R1, R2, R3, F2, and F3, whereas root biomass was increased at R2, R3, F2, F3, and F4, showing radicular better plant growth than foliar applications. Furthermore, HS changed phytohormonal balance in shoots and roots. However, it was with radicular applications, especially at R2, where phytohormonal profile was best associated with plant growth due to the increases observed in IAA, GAs, JA, SA, tZ, and decreased ABA. However, further research is needed to clarify the involvement of hormones in the growth‐promoting action of HS.

Salt stress effects on growth, physiology, and ionic concentrations in hydroponically grown barley genotypes

Soil salinity is a major abiotic stress that severely affects crop production in different regions of the globe. Barley is an essential cereal crop and there is a significant genetic variation among barley varieties for tolerance towards salt stress. Understanding of salinity tolerance mechanisms assists in developing salt tolerant barley varieties in a hydroponics experiment. There were twelve barley varieties and two NaCl stress levels (Control, 100 and 200 mM) in this study. The nursery of barley was seeded in sand and at two-leaf stage; plants were transplanted into hydroponic tubs. The plants were grown under salt stress for 65 days and data regarding several morpho-physiological parameters were collected. The statistical analysis of the collected data was implemented by using completely randomized design (CRD) with factorial arrangement. Exposure to NaCl stress significantly reduced shoot and root growth and relative leaf water contents (RLWC), while increasing Na+ concentration, with B-9006 showing the highest root dry weight (0.39 g) and YSM1 recorded the lowest root dry weight (0.10 g) under 100 mM NaCl. The maximum (232 ppm) Na+ concentration in leaf sap was observed in variety B-15011 (70 % from control) and minimum was observed in B-15018. Maximum K+ mM concentration in leaf sap was found as 72 % in Aia-03 and minimum was observed as 50 % in B-15035. At stress level of 200 mM, highest shoot dry weight (2.52 g) was observed in ZP2 (73 % decreased from control) while minimum shoot dry weight (0.19 g) (96 % decrease from control) was recorded in Franklin genotype. Maximum root dry weight (0.24 g) was observed in B-9006 genotype while minimum root dry weight (0.04 g) was recorded in Gairdner. Maximum K+/Na+ ratio (1.20) was recorded in B-15018 and minimum (0.14) was seen in B-15035. Therefore, based on our results, barley genotypes can be classified into salt-tolerant (B-9006, B-15018, Yerong, Aia-03), salt-sensitive (Gairdner, Franklin, B-15035, B-05011), and moderately tolerant groups at both 100 and 200 mM NaCl levels.

Enhanced pollution removal from canal water by coupling aeration to floating treatment wetlands

Floating treatment wetlands (FTWs) are natural solutions for purifying polluted water, providing a green surface area and improving city landscape. This study investigated if the efficiency of FTWs can be improved by aeration for treating contaminated canal water. The three used plant species were Canna generalis, Phragmites australis, and Cyperus alternifolius. The experiment was carried out in three FTWs with aeration and three without aeration to compare the removal for COD, NH4 +-N, E. coli, PO4 3−-P, and Fe. In the aerated FTWs, air blowers were installed to run at two different air flow rates of 2.5 L min−1 (Batch 1) and 1.0 L min−1 (Batch 2). Aeration increased the dissolved oxygen concentrations in each tank, which came over 6.5 mg L−1 in both batches. This study sheds light on the positive impact of aeration has on COD and NH4 +-N removal: these are nearly three-fold higher compared to non-aeration conditions and reached approximately 99% (1.7-log reduction) for E. coli removal. Additionally, the plant growth rate in the aerated FTWs was higher than in the non-aerated ones. The average shoot growth rate of Phragmites australis was 0.76 cm d−1 for the aerated FTW which was two-fold higher compared to the non-aerated one.

Effect of rock phosphate direct application on tropical legumes under different soil types of Sudan Savanna

ABSTRACT Direct application of low-grade rock phosphate (RP) is a less expensive alternative than the application of chemical phosphorus (P) for small holders relying on nutrient-deficient weathered soils. However, the effect of RP application on growth and yield is unstable for different crop species and soil water conditions. To identify legume species effective for RP direct application, five tropical legumes (cowpea, groundnut, bambara nut, mung bean, and soybean) were tested under two soil types with different water-holding capacities in Sudan Savanna; Lixisols and Plinthosols. The experiment was conducted under three conditions of P treatment, namely, RP application, triple super phosphate (TSP) application, and no phosphorus fertilizer application (0P). Under RP treatment, higher grain yield was obtained in Lixisols, which had a higher water-holding capacity. However, the yield increase was suppressed in the year with more rainfall owing to drastic changes in the soil moisture content, which caused excessive soil moisture stress during vegetative growth periods. Among the five legume species, cowpea and groundnut showed higher grain yields under the RP treatment than did other species. RP application increased shoot biomass but caused small changes in the shoot P and N concentrations. Soybean in Plinthosols had the highest yield ratio of RP/0P, but the absolute yield was low because of the insufficient soil water availability caused by the low water-holding capacity. RP direct application can assist shoot growth and yield, but it rarely compensates for basal yield differences between soil types and among legume species.

Rice night-time thirst: Genotype nutrient needs reflected in nocturnal transpiration

To enhance rice grain protein content, understanding strategies to improve nitrogen uptake is crucial. While the impact of transpiration on nitrogen flux is known in trees, its role in rice is unclear due to inconsistent results. Our study used a phenomics facility for real-time transpiration measurements during the entire crop growth period. We hypothesized that genotypes respond differently to transpiration regulation based on nitrogen needs. This study investigates the morphological responses and grain protein content (GPC) of two genotypes of rice, GEN-RIC_784 and GEN-RIC_384, under varying light and nitrogen conditions. GEN-RIC_784 exhibited lower reductions in biomass and total leaf area under limiting nitrogen and light compared to GEN-RIC_384. Both genotypes showed comparable reduction in biomass and leaf area when low nitrogen was combined with low light (LN + LL) condition. GEN-RIC_784 flowered early under low light, while GEN-RIC_384 did so only in LN + LL conditions. GEN-RIC_384 experienced significant yield reductions under all treatments except LN + LL, while maintaining high GPC compared to control. In contrast, GEN-RIC_784 showed a >50% reduction in GPC under low nitrogen conditions. Cumulative water transpired decreased notably only under LN + LL for both genotypes. GEN-RIC_384 had higher daytime transpiration declines across treatments and increased nighttime transpiration in CN + LL and LN + AL treatments. Daytime transpiration rates per leaf area were higher across treatments compared to controls. Water use efficiency decreased in both genotypes, most prominently under LN + LL. Across growth stages, transpiration trends varied, with notable increases under LN + AL and LN + LL. GEN-RIC_784 showed higher transpiration during vegetative stages, while GEN-RIC_384 showed higher nocturnal transpiration under CN + LL. Nitrogen supplementation affected shoot growth and chlorophyll content, particularly in GEN-RIC_384, with notable reductions when nitrogen was withheld at night. The study underscores the complex genotype-light-nitrogen interactions in rice, offering insights for enhancing rice productivity and grain quality under diverse environmental conditions.

Exploring the phytoremediation capacity of Portulaca oleracea naphthalene aromatic hydrocarbon contaminants: a physiological and biochemical study.

This study is aimed to explore the potential of purslane (Portulaca oleracea L.) as a phytoremediation candidate for the removal of naphthalene in a hydroponic system; moreover, the impacts of naphthalene on the physiological and biochemical characteristics of the plant were investigated. Four different naphthalene concentrations (0, 15, 30, and 60ppm) were selected for the experiments, with an additional control treatment without plants containing 60ppm naphthalene. Each treatment, utilizing a total of 20 hydroponic containers, consisted of 4 replicates. The results indicated that naphthalene led to a reduction in root and shoot growth. The root weight decreased from 17mg in the control group to 6mg in the 60ppm naphthalene treatment, while the shoot weight decreased from 107.5mg in the control group to 65.7mg in the 60ppm naphthalene treatment. Besides, the different naphthalene concentrations had an impact on the photosynthetic pigments. Compared to the control treatment, under severe stress conditions, chlorophyll a decreased by 51.85%, chlorophyll b decreased by 48.14%, and carotenoids decreased by 54.59%; however, anthocyanin, compared to the control treatment, increased by 30.1% under severe stress conditions. The presence of naphthalene also resulted in increased levels of malondialdehyde, hydrogen peroxide, and proline in both roots and shoots at various naphthalene concentrations. In roots, malondialdehyde increased by 40.74%, H2O2 increased by 3%, and proline increased by 75.6%, while malondialdehyde increased by 43.16%, H2O2 increased by 5.34%, and proline increased by 59.48% in shoots under severe stress conditions and compared to the control treatment. Root and shoot protein levels decreased by 64.49% and 32.26%, respectively. Furthermore, the antioxidant enzymes of glutathione S-transferase, superoxide dismutase, catalase, and ascorbate peroxidase showed increased activities in both roots and shoots under severe naphthalene stress conditions. Purslane demonstrated the ability to remove approximately 80% of naphthalene from the medium. In conclusion, this plant has an effective participation in naphthalene uptake and mitigates the adverse effects of naphthalene by enhancing antioxidant enzyme and proline activities.

Phoma herbarum: A Potential Biocontrol Agent Against Weeds, that Promotes Wheat Growth

The usage of chemical weedicide adversely affects the soil fertility and environment. Hence, in order to reduce the use of chemical weedicide, current study was aimed to isolate plant pathogenic microorganisms from diseased weeds and evaluate their potential as a bioherbicide in wheat field. Twelve bacterial and thirty-one fungal isolates were screened to determine their bioherbicidal activity against prevalent weeds (Avena fatua, Phalaris minor, and Chenopodium album) by using detached leaf assay and in-vitro seed testing methods. Among the forty-three isolates, two potential isolates were selected for further studies. Potential fungal isolates DGL 8C and DGL 7A with significant bioherbicidal activity were molecularly (ITS sequencing) identified as Phoma herbarum R21 (GenBank ID- ON705696) and K_NESO2 (GenBank ID- ON705704). Phoma herbarum R21 was chosen for further research due to its superior herbicidal effect and positive influence on wheat growth. Effective herbicidal activity (up to 90%) of potential isolate was obtained in pre-germination testing, compared to control. Cell free culture filtrate (CFCF) treatment showed nonspecific inhibition in the germination of weeds and wheat. While, CFCF selectively deteriorated the target weeds in post-germination treatment. Phoma herbarum R21 enhanced the growth of Durum wheat varieties Poshan and Tejas, as it promoted the growth of shoot, root, and fresh weight up to 88% compared to control. Phoma herbarum R21 significantly inhibited the growth of phytopathogenic fungi up to 57%. In this study, Phoma herbarum R21 was identified as a potential bioherbicide against the weeds of wheat along with its growth promoting and antifungal activities.

Limited genetic diversity found among genotypes of the Entada landrace (Ensete ventricosum, (Welw.) Chessman) from Ethiopia.

The Entada landrace of enset (Ensete ventricosum (Welw.) Chessman) is probably the most unique indigenous crop in Ethiopia, being maintained and utilized by the Ari people in the South of Ethiopia. Here we describe genetic diversity, selection signatures and relationship of Entada with cultivated and wild enset using 117 Entada genotypes collected from three Entada growing regions in Ethiopia (Sidama, South and North Ari). A total number of 1,617 high-quality SNP markers, obtained from ddRAD-sequences, were used for the diversity studies. Phylogenetic analysis detected a clear distinction between cultivated enset, Entada and wild enset with Entada forming a completely separated clade. However, extremely short branch lengths among the Entada genotypes indicate very little molecular evolution in the Entada lineages. Observed and expected heterozygosities were high, 0.73 and 0.50, respectively. Overall, our results strongly indicate that the Entada genotypes we have studied originated from one or a few clonal lineages that have been propagated and spread among farmers as clones. Prolonged clonal propagation of heterozygous genotypes from a single or few founding lineages has led to populations with very little or no diversity between genotypes, and high heterozygosity within genotypes. Signatures of directional selection were identified at eight loci based on an FST outlier analysis. Four candidate genes detected are involved in axillary shoot growth and might be involved in controlling natural sucker formation in Entada.

Characteristic Analysis of the Soil Bacterial Community Structure of Dendrocalamus brandisii from Seven Geographical Provenances in Yunnan Province

Soil is the basis of bamboo growth and quality formation of bamboo shoots and has an important contribution to the sustainable development of agriculture. To this end, We studied the soil properties and microbial communities of Dendrocalamus brandisii by collecting twenty-one soil samples from its seven typical geographic provenances in Yunnan Province, China. Bacterial 16S rRNA gene amplicons were used to detect soil bacteria and predict bacterial functions using Tax4Fun. The results indicated that the soil bacterial diversity indices (ACE, Chao1, Simpson, and Shannon) were significantly different among different geographical provenances. The dominant bacterial groups at the phylum level in all seven regions were Proteobacteria (19.78~29.06%), Actinobacteria (13.53~30.01%), Chloroflexi (8.03~31.47%), and Acidobacteria (7.12~19.17%), with markedly different constitution proportions. Total phosphorus, available potassium, and pH were the main environmental factors affecting soil bacterial communities. There were significant differences in the secondary metabolic pathways and phenotypes of soil bacterial functions, exhibiting a diversity of functions. The geographical variables of the soil bacterial community in D. brandisii varied with spatial scales. Environmental factors such as available potassium (AK), pH, and total nitrogen (TN) have an impact on soil bacterial communities.

Potassium indole-3-butyric acid affects rice's adaptability to salt stress by regulating carbon metabolism, transcription factor genes expression, and biosynthesis of secondary metabolites.

Soil salinity pollution is increasing worldwide, seriously affecting plant growth and crop production. Existing reports on how potassium indole-3-butyric acid (IBAK) regulates rice salt stress adaptation by affecting rice carbon metabolism, transcription factor (TF) genes expression, and biosynthesis of secondary metabolites still have limitations. In this study, an IBAK solution at 40 mg L-1 was sprayed on rice leaves at the seedling stage. The results showed that the IBAK application could promote shoot and root growth, decrease sucrose and fructose content, increase starch content, and enhance acid invertase (AI) and neutral invertase (NI) activity under salt stress, indicating altered carbon allocation. Furthermore, the expression of TF genes belonging to the ethylene responsive factor (ERF), WRKY, and basic helix-loop-helix (bHLH) families was influenced by IBAK. Many key genes (OsSSIIc, OsSHM1, and OsPPDKB) and metabolites (2-oxoglutaric acid, fumaric acid, and succinic acid) were upregulated in the carbon metabolism pathway. In addition, this study highlighted the role of IBAK in regulating the biosynthesis of secondary metabolites pathway, potentially contributing to rice stress adaptability. The results of this study can provide new sustainable development solutions for agricultural production.

Bacterial Volatile Organic Compounds as a Strategy to Increase Drought Tolerance in Maize (Zea mays L.): Influence on Plant Biochemistry.

Maize is highly susceptible to drought, which affects growth and yield. This study investigated how bacterial volatile organic compounds (BVOCs) affect maize drought tolerance. Drought reduced shoot size but increased root length, an adaptation for accessing deeper soil moisture. BVOCs from strain D12 significantly increased root length and shoot growth under drought conditions. Drought also altered root biochemistry, decreasing enzyme activity, and increased osmolyte levels. BVOCs from strains F11 and FS4-14 further increased osmolyte levels but did not protect membranes from oxidative damage, while BVOCs from strains D12 and D7 strains reduced osmolyte levels and cell damage. In shoots, drought increased the levels of osmolytes and oxidative stress markers. BVOCs from FS4-14 had minimal effects on shoot biochemistry. BVOCs from D12 and F11 partially restored metabolic activity but did not reduce cell damage. BVOCs from D7 reduced metabolic activity and cell damage. These results suggest that BVOCs can modulate the biochemical response of maize to drought, with some strains evidencing the potential to enhance drought tolerance.

Combined effects of polyamide microplastic and sulfamethoxazole in modulating the growth and transcriptome profile of hydroponically grown rice (Oryza sativa L.)

The use of reclaimed water from wastewater treatment plants for irrigation has a risk of introducing micropollutants such as microplastics (MPs) and antimicrobials (AMs) into the agroecosystem. This study was conducted to investigate the effects of single and combined treatment of 0.1 % polyamide (PA ∼15 μm), and varying sulfamethoxazole (SMX) levels 0, 10, 50, and 150 mg/L on rice seedlings (Oryza sativa L.) for 12 days. The study aimed to assess the impact of these contaminants on the morphological, physiological, and biochemical parameters of the rice plants. The findings revealed that rice seedlings were not sensitive to PA alone. However, SMX alone or in combination with PA, significantly inhibited shoot and root growth, total biomass, and affected photosynthetic pigments. Higher concentrations of SMX increased antioxidant enzyme activity, indicating oxidative stress. The roots had a higher SMX content than the shoots, and the concentration of minerals such as iron, copper, and magnesium were reduced in roots treated with SMX. RNA-seq analysis showed changes in the expression of genes related to stress, metabolism, and transport in response to the micropollutants. Overall, this study provides valuable insights on the combined impacts of MPs and AMs on food crops, the environment, and human health in future risk assessments and management strategies in using reclaimed water.