Plant Growth Research Articles

A WUSCHEL-related homeobox transcription factor, SlWOX4, negatively regulates drought tolerance in tomato.

CRISPR/Cas9-mediated knockout of SlWOX4 gene in tomato enhances tolerance to drought stress. Drought stress is one of the major abiotic factors that seriously affects plant growth and crop yield. WUSCHEL-related homeobox (WOX) transcription factors are involved in plant growth, development and stress response. However, little is known about the role of WOX genes in drought tolerance in tomato. Here, SlWOX4, a member of the WOX family in tomato, was functionally characterized in mediating drought tolerance. SlWOX4 was homologous to Nicotiana tabacum NtWOX4 with a conserved HD domain, and was localized in the nucleus. SlWOX4 was significantly down-regulated by drought and abscisic acid (ABA) treatments. The loss-of-functionmutations of SlWOX4 produced using the CRISPR-Cas9 system in tomato improved drought tolerance by reducing water loss rate and enhancing stomatal closure. In addition, the wox4 lines exhibited reduced accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA), increased antioxidant enzyme activity, proline contents and ABA contents under drought stress. Moreover, gene editing of SlWOX4 in tomato enhanced drought tolerance by regulating the expression of genes encoding antioxidants and ABA signaling molecules. In summary, SlWOX4 gene might negatively regulate drought stress tolerance in tomato and has great potential as a drought-resistant crop-breeding target genes.

Regulation of root-associated microbiomes and root exudates by different tobacco species

BackgroundThe root-associated microbiomes are crucial in promoting plant growth and development through symbiotic interactions with their hosts. Plants may shape their microbiomes by secreting specific root exudates. However, the potential mechanisms how plant species determine root exudates and drive microbiome assembly have been little studied. In this study, three wild tobaccos and one cultivated tobacco were used to investigate the commonalities and differences of both root-associated microbiomes and root exudates.ResultsAmplicon sequencing results suggested that tobacco species significantly affected microbial communities in both the rhizosphere and root endosphere, with the strongest impact on the fungal community in the root endosphere. The microbial networks of wild tobacco species were more stable than that of the cultivated tobacco, and fungal members played a more important role in the networks of wild tobacco species, while bacterial members did so in the cultivated tobacco. The rhizosphere bacteria of wild tobacco species showed a higher functional diversity than that of the cultivated tobacco, while the bacteria in the root endosphere presented a contrary pattern. Metabolomics analysis showed significant differences in the composition and abundance of root exudates among the four tobacco species, and the greatest difference was found between the three wild species and the cultivated one. Correlation analysis showed the strongest correlation between metabolites and rhizosphere bacteria, in which O-benzoic acid (2-methoxybenzoic acid) had the most positive correlations with rhizosphere bacteria, while β-ureidoisobutenoic acid had the most negative correlations with rhizosphere bacteria. The rhizosphere bacteria Streptomyces, Hydrophilus and Roseobacter had the strongest positive correlations with metabolites, and the rhizosphere bacterium Nitrobacter had the most negative correlations with metabolites.ConclusionThis study revealed the differences of microbial communities and root exudates in the rhizosphere and root endosphere of four tobacco species, which can further improve our understanding of plant–microbiome interactions during crop domestication.Graphical

Regulatory Effects of Chlormequat Chloride on the Yield and Chemical Composition of Angelica sinensis Radix

Chlormequat chloride (CCC), as a commonly used plant growth regulator in the production of rhizomatous medicinal herbs, can effectively control the bolting phenomenon in Angelica sinensis, significantly increasing the yield of underground rhizomes (medicinal part). However, its specific effects on the intrinsic quality of Angelica sinensis, especially medicinal components, require further investigation. The objective of this study is to conduct a thorough examination of CCC residue and its influence on the yield and medicinal components of Angelica sinensis. By spraying different concentrations of CCC on Angelica sinensis, we systematically monitored the final yield of Angelica sinensis Radix (ASR) in each treatment group and the residual concentration of CCC in ASR. Using UPLC-QTOF-MS technology, we conducted an in-depth analysis of the metabolic profile of ASR. Subsequently, UFLC-MS/MS was employed to accurately quantify the changes in the content of nine key active components in ASR. The results of this study indicate that the application of CCC significantly improves the yield of ASR, with the best effect observed at 0.1 g/L, resulting in a yield increase of 24.8%. Meanwhile, the residual amount of CCC in ASR is positively correlated with the application concentration, with the residual levels as high as 7.12 mg/kg in the high-concentration treatment group. Metabolomic analysis preliminarily identified 21 chemical components in ASR, including four organic acids and 13 phthalides. It is worth noting that the quantitative analysis results indicate significant changes in active components such as butylphthalide, Z-ligustilide, and ferulic acid after the application of CCC. Specifically, high-concentration CCC significantly increased the content of butylphthalide and levistolide A, while low-concentration CCC significantly promoted the accumulation of coniferyl ferulate and senkyunolide A, accompanied by a significant decrease in Z-ligustilide and ferulic acidy. In conclusion, while CCC use can increase yield, the associated increase in residues and imbalanced composition ratios may threaten the quality and safety of ASR. Therefore, it is crucial to control the amount of CCC used rationally to balance yield enhancement and quality assurance.

Deciphering genome sequence of Paenibacillus illinoisensis strain YWY-3.1: A chitinase, cellulase, and amylase producer

The chitin-degrading Paenibacillus illinoisensis YWY-3.1 was isolated from the lake water at Yok Don National Park, Vietnam. Previous evaluations reported that strain YWY-3.1 had high activities of chitinases, cellulases, and amylases; it also produced remarkable levels of numerous promoting traits for plant growth. This study aimed to sequence and analyze the genome sequence of strain YWY-3.1 for further explorations and applications in agriculture and related fields. The whole genome sequencing revealed the P. illinoisensis YWY-3.1 genome contained 6,451,623 bp, 47.3 % GC, 5786 coding sequences, 88 tRNA, and 1 rRNA. It shared 95.49 % ANI and 87.1 % dDDH to those of P. illinoisensis NBRC 15959 (GCA 004000925). Among the coding sequences, COG deduced 4,991, and KEGG predicted 2819. The genome harbored 338 carbohydrate-active enzymes, including 195 GHs, 44 GTs, 13 PLs, 37 CEs, 3 AAs, and 46 CBMs; among them, 6 GH18 chitinases, 5 GH5 cellulases, 2 GH10 xylanases, 1 GH11 xylanase, and 2 GH13 α-amylases were identified. It contained 49 genes involved in environmental adaptation and plant growth. Moreover, 7 BGCs, with 3 being novel clusters, were identified from the genome. This work provided insight into the genomic information of P. illinoisensis YWY-3.1 and potential gene resources, especially chitinases, cellulases, xylanases, α-amylases, and novel BGCs for further explorations and applications.

Molecular characterization of plant growth-promoting Trichoderma from Saudi Arabia.

Fungi in the genus Trichoderma are widespread in the environment, mainly in soils. They are used in agriculture because of their mycoparasitic potential; Trichoderma have the ability to increase plant health and provide protection against phytopathogens, making them desirable plant symbionts. We isolated, identified, and characterized Trichoderma from different regions of Saudi Arabia and evaluated the ability of Trichoderma to promote plant growth. Morphological and molecular characterization, along with phylogenetic studies, were utilized to differentiate between Trichoderma species isolated from soil samples in the Abha and Riyadh regions, Saudi Arabia. Then, plant growth-promoting traits of the isolated Trichoderma species were assessed. Eight Trichoderma isolates were characterized via morphological and molecular analysis; six (Trichoderma koningiopsis, Trichoderma lixii, Trichoderma koningii, Trichoderma harzianum, Trichoderma brevicompactum, and Trichoderma velutinum) were from Abha and two (T. lixii and T. harzianum) were from Riyadh. The isolated Trichoderma strains belonged to three different clades (Clade 1: Harzianum, Clade 2: Brevicompactum, and Clade 3: Viride). The Trichoderma isolates varied in plant growth-promoting traits. Seeds treated with most isolates exhibited a high percentage of germination, except seeds treated with the T3-T. koningii isolate. 100% germination was reported for seeds treated with the T4-T. harzianum and T6-T. brevicompactum isolates, while seeds treated with the T1-T. koniniopsis and T5-T. lixii isolates showed 91.1% and 90.9% germination, respectively. Seeds treated with the T8-T. velutinum, T2-T. lixii, and T7-T. harzianum isolates had germination rates of 84.1%, 82.2%, and 72.7%, respectively. The Trichoderma isolate T5-T. lixii stimulated tomato plant growth the most, followed by T7-T. harzianum, T8-T. velutinum, T4-T. harzianum, T1-T. koniniopsis, T2-T. lixii, and T6-T. brevicompactum; the least effective was T3-T. koningii. A maximum fresh weight of 669.33mg was observed for the T5-T. lixii-treated plants. The Abha region had a higher diversity of Trichoderma species than the Riyadh region, and most isolated Trichoderma spp. promoted tomato growth.

Management of Nutrients in Soybean (Glycine max) Crops: A Review

Effective nutrient management is crucial for maximizing soybean (Glycine max) yield, promoting sustainable farming methods, and satisfying worldwide food requirements. This paper analyses significant discoveries and optimal methods in nutrient management for soybean crops, with a focus on the cruciality of efficient techniques to optimize yield, quality, and environmental conservation. Soybeans have distinct nutritional needs during their many growth stages, with nitrogen (N), phosphorus (P), potassium (K), and micronutrients playing vital roles in plant growth, yield formation, and stress resistance. Optimal fertilization, determined through soil analysis and considering the specific requirements of the crops, is crucial for providing sufficient nutrients while minimizing negative environmental consequences such as nutrient runoff, leaching, and greenhouse gas emissions. Novel developments and advancements, such as precision agriculture, variable rate fertilization, and smart fertilizers, present inventive methods to enhance the efficiency of nutrient management procedures. These technological improvements allow for the precise distribution of nutrients to specific areas, using data to make informed decisions and improve the efficiency of resources. This ultimately leads to better crop performance and sustainability. In addition, efficient nutrient management enhances soil health, increases resistance to both living organisms and non-living environmental pressures and ensures economic sustainability for farmers. Soybean producers may achieve optimal yields, quality, and profitability while minimizing environmental hazards by implementing integrated nutrient management systems, including organic amendments, and closely monitoring crop nutrition. To summarise, this review emphasizes the significance of nutrient management in soybean production, emphasizing the necessity for comprehensive strategies that take into account agronomic, environmental, and economic factors. Ongoing research, innovation, and information sharing are crucial for improving nutrient management strategies and guaranteeing the long-term sustainability of soybean cropping systems.

Bioactive Potential of Actinobacteria Strains Isolated from the Rhizosphere of Lavender, Lemon Balm, and Oregano

The objective of this study was to isolate and characterize actinobacteria from the rhizosphere of medicinal and aromatic plants, specifically lavender (Lavandula angustifolia Mill.), lemon balm (Melissa officinalis L.), and oregano (Origanum vulgare L.). Rhizospheric soil samples revealed a high abundance of culturable actinobacteria (6.97–7.23 log10 CFU/g). Six isolates were selected for their promising enzymatic activities (lignin peroxidase, carboxymethyl cellulase) and antimicrobial properties. Isolates M345 and M162 exhibited the highest cellulase activity indices (3.19 ± 0.71 and 2.54 ± 0.22, respectively), with five isolates producing lignin peroxidase. These actinobacteria also demonstrated plant growth-promoting traits such as phosphate solubilization and nitrogen fixation, along with strong antimicrobial activity against Gram-negative bacteria and phytopathogenic fungi. Additionally, they significantly enhanced maize seed germination, increasing the vigor index from 4283.33 ± 1264.37 to 6248.28 ± 1661.94 compared to that of the control. These results indicate that the isolated actinobacteria strains hold potential as microbial inoculants for sustainable agriculture, contributing to soil health, plant growth, and pathogen management.

The RNA helicase LOS4 regulates pre-mRNA splicing of key genes (EIN2, ERS2, CTR1) in the ethylene signaling pathway.

The Arabidopsis RNA helicase LOS4 plays a key role in regulating pre-mRNA splicing of the genes EIN2, CTR1, and ERS2 in ethylene signaling pathway. The plant hormone ethylene plays diverse roles in plant growth, development, and responses to stress. Ethylene is perceived by the membrane-bound ethylene receptors complex, and then triggers downstream components, such as EIN2, to initiate signal transduction into the nucleus, leading to the activation of ethylene-responsive genes. Over the past decades, substantial information has been accumulated regarding gene cloning, protein-protein interactions, and downstream gene expressions in the ethylene pathway. However, our understanding of mRNA post-transcriptional processing and modification of key genes in the ethylene signaling pathway remains limited. This study aims to provide evidence demonstrating the involvement of the Arabidopsis RNA helicase LOS4 in pre-mRNA splicing of the genes EIN2, CTR1, and ERS2 in ethylene signaling pathway. Various genetic approaches including RNAi gene silencing, CRISPR-Cas9 gene editing, and amino acid mutations were employed in this study. When LOS4 was silenced or knocked down, the ethylene sensitivity of etiolated seedlings was significantly enhanced. Further investigation revealed errors in the EIN2 pre-mRNA splicing when LOS4 was knocked down. In addition, aberrant pre-mRNA splicing was observed in the ERS2 and CTR1 genes in the pathway. Biochemical assays indicated that the los4-2 (E94K) mutant protein exhibited increased ATP binding and enhanced ATP hydrolytic activity. Conversely, the los4-1 (G364R) mutant had reduced substrate RNA binding and lower ATP binding activities. These findings significantly advanced our comprehension of the regulatory functions and molecular mechanisms of RNA helicase in ethylene signaling.

Artificial Neural Network Model for Predicting Carrot Root Yield Loss in Relation to Mechanical Heading

Modelling and predicting agricultural production processes have high cognitive and practical values. Plant growth, the threat of pathogens and pests, and the structure of agricultural machinery treatments are mostly non-linear, measurable processes that can be described mathematically. In this paper, a multiple regression analysis was carried out in the first step to check the non-linearity of the data and yielded a coefficient of determination of R2 = 0.9741 and the coefficient of determination corrected for degrees of freedom was R2adj = 0.9739. An artificial neural network model, called CH-NET, is then presented to predict the yield loss of carrot roots by leaving root mass in the field during harvest at the mechanical heading stage. The proposed network model has an architecture consisting of an input layer, three hidden layers with 12 neurons each, and an output layer with one neuron. Twelve input criteria were defined for the analysis and testing of the network, eight of which related to carrot root parameters and four to the heading machine. The training, testing, and validation database of the CH-NET network consisted of the results of field trials and tests of the operation of the patented (P.242097) root heading machine. The proposed CH-NET neural network model achieved global error (GE) values of 0.0931 t·ha−1 for predicting carrot root yield losses for all twelve criteria adopted. However, when the number of criteria is reduced to eight, the error increased to 0.0991 t·ha−1. That is, the prediction was realised with an accuracy of 90.69%. The developed CH-NET model allows the prediction of economic losses associated with root mass left in the field or contamination of the raw material with undercut leaves. The simulations carried out showed that minimum root losses (0.263 t·ha−1) occur at an average root head projection height of 38 mm and a heading height of 20 mm from the ridge surface.

(±)-Catechins inhibit prehaustorium formation in the parasitic weed Phelipanche ramosa and reduce tomato infestation.

Phelipanche ramosa L. (Pomel) is a noxious parasitic weed in field and vegetable crops in Mediterranean countries. Control of this pest is complex and far from being achieved, and new environmentally-friendly strategies are being sought. The present study evaluates the possibility of using (±)-catechins as a natural herbicide against broomrapes. The results show that (±)-catechins have no effect on GR24-induced germination over a wide concentration range (10-4 to 10-10 m), nor on radicle elongation after germination, but strongly inhibit, at 10-4 and 10-5 m, prehaustorium formation in response to the haustorium-inducing factor, cis/trans-zeatin. Accordingly, pot experiments involving the supplies of 10-5 m of (±)-catechins to tomato plants infested or not with P. ramosa demonstrate that (±)-catechins do not influence growth of non-parasitized tomato plants and prevent heavy infestation by strongly reducing parasite attachments and inducing parasite necrosis once they are attached. This study points the potential use of (±)-catechins for parasitic weed control. It raises also the question of the mechanisms involved in the inhibition of prehaustorium formation and the necrosis of parasite attachments in response to (±)-catechins application. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Enhancing Olive Cultivation Resilience: Sustainable Long-Term and Short-Term Adaptation Strategies to Alleviate Climate Change Impacts

Olive cultivation, an icon of Mediterranean agriculture, economy, and cultural heritage, faces significant challenges due to climate change and soil degradation. Climate projections indicate that altered precipitation patterns, rising temperatures, and increased frequency of extreme weather events will adversely affect olive tree growth, fruit quality, and yield. This review provides a novel perspective on addressing these challenges through both long-term and short-term adaptation strategies, emphasizing innovative products, advanced technologies, and practical solutions that must work synergistically and be tailored to regional conditions. Long-term practices refer to proactive strategies for enduring climate resilience, including cover cropping, mulching, soil amendments, and breeding programs which enhance soil health, improve water retention, and increase the trees’ resilience. Short-term strategies focus on immediate impacts, offering immediate stress relief and enhanced plant physiological responses, including optimized irrigation systems, pruning management, particle coating films, biostimulants, and plant growth regulators. The review underscores the importance of aligning agricultural practices with sustainability goals and evolving environmental policies and the education of farmers and policymakers. By integrating adaptive practices and technological advancements, the olive sector can better address climate challenges, contribute to global food security, and advance environmental sustainability.

Comprehensive studies of the serine carboxypeptidase-like (SCPL) gene family in Carya cathayensis revealed the roles of SCPL4 in epigallocatechin-3-gallate (EGCG) synthesis and drought tolerance

Hickory (Carya cathayensis) nuts are rich in epigallocatechin-3-gallate (EGCG) with multiple health functions. EGCG also regulates plant growth, development and stress responses. However, research on the synthesis mechanism of EGCG and its function in hickory is currently limited. Herein, 44 serine carboxypeptidase-like (SCPL) members were identified from the hickory genome and classified into three major categories: SCPL-I, SCPL-II, and SCPL-III. In the CcSCPLs-IA branch, CcSCPL3/4/5/8/9/11/13 showed differential expression patterns in various tissues, especially with relatively high expression levels in plant roots, female flowers and seed coat. These proteins have a catalytic triad composed of serine (Ser), aspartic acid (Asp) and histidine (His). Ser-His in the triad and arginine (Arg) mediated the docking of CcSCPL3/4/5/11 with 1-O-galloyl-β-d-glucose (βG) and epigallocatechin (EGC), whereas the Asp of the triad did not. CcSCPL4 was further confirmed to promote the synthesis of EGCG in tobacco leaves. CcSCPL4 may function as monomer and be mainly localized within cellular structures outside the nucleus. Notably, the expression level of CcSCPL4 significantly changed after drought, cold, and salt stress, with the highest expression level under drought stress. Meanwhile CcSCPL4 over-expression could enhance the drought resistance of Saccharomyces cerevisiae and Arabidopsis. This study elucidates key enzymes for EGCG synthesis and their role in drought resistance, providing insights into the EGCG synthesis pathway and molecular breeding of hickory in future.

Effectiveness of copper oxychloride coated with iron nanoparticles against earthworms

This study examines the potential of iron nanoparticle-coated copper oxychloride in mitigating its toxic effects on earthworms, a key component of sustainable agriculture due to their role in enhancing soil quality and promoting plant growth. While earthworms and their coelomic fluid play a crucial role in enhancing soil health and promoting plant growth. Copper oxychloride, a commonly used fungicide, induces oxidative stress by disrupting antioxidant defense mechanisms in living systems. Through probit analysis, the median lethal concentration (LC50) of copper oxychloride was determined to be 2511.9 mg/kg. Artificial soil was treated with copper oxychloride at 60% and 80% of LC50, but the addition of iron nanoparticle-coated fungicide successfully reduced earthworm mortality to 0%. These findings offer promising insights into protecting non-target organisms from fungicide toxicity while maintaining agricultural productivity. The findings present a potential breakthrough in sustainable agriculture by demonstrating how nanotechnology can mitigate the harmful effects of fungicides on essential soil fauna. The use of iron nanoparticle-coated fungicides not only protects earthworms but also offers a path to maintaining ecological balance and enhancing crop productivity without compromising soil health.

The effect of agro-ecological zone on the chemical composition of feed resources in the Gera district, southwest Ethiopia

The poor quality of available feed resources is the major limiting factor for livestock production in Ethiopia. The aim of this study was to determine and compare the chemical composition of major feed resources in three agro-ecological zones (AEZs) of the Gera District, southwest Ethiopia. Three representative samples of natural pasture (Cynodon dactylon, Pavonia schimperiana Hochst and Rhynchosia ferruginea), three indigenous fodder trees and shrubs (IFTSs) (Erythrina abyssinica, Vernonia amygdalina and Maytenus undat), two cultivated forages (Pennisetum purpureum and Pennisetum pedicellatum) and five crop residues (Hordeum vulgare (barley), Zea mays (maize), Sorghum bicolor (sorghum), Triticum aestivum (wheat) and Eragrostis tef (Teff)) were randomly and separately collected from the Highland (HL), midland (ML) and lowland (LL) AEZs. The samples were analyzed for ash, dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), ether extract (EE), and acid detergent lignin (ADL) content using standard analytical methods. The results showed that AEZ significant (P < 0.05) affected the chemical composition parameters of most of the feed samples. Regardless of the feed sample and AEZs, the mean DM, CP, ash, EE, NDF, ADF, ADL and CF content varied from 89.17% in Pennisetum purpureum to 92.22 ± 0.51 in Erythrina abyssinica, 2.90 ± 0.22% in Triticum aestivum to 10.70 ± 0.52 in Vernonia amygdalina, 7.24 ± 0.19% in Sorghum bicolor to 13.25 ± 0.51% in Pavonia Schimperiana Hochst, 1.33 ± 0.04% in Triticum aestivum to 2.39 ± 0.15% in Maytenus undata, 57.65 ± 1.19% in Erythrina Abyssinica to 79.16 ± 1.04% in Triticum aestivum, 34.57% in Pennisetum purpureum to 59.41 ± 0.98% in Sorghum bicolor, 8.15 ± 0.62% in Rhynchosia ferruginea to 12.65 ± 0.57% in Triticum aestivum and 37.51% in Pennisetum pedicelatum to 69.93 ± 0.65% DM in Triticum aestivum, respectively. It was observed that IFTSs had the highest CP and the lowest NDF, implying their potential for protein supplement, whereas crop residues had the lowest CP and the highest NDF, indicating the need for their treatment using urea or supplementing animals with protein source feeds, especially during the dry season. In conclusion, AEZ has an influence on the chemical composition traits of feed resources attributed to its effects on the microclimate conditions that affect plant growth and maturation in the study sites.

Isolation and functional determination of inward-rectifier K+ channel PbrAKT1 in pear

ABSTRACT Potassium (K+) is essential to plant growth and development. The absorption and transport of K+ by plant roots occurs mainly through K+ channels or transporters. In this study, an AKT1-type channel named PbrAKT1 was successfully cloned and characterised by a series of detailed procedures, including protein sequence alignment, expression and subcellular localisation analysis, as well as functional verification by heterologous expression function validation in yeast mutant R5421, Arabidopsis akt1 mutant, and Xenopus oocytes. The results showed that PbrAKT1 is preferentially expressed in pear roots and exhibits plasma membrane localisation, but its expression is unaffected by low K+ treatment. PbrAKT1 exhibits the function of an inwardly-rectifying K+ channel, and its activity is autonomously regulated when expressed in Xenopus oocytes. In addition, a series of heterologous expression experiments confirmed that PbrAKT1 plays an indispensable role in the processes of K+ transport, as well as alleviating the low-K+ -sensitive phenotype of yeast mutant R5421 and Arabidopsis akt1 mutant. In summary, PbrAKT1 plays an indispensable role in the processes of K+ transport and provide new information on the molecular mechanism of K+ absorption in pear roots.

The Degradation and Migration of Cyclanilide in Soil and Sediment in China.

The environmental fate of a plant growth regulator cyclanilide was studied in this paper. The degradation, adsorption, and migration behaviors of cyclanilide were detailly measured in the laboratory. The results showed that the DT50 of cyclanilide degradation in the Jiangxi red, Taihu paddy, Changshu wushan, Shaanxi tide, and Dongbei black soils was 42.3 d, 31.9 d, 14.4 d, 30.4 d as well as 27.4 d under aerobic conditions and 32.3 d, 37.4 d, 29.3 d, 48.9 d as well as 27.0 d under water anaerobic conditions, respectively, with the main metabolite being 2,4-dichloroaniline (2,4-D). The DT50 of 2,4-D ranged from 5.26 to 27.1 days under aerobic conditions, and from 10.6 to 54.1 days under anaerobic conditions. The adsorption of cyclanilide by the soils was well fitted by the empirical linear adsorption isotherm, and the adsorption constant (Kd, H) values in the Jiangxi red, Taihu paddy, Changshu wushan, Shaanxi tide, and Dongbei black soils were 7.08, 4.49, 4.05, 3.20, and 1.41, respectively. The results of a mobility test showed that cyclanilide had strong mobility in the most test soils. Furthermore, soil pH is the dominant element affecting the adsorption of cyclanilide in the soils. Under aerobic environment, the DT50 of total cyclanilide in river and lake water-sediment systems were 30.7 d and 34.0 d, respectively; under anaerobic environment, their DT50 were 30.8 d and 31.4 d, respectively. In water-sediment systems, 2,4-D mainly exists in aqueous phase and the DT50 ranged from 5.23 to 8.76 days. This work demonstrated that cyclanilide has the potential risk to contaminate environment and attention should be paid to its application.

The Serratia sp. strain C2 confers tomato tolerance to high salt, virus infection and both stresses in combination

Besides increasing plant growth, several Plant Growth Promoting Rhizobacteria (PGPR), can enhance tolerance to biotic and/or abiotic stresses of numerous plant species. While cultivated plants are frequently subject to combined stresses in the field, there is limited knowledge of the effect of PGPR on plants undergoing simultaneous stress conditions. Therefore, we tested the beneficial properties of the halotolerant PGPR Serratia sp. strain C2, previously shown to enhance salt stress tolerance in barley, on tomato plants exposed to salinity, to Potato Virus Y (PVY) infection, and both stresses simultaneously. In our experimental conditions, C2 inoculation improved tomato tolerance to salt stress and positively correlated with a 46–68 % decrease in the level of PVY RNA compared to non-inoculated tomato plants. Morphometric, physiological and biochemical analyses (e.g., chlorophyll, sugar and proline accumulation, oxidative stress status and NDVI) indicated that C2 treatments had beneficial effects on tomato growth under simple and combined stress conditions. This is the first report of a PGPR enhancing tolerance not only to individually induced salinity and PVY infection, but also to both stresses in combination. Moreover, the expression analysis of selected genes involved in stress responses and RNA silencing-mediated antiviral immunity suggests that C2 can interfere with distinct defence response pathways to enhance stress tolerance in tomato. These pioneering results support the perspective of using PGPR as multi-spectrum and multi-host biostimulants for improving plant growth and protection from biotic, abiotic, and combined stresses to promote sustainable crop production in the face of environmental changes.

Reading m6A marks in mRNA: A potent mechanism of gene regulation in plants.

Modifications to RNA have recently been recognized as a pivotal regulator of gene expression in living organisms. More than 170 chemical modifications have been identified in RNAs, with N6-methyladenosine (m6A) being the most abundant modification in eukaryotic mRNAs. The addition and removal of m6A marks are catalyzed by methyltransferases (referred to as "writers") and demethylases (referred to as "erasers"), respectively. In addition, the m6A marks in mRNAs are recognized and interpreted by m6A-binding proteins (referred to as "readers"), which regulate the fate of mRNAs, including stability, splicing, transport, and translation. Therefore, exploring the mechanism underlying the m6A reader-mediated modulation of RNA metabolism is essential for a much deeper understanding of the epigenetic role of RNA modification in plants. Recent discoveries have improved our understanding of the functions of m6A readers in plant growth and development, stress response, and disease resistance. This review highlights the latest developments in m6A reader research, emphasizing the diverse RNA-binding domains crucial for m6A reader function and the biological and cellular roles of m6A readers in the plant response to developmental and environmental signals. Moreover, we propose and discuss the potential future research directions and challenges in identifying novel m6A readers and elucidating the cellular and mechanistic role of m6A readers in plants.

Evolution and functional divergence of glycosyltransferase genes shaped the quality and cold tolerance of tea plants.

Plant glycosyltransferases (UGTs) play a key role in plant growth and metabolism. Here, we examined the evolutionary landscape among UGTs in 28 fully sequenced species from early algae to angiosperms. Our findings revealed a distinctive expansion and contraction of UGTs in the G and H groups in tea (Camellia sinensis), respectively. Whole-genome duplication and tandem duplication events jointly drove the massive expansion of UGTs, and the interplay of natural and artificial selection has resulted in marked functional divergence within the G group of the sinensis-type tea population. In Cluster II of group G, differences in substrate selection (e.g., Abscisic Acid) of the enzymes encoded by UGT genes led to their functional diversification, and these genes influence tolerance to abiotic stresses such as low temperature and drought via different modes of positive and negative regulation, respectively. UGTs in Cluster III of the G group have diverse aroma substrate preferences, which contributes a diverse aroma spectrum of the sinensis-type tea population. All Cluster III genes respond to low-temperature stress, whereas UGTs within Cluster III-1, shaped by artificial selection, are unresponsive to drought. This suggests that artificial selection of tea plants focused on improving quality and cold tolerance as primary targets.

Characterization and expression analysis of the MADS-box gene AGL8 in cotton: insights into gene function differentiation in plant growth and stress resistance.

AGAMOUS-LIKE 8 (AGL8) belongs to the MADS-box family, which plays important roles in transcriptional regulation, sequence-specific DNA binding and other biological processes and molecular functions. The genome of cotton, a representative polyploid plant, contains multiple AGL8 genes. However, their functional differentiation is still unclear. In this study, a comprehensive genomic analysis of AGL8 genes was conducted. Cotton AGL8s were subdivided into four subgroups (Groups 1, 2, 3, and 4) based on phylogenetic analysis, and different subgroups of AGL8s presented different characteristics, including different structures and conserved motifs. With respect to the promoter regions of the GhAGL8 genes, we successfully predicted cis-elements that respond to phytohormone signal transduction and the stress response of plants. Transcriptome data and real-time quantitative PCR validation indicated that three genes, namely, GH_D07G0744, GH_A03G0856 and GH_A07G0749, were highly induced by methyl jasmonate (MeJA), salicylic acid (SA), and abscisic acid (ABA), which indicated that they function in plant resistance to abiotic and biotic stresses. The information from the gene structure, number and types of conserved domains, tissue-specific expression levels, and expression patterns under different treatments highlights the differences in sequence and function of the cotton AGL8 genes. Different AGL8s play roles in vegetative growth, reproductive development, and plant stress resistance. These results lay a foundation for further study of GhAGL8s in cotton.