Inhibition Of Shoot Growth Research Articles

Alternative oxidase of plants mitochondria is related with increased resistance of tomato mtDNA to the difenoconazole exposure

It is known that plant mitochondria and mitochondrial DNA (mtDNA) are more resistant to damage than animal mitochondria. We hypothesized that this phenomenon may be related to alternative respiratory pathways in plants mitochondria, in particular alternative oxidase (AOX). The results of a pot experiment demonstrated that the application of the fungicide difenoconazole at concentrations that were 3-, 5-, and 10-times higher than the recommended dosage resulted in a 106 %, 76 %, and 90 % increase in mitochondrial DNA damage in tomato shoots, respectively, in comparison to the shoots treated with difenoconazole at the dosage recommended by the manufacturer. Inhibition of shoot growth was observed in response to treatment with difenoconazole at a dose 10times higher than recommended. It is noteworthy that when tomatoes were treated with difenoconazole at this concentration, there was a tendency for the expression of inducible aox1a. In a field experiment, difenoconazole at a concentration of 5 times higher than recommended resulted in a 10 % increase in mtDNA damage in the fruits compared to the control. Similar results were obtained in an in vitro experiment. The addition of low doses of difenoconazole to intact tomato mitochondria did not cause mtDNA damage. The observed damages occured only when 200 μM difenoconazole was added. In contrast, incubation of 20 μM difenoconazole with SHAM, which inhibits AOX, resulted in a 115 % increase in mtDNA damage compared to the use of the same concentration without difenoconazole. This finding is consistent with the damaging effect induced by 200 μM difenoconazole. The increase in difenoconazole toxicity induced by SHAM and the elevation in aox1a gene expression resulting from the treatment with a 10 times higher than the recommended dose of difenoconazole may signify a pivotal function of AOX in the increased resistance of plant mtDNA to the pesticide exposure.

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.

Toxicity of antimony to plants: Effects on metabolism of N and S in a rice plant

Excess antimony (Sb) has been shown to damage plant growth. Rice plants readily absorb a large amount of Sb after a long period of flooding, yet the mechanisms underlying Sb toxicity in plants have not been solved. This study was conducted to explore the effects of Sb on the uptake of N and S, and monitor the concentrations of reduced glutathione (GSH) and enzymes associated with these processes. In addition, we analyzed differentially expressed metabolites (DEMs) correlated with amino acids (AAs) and oligopeptides, specifically DEMs containing sulfur (S), GSH and indole–3–acetic acid (IAA). The results showed that antimonite [Sb(III)] inhibited shoot growth whereas antimonate [Sb(V)] stimulated shoot growth. Interestingly, Sb(III)5/10 enhanced shoot concentrations of total nitrogen (N), NH4+–N [only at Sb(III)10] and S; but reduced the shoot concentrations of NO3–N and soluble protein. Sb(III)5/10 addition significantly increased oxidized glutathione (GSSG) concentration and activities of glutathione peroxidase (GSH–Px) and glutathione S-transferase (GST) but non–significantly affected concentration of reduced glutathione (GSH) and activities of γ-glutamylcysteine synthetase (GCL) and glutathione reductase (GR), suggesting Sb(III) restricted GSH recycling. Addition of Sb (1) increased the abundance of DEMs associated with lignins, Ca uptake, toxicity/detoxification, and branched chain AAs; (2) decreased the abundance of AAs inclcuding isoleucine (Ile), leucine (Leu), tryptophan (Trp), tyrosine (Tyr) and histidine (His); (3) increased the abundance of arginine (Arg), putrescine (Put) and spermidine (Spd); and (4) affected methylation and acetylation of many AAs, especially acetylation.

Overexpression of the ribosome-inactivating protein OsRIP1 modulates the jasmonate signaling pathway in rice.

Ribosome-inactivating proteins (RIPs) are plant enzymes that target the rRNA. The cytoplasmic RIP, called OsRIP1, plays a crucial role in regulating jasmonate, a key plant hormone. Understanding the role of OsRIP1 can provide insights into enhancing stress tolerance and optimizing growth of rice. Transcription profiling by mRNA sequencing was employed to measure the changes in gene expression in rice plants in response to MeJA treatment. Compared to wild type (WT) plants, OsRIP1 overexpressing rice plants showed a lower increase in mRNA transcripts for genes related to jasmonate responses when exposed to MeJA treatment for 3 h. After 24 h of MeJA exposure, the mRNA transcripts associated with the gibberellin pathway occurred in lower levels in OsRIP1 overexpressing plants compared to WT plants. We hypothesize that the mechanism underlying OsRIP1 antagonization of MeJA-induced shoot growth inhibition involves cytokinin-mediated leaf senescence and positive regulation of cell cycle processes, probably via OsRIP1 interaction with 40S ribosomal protein S5 and α-tubulin. Moreover, the photosystem II 10kDa polypeptide was identified to favorably bind to OsRIP1, and its involvement may be attributed to the reduction of photosynthesis in OsRIP1-overexpressing plants subjected to MeJA at the early timepoint (3 h).

The effects of monoculture and intercropping on photosynthesis performance correlated with growth of garlic and perennial ryegrass response to different heavy metals

BackgroundThe potential of phytoremediation using garlic monoculture (MC) and intercropping (IC) system with perennial ryegrass to enhance the uptake of cadmium (Cd), chromium (Cr), and lead (Pb) were investigated.ResultsPositive correlations were found between MC and IC systems, with varying biomass. Production of perennial ryegrass was affected differently depending on the type of toxic metal present in the soil. Root growth inhibition was more affected than shoot growth inhibition. The total biomass of shoot and root in IC was higher than MC, increasing approximately 3.7 and 2.9 fold compared to MC, attributed to advantages in root IC crop systems. Photosystem II efficiency showed less sensitivity to metal toxicity compared to the control, with a decrease between 10.07–12.03%. Among gas exchange parameters, only Cr significantly affected physiological responses by reducing transpiration by 69.24%, likely due to leaf chlorosis and necrosis.ConclusionThis study exhibited the potential of garlic MC and IC with perennial ryegrass in phytoremediation. Although the different metals affect plant growth differently, IC showed advantages over MC in term biomass production.

Effects of Phloretin on Seedling Growth and Histochemical Distribution of Phenols, Polysaccharides and Lipids in Capsella bursa-pastoris (L.) Medik.

The present study evaluates the phytotoxic effects of phloretin, a prevalent secondary metabolite of apple trees, on the broadleaf weed Capsella bursa-pastoris (L.) Medik. known for its resistant myxospermous seeds that form a long-lasting soil bank. The results indicate a significant, dose-dependent inhibitory effect of phloretin on the growth and morphological parameters of weed seedlings grown in vitro. Although the applied phloretin concentrations (250-1000 µM) were not lethal to the C. bursa-pastoris seedlings after two weeks, the metabolism of the seedlings was impaired, resulting in an accumulation of lipid droplets in the root tips and root hairs. Histochemical analysis shows deposits of phenols in the root epidermal cells, which are probably aggregates of phloretin or its metabolic derivatives. The accumulation of pectin in the cell walls of root border cells in phloretin-treated seedlings indicates an attempt to reduce the uptake of phloretin and reduce its concentration in the cells. Inhibition of shoot growth associated with chlorosis and reduced photosynthetic pigment content is a consequence of seedling exposure to phloretin. This study provides a basis for further evaluation of phloretin as a new bioherbicidal compound and for elucidating the mechanism underlying its phytotoxic activity.

Endogenous cytokinins in plants of Secale cereale (Poaceae) under the effects of soil drought

Due to ongoing global climate changes and anthropogenic stress, soil drought has emerged as a significant threat, hindering plant growth, development, and resulting in crop losses. While phytohormones play a vital role in the formation of stress resistance mechanisms, cytokinins, in particular, remain poorly understood in cultivated cereals. The objective of our study was to investigate the impact of soil drought on plant growth and the homeostasis of endogenous cytokinins in both the aerial parts and roots of winter rye (Secale cereale) during the initial stages of vegetation. We aimed to elucidate the relationship between growth processes and the balance of these phytohormones. The plants were cultivated in a phytochamber using sand culture, and drought stress was induced by withholding water from nine-day-old plants for a period of eight days. The shoots and roots of 17-day-old plants were collected when dehydrated plants reached the critical wilting point. The content of endogenous cytokinins was analyzed using HPLC-MS. Our findings revealed that the inhibition of shoot growth and root elongation in stressed plants coincided with a reduction in the content of trans-zeatin riboside. This observation suggests that trans-zeatin riboside acts as a growth regulator in winter rye under soil drought conditions. Moreover, we observed an elevation in the levels of trans-zeatin and isopentenyladenine in the shoots and roots of stressed rye plants, indicating the involvement of these hormones in the formation of a "protective anti-stress block." These results highlight the multifunctional activity of cytokinins and demonstrate their role in regulating various components of the water deficit response. Consequently, our study expands our understanding of the role of cytokinins in the development of stress resistance in cereals.

Tissue-Specific Tolerance to High-Temperature and Nutrient-Poor Conditions in a Canopy-Forming Macroalga, Surviving at an Ocean Warming Hotspot.

Most canopy-forming macroalgae have disappeared from temperate reefs in southern Japan, one of the ocean warming hotspots, but Sargassum nipponicum is surviving in this region. As this species' annual shoots emerge from holdfasts during summer, both plant components may be highly tolerant to warm and nutrient-poor conditions in this season. The present study examined the effects of temperature and nutrient conditions on holdfast growth, shoot emergence from holdfasts, and shoot growth in S. nipponicum samples collected in Tanegashima Island, southern Japan. The summer temperature in this region (30 °C) allowed holdfast growth and shoot emergence but inhibited shoot growth. Nutrient-poor conditions had limited effects on the first two parameters but suppressed shoot growth. These results suggested that during warm summers and under nutrient-poor conditions in southern Japan, shoots can emerge from S. nipponicum holdfasts but cannot further grow. Additionally, nutrient loading from a nearby river was higher at the only site dominated by S. nipponicum, than at the other sites where this species was absent on Tanegashima Island. This was observed especially between autumn and winter, implying that such a nutrient-rich environment may contribute to shoot growth in S. nipponicum and to the persistence of its population in the area.

Sesquiterpene lactones enriched-fractions obtained from Cynara cardunculus extract diaultrafiltration

Sesquiterpene lactones (SL) are allelopathic compounds that demonstrate great potential of use in sustainable weed management. In this study, membrane processing technology was used for ethanolic Cynara cardunculus leaves extract (CcLE) ultra- and nanofiltration to produce SL-enriched fractions with increased phytotoxic activity. Experiments were conducted to select an ultrafiltration membrane (DuraMem500, DuraMem900 and SuezGH2000) for SL recovery and high molecular weight compounds (MWC) removal. SuezGH2000, which had rejection percentage of 50 % and 88 % for cynaropicrin (Cyn) and chlorophyll, respectively, was used for a sequential purification along with DuraMem200 for lower MWC removal. Since Cyn content on initial feed (11.9 %) and permeate (11.2 %) were similar, as well as phytotoxic activity, the results suggested that DuraMem200 was unsuitable for CcLE fractionation. SuezGH2000 revealed a slight increase on SL content, so, the permeation profile and enhancement of SL content were evaluated. An increase on SL content (36.0–71.0 %) was obtained after 2.3 diavolumes, followed by a decrease between 2.6 and 4.7 diavolumes. Phytotoxic activity evaluations revealed a direct association with SL content with enhancement of activity, particularly at inhibiting shoot growth of Portulaca oleracea. This study revealed SuezGH2000 effectiveness on SL purity improvement on CcLE fractions after 2.3 diavolumes and its potential to be used as a bioherbicide active component.

Transcriptomic and metabolomic analysis provides insight into imazethapyr toxicity to non-target plants.

Imazethapyr is a widely used imidazolinone herbicide worldwide, and its potential adverse effects on non-target plants have raised concerns. Understanding the mechanisms of imazethapyr phytotoxicity is crucial for its agro-ecological risk assessment. Here, the comprehensive molecular responses and metabolic alterations of Arabidopsis in response to imazethapyr were investigated. Our results showed that root exposure to imazethapyr inhibited shoot growth, reduced chlorophyll contents, induced photoinhibition and decreased photosynthetic activity. By non-target metabolomic analysis, we identified 75 metabolites that were significantly changed after imazethapyr exposure, and they are mainly enriched in carbohydrate, lipid and amino acid metabolism. Transcriptomic analysis confirmed that imazethapyr significantly downregulated the genes involved in photosynthetic electron transport and the carbon cycle. In detail, 48 genes in the photosynthetic lightreaction and 11 genes in Calvin cycle were downregulated. Additionally, the downregulation of genes related to electron transport in mitochondria provides strong evidence for imazethapyr inhibiting photosynthetic carbon fixation and cellular energy metabolism as one of mechanisms of toxicity. These results revealed the molecular and metabolic basis of imazethapyr toxicity on non-target plants, contributing to environmental risk assessment and mitigate negative impact of imazethapyr residues in agricultural soils.

Changes in Metabolites and Allelopathic Effects of Non-Pigmented and Black-Pigmented Lowland Indica Rice Varieties in Phosphorus Deficiency

Phosphorus (P) levels alter the allelopathic activity of rice seedlings against lettuce seeds. In this study, we investigated the effect of P deficiency on the allelopathic potential of non-pigmented and pigmented rice varieties. Rice seedlings of the white variety Khao Dawk Mali (KDML105, non-pigmented) and the black varieties Jao Hom Nin (JHN, pigmented) and Riceberry (RB, pigmented) were cultivated under high P (HP) and low P (LP) conditions. Morphological and metabolic responses to P deficiency were investigated. P deficiency inhibited shoot growth but promoted root growth of rice seedlings in all three varieties. Moreover, P deficiency led to decreased cytosolic phosphate (Pi) and total P concentrations in both shoot and root tissues. The subsequent reduction in internal P concentration enhanced the accumulation of phenolic compounds in both shoot and root tissues of the seedlings. Subsequently, allelopathy-based inter- and intra-specific interactions were assessed using water extracts from seedlings of the three varieties grown under HP and LP conditions. These extracts were tested on seeds of lettuce, the weed Dactyloctenium aegyptium, and the same rice variety. The shoot and root extracts from P-deficient seedlings reduced the germination of all recipient plants. Specifically, the shoot extract from P-deficient KDML105 seedlings reduced the germination index (GI) of lettuce seeds to 1%, while those from P-deficient RB and JHN seedlings produced GIs of 32% and 42%, respectively. However, when rice seeds were exposed to their own LP shoot and root extracts, their GIs increased up to 4-fold, compared with the HP extracts. Additionally, the shoot extracts from P-deficient plants also stimulated the germination of D. aegyptium by about 2–3-fold, whereas the root extracts did not have this effect. Therefore, P starvation led to the accumulation and exudation of phenolics in the shoots and roots of rice seedlings, altering their allelopathic activities. To adapt to P deficiency, rice seedlings potentially release signaling chemicals to suppress nearby competing species while simultaneously promoting their own germination and growth.

The AP2/ERF transcription factor MdDREB2A regulates nitrogen utilisation and sucrose transport under drought stress.

Drought stress is one of the main environmental factors limiting plant growth and development. Plants adapt to changing soil moisture by modifying root architecture, inducing stomatal closure, and inhibiting shoot growth. The AP2/ERF transcription factor DREB2A plays a key role in maintaining plant growth in response to drought stress, but the molecular mechanism underlying this process remains to be elucidated. Here, it was found that overexpression of MdDREB2A positively regulated nitrogen utilisation by interacting with DRE cis-elements of the MdNIR1 promoter. Meanwhile, MdDREB2A could also directly bind to the promoter of MdSWEET12, which may enhance root development and nitrogen assimilation, ultimately promoting plant growth. Overall, this regulatory mechanism provides an idea for plants in coordinating with drought tolerance and nitrogen assimilation to maintain optimal plant growth and development under drought stress.

Transcriptome Profiling Reveals the Gene Network Responding to Low Nitrogen Stress in Wheat

As one of the essential nutrients for plants, nitrogen (N) has a major impact on the yield and quality of wheat worldwide. Due to chemical fertilizer pollution, it has become increasingly important to improve crop yield by increasing N use efficiency (NUE). Therefore, understanding the response mechanisms to low N (LN) stress is essential for the regulation of NUE in wheat. In this study, LN stress significantly accelerated wheat root growth, but inhibited shoot growth. Further transcriptome analysis showed that 8468 differentially expressed genes (DEGs) responded to LN stress. The roots and shoots displayed opposite response patterns, of which the majority of DEGs in roots were up-regulated (66.15%; 2955/4467), but the majority of DEGs in shoots were down-regulated (71.62%; 3274/4565). GO and KEGG analyses showed that nitrate reductase activity, nitrate assimilation, and N metabolism were significantly enriched in both the roots and shoots. Transcription factor (TF) and protein kinase analysis showed that genes such as MYB-related (38/38 genes) may function in a tissue-specific manner to respond to LN stress. Moreover, 20 out of 107 N signaling homologous genes were differentially expressed in wheat. A total of 47 transcriptome datasets were used for weighted gene co-expression network analysis (17,840 genes), and five TFs were identified as the potential hub regulatory genes involved in the response to LN stress in wheat. Our findings provide insight into the functional mechanisms in response to LN stress and five candidate regulatory genes in wheat. These results will provide a basis for further research on promoting NUE in wheat.

Effect of methyl jasmonate seed treatment on physiological processes in wheat plants under conditions of increased zinc content in substrate

The effect of methyl jasmonate (MeJA, 10 μM) seed treatment on seed germination, growth and some parameters of photosynthesis and water metabolism in wheat (Triticum aestivum L.) plants of the Zlata variety grown at optimal (5 mg/kg) or excessive (46 mg/kg) zinc content in the substrate was studied. It was shown that elevated zinc concentrations inhibited shoot growth and led to a decrease both in chlorophyll content and transpiration intensity. MeJA seed treatment stimulated germination, but slightly inhibited plant growth during the tillering phase at optimum zinc content in the substrate. Conversely, at higher zinc levels, MeJA seed treatment reduces its inhibitory effect on plant growth and transpiration rate.

Effect of tebuconazole and azoxystrobin on the physiological parameters of wheat seedlings and their resistance to water stress

Strobilurin and triazole class fungicides are actively used in agriculture as part of dressers to protect plants from fungal disease. In addition, they have various physiological effects on plants, including increased resistance to adverse environmental factors. The combined effect of these fungicides under water stress is understudied. The present work aims to examine the individual and combined effects of tebuconazole and azoxystrobin on the growth characteristics of wheat and its resistance to water stress. The study used winter wheat (Triticum aestivum L. ) plants grown from seeds treated with tebuconazole (2 mg/50 g seeds) and azoxystrobin (4 mg/50 g seeds) suspensions separately or together. In order to create water stress, five-day seedlings were transferred to 20% polyethylene glycol solution (PEG 6000), with stability assessed at seven and nine days. Tebuconazole was found to have a retardant effect on shoots and stimulate root growth. Azoxystrobin inhibited shoot growth and particularly root growth. When used together, tebuconazole partially reduced azoxystrobin-induced root inhibition. Azoxystrobin increased the negative effect of water stress, while tebuconazole effectively protected the root system of seedlings, partially reducing the effect of azoxystrobin. The stimulation of root growth with tebuconazolewas concluded to play an important role in providing resistance of winter wheat to water stress and to have the potential for use in agriculture.

Cytokinin-mediated shoot proliferation and its correlation with phytoremediation effects in Cd-hyperaccumulator ecotype of Sedum alfredii

The phytohormones cytokinins (CKs) are known to regulate apical/auxiliary meristems, control shoot growth and are associated with nutrient uptake and high biomass production. In this study, different cytokinins were tested on Sedum alfredii (S.alfredii) for shoot proliferation and growth performance as well as their correlation with phytoextraction efficiency. Among the tested cytokinins, Zeatin (ZTN) treatments produced the highest number of shoots (5–6 per explant) with 5 and 10 μM ZTN concentrations which are shown as zeatin (ZTN) > kinetin (KTN) > benzylaminopurine (BA) > thidiazuron (TDZ). Maximum biomass production was produced on these media. The maximum biomass (0.14 g) was found in 10 μM ZTN concentration with a 1-fold difference (mean value: 0.02 g) from CK (0.12 g). However, the lowest biomass (0.11 g) was found with 4 μM TDZ, with a 1-fold difference (mean value: 0.02 g) from CK (0.13 g) which suppressed shoot growth. The leaf area and leaf chlorophyll index were significantly increased in all cytokinins except TDZ, and the relation was ZTN > KTN > BA>CK > TDZ. Cadmium accumulation was significantly higher in treatments containing cytokinins as compared to cytokinin-free media. Zeatin at 10 μM concentration was the most effective for high biomass production and correlated with higher cadmium uptake efficiency. The results suggest that cytokinins particularly ZTN, play a crucial role in enhancing both biomass production and cadmium, uptake efficiency in S. alfredii. Therefore, in large-scale phytoremediation initiatives conducted in field conditions, cytokinins can be utilized as growth regulators to enhance biomass production and cadmium extraction efficiency in S.alfredii.

ПРИЖИВАЕМОСТЬ И КИНЕТИКА РОСТОВЫХ ПРОЦЕССОВ РАЗЛИЧНОГО ТИПА МИКРОЧЕРЕНКОВ ВИНОГРАДА IN VITRO

New data on the peculiarities of the growth and development of plants of the Mahrovatchik and Belobulaniy grape varieties during subcultiva-tion, depending on the location of donor micro-gears on the shoot, are presented. There are 3 types of micro gears:type 1−1–4 micro gears from the lower part of the shoot, type 2 –from the middle part, 5−8 from the base of the shoot; type 3 − from the upper part of the shoot, 9−12 from the base of the shoot. When cultivated in conditions of high temperature and low humidi-ty, the best development was noted in the plants of the Mahrovatchik variety formed from the eyes of the middle part of the shoot. Inhibi-tion of shoot growth and higher plant viability during the entire cultivation period allows us to consider type 1 (bottom) of micro-gears optimal for laying a collection, and micro-gears of the upper and middle part of the shoot to be used for mass reproduction of the Belobulaniy varie-ty. The high regenerative ability of the ripened micro-gears of the Cabernet Sauvignon variety has been proven.

Shoot Growth and Virus Elimination by Antiviral Agents in Node Cultures of Three Rose Cultivars

Background and objective: This study was carried out to examine the effects of antiviral agents on shoot growth and virus elimination during node culture in rose 'Deep Purple', 'Natal Briar' and 'Pink Beauty' infected with TRSV and ArMV.Methods: Three varieties of roses confirmed to be infected with TRSV and ArMV through ImmunoStrip® Tests were node-cultured, and the medium was treated with antiviral agents ribavirin and vidarabine at 0, 10, 20, and 40 mg⋅L<sup>-1</sup> . After 60 days of culture, shoot growth and virus infection rates were evaluated.Results: In 'Deep Purple', vidarabine treatment inhibited shoot growth and survival rate more than ribavirin, and had no effect on virus elimination. Treatment of 20 mg⋅L<sup>-1</sup> ribavirin was no significant difference in shoot growth and survival rate compared to control, and TRSV and ArMV infection rates were lowered to 25% and 0%, respectively. In 'Natal Briar', treatment of 10-20 mg⋅L<sup>-1</sup> ribavirin showed no statistical difference in shoot growth compared to the control, but the infection rates of TRSV and ArMV were 100%. The shoot growth and survival rate were greatly suppressed in treatment of 10 mg⋅L<sup>-1</sup> vidarabine, but both TRSV and ArMV infection rates were 50%. In 'Pink Beauty', the higher the treatment concentration of ribavirin and vidarabine, the more the shoot growth was suppressed. Ribavirin had no effect on TRSV elimination, and 20 mg⋅L<sup>-1</sup> vidarabine treatment showed that both TRSV and ArMV infection rates were 50%.Conclusion: Depending on the type and concentration of the antiviral agent, the elimination effects of viruses were different for each variety of rose. It was most effective to treat 20 mg⋅L<sup>-1</sup> ribavirin in 'Deep Purple', 10 mg⋅L<sup>-1</sup> vidarabine in 'Natal Briar', and 20 mg⋅L<sup>-1</sup> vidarabine in 'Pink Beauty' in media for TRSV and ArMV elimination.

Deciphering the biochemical regulation of metabolic pathways in abating stress-induced damages during co-exposure of arsenic and fluoride in a non-aromatic and an aromatic rice variety.

The aim of the current work was to decipher the systemic damage and biochemical defense machinery due to combined arsenic (5mg L-1 Na3AsO4) and fluoride (50mg L-1 NaF) stress in two rice cultivars viz., IR-64 (non-aromatic) and Gobindobhog (aromatic), grown for 14days, under 16/8h light/dark photoperiodic cycle at 32°C. Higher accumulation of arsenic and fluoride in Gobindobhog generated higher levels of H2O2 that caused higher electrolyte leakage, along with malondialdehyde and methylglyoxal formation. Higher oxidative damages severely compromised seed germination and led to chlorophyll loss, inhibition of root and shoot growth and fresh and dry weight of the seedlings. On the contrary, oxidative damage was less pronounced in IR-64, as compared to that of Gobindobhog, which can be attributed to higher accumulation of protective metabolites, i.e., osmolytes and antioxidants. Higher levels of osmolytes (proline, glycine betaine and amino acids) in IR-64 helped in maintaining the osmotic balance of the cells and theintegrity of the cell membrane. Additionally, up regulated activity of enzymatic antioxidants (catalase, superoxide dismutase, ascorbate peroxidase, glutathione peroxidase and glutathione S-transferase) along with elevated levels of non-enzymatic antioxidants (flavonoids, phenolics, xanthophylls and carotenoids) played a pivotal role in controlling oxidative damages and strengthening the defense machinery in IR-64, as compared to that of Gobindobhog where lesser enhancement in the level of the above mentioned protective metabolites was noted. The present work illustrated differential phytotoxicity in rice seedlings and elucidated the yet uncharacterized biohazard associated with arsenic and fluoride co-contamination, with better adaptive features of IR-64, compared to Gobindobhog, which appeared as the sensitive variety.

Effects of Salt Tolerance Training on Multidimensional Root Distribution and Root-Shoot Characteristics of Summer Maize under Brackish Water Irrigation.

To investigate the impact of brackish water irrigation on the multidimensional root distribution and root-shoot characteristics of summer maize under different salt-tolerance-training modes, a micro-plot experiment was conducted from June to October in 2022 at the experimental station in Hohai University, China. Freshwater irrigation was used as the control (CK), and different concentrations of brackish water (S0: 0.08 g·L-1, S1: 2.0 g·L-1, S2: 4.0 g·L-1, S3: 6.0 g·L-1) were irrigated at six-leaf stage, ten-leaf stage, and tasseling stage, constituting different salt tolerance training modes, referred to as S0-2-3, S0-3-3, S1-2-3, S1-3-3, S2-2-3, and S2-3-3. The results showed that although their fine root length density (FRLD) increased, the S0-2-3 and S0-3-3 treatments reduced the limit of root extension in the horizontal direction, causing the roots to be mainly distributed near the plants. This resulted in decreased leaf area and biomass accumulation, ultimately leading to significant yield reduction. Additionally, the S2-2-3 and S2-3-3 treatments stimulated the adaptive mechanism of maize roots, resulting in boosted fine root growth to increase the FRLD and develop into deeper soil layers. However, due to the prolonged exposure to a high level of salinity, their roots below 30 cm depth senesced prematurely, leading to an inhibition in shoot growth and also resulting in yield reduction of 10.99% and 11.75%, compared to CK, respectively. Furthermore, the S1-2-3 and S1-3-3 treatments produced more reasonable distributions of FRLD, which did not boost fine root growth but established fewer weak areas (FLRD < 0.66 cm-3) in their root systems. Moreover, the S1-2-3 treatment contributed to increasing leaf development and biomass accumulation, compared to CK, whereas it allowed for minimizing yield reduction. Therefore, our study proposed the S1-2-3 treatment as the recommended training mode for summer maize while utilizing brackish water resources.