Journal of Plant Growth Regulation最新文献

Pyrazoles have a broad range of biological properties that make them potentially useful for treating tuberculosis, microbial/fungal infections, and inflammation. In this study, the pyrazole 1,3-diaryl-1H-pyrazol-5-yl)(aryl)methanone (DPAM-1) prepared via catalytic aminooxygenation increased the sensitivity of Arabidopsis to salinity stress. An RNA-seq transcriptome analysis revealed DPAM-1 increased the expression of fewer genes than the coronatine treatment that enhanced salinity stress sensitivity, suggestive of the selective mode of action of DPAM-1. The up-regulated genes included marker genes for brassinosteroid (BR) responses. The responsiveness of BR-related genes, such as CONSTITUTIVE PHOTOMORPHOGENIC DWARF, DWARF4, Small auxin-up RNA_Ac1, and for touch 4 (TCH4)/xyloglucan endotransglucosylase/hydrolase 22 (XTH22), was verified by treatments with brassinolide (BL) and brassinazole (BR biosynthesis inhibitor) and analyses involving the brassinosteroid insensitive 1–5 (bri1-5) mutant carrying a weak allele encoding BRASSINOSTEROID INSENSITIVE 1 receptor kinase under our growth conditions. Among the examined genes, the transcription of only TCH4 increased after the DPAM-1 treatment. Examinations of the bri1-5 mutant indicated that DPAM-1 did not significantly affect the sensitivity of bri1-5 plants to salinity stress, suggesting the increased salinity stress sensitivity following the DPAM-1 treatment was partly mediated by the BR signaling pathway. In the present study, the BL treatment differentially altered the salinity stress tolerance of the Columbia and Wassilewskija accessions. The contribution of BR signaling to salinity stress tolerance during the diversification of Arabidopsis accessions and the potential applicability of DPAM-1 for elucidating the interplay between BR and other phytohormones were assessed.

It is critical to improve the adaptability of plants to drought stress through exogenous addition method. This study explored the combined effects of sodium nitroprusside (SNP) and melatonin (MT) on improving drought resilience in dryland maize. We hypothesized that the joint application of SNP + MT would enhance drought resilience through both above- and below-ground interactions. Maize plants were treated with SNP, MT, and a combination of both under different water stress conditions. The combined treatment was observed to significantly improve chlorophyll contents, water use efficiency (WUE), while reducing oxidative stress markers, compared to separate treatments and controls (CK). These improvements led to enhanced plant biomass and yield productivity under the conditions of drought. Specifically, leaf chlorophyll levels increased averagely by 24.22% under well-watered (WW) conditions, and 27.94% under mild water-stressed (MWS) conditions, respectively. In addition, the content of chlorophyll b increased by 13.27 and 56.32% in WW and MWS, respectively. Particularly, the combined treatment resulted in higher WUE, lower oxidative stress, and higher nutrient content [nitrogen, phosphorus, and potassium (NPK)], contributing to improved plant growth and yield. The examination uncovered noteworthy associations (p < 0.05) between these interventions and physiological characteristics, including heightened WUE, diminished oxidative stress, and augmented nutrient content. These factors contributed to the enhancement of plant production and biomass. The research also investigated the effects of microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN). Therefore, the combined application of SNP and MT can act as a promising strategy to enhance drought tolerance in maize, demonstrating a fine potential to improve crop productivity in drought-prone areas.

Nodule development is a process that is tightly regulated by phytohormones, mainly gibberellins and cytokinins. During nodule development gibberellins and cytokinins play an important role in the infection development and organogenesis. However, the interaction between these phytohormones is not yet clear. In our research we first demonstrated that the BELL1-2 transcription factor can influence gibberellin and cytokinin biosynthesis genes during nodule development. It was also found that BELL1-2 can regulate SHY2-like gene which is specifically involved in the control of meristem maintenance and organogenesis. Localisation of the expression of the pMtBELL1-2::GUS promoter showed that the gene is expressed in the primordia, as well as in the infection zone and the nitrogen-fixing zone of mature nodules. Furthermore, we detected an increase in the infection zone in M. truncatula nodules with BELL1-2 RNAi due to the modified growth of the infection threads. In summary, we conclude that BELL1-2 plays an important role in the control of infection and organogenesis in legume plants.

Identification of early responsive genes is very useful in determining the plant's defense system against pathogens. It also has a great interest from the aspect of identifying early responsive inducible promoters and their application in the breeding of resistant cultivars. In the present study, based on the expression data analysis of chickpea genes against the infection with the fungus Ascochyta rabiei that causes chickpea Ascochyta blight, a transcript was identified with high inducibility 3 hours after inoculation with this pathogen. The position of this transcript on the chickpea genome was identified by comparing the transcriptomic and genomic data and the corresponding predicted gene sequence was selected. However, the comparison of these proteins with the predicted protein sequence in the chickpea genome led to the mentioned transcript being investigated under the name of CaDRRG. In order to analyze the sequence of this gene inducible promoter, its upstream sequence was retrieved from genomic data and the position of consensus regulatory elements such as TATA-box and CAAT-box was determined on it. Moreover, the position and number of Cis-regulatory elements known to be inducible against pathogens such as, AS-1, W-box, and G-box, were identified in the promoter sequence. In addition, by comparing the upstream sequence of CaDRRG gene with other genes with the highest induction level in response to A. rabiei, three new potential regulatory elements were identified in the promoter sequence of this gene. The fragment containing these regulatory elements was tracked and sequenced in resistant and sensitive chickpea genotypes. Multiple sequence alignment of the CaDRRG gene promoter sequence in different chickpea genotypes led to the identification of several point mutations outside the positions of the identified regulatory elements. In a preliminary experiment to analyze the induction capacity of the CaDRRG gene promoter sequence, about 700 bp of this sequence was cloned upstream of the beta-glucuronidase reporter gene and its basal expression and inducibility in response to the treatment of A. rabiei fungal extract was investigated on Nicotiana benthamiana leaves by agroinjection method. The assessment of beta-glucuronidase enzyme activity in tobacco leaf discs after treatment with fungal extract and its comparison with the basal expression level confirmed the inducibility of this fragment which was observationally compared with the expression level of CaMV 35S constitutive promoter. Although the results of the preliminary analysis showed that the selected fragment has the potential to be used as an inducible promoter for the expression of resistance genes against A. rabiei, more additional studies are necessary to identify the regulatory elements responsible for responding to this fungal pathogen.

This study was carried out to understand the effect of MeJA on root growth, in vitro production of some bioactive compounds, and expression levels of the 1-Deoxy-D-xylulose 5-phosphate reductoisomerase (DXR), secologanin synthase (SLS), 3-hydroxy-3-methylglutaryl-CoA (HMGR), and geranyl diphosphate synthase (GPPS) genes in root cultures of endangered Gentiana lutea and endemic Gentiana boissieri. For this purpose, MeJA at different concentrations (0.1, 0.5, and 1.0 mM) was applied to the one-week-old root cultures for 2, 4, 6, 8, and 10 days. After harvest, roots were evaluated in terms of root growth criteria and contents of loganic acid (iridoid), isogentisin (xanthone), swertiamarin, sweroside, amarogentin, and gentiopicroside (secoiridoids). In the study, the effects of MeJA applications on the activities of the DXR, SLS, HMGR, and GPPS genes, believed to be responsible for iridoid, xanthone, and secoiridoid synthesis, were also investigated. It was determined that all the criteria examined significantly changed depending on MeJA concentration and harvest time. Regarding metabolite contents, the most appropriate applications were found to be 0.5 mM and 1.0 mM MeJA for 8 days for G. lutea and 0.5 mM MeJA for 4 days for G. boissieri. Additionally, the expression levels of the genes were found to change with MeJA treatments, but it was noted that establishing a linear relationship with a single substance was not possible. Another noteworthy result was that the accumulation of loganic acid, swertiamarin, sweroside, and gentiopicroside was higher in the roots of G. boissieri than in those of G. lutea. In conclusion, it was determined that in vitro production of iridoid, xanthone, and secoiridoids with significant pharmaceutical effects in Gentiana root cultures could be increased with MeJA applications. The study also revealed the need for more detailed research, including genomic analyses of Gentiana species and identification of genes associated with metabolite biosynthesis.

In vitro mutagenesis is an indispensable and effectual method of mutation breeding which can be applied in comprehensive endeavours of different agricultural areas to sustain the needs of an ever-expanding and nutritionally demanding human population as well as to combat climate change. Mutagenesis has helped in developing a large number of improved mutant varieties over the years and enhancing plant breeding efforts worldwide. In vitro mutation induction, on the other hand, offers a tremendous potential for increasing food yields, which might ensure the improvement in way of living. In vitro mutagenesis can also contribute in resolving or at least limiting some of the constraints caused by various stresses, which can precipitate significant yield losses in crops and also have a considerable impact on their productivity. This review combines the most relevant and comprehensive work related to the mutation breeding approaches and their role in crop improvement to assure food and nutrition security. It focuses on different mutagenic players, e.g. physical (gamma rays, X-rays, etc.), chemical (Alkylating agents, azides, base analogues, sodium azide, benzene, etc.) and biological (various viruses and bacterial species), their applications and impact on in vitro mutagenesis. It covers various conventional and modern approaches of mutagenesis and their role in sustainable agriculture and crop improvement. In addition, various molecular approaches involved in mutation breeding technologies are discussed thoroughly. This article emphasized on the potential of induced mutagenesis techniques for crop improvement to meet the food and nutrition demands of a growing population. In conclusion, in vitro mutagenesis stands as a powerful tool in the realm of crop improvement, offering targeted genetic modifications that can enhance desirable traits.

Several cyanobacteria have been used as effective natural biostimulants under different stresses, but the utilization of Spirulina platensis has not been extensively investigated. The effects of living S. platensis (25 mg/L on dry weight basis) added twice as soil addition on growth, photosynthetic pigmentation, and antioxidant defenses of Triticum aestivum plants grown under normal and two drought stresses (80 and 60% Field capacity) were evaluated. Under drought stress conditions, growth parameters (shoot height, fresh, and dry weights, photosynthetic pigments) and antioxidant defenses were significantly inhibited by recording relatively lower values of the measured characters than the control. The treatment of wheat plants with S. platensis was successful in improving all growth metrics. Under 80 and 60% FWC, the fresh and dry weight of the shoot increased by approximately 25%, while the height of the shoot improved by approximately 33%. The contents of photosynthetic pigment (chl. a, b, and carotenoids) of T. aestivum were significantly induced by 38%, 31%, and 34%, respectively, under 60% FWC. Antioxidant capacity percentages as scavengers of different free radicals (OH^¯⋅, H₂O₂, NO, and metal chelating), and inhibition of lipid peroxidation, in addition to enzymes (CAT and APX), non-enzymatic antioxidants (phenolics, reducing power, total antioxidants) were significantly improved in Spirulina-enriched soil. The activity of antioxidant enzymes (SOD, CAT, POD, and APX) increased significantly in the shoot of wheat seedling by 150%, 83%, 193% and 11%, respectively, under 60% FWC. Components of soluble metabolites (carbohydrates, free amino acids, and soluble proteins) of T. aestivum were significantly enhanced in Spirulina-treated soil. The roots of wheat seedlings treated with S. platensis showed the highest increase in soluble proteins, free amino acids, and soluble carbohydrates (21.67, 4.68, and 41.67 mg g⁻¹ FW, respectively). The application of Spirulina-based biostimulators is aligned with the sustainable agriculture concept by significant improving the content of photosynthetic pigments, confirming the correlation between growth and the measured antioxidants parameters of T. aestivum. The PCA biplot indicated a great contradiction between chlorophyll pigments, soluble metabolites (proteins, amino acids, and carbohydrates), phenolics, reducing power and flavonoids, and all growth indicators and antioxidant abilities. Therefore, the results of this study support the use of the Spirulina platensis treatment, which was mainly effective in improving the growth of wheat plants by reducing the detrimental effects of drought stress in dry conditions.

Ethylene is a pivotal regulator of coffee anthesis, and 1-methylcyclopropene (1-MCP), an ethylene action inhibitor, offers a potential to manage flowering in coffee plants. This study aimed to identify the effect of 1-MCP on gene expression of ethylene receptors, and compare the interaction in silico between 1-MCP and different ethylene receptors to understand what could be associated with coffee anthesis promotion by this molecule. The study involved phenotypic characterization, ethylene quantification, RNA expression profiling, phylogenetic analysis, homology modeling, and molecular docking. Results revealed that 1-MCP accelerated floral bud development to anthesis within 12 days, contrasting with water treated floral buds which exhibited progress just after a rainfall event. Moreover, 1-MCP application notably increased ethylene levels in both leaves and floral buds. Gene expression analysis indicated that 1-MCP modulates ethylene related gene expression differently in leaves and floral buds. Decreasing the expression of signaling genes in floral buds (CaERS1-like, ETR2-like, ETR4-like and EIN4-like), increasing it in leaves (ETR1-like, ETR2-like, ETR4-like and CaCTR1-like); and increasing the expression of CaACO3-like (biosynthesis related gene) in floral buds. Molecular docking studies suggested that ethylene may exhibit a higher affinity for receptors with lower interaction energy with 1-MCP. In conclusion, 1-MCP could be a promising tool to promote anthesis in coffee trees by modulating ethylene related processes, as the interaction between 1-MCP and ethylene receptors may influence ethylene sensitivity through different modulation of gene expression in leaves and floral buds.

Drought is one of the main constraints affecting crop production in the current climate change scenario. The desert area of Chihuahua in Mexico has limited water availability and is therefore susceptible to drought. Plant photosynthetic performance is the main determining factor of crop productivity, especially under stress conditions. The present study aimed to conduct a comparative analysis of three maize hybrids (P1898, P1445, and P1382) grown under drought stress, focusing on yield, physiological aspects, photosynthetic efficiency, and stomatal activity. A field experiment with these hybrids was carried out in the municipality of Cuauhtémoc, Chihuahua, Mexico, which is characterized by a low precipitation regime. The results indicated that the P1898 hybrid achieved the highest yield and was the best adapted to drought conditions. The analysis of photosynthesis parameters suggests favorable adaptations in both the P1898 and P1382 hybrids such as excess energy dissipation. Additionally, the P1898 hybrid exhibited a greater stomatal area, potentially enhancing CO₂ uptake and heat dissipation via transpiration. The P1382 hybrid demonstrated greater efficiency in photosynthetic energy use and improved water use efficiency (WUE), likely due to its stomatal adaptations. These findings suggest that the P1898 hybrid is the most suitable maize cultivar for cultivation in regions prone to drought and high temperatures, owing to its superior yield and photosynthetic adaptations.