Flower Induction Research Articles

Daylength Influences Time to Harvest and Stem Quality of Pycnosorus globosus and Caryopteris incana Specialty Cut Flowers

As the demand for locally grown specialty cut flowers increases, cultivars of Pycnosorus globosus and Caryotperis incana are becoming more available for growers to produce as cuts. However, protocols for year-round greenhouse production are limited. Therefore, our objective was to determine if the photoperiod influences flower induction and development, time to harvest, yield, and morphology of billy buttons (Pycnosorus globosus) ‘Paintball Globe’ and ‘Paintball Poppy’ and bluebeard (Caryopteris incana) ‘Pagoda Lagoon’ and ‘Pagoda Dark Pink’ to facilitate commercial greenhouse production. Shoot-tip cuttings were rooted and transplanted into bulb crates and placed in a greenhouse with a mean daily air temperature of 20 °C and 9-, 10-, 11-, 12-, 13-, 14-, 15-, or 16-hour photoperiods or a 9-hour short day (SD) with a 4-hour night interruption (NI) from 2200 to 0200 HR for 11 weeks. Billy buttons initiated inflorescences and developed flowers under all daylengths; however, the greatest stem lengths were recorded under long days (LDs). Bluebeard inflorescences initiated under all daylengths were tested. Time to visible inflorescence and flower was hastened under daylengths ≤14 hours, whereas inflorescences under the 16-h photoperiod or 4-h NI never fully developed. For ‘Pagoda Lagoon’ and ‘Pagoda Dark Pink’, the critical daylengths for flower development were 14 hours and 15 hours, respectively. On average, only bluebeard ‘Pagoda Lagoon’ harvested under photoperiods ≥10 hours developed marketable stem lengths (>40 cm). To hasten time to visible inflorescence and harvest and ensure marketable stem lengths, billy buttons should be grown under daylengths ≥13 hours. Based on these results, we recommend growing bluebeard under a 16-hour photoperiod or NI for 4 to 6 weeks to promote vegetative growth, followed by an 11- to 14-hour photoperiod for flower induction and development. We classify billy buttons as a day-neutral plant for flower induction and a facultative LD plant for flower development. Similarly, bluebeard can be classified as a facultative SD plant for flower induction and an obligate SD plant for flower development.

Overexpression of lily MicroRNA156-resistant SPL13A stimulates stem elongation and flowering in Lilium formosanum under non-inductive (non-chilling) conditions.

Flowering plants undergo juvenile vegetative, adult vegetative, and reproductive phases. Lily plants (Lilium spp.) develop scaly leaves during their juvenile vegetative phase. Stem elongation occurs in the adult vegetative phase and is followed by floral transition. As the duration of the juvenile vegetative phase is long in lilies, the microRNA156 (miR156) and SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE (SPL) modules are expected to play a major role in vegetative phase change and flower induction. In the present study, we aimed to explore the functions of lily SLP13A. We evaluated phenotypic changes and gene expression in L. formosanum plants overexpressing miR156-resistant SPL13A (rSPL13A) and examined the accumulation levels of gene transcripts and mature miRNAs in non-transformed L. longiflorum plants. Lily plants overexpressing rSPL13A exhibited stem elongation under non-inductive conditions, and FLOWERING LOCUS T (FT) genes were poorly involved in this stem elongation. Flowering was induced in the transformed plants with elongated stems, and the accumulation of MADS5 (APETALA1) transcripts and mature miR172 was elevated in these plants. In non-transformed lilies, SPL13A transcripts were highly accumulated in the shoot apices of both juvenile and adult plants. As mature miR156 was poorly accumulated in the shoot apices of the adult plants, SPL13A was active enough to stimulate stem elongation and flower induction. In contrast, mature miR156 was reliably detected in shoot apices of the juvenile plants. Because our transient assay using tobacco plants expressing a SPL13A-GFP fusion protein indicated that miR156 repressed SPL13A expression mainly at the translational level, SPL13A activity should be insufficient to stimulate stem elongation in the juvenile plants. In addition, the accumulation of MADS5 transcripts and mature miR172 in the shoot apices increased with plant growth and peaked before the transition to the reproductive phase. Therefore, we conclude that SPL13A regulates stem elongation in the adult vegetative phase, which differs from the mechanisms evaluated in Arabidopsis and rice, wherein stem elongation proceeds in a reproductive phase and FT genes are heavily involved in it, and that SPL13A induces flowering by the activation of genes related to the age pathway underlying floral transition, as APETALA1 and primary-MIR172 are mainly involved in this pathway.

Exogenously Applied Gibberellic Acid Alters Cannabinoid Profile in Cannabis sativa L.

Cannabis sativa (C. sativa L.) has garnered significant attention worldwide due to its widespread use as a pharmaceutical agent. With the increasing clinical application of C. sativa and cannabinoid therapeutics, there is strong interest in the development of superior plant varieties and optimisation of growth conditions to enhance secondary metabolite yield. Our RNA sequencing analysis revealed differential expression of hormone-related transcripts in developing C. sativa trichomes, suggesting the involvement of hormone signalling pathways in cannabinoid production. Leveraging the potency of exogenous hormones on plants, this study sought to determine if the application of cytokinin (CK), gibberellic acid (GA) and jasmonic acid (JA) modified trichome morphology and the cannabinoid profile over an 8-week period following the induction of flowering. Exogenous hormone application led to alterations in trichome morphology, with each treatment significantly reducing trichome head width by the final week of assessment. Interestingly, GA application also resulted in a significant reduction in the concentration of Δ-9-tetrahydrocannabinol (THC), Δ-9-tetrahydrocannabinolic acid (THCA), cannabidiol (CBD) and cannabidiolic acid (CBDA) by week 8 post floral induction, however, JA and CK treatment did not consistently modulate the accumulation of these cannabinoids. The minor cannabinoids, cannabidivaranic acid (CBDVA), cannabicyclolic acid (CBLA), cannabicyclol (CBL), cannabichromene (CBC), cannabigerolic acid (CBGA) and cannabigerol (CBG), were also affected by hormone treatments, with varying degrees of accumulation observed. These findings underscore the intricate interplay between phytohormones and secondary metabolite biosynthesis in C. sativa. Our study highlights the potential of hormone modulation as a strategy to enhance cannabinoid yield and offers some insights into the regulatory mechanisms governing cannabinoid biosynthesis in C. sativa trichomes.

Genome-wide analysis of the MADS-box gene family in mango and ectopic expression of MiMADS77 in Arabidopsis results in early flowering

Mango (Mangifera indica L.) is an important tropical fruit, and timely flowering and fruit setting are very important for mango production. The MADS-box gene family is involved in the regulation of flower induction, floral organ specification, and fruit development in plants. The identification and analysis of the MADS-box gene family can lay a foundation for the study of the molecular mechanism of flowering and fruit development in mango. In this study, 119 MiMADS-box genes were identified on the basis of genome and transcriptome data. Phylogenetic analysis revealed that these genes can be divided into two classes. Forty-one type I proteins were further divided into three subfamilies, and seventy-eight type II proteins were further classified into eleven subfamilies. Several pairs of alternative splicing genes were found, especially in the SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) subfamily. The MiMADS-box genes were distributed on 18 out of the 20 mango chromosomes. Cis-element analysis revealed many light-, stress-, and hormone-responsive elements in the promoter regions of the mango MiMADS-box genes. Expression pattern analysis revealed that these genes were differentially expressed in multiple tissues in mango. The highly expressed MiMADS77 was subsequently transformed into Arabidopsis, resulting in significant early flowering and abnormal floral organs. Yeast two-hybrid (Y2H) assays revealed that MiMADS77 interacts with several MiMADS-box proteins. In addition, we constructed a preliminary flowering regulatory network of MADS-box genes in mango on the basis of related studies. These results suggest that MiMADS77 genes may be involved in flowering regulation of mango.

Effects of LED Light on Aromatic Medicinal Plants from Lavandula, Salvia, and Thymus Genera: A Systematic Review

LED light technology has been used in recent years in plant breeding due to its proven energy efficiency, low cost, and high quality for the enhancement of crops, including some aromatic medicinal plants (AMPs). Nonetheless, although several studies have shown that specific wavelengths can increase the content of bioactive compounds used by pharmaceutical, medical, and perfumery industries, there is limited information on this topic and the possible implications for plant stress in AMPs. The current systematic review focused on the effects of LED light on the physiological response, metabolite synthesis, and flowering induction in three important AMP genera: Lavandula, Salvia, and Thymus, belonging to the Lamiaceae family. A literature search was performed in the Web of Science and Scopus databases. This review is reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The bibliographic analysis highlights the significant variation in physiological responses to different light spectra between species, even within the same genera, implying a need to optimize light conditions in each species to achieve the best results. Finally, this review provides essential information for laying the groundwork for future research focused on enhancing AMPs using LED light to overcome various types of stress.

Optimizing cannabis cultivation: an efficient in vitro system for flowering induction

BackgroundCannabis sativa L. is a versatile medicinal plant known for its therapeutic properties, derived from its diverse array of secondary metabolites synthesized primarily in female flower organs. Breeding cannabis is challenging due to its dioecious nature, strict regulatory requirements, and the need for photoperiod control to trigger flowering, coupled with highly dispersible pollen that can easily contaminate nearby female flowers. This study aimed to develop a protocol for in vitro flowering in cannabis, investigate factors affecting in vitro flower production, and generate viable in vitro seeds, potentially offering a method for producing sterile cannabinoids or advancing breeding techniques.ResultsWe show that the life cycle of cannabis can be fully completed in tissue culture; plantlets readily produce inflorescences and viable seeds in vitro. Our findings highlight the superior performance of DKW medium with 2% sucrose in a filtered vessel and emphasize the need for low light intensity during flower induction to optimize production. The improved performance in filtered vessels suggests that plants conduct photosynthesis in vitro, highlighting the need for future investigations into the effects of forced ventilation to refine this system. All tested lines readily developed inflorescences upon induction, with a 100% occurrence rate, including male flowering. We revealed the non-dehiscent trait of in vitro anthers, which is advantageous as it allows for multiple crosses to be conducted in vitro without concerns about cross-contamination.ConclusionThe current work developed and optimized an effective protocol for in vitro flowering and seed production in cannabis, potentially providing a platform for sterile cannabinoid production and an efficient tool for breeding programs. This system allows for the full and consistent control of plant growth conditions year-round, potentially offering the reliable production of sterile molecules suitable for pharmacological use. As a breeding strategy, this method overcomes the complex challenges of breeding cannabis, such as the need for large facilities, by enabling the production of hundreds of lines in a small facility. By offering precise control over factors such as plant growth regulators, light intensity, photoperiod, and temperature, this system also serves as a valuable tool for studying flowering aspects in cannabis.

DNA demethylation is involved in nitric oxide-induced flowering in tomato

Flowering is one of the most important phenological periods, as it determines the timing of fruit maturation and seed dispersal. To date, both nitric oxide (NO) and DNA demethylation have been reported to regulate flowering in plants. However, there is no compelling experimental evidence of the relationship between NO and DNA demethylation during plant flowering. In this study, an NO donor and a DNA methylation inhibitor were used to investigate the involvement of DNA demethylation in NO-mediated tomato (Solanum lycopersicum cv. Micro-Tom) flowering. The results showed that the promoting effect of NO on tomato flowering was dose-dependent, with the most positive role observed at 10 μmol L-1 of the NO donor S-nitrosoglutathione (GSNO). Treatment with 50 μmol L-1 of the DNA methylation inhibitor 5-azacitidine (5-AzaC) also significantly promoted tomato flowering. Moreover, GSNO and 5-AzaC increased the peroxidase (POD) and catalase (CAT) activity and cytokinin (CTK) and proline contents, while they decreased the gibberellic acid (GA3) and indole-3-acetic acid (IAA) contents. Co-treatment with GSNO and 5-AzaC accelerated the positive effects of GSNO and 5-AzaC in promoting tomato flowering. Meanwhile, compared with GSNO or 5-AzaC treatment alone, co-treatment with GSNO+5-AzaC significantly increased the global DNA demethylation levels in different tissues in tomato. The results also indicate that DNA demethylation may be involved in NO-induced flowering. The expression of flowering genes was significantly altered by the GSNO+5-AzaC treatment. Among these genes, five flowering induction genes-ARGONAUTE 4 (AGO4A), SlSP3D/SINGLE FLOWER TRUSS (SFT), MutS HOMOLOG 1 (MSH1), ZINC FINGER PROTEIN 2 (ZFP2), and FLOWERING LOCUS D (FLD) were selected as candidate genes for further study. Then, McrBC-PCR analysis showed that the DNA demethylation of the SFT gene in the apex and the FLD gene in the stem might be involved in NO-induced flowering. Therefore, our study shows that NO might promote tomato flowering by mediating the DNA demethylation of flowering induction genes. This study provides direct evidence of a synergistic effect of NO and DNA demethylation in promoting tomato flowering.

Characterization of Male Flower Induction by Silver Thiosulfate Foliar Spray in Female Cannabis at the Middle Reproductive Stage for Breeding.

Cannabis (Cannabis sativa) is a versatile crop belonging to the Cannabaceae family, and is dioecious, typically with separate male and female plants. The flowers of female plants, especially the trichomes, accumulate relatively higher contents of cannabinoids compared with those of male plants. For this reason, to obtain seeds that are genetically female, it is desirable to induce the development of male flowers on a female plant that produces genetically female haploid gametes. Silver thiosulfate (STS) is a highly effective chemical for male flower induction. We investigated male flower induction in three commercial cultivars of female cannabis (Spectrum303, SuperwomanS1, and CBGambit) regarding the treatment frequency, stage of application, and concentration of STS applied as a foliar spray. All three cultivars showed adequate induction of male flowers in response to 1.5 mM STS applied at the early reproductive stage. In particular, SuperwomanS1 was most highly responsive to induction of male flowers, even when treated with 0.3 mM STS at the early reproductive stage. Treatment with three applications of STS was more effective compared with a single application, but a single application of 1.5 mM STS at the early reproductive stage was sufficient for male flower induction. A single STS application during the middle stage of reproductive growth was inadequate for induction of male flowers. However, 6 weeks after three applications of STS, CBGambit exhibited approximately 54% male flower induction at 0.3 mM STS, Spectrum303 showed approximately 56% induction at 3 mM STS, and SuperwomanS1 yielded approximately 26% induction at 1.5 mM (expressed as percentage of total number of individuals with the induced male flowers). Pollen stainability tests using KI-I2 solution and Alexander's staining showed high pollen viability with over 65% at different single STS concentrations, indicating that pollen grains induced by STS have sufficient viability for the self-pollination. This study demonstrated that different cultivars of cannabis respond diversely to different STS concentrations and highlighted the potential benefits of three STS applications during the middle reproductive stage for cannabis breeding.

Impact of NaCl stress on phytoconstituents and bioactivity of Matricaria chamomilla: a multi-analytical approach

Matricaria chamomilla (Asteraceae), commonly known as chamomile can tolerate freezing temperatures and grows in many soil types. This plant is found on all continents and has significant medicinal value. There are more than 120 chemicals detected in chamomile flowers, with the majority found in the essential oil. In this study, M. chamomilla was given the NaCl stress of 0 mM, 1 mM, 100 mM, and 150 mM concentrations This study was the first to assess the efficacy of German chamomile upon exposure to salt stress hence plant particles that had been dried and powdered were analyzed using, phytochemical tests, Fourier Transform Infrared and UV–Vis spectroscopy, thin layer chromatography, fluorescence recovery after photobleaching assay, antibacterial and antioxidant activity. The characterization and results of these activities show amazing results which enhance their antibacterial property with an increased zone of inhibition when the samples of salt stress of the above-given concentrations were compared to the control samples. More graph analysis indicates an effective impact of salt stress on the phytoconstituents of M. chamomilla. Other than that, there was a clear flower induction upon salt stress, as a variety of compounds are regarded as essential to the biological functions of chamomile flowers according to the phytoconstituent screening which can be further used in the cosmetic industry, pharmaceutical industry, and all other fields as well for various application as a nano-drug or bio-drug. Due to this, this plant became essential for plant biotechnology research.

Characterization of the roles of MiSPL4a and MiSPL4b in flowering time and drought resistance in Arabidopsis

SQUAMOSA promoter-binding protein-like 3/4/5 (SPL3/4/5) genes are involved mainly in regulating plant flowering through the gibberellin and age pathways. In our previous study, two SPL4-like genes, MiSPL4a and MiSPL4b (MiSPL4a/b), were identified and analyzed in mango, and their highest expression levels were detected in flowers. However, the functions of MiSPL4a and MiSPL4b in mango remain unclear. In this study, bioinformatics, expression, function and interacting proteins were analyzed. The results revealed that MiSPL4a was highly expressed in leaves at the early stage of the flower induction period, while MiSPL4b increased the highest expression peak during the vegetative period. MiSPL4a/b genes were induced by drought treatment. Overexpression of MiSPL4a/b accelerated early flowering and increased the expression levels of several flowering-related genes, such as APETALA1 (AtAP1), FRUITFULL (AtFUL), and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (AtSOC1) in Arabidopsis thaliana. The MiSPL4a/b transgenic plants presented increased resistance to drought and abscisic acid (ABA) treatment, and the MiSPL4b transgenic plants were sensitive to prohexadione-calcium (Pro-Ca) treatment. In addition, MiSPL4a and MiSPL4b interact with MiSOC1, Mi14–3–3, and several stress-related proteins. In summary, these findings indicated that in transgenic Arabidopsis, MiSPL4a/b genes have the function of accelerating flowering and enhancing stress resistance.

Network preservation analysis to identify transcriptional biomarkers related to flowering in Crocus sativus.

Crocus sativus L. is known as an ornamental geophyte and a source of valuable spice and secondary metabolites. Network preservation module analysis is one of the best approaches to revealing special features of different conditions. It can determine patterns of divergence and conservation between transcriptome data. Herein, we explored the regulatory genes of the flowering process by RNA-Seq data containing flowering and non-flowering samples in gene expression profiles. Persevered module analysis revealed three significant non-persevered modules related to the flowering process, namely pink, green, and blue. Several hub genes associated with non-preserved modules such as PIA1, NAC90, ALY3, Sus3, MYB31, ARF5/MP, MYB31, HD-ZIP, SEP3d, OR_B, AGL6a, bZIP(TGA1) and GRAS were identified. These candidate genes can be considered key diagnostic biomarkers for the flowering process. Here, we also compared two approaches, WGCNA and NetRep for module preservation analysis. The results of these methods were consistent with non-preserved modules. NetRep was a faster (11 times) and more efficient (run more than 10000 permutations for each comparison) method than WGCNA module preservation. Differential expression genes (DEGs) screening showed that many hub genes were downregulated in non-flowering than flowering samples. Our finding revealed regulatory mechanisms of the flowering process in C. sativus as can be developed transcriptional biomarkers which could pave the way for promoting saffron yield via flowering induction.

Rice CRYPTOCHROME-INTERACTING BASIC HELIX-LOOP-HELIX 1-LIKE interacts with OsCRY2 and promotes flowering by upregulatingEarly heading date 1.

Flowering time is a crucial adaptive response to seasonal variation in plants and is regulated by environmental cues such as photoperiod and temperature. In this study, we demonstrated the regulatory function of rice CRYPTOCHROME-INTERACTING BASIC HELIX-LOOP-HELIX 1-LIKE (OsCIBL1) in flowering time. Overexpression of OsCIB1L promoted flowering, whereas the oscib1l knockout mutation did not alter flowering time independent of photoperiodic conditions. Cryptochromes (CRYs) are blue light photoreceptors that enable plants to sense photoperiodic changes. OsCIBL1 interacted with OsCRY2, a member of the rice CRY family (OsCRY1a, OsCRY1b, and OsCRY2), and bound to theEarly heading date 1(Ehd1) promoter, activating the rice-specific Ehd1-Heading date 3a/RICE FLOWERING LOCUS T 1pathway for flowering induction. Dual-luciferase reporter assays showed that the OsCIBL1-OsCRY2 complex required blue light to induce Ehd1 transcription. Natural alleles resulting from nonsynonymous single nucleotide polymorphisms in OsCIB1L and OsCRY2 may contribute to the adaptive expansion of rice cultivation areas. These results expand our understanding of the molecular mechanisms controlling rice flowering and highlight the importance of blue light-responsive genes in the geographic distribution of rice.

Cassava Breeding and Cultivation Challenges in Thailand: Past, Present, and Future Perspectives.

Cassava (Manihot esculenta Crantz) was introduced to Southeast Asia in the 16th-17th centuries and has since flourished as an industrial crop. Since the 1980s, Thailand has emerged as the leading producer and exporter of cassava products. This growth coincided with the initiation of cassava breeding programs in collaboration with the International Center for Tropical Agriculture (CIAT), focusing on root yield and starch production. The success of Thai cassava breeding programs can be attributed to the incorporation of valuable genetic diversity from international germplasm resources to cross with the local landraces, which has become the genetic foundation of many Thai commercial varieties. Effective evaluation under diverse environmental conditions has led to the release of varieties with high yield stability. A notable success is the development of Kasetsart 50. However, extreme climate change poses significant challenges, including abiotic and biotic stresses that threaten cassava root yield and starch content, leading to a potential decline in starch-based industries. Future directions for cassava breeding must include hybrid development, marker-assisted recurrent breeding, and gene editing, along with high-throughput phenotyping and flower induction. These strategies are essential to achieve breeding objectives focused on drought tolerance and disease resistance, especially for CMD and CBSD.

Molecular cloning and characterization of FLOWERING LOCUS T (FT)gene from kinnow mandarin (Citrus reticulata)

FLOWERING LOCUS T (FT) is considered as a crucial regulator involved in early flowering induction which functions by switching the vegetative phase into reproductive phase. The role of early flowering has been elucidated by many workers but till date, there has been no report on cloning of FT gene from Kinnow mandarin (Citrus reticulata Blanco). An experiment was conducted during 2022–23 at Punjab Agricultural University, Ludhiana, Punjab for molecular cloning and characterization of FT gene from Kinnow mandarin. During the study, FT gene was cloned into pGEM-T Easy vector and characterized using in silico analysis. Sequence analysis revealed that the FT gene is comprised of 822 nucleotides, including a 5’- untranslated region (UTR) of 137 bp, a coding sequence (CDS) of 534 bp, and a 3’-UTR region of 151 bp. The BLASTn results of CrFT CDS showed high similarity to FT-like genes of other citrus species including C. unshiu, C. sinensis, and C. clementina which were found homologous to Phosphatidylethanolamine binding protein (PEBP). The predicted molecular weight of protein was approximately 20 kDa and isoelectric point (pI) was 6.73 indicating slightly acidic nature of the protein. The instability, aliphatic and GRAVY (Grand Average of Hydropathy) indices of the protein were determined as 40.97, 73.16 and -0.491, respectively. This study would help to elucidate the molecular mechanism behind flowering in Kinnow mandarin and facilitate the molecular breeding studies targeted to obtain early flowering phenotypes.

ENHANCEMENT OF FLOWER INDUCTION IN HARUMANIS MANGO (Mangifera indica L.) WITH ETHEPHON APPLICATION DURING OFF-SEASON

In cultural practice of Harumanis tree, plant growth regulator such as paclobutrazol is applied at late vegetative stage to induce flowering. However, starting from 2020 to 2023, there is a sharp yield reduction due to the unexpected weather condition. Unexpected heavy rain had caused Harumanis flower to drop from the panicle before the pollination occur. Due to this problem, ethephon was identified as an alternative plant growth regulator for flower induction. Ethephon is an ethylene releasing agent that help mediate many aspects in plant growth and development such as shoot development and flower induction. Thus, the objective of this study is to observe the influence of ethephon application during off-season on vegetative growth stage and flower induction of harumanis tree. Total of 32 Harumanis trees (3 years old) in Research Plot, Unit Ladang Universiti Teknologi MARA Perlis were treated with ethephon in September 2023 by foliar spray until run-off on the plant canopy. Treatments were arranged according to Randomized Completely Block Design (RCBD) with three different concentrations of ethephon and being diluted 2 hours before application which are 400 ppm, 600 ppm, and 800 ppm and control (without application). The parameters were recorded 2 weeks interval: number of leaves, number of buds, length of bud, relative chlorophyll content, stomatal density, day to flowering, and number of flower panicles. The vegetative growth stage shows significant difference among concentrations applied where number of leaves is higher with 400 ppm. Meanwhile, the flower formation occurs after 2 months and 4 months of ethephon application at treatment of 800 ppm and 400 ppm respectively. However, there is no significant difference presented on the Harumanis physiological characteristics. As from this study, it can be concluded that the application of ethephon influences the growth of performance and flower formation of Harumanis when applied with specific concentration.

Bioprocess of Gibberellic Acid by Fusarium fujikuroi: The Challenge of Regulation, Raw Materials, and Product Yields.

Gibberellic acid (GA3) is a tetracyclic diterpenoid carboxylic acid synthesized by the secondary metabolism of Fusarium fujikuroi. This phytohormone is widely studied due to the advantages it offers as a plant growth regulator, such as growth stimulation, senescence delay, flowering induction, increased fruit size, and defense against abiotic or biotic stress, which improve the quality and yield of crops. Therefore, GA3 has been considered as an innovative strategy to improve agricultural production. However, the yields obtained at large scale are insufficient for the current market demand. This low productivity is attributed to the lack of adequate parameters to optimize the fermentation process, as well as the complexity of its regulation. Therefore, this article describes the latest advances for potentializing the GA3 production process, including an analysis of its origins from crops, the benefits of its application, the related biosynthetic metabolism, the maximum yields achieved from production processes, and their association with genetic engineering techniques for GA3 producers. This work provides a new perspective on the critical points of the production process, in order to overcome the limits surrounding this modern line of bioengineering.

Climate–resilient strategy for shortening the crop cycle in rice and the host influenced rhizosphere microbiome

We present the field rapid generation advancement procedure for shortening the crop cycle in rice. The practical protocol developed by us using different maturity groups of rice showed promising early flower induction. We observed a shortening of crop cycle to about 35–40 days depending on the variety. The spacing between the plants was the major influencer for flower induction compared to other interventions tested viz., clipping, potassium di-hydrogen phosphate and paclobutrazol spray. Our raised bed direct seeding strategy completely avoided the transplantation. The work flow for flower induction can be a reference to increase generations of rice breeding. The rhizosphere bacterial dynamics using 16srRNA gene amplicon sequencing showed the Acinetobacter population abundance as a key mediator and marker for flowering time. The alpha diversity at flowered and unflowered stage showed the species richness as Control < Pusa Sugandh 5 < BPT-5204. The rice rhizosphere of this ecosystem had an abundance of Methylotrophs that utilize methane as a carbon source suggesting that the developed method is a green technique suitable for generation advancement that can be replaced for flooded condition assisted breeding in rice. Selective enrichment of functional abundance between varieties suggested the host - influenced microbiome for early flowering in rice. This protocol is expected to greatly accelerate the process of new variety breeding and the construction of mapping populations.

Improving mangoes' productivity and crop water productivity by 24-epibrassinosteroids and hydrogen peroxide under deficit irrigation

In nature, plants are frequently subjected to a wide range of abiotic stresses that drastically reduce crop productivity. Deficit in irrigation is one of the main factors of abiotic stresses that affect agricultural productivity. Nevertheless, not much research has been done on how to use water with brassinosteroids (Br) and hydrogen peroxide (H2O2)in deficit water conditions in order to reach comparatively good values of mango tree growth, productivity, and fruit quality as well as crop water productivity (WPC). A split-plot experiment in a complete randomized block system design study with 3 regulated deficit irrigation levels i.e. 100% IR (Irrigation requirement), 80% IR, and 60% IR was implemented in 2022 and 2023, each irrigation regime was combined with the foliar application of distilled water (control), 1 mg/L Br, 10 mM H2O2, 1 mg/L Br + 10 mM H2O2. Foliar treatments were applied at 3 different phenological stages: flower bud induction and differentiation, full bloom, and beginning of fruit set. The results showed that fruit shape index and acidity significantly improved as irrigation volume increased, however, the proportion of fruit mineral content and fruit chemical characteristics was inversely correlated with the volume of water. Meanwhile, moderate regular deficit irrigation (80% IR) achieved marked increases in leaf minerals and total chlorophyll content, fruit quality, yield, and water use efficiency. Drought stress (60% IR) significantly decreased fruit set, fruit retention, yield traits, and fruit physical and chemical properties, at the same time, significant improvements in the content of stress indicators (proline, total phenols, and carotenoids) were observed compared with control. All treatments with Br and H2O2 alone or in combination under drought stress had a pronounced effect in this regard. Overall, foliar spray of 1 mg/L Br+10 mM H2O2 was the most powerful treatment that emended the unpropitious effect of water stress.

Real-time emulation of future global warming reveals realistic impacts on the phenological response and quality deterioration in rice

Decreased production of crops due to climate change has been predicted scientifically. While climate-resilient crops are necessary to ensure food security and support sustainable agriculture, predicting crop growth under future global warming is challenging. Therefore, we aimed to assess the impact of realistic global warming conditions on rice cultivation. We developed a crop evaluation platform, the agro-environment (AE) emulator, which generates diverse environments by implementing the complexity of natural environmental fluctuations in customized, fully artificial lighting growth chambers. We confirmed that the environmental responsiveness of rice obtained in the fluctuation of artificial environments is similar to those exhibited in natural environments by validating our AE emulator using publicly available meteorological data from multiple years at the same location and multiple locations in the same year. Based on the representative concentration pathway, real-time emulation of severe global warming unveiled dramatic advances in the rice life cycle, accompanied by a 35% decrease in grain yield and an 85% increase in quality deterioration, which is higher than the recently reported projections. The transcriptome dynamism showed that increasing temperature and CO2 concentrations synergistically changed the expression of various genes and strengthened the induction of flowering, heat stress adaptation, and CO2 response genes. The predicted severe global warming greatly alters rice environmental adaptability and negatively impacts rice production. Our findings offer innovative applications of artificial environments and insights for enhancing varietal potential and cultivation methods in the future.

The Alteration in Physiological Status, Growth and Essential Oil Profile of French Marigold (Tagetes patula L.) Owing to Seaweed Extract and Salicylic Acid Application

PurposeMedicinal plants show a relevant importance in human life and health. The use of natural substances in crop management is not only significant for the plant healthy growth and yield, but also for obtaining safe products. The study aimed to examine the effect of seaweed extract (SW) as a natural source of nutrition and salicylic acid (SA) on plant health, physiology and essential oil profile of French marigold (Tagetes patula L.).MethodsThree levels of salicylic acid, SA50, SA100 and SA200, (50, 100, and 200 mg L− 1) and three levels of seaweed extract, SW2, SW4 and SW6 (2.0, 4.0, and 6.0 ml L− 1), in comparison with control treatment (tap water) were applied as foliar sprayings. The seven treatments were arranged in randomized complete block design and were replicated thrice in two growing seasons (2020 and 2021).ResultsFindings pointed out that SA200 increased plant height, branches number plant− 1, stem diameter, leaf area, leaves number plant− 1, plant fresh weight, and plant dry weight by 32.9, 112.2, 59.2, 34.4, 44.3, 33.0 and 56.9% (averages of the two seasons), respectively, compared to the control treatment (tap water). SW6 increased carotenoids content by 34.8 and 46.4% in 2020 and 2021 seasons, respectively. Salicylic acid at the rate of 200 mg L− 1 along seaweed extract at 6 ml L− 1 gave the highest values of total sugars and free amino acids. SA200 alone recorded the maximal value of peroxidase activity surpassing the other treatments. SW6 possessed the greatest essential oil content in both seasons, statistically equaling SA200 in the first season. Huge variations in essential oil profile were recorded under the tested trial treatments.ConclusionIt could be concluded that salicylic acid and seaweed extract foliar application unveiled their involvement in diverse physiological and developmental responses; pigment formation, enzyme activities, flower induction, nutrient uptake, essential oil metabolism, and overall plant growth and development. It is recommended to use the highest concentrations of the tested substances (SA at 200 mg L− 1 or SW at 6.0 ml L− 1) for achieving distinctive improvements in physiological responses of French marigold plant.