Roots Of Seedlings Research Articles

Boron Reduced Copper Excess-Induced Oxidative Damage in Citrus sinensis by Modulating Reactive Oxygen Species and Methylglyoxal Formation and Their Detoxification Systems.

Citrus is mainly cultivated in acid soil with low boron (B) and high copper (Cu). In this study, Citrus sinensis seedlings were submitted to 0.5 (control) or 350 μM Cu (Cu excess or Cu exposure) and 2.5, 10, or 25 μM B for 24 weeks. Thereafter, H2O2 production rate (HPR), superoxide production rate (SAPR), malondialdehyde, methylglyoxal, and reactive oxygen species (ROS) and methylglyoxal detoxification systems were measured in leaves and roots in order to test the hypothesis that B addition mitigated Cu excess-induced oxidative damage in leaves and roots by reducing the Cu excess-induced formation and accumulation of ROS and MG and by counteracting the impairments of Cu excess on ROS and methylglyoxal detoxification systems. Cu and B treatments displayed an interactive influence on ROS and methylglyoxal formation and their detoxification systems. Cu excess increased the HPR, SAPR, methylglyoxal level, and malondialdehyde level by 10.9% (54.3%), 38.9% (31.4%), 50.3% (24.9%), and 312.4% (585.4%), respectively, in leaves (roots) of 2.5 μM B-treated seedlings, while it only increased the malondialdehyde level by 48.5% (97.8%) in leaves (roots) of 25 μM B-treated seedlings. Additionally, B addition counteracted the impairments of Cu excess on antioxidant enzymes, ascorbate-glutathione cycle, sulfur metabolism-related enzymes, sulfur-containing compounds, and methylglyoxal detoxification system, thereby protecting the leaves and roots of Cu-exposed seedlings against oxidative damage via the coordinated actions of ROS and methylglyoxal removal systems. Our findings corroborated the hypothesis that B addition alleviated Cu excess-induced oxidative damage in leaves and roots by decreasing the Cu excess-induced formation and accumulation of ROS and MG and by lessening the impairments of Cu excess on their detoxification systems. Further analysis indicated that the pathways involved in the B-induced amelioration of oxidative stress caused by Cu excess differed between leaves and roots.

The endophytic potential, Bacillus spp. for controlling Meloidogyne sp. and increasing tomato growth and production

Meloidogyne spp. is responsible of root swelling, one of the primary disease in tomato plants. Controlling this nematode is challenging due to its wide host range. The use of synthetic nematicides harms the environment; therefore, alternative controls, such as biological methods, are necessary. Among the biological agents, one group includes endophytic bacteria that reside in plant tissues and do not cause harm to plants. These bacteria enhance plant resistance to pests and pathogens while promoting plant growth. The study aimed to acquire endophytes, Bacillus spp. strains capable of controlling Meloidogyne sp. while stimulating the growth of tomato plants. The research employed a completely randomized design (CRD) comprising seven treatments and five replications. The treatments consisted of B. cereus strain SNE 2.2, TLE 2.3 and TLE 1.1, B. pseudomycoides strain EPL 1.1.3, B. toyonensis strain EPL 1.1.4, positive control (without the introduction of Bacillus spp. and inoculation with Meloidogyne sp.) and negative control (without Bacillus spp. and without Meloidogyne sp.). Bacillus spp. endophyites were introduced in two stages: into the seeds and into the roots of tomato seedlings for 15 min. The observed variables were the development of Meloidogyne sp., endophytic colonization of Bacillus spp., and plant growth. The results demonstrated that all Bacillus spp. were effective in controlling Meloidogyne sp. and enhancing the growth of tomato plants. The best isolate in controlling Meloidogyne sp. and increasing the growth of tomato plants was B. cereus strain SNE2.2.

Application of ethanol alleviates heat damage to leaf growth and yield in tomato.

Chemical priming has emerged as a promising area in agricultural research. Our previous studies have demonstrated that pretreatment with a low concentration of ethanol enhances abiotic stress tolerance in Arabidopsis and cassava. Here, we show that ethanol treatment induces heat stress tolerance in tomato (Solanum lycopersicon L.) plants. Seedlings of the tomato cultivar 'Micro-Tom' were pretreated with ethanol solution and then subjected to heat stress. The survival rates of the ethanol-pretreated plants were significantly higher than those of the water-treated control plants. Similarly, the fruit numbers of the ethanol-pretreated plants were greater than those of the water-treated ones. Transcriptome analysis identified sets of genes that were differentially expressed in shoots and roots of seedlings and in mature green fruits of ethanol-pretreated plants compared with those in water-treated plants. Gene ontology analysis using these genes showed that stress-related gene ontology terms were found in the set of ethanol-induced genes. Metabolome analysis revealed that the contents of a wide range of metabolites differed between water- and ethanol-treated samples. They included sugars such as trehalose, sucrose, glucose, and fructose. From our results, we speculate that ethanol-induced heat stress tolerance in tomato is mainly the result of increased expression of stress-related genes encoding late embryogenesis abundant (LEA) proteins, reactive oxygen species (ROS) elimination enzymes, and activated gluconeogenesis. Our results will be useful for establishing ethanol-based chemical priming technology to reduce heat stress damage in crops, especially in Solanaceae.

Identification and virulence test of a new pathogen that causes verticillium striping on rapeseed in northwestern China

Five stems of rapeseed with abundant black microsclerotia were collected from Huangyuan County of Qinghai Province, China, and fungal isolates were obtained from the stems. They were identified based on morphology, molecular features and specific PCR detection. The results showed that the 10 fungal isolates belonged to Verticillium longisporum lineage A1/D3. One of the 10 isolates (HW7-1) was tested for virulence on three species of rapeseed, including B. napus Zhongshuang 9, B. rapa Qingyou 9 and B. juncea Tayou 2 by conidia inoculation of HW7-1 on roots of young seedlings. Control seedlings were inoculated with V. dahliae conidia or water alone. The seedlings of these treatments were transplanted in culture mix and incubated in a growth chamber (20 ​°C). Results suggested that the control seedlings of three cultivars appeared quite healthy, while the seedlings inoculated with HW7-1 turned yellowing leaves, seedling stunting or even death after 22 days post-inoculation. V. longisporum was re-isolated from he yellow leaves, thus fulfilling Koch's postulates. Moreover, compared to the control treatments, inoculation with HW7-1 caused flowering delay and seed yield reduction on Tayou 2 with production of microsclerotia on the stems. To our knowledge, this is the first report of V. longisporum lineage A1/D3 on rapeseed in northwestern China.

Potassium Solubilizers, Aspergillus sp. and Trichoderma sp. Promote Growth in Tomato


 
 
 Potassium (K) is the third most significant plant macronutrient that plays a crucial role in growth and development of plants. K is abundant in soil, but 90-98% of K exists as insoluble minerals and only 1-2% becomes available to the plants. Certain microbes, K solubilizing microbes (KSMs), can solubilize unavailable forms of K and making it available to plants. The objective of the current study was to evaluate the growth promotion ability of two previously (2019) isolated KSMs, Aspergillus sp. and Trichoderma sp in-vitro and under greenhouse conditions using feldspar as the K source. Khandeparkar‘s selection ratio calculated based on K solubilizing assay on Alexandrov medium showed that Aspergillus (1.72+0.16) has a higher and faster K solubilization ability than Trichoderma (1.0+0.16). Effect of KSMs was assayed in a Tomato seed germination assay carried out in Petri plates with KSMs treated and non-treated soils. Both Aspergillus (58%) and Trichoderma (72%) showed enhanced percentage germination of tomato seeds under in vitro conditions compared to that of controls (Aspergillus sp.: 24%, 14%, 22.7%, 51.3%, 39.3%, Trichoderma sp.: 22%, 12%, 13%, 59%, 51%) which was statistically significant (Aspergillus, P=0.026; Trichoderma, P=0.003) at 0.05 confidence level. Seedling length (P=0.102, P=0.028) and root length (P=0.453, P=0.002) of tomato were enhanced when raised in non-autoclaved natural soil than autoclaved natural soil inoculated with Aspergillus and Trichoderma respectively. The greenhouse experiment was carried out with same experimental set up as an in vitro assay. No significant difference was observed in shoot length, number of leaves and length of leaves of tomato plants planted in soil treated with Aspergillus (P=0.093, P=0.906, P=0.260) and Trichoderma (P=0.334, P=0.239, P=0.243) respectively in comparison to controls during the vegetative stage (2 months after sawing). However, flowering was started four days early in plants planted in non-autoclaved soil treated with Aspergillus sp. suggesting that the impact of Aspergillus sp. starts to become visible in the reproductive stage. The results suggest that K solubilizing ability of Aspergillus sp. and Trichoderma sp. seem to show a positive effect on germination ability of tomato, however, only Aspergillus sp. seems to have a positive effect on the later stages of plant growth where K is mainly needed for flower and fruit development. Therefore, Aspergillus sp. can be a potential candidate to be used in up scaling the natural K fertilizers such as feldspar after intensive future experimentation.
 Keywords: Plant Growth Promoting Microbes (PGPMs), Growth promotion, K deficiency
 
 

Adaptation Strategies of Seedling Root Response to Nitrogen and Phosphorus Addition.

The escalation of global nitrogen deposition levels has heightened the inhibitory impact of phosphorus limitation on plant growth in subtropical forests. Plant roots area particularly sensitive tissue to nitrogen and phosphorus elements. Changes in the morphological characteristics of plant roots signify alterations in adaptive strategies. However, our understanding of resource-use strategies of roots in this environment remains limited. In this study, we conducted a 10-month experiment at the Castanopsis kawakamii Nature Reserve to evaluate the response of traits of seedling roots (such as specific root length, average diameter, nitrogen content, and phosphorus content) to nitrogen and phosphorus addition. The aim was to reveal the adaptation strategies of roots in different nitrogen and phosphorus addition concentrations. The results showed that: (1) The single phosphorus and nitrogen-phosphorus interaction addition increased the specific root length, surface area, and root phosphorus content. In addition, single nitrogen addition promotes an increase in the average root diameter. (2) Non-nitrogen phosphorus addition and single nitrogen addition tended to adopt a conservative resource-use strategy to maintain growth under low phosphorus conditions. (3) Under the single phosphorus addition and interactive addition of phosphorus and nitrogen, the roots adopted an acquisitive resource-use strategy to obtain more available phosphorus resources. Accordingly, the adaptation strategy of seedling roots can be regulated by adding appropriate concentrations of nitrogen or phosphorus, thereby promoting the natural regeneration of subtropical forests.

Exogenous Calcium Alleviates Oxidative Stress Caused by Salt Stress in Peanut Seedling Roots by Regulating the Antioxidant Enzyme System and Flavonoid Biosynthesis.

Soil salinity is one of the adversity stresses plants face, and antioxidant defense mechanisms play an essential role in plant resistance. We investigated the effects of exogenous calcium on the antioxidant defense system in peanut seedling roots that are under salt stress by using indices including the transcriptome and absolute quantitative metabolome of flavonoids. Under salt stress conditions, the antioxidant defense capacity of enzymatic systems was weakened and the antioxidant capacity of the linked AsA-GSH cycle was effectively inhibited. In contrast, the ascorbate biosynthesis pathway and its upstream glycolysis metabolism pathway became active, which stimulated shikimate biosynthesis and the downstream phenylpropanoid metabolism pathway, resulting in an increased accumulation of flavonoids, which, as one of the antioxidants in the non-enzymatic system, provide hydroxyl radicals to scavenge the excess reactive oxygen species and maintain the plant's vital activities. However, the addition of exogenous calcium caused changes in the antioxidant defense system in the peanut root system. The activity of antioxidant enzymes and the antioxidant capacity of the AsA-GSH cycle were enhanced. Therefore, glycolysis and phenylpropanoid metabolism do not exert antioxidant function, and flavonoids were no longer synthesized. In addition, antioxidant enzymes and the AsA-GSH cycle showed a trade-off relationship with sugars and flavonoids.

Auxin and hydrogen peroxide (H2O2) interaction differentially regulate seedling growth, Na+/K+ ratio and H2S homeostasis accompanying NaCl stress in etiolated sunflower (Helianthus annuus L. cv. Microgreen) seedling roots and cotyledons

Although H2S has been reported to modulate auxin and H2O2 signaling during abiotic stress, no reports decipher the interactive roles of exogenous auxin and H2O2 on the regulation of endogenous H2S homeostasis. In the present work, auxin (IAA) and hydrogen peroxide (H2O2) interaction appear to be crucial in regulating Na+/K+ homeostasis, recovery in seedling growth and H2S accumulation in NaCl-stressed sunflower seedlings. Interestingly, impairment in endogenous IAA transport (TIBA application) also impacts H2S accumulation in the roots and cotyledons. IAA supplementation is effective in reducing Na+/K+ ratio and electrolytic leakage in roots, which reverses in the presence of TIBA (polar auxin transport inhibitor) application. IAA and H2O2-mediated modulation of H2S content corroborates with l-DES activity in seedling roots and cotyledons. In contrast to cotyledons, roots exhibited a reduction in H2S content in the presence of treatments (IAA and H2O2). H2O2 supplementation seems to partially circumvent the changes caused by the disruption of auxin transport. Thus, we hypothesize that auxin might imply H2O2 as a crucial signaling component in the regulation of H2S levels in sunflower tissues. To sum up, IAA and H2O2 interaction regulates root growth, LR proliferation, Na+/K+ ratio, and H2S metabolism in sunflower seedling roots.

Positive interaction of trembesi (Samanea saman) and arbuscular mycorrhizae fungi in Pb stabilization of gold-mine tailing media

Abstract. Setyaningsih L, Ramadhani FA, Muttaqin Z, Maslahat M. 2024. Positive interaction of trembesi (Samanea saman) and arbuscular mycorrhizae fungi in Pb stabilization of gold-mine tailing media. Biodiversitas 25: 379-385. This experiment aimed to determine the ability of trembesi (Samanea saman Merr.) seedlings inoculated with AMF (Glomus manihotis) to reduce Pb from gold mine tailings media. Therefore, using plants and Arbuscular Mycorrhizae Fungi (AMF) is an alternative choice that can be considered to support a phytoremediation program to reduce Pb contamination in tailing areas. The experiment was conducted using a completely randomized design in a greenhouse with two factors, i.e., with and without AMF, and four different Pb treatments (0, 0.5, 1, and 1.5 mM). AMF-inoculated seedlings were grown on tailings media and exposed to Pb in different concentrations for 5 weeks. The results showed that the seedlings were still able to grow on the media with Pb up to 1.5 mM with a tolerance index of 91.6%. AMF induced the plant to accumulate Pb dramatically higher, even though this absorption tended to reduce plant biomass. Root tissue stored significantly higher Pb than stem and leaf tissue, with an average concentration was 526.29 mg/kg in the roots of mycorrhizal seedlings. The bioaccumulation level of Pb in mycorrhizal seedlings was significantly higher. The value of the transport factor was below 1, indicating that S. saman seedlings carried out the phytostabilization. The interaction of AMF with S. saman has a big potential to be applied in efforts to remediate Pb in tailings.

Effects of Copper Compounds on Phenolic Composition of the Common and Tartary Buckwheat Seedlings

Food producers actively seek effective seed-coating agents to ensure optimal antimicrobial protection and/or nutritional support for young plants. In this context, our study aimed to investigate the impact of various copper compounds on the germination and early growth stages of two important crops, common and Tartary buckwheat. Microparticles (MPs) and nanoparticles (NPs) of copper oxide (CuO) were selected as potential seed treatment agents and compared to Cu salt in a comprehensive germination assay. The results indicated that seed germination remained unaffected by the tested copper compounds after eight days, while there was a significant reduction in seedlings fresh weight and root length. Treated common buckwheat seedlings exhibited extreme increases in all tested phenolic metabolites, even at low concentrations of Cu compounds. In contrast, in Tartary buckwheat seedlings, the already higher concentrations of flavonoids and tannins were mostly slightly decreased. Considering all the results, CuO NPs emerged as the most severe form of Cu, while CuO MPs may have the highest potential for applications in agriculture and food sciences. This finding has implications for producers seeking seedlings enriched in beneficial phenolic compounds for human health, as well as for farmers aiming to boost the antioxidative system of plants to mitigate stress.

Co-inoculation of Soybean Seedling with Trichoderma asperellum and Irpex laceratus Promotes the Absorption of Nitrogen and Phosphorus.

Soybean are one of the main oil crops in the world. The study demonstrated that co-inoculation with Trichoderma asperellum(Sordariomycetes, Hypocreomycetidae) and Irpex laceratus (Basidiomycota, Polyporales) isolated from Kosteletzkya virginica can promote the growth of soybean seedlings. The two fungi were found to produce various enzymes, including cellulase, amylase, laccase, protease, and urease. Upon inoculation, T. asperellum mainly colonized within the phloem of the roots in soybean seedlings, while I. laceratus mainly in the xylem and phloem of the roots. Physiological parameters, such as plant height, root length, and fresh weight, were significantly increased in soybean seedlings co-inoculated with T. asperellum and I. laceratus. Moreover, the expression of key genes related to N and P absorption and metabolism was also increased, leading to improved N and P utilization efficiency in soybean seedlings. These results indicate that the two fungi may have complementary roles in promoting plant growth, co-inoculation with T. asperellum and I. laceratus can enhance the growth and nutrient uptake of soybean. These findings suggest that T. asperellum and I. laceratus have the potential to be used as bio-fertilizers to improve soybean growth and yield.

Toxic effects of atmospheric deposition in mining areas on wheat seedlings.

Storage and transportation of coal, as well as operation of coal-fired power plants, produce amounts of metallic exhaust that may lead to different atmospheric environment in the overlapped areas of farmland and coal resource (OAFCR) environment. To investigate the effects of different atmospheric environment in the OAFCR region (north of Xuzhou) on wheat seedlings (AK-58), a box experiment was conducted and compared to an area far from the OAFCR (south of Xuzhou). The study revealed that (1) compared to the southern suburb of Xuzhou, the fresh and dry weight, activities of photosynthetic enzymes and POD of wheat seedlings in the OAFCR reduced obviously. (2) Significantly higher levels of Cr, Cd, Pb, Zn, and Cu were found in the shoots and roots of wheat seedlings in the OAFCR, with lower transfer factor for heavy metals (except Cd and As) in comparison to those in the southern suburb. And the bioconcentration factors of heavy metals (except As) in wheat seedlings in the OAFCR were significantly higher. (3) Nearly 90% of heavy metals (Pb, Cu, Cd, Zn, and Cr) absorbed by wheat were stored in cell walls and soluble fractions, with significantly higher contents of Cu and Cr in wheat seedlings' cell walls and higher contents of Pb, Zn, and Cd in soluble components found in the OAFCR. Our results showed that atmospheric deposition in the mining area has a certain toxic effect on wheat seedlings, and this study provides a theoretical basis for OAFCR crop toxicity management.

Application technique and concentration of biofertilizer from rhizosphere of cocoa (Theobroma cacao L.) given biosurfactant dietanolamide oil palm on the growth of cocoa seedlings

This research aimed to know the influence of application technique and biofertilizer that given concentration of biosurfactant diethanolamide (DEA) for the growth of cocoa seedlings and also to know the interaction between application technique and concentration level of biofertilizer given DEA growth of cacao seedling (Theobroma cacao L.). This research was conducted in UPTD SITANDU, Banten and the Soil Agroclimate Laboratory, Faculty of Agriculture, University of Sultan Ageng Tirtayasa from December 2020 until March 2021, by using randomize complete block design with two factors. The first factor is technique application T1 at soil, T2 at leaf, and T3 with combination soil and leaf fertilization), and the second factor is concentration level of biofertilizer given DEA P1 10 ml and 5%, P2 10 ml and 10%, P3 20 ml and 5%, P4 20 ml and 10%. As a result, there were twelve possible treatment combinations, and each was applied three times. Parameters total chlorophyll (unit), root length (cm), stem diameter (mm), seedlings dry weight (g) and root shoot rasio (g). The results there was no interaction effect between the two treatments, namely application technique and concentration level of biofertilizer with DEA biosurfactant, on all observed parameters of cocoa seedlings.

DNA methylation impacts soybean early development by modulating hormones and metabolic pathways.

Genomic DNA methylation patterns play a crucial role in the developmental processes of plants and mammals. In this study, we aimed to investigate the significant effects of epigenetic mechanisms on the development of soybean seedlings and metabolic pathways. Our analyses show that 5-azaC-treatment affects radicle development from two Days After Imbibition (DAI), as well as both shoot and root development. We examined the expression levels of key genes related to DNA methylation and demethylation pathways, such as DRM2, which encodes RNA-directed DNA Methylation (RdDM) pathway, SAM synthase, responsible for methyl group donation, and ROS1, a DNA demethylase. In treated seedling roots, we observed an increase in DRM2 expression and a decrease in ROS1 expression. Additionally, 5-azaC treatment altered protein accumulation, indicating epigenetic control over stress response while inhibiting nitrogen assimilation, urea cycle, and glycolysis-related proteins. Furthermore, it influenced the levels of various phytohormones and metabolites crucial for seedling growth, such as ABA, IAA, ethylene, polyamines (PUT and Cad), and free amino acids, suggesting that epigenetic changes may shape soybean responses to pathogens, abiotic stress, and nutrient absorption. Our results assist in understanding how hypomethylation shapes soybean responses to pathogens, abiotic stress, and nutrient absorption crucial for seedling growth, suggesting that the plant's assimilation of carbon and nitrogen, along with hormone pathways, may be influenced by epigenetic changes.

Glutaredoxin regulation of primary root growth is associated with early drought stress tolerance in pearl millet.

Seedling root traits impact plant establishment under challenging environments. Pearl millet is one of the most heat and drought tolerant cereal crops that provides a vital food source across the sub-Saharan Sahel region. Pearl millet's early root system features a single fast-growing primary root which we hypothesize is an adaptation to the Sahelian climate. Using crop modeling, we demonstrate that early drought stress is an important constraint in agrosystems in the Sahel where pearl millet was domesticated. Furthermore, we show that increased pearl millet primary root growth is correlated with increased early water stress tolerance in field conditions. Genetics including genome-wide association study and quantitative trait loci (QTL) approaches identify genomic regions controlling this key root trait. Combining gene expression data, re-sequencing and re-annotation of one of these genomic regions identified a glutaredoxin-encoding gene PgGRXC9 as the candidate stress resilience root growth regulator. Functional characterization of its closest Arabidopsis homolog AtROXY19 revealed a novel role for this glutaredoxin (GRX) gene clade in regulating cell elongation. In summary, our study suggests a conserved function for GRX genes in conferring root cell elongation and enhancing resilience of pearl millet to its Sahelian environment.

Glutaredoxin regulation of primary root growth is associated with early drought stress tolerance in pearl millet

Seedling root traits impact plant establishment under challenging environments. Pearl millet is one of the most heat and drought tolerant cereal crops that provides a vital food source across the sub-Saharan Sahel region. Pearl millet’s early root system features a single fast-growing primary root which we hypothesize is an adaptation to the Sahelian climate. Using crop modeling, we demonstrate that early drought stress is an important constraint in agrosystems in the Sahel where pearl millet was domesticated. Furthermore, we show that increased pearl millet primary root growth is correlated with increased early water stress tolerance in field conditions. Genetics including genome-wide association study and quantitative trait loci (QTL) approaches identify genomic regions controlling this key root trait. Combining gene expression data, re-sequencing and re-annotation of one of these genomic regions identified a glutaredoxin-encoding gene PgGRXC9 as the candidate stress resilience root growth regulator. Functional characterization of its closest Arabidopsis homolog AtROXY19 revealed a novel role for this glutaredoxin (GRX) gene clade in regulating cell elongation. In summary, our study suggests a conserved function for GRX genes in conferring root cell elongation and enhancing resilience of pearl millet to its Sahelian environment.

Nanopore Direct RNA Sequencing Reveals the Short-Term Salt Stress Response in Maize Roots

Transcriptome analysis, relying on the cutting-edge sequencing of cDNA libraries, has become increasingly prevalent within functional genome studies. However, the dependence on cDNA in most RNA sequencing technologies restricts their ability to detect RNA base modifications. To address this limitation, the latest Oxford Nanopore Direct RNA Sequencing (ONT DRS) technology was employed to investigate the transcriptome of maize seedling roots under salt stress. This approach aimed to unveil both the RNA transcriptional profiles and alterations in base modifications. The analysis of the differential expression revealed a total of 1398 genes and 2223 transcripts that exhibited significant variation within the maize root system following brief exposure to salt stress. Enrichment analyses, such as the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway assessments, highlighted the predominant involvement of these differentially expressed genes (DEGs) in regulating ion homeostasis, nitrogen metabolism, amino acid metabolism, and the phytohormone signaling pathways. The protein–protein interaction (PPI) analysis showed the participation of various proteins related to glycolytic metabolism, nitrogen metabolism, amino acid metabolism, abscisic acid signaling, and the jasmonate signaling pathways. It was through this intricate molecular network that these proteins collaborated to safeguard root cells against salt-induced damage. Moreover, under salt stress conditions, the occurrence of variable shear events (AS) in RNA modifications diminished, the average length of poly(A) tails underwent a slight decrease, and the number of genes at the majority of the variable polyadenylation (APA) sites decreased. Additionally, the levels of N5-methylcytosine (m5C) and N6-methyladenosine (m6A) showed a reduction. These results provide insights into the mechanisms of early salt tolerance in maize.

Spring Growth Variation in Pioneer and Fibrous Roots in Abies sachalinensis Seedlings from Provenances with Contrasting Snow Cover Environments

Spring Growth Variation in Pioneer and Fibrous Roots in <i>Abies sachalinensis</i> Seedlings from Provenances with Contrasting Snow Cover Environments

First report of root rot in Trichosanthes kirilowii (Chinese cucumber) caused by Fusarium sulawesiense in China.

Trichosanthes kirilowii (Chinese cucumber) is one of the important perennial herbaceous vines in China, with putative pharmacological activities including anti-tumor and lowering blood lipids. In July 2022, T. kirilowii plants with brownish roots and chlorotic leaves were observed in several orchards in Qianshan, Anhui province, China (30°34'N, 116° 30'E). The disease incidence reached approximately 10% within an area spanning 20 ha, and was higher in poorly drained orchards. To investigate this root rot disease, five symptomatic plants were collected from the diseased orchards in Qianshan. Subsequently, small sections of the diseased roots were surface sterilized using 1% sodium hypochlorite and 75% ethanol for 45 seconds each. Then, sterilized roots were placed onto PDA (20% diced potato, 2% glucose, and 1.5% agar, and distilled water) and incubated at 28℃ in the dark for 6 days. A total of eight isolates with similar morphology were obtained and purified by single spore culturing. Two representative isolates (QSJ4 and QSJ5) were chosen for further analysis. When grown on PDA, the surface of each colony was white with dense aerial mycelium and pale orange color in the center with a white edge on the reverse side. Macroconidia produced on carnation leaf agar plates were falcate, slightly curved, and 3 to 5 septate, with papillate apical cells and indistinct basal cells. Macroconidia were 17.4-42.3 × 2.4-5.8 μm (n = 100). Microconidia were ellipsoidal in shape, slightly curved or not curved, and most were 1-septate, 9.6-16.7 × 1.5-3.8 μm (n = 40). The identity was determined by sequencing four loci (i. e., ITS, CAL, EF1-α and RPB2) from two representative isolates (Liu et al. 1999; O'Donnell et al. 1998, 2000; Reeb et al. 2004; White et al. 1990). Sequences were deposited in GenBank [ITS (OR267397, OR267398), CAL (OR296634, OR296635), EF1-α (OR296637, OR296638) and RPB2 (OR296640, OR296641)]. A phylogenetic analysis was performed with three loci (CAL, EF1-α, RPB2) comprising a concatenated dataset of 68 strains in the Fusarium incarnatum-equiseti species complex (Han et al., 2023). The results showed that isolates QSJ4 and QSJ5 clustered closely together with reference strains of F. sulawesiense. Pathogenicity tests were conducted by inoculating three-week-old healthy T. kirilowii seedings (cv. Wanlou No. 9) cultivated in substrate soil in pots with a diameter of 17 cm and a height of 10.5 cm. A 20 mL aliquot of spore suspension (106 conidia/mL) of F. sulawesiense was inoculated to the roots of potted seedlings by irrigation. Each strain was inoculated onto three seedlings. The potted seedlings were inoculated with sterile water as the negative control. Inoculated seedlings were incubated in a growth chamber at 25℃ and 75% relative humidity. After one week, typical symptoms of root necrosis and leaf chlorosis were observed on the inoculated seedlings. Disease symptoms were not observed on the control seedlings. All seedlings showing root necrosis and leaf chlorosis caused by the inoculations were subjected to fungal isolation, and the results showed that the reisolated colonies matched the inoculated ones for morphologies and ITS sequences. Fusarium sulawesiense has been previously reported to cause disease on Cucumis melo L. in Brazil (Medeiros Araujo et al. 2021), Musa acuminata Colla in south Sulawesi (Maryani et al. 2019), Luffa aegyptiaca Miller and Musa nana Lour. in China (Wang et al. 2019). To our knowledge, this is the first report of F. sulawesiense causing Fusarium root rot of T. kirilowii in China.

The Effect of Applying Azolla Liquid Organic Fertilizer in the Growth of Oil Palm Seedlings in Pre-Nursery

&#x0D; &#x0D; &#x0D; &#x0D; The development and replanting of smallholder oil palm is rapid and massive; its success from the beginning is determined, among others, by sufficient quantities of seeds with good quality. Nutrient management is the highest priority in nurseries, and along with strengthening the application of sustainability principles in the palm oil industry, alternative sources of nutrients other than inorganic fertilizers are needed. This study aimed to determine the right concentration of Azolla liquid organic fertilizer to increase the growth of oil palm seedlings in pre-nursery. The study was a single factor arranged in a completely randomized design. The studied treatment of POC Azolla concentrations of 100, 85, 75, 65, 55, 45, 35, 25, 15%, plus compost treatment of Azolla solids, NPKMg (15-15-6-4) and urea with 8 repetitions. Required seedlings (9+3) x 8 = 96 polybags. The results showed that applying Azolla POC concentration of 15-35% and solid Azolla compost provided the growth of oil palm seedlings in the pre-nursery, which tended to be better than inorganic fertilizers. POC in this concentration range also results in a better seedling root system, thus potentially increasing the adaptability of oil palm seedlings after being transplanted on permanent land&#x0D; &#x0D; &#x0D; &#x0D; &#x0D;