Dendrobium denneanum, valued for its ornamental and medicinal properties, exhibits significant regulation of flowering and secondary metabolism by light intensity. This study employed physiological, biochemical, and transcriptomic analyses to compare the regulatory effects of five light intensity gradients (50, 100, 200, 400, and 600 µmol m⁻² s⁻¹) on flowering traits and secondary metabolism in D. denneanum at different developmental stages. Results demonstrated that 400 µmol m⁻² s⁻¹ markedly promoted flower organ growth, extending the flowering period, increasing the flowering rate, and enhancing flower color saturation, while simultaneously improving photosynthetic capacity and secondary metabolite accumulation. Notably, the regulatory effects of light intensity on floral morphological traits were most pronounced during the full blooming stage (S2), when flowers exhibited the greatest improvements in organ expansion, pigmentation, and bioactive compound accumulation. Transcriptomic analysis revealed that this light intensity upregulated photosynthetic light-harvesting processes and regulated carbon metabolism, optimizing light energy utilization and carbon flux to support flower development and flavonoid synthesis. Genes in the phenylpropanoid/flavonoid pathway were significantly upregulated, likely serving as key genes of flower coloration and medicinal component accumulation. Additionally, the mitogen-activated protein kinase (MAPK) signaling pathway suppressed stress-related genes and upregulated growth-related genes, promoting stomatal development and maintaining reactive oxygen species (ROS) balance to enhance stress tolerance.The transcriptomic results were further validated by quantitative real-time PCR (qRT-PCR). These findings highlight how 400 µmol m⁻² s⁻¹ optimizes photosynthetic efficiency, metabolic redirection, and growth-stress equilibrium, offering novel insights into light-mediated regulatory mechanisms in Orchidaceae plants and a foundation for precision cultivation strategies.
Catharanthus roseus is the sole natural source of the anticancer bisindole alkaloids vinblastine and vincristine, but leaf yields are intrinsically low. This study evaluated whether targeted in vitro and in vivo elicitation could enhance alkaloid accumulation and whether these changes were associated with selected physiological stress markers and with responses of terpenoid indole alkaloid-related transcripts. Microplants and calli were cultured on Murashige-Skoog medium; pot-grown plants received sodium chloride (NaCl), salicylic acid (10⁻⁵ M), methyl jasmonate (MeJA; 500 µM), ultraviolet-B (UV-B), or MeJA plus UV-B under controlled pot-culture conditions. Vinblastine and vincristine were quantified by high-performance liquid chromatography; hydrogen peroxide, electrolyte leakage, proline, ascorbate, and chlorophyll were assayed; and transcript levels of strictosidine synthase (CrSTR), tryptophan decarboxylase (CrTDC), and deacetylvindoline O-acetyltransferase (CrDAT) were measured by quantitative reverse-transcription PCR. Elicitation significantly altered alkaloid accumulation (p < 0.001): callus formation/NaCl treatment 8 (CFNT8) reached 11.44 µg g⁻¹ dry weight (DW) vinblastine and 23.35 µg g⁻¹ DW vincristine. In the selected follow-up subset, high-alkaloid treatments were associated with higher hydrogen peroxide (2.41 µmol g⁻¹), electrolyte leakage (0.44 µS cm⁻¹ g⁻¹), proline (96 µg g⁻¹), and ascorbate (26.14 mg g⁻¹), lower chlorophyll, and increased CrSTR (14.3-fold), CrTDC (5.1-fold), and CrDAT (24.1-fold) transcript abundance. Exploratory principal component analysis explained 88.85
WRKY transcription factors play critical roles in plant hormone signaling and in responses to various abiotic and biotic stresses. However, research on the relationship between WRKY transcription factors and iron deficiency in apple trees is limited. This study adopted real-time quantitative PCR (RT-qPCR) to detect WRKY gene expression in Malus halliana. The results revealed that the MhWRKY46 gene exhibited the highest expression level in response to iron deficiency stress. Furthermore, the precise regulatory mechanisms governing its role in iron deficiency stress are not yet fully elucidated. Accordingly, MhWRKY46 was selected for subsequent functional verification. Transgenic Arabidopsis thaliana plants overexpressing the MhWRKY46 gene demonstrated improved tolerance to iron deficiency stress. Additionally, overexpression in apple calli significantly enhanced growth under iron-deficient conditions compared with wild type. Physiological measurements indicated that the overexpression of the MhWRKY46 gene not only enhanced the tolerance of Arabidopsis thaliana to iron deficiency stress by promoting chlorophyll production, but also increased the resilience of apple calli to iron deficiency by lowering pH levels, enhancing the activity of antioxidant enzymes, and increasing iron content. In conclusion,the overexpression of the MhWRKY46 gene significantly improved the tolerance of both Arabidopsis thaliana and apple calli to iron deficiency stress.
The gigabytes of eukaryotic genomes are indexed by biochemical modifications including methylation and highly compressed and stacked in the nuclei. Thus, organized access and expression of the genetic codes hidden in the highly compacted genomes is critical. The methyl-CpG-binding domain (MBD) proteins can specifically recognize and bind to the methylated CpG sites and regulate gene expression. To date, few MBD genes have been functionally characterized in plants and their regulatory mechanisms remain unclear. Brassica napus is an important crop sensitive to osmotic stress. Here, a total of 38 putative MBD-domain proteins were identified in Brassica napus and their potential roles in abiotic stress were investigated. BnaC09.MBD7 (BnaC09G0432500ZS) and BnaA10.MBD7 (BnaA10G0153000ZS) are a pair of closely related paralogs with similar expression patterns. Both the BnaC09.MBD7 and BnaA10.MBD7 showed nuclear localization. Heterologous expression of either BnaC09.MBD7 or BnaA10.MBD7 in Arabidopsis thaliana conferred tolerance to drought and salt stresses. However, the transgenic plants over-expressing BnaC09.MBD7 or BnaA10.MBD7 showed largely non-overlapped transcriptomes, suggesting they might act independently to reinforce the stress tolerance. Our results functionally characterized BnaC09.MBD7 and BnaA10.MBD7 of Brassica napus in response to osmotic stress and provided insights into the regulatory mechanisms BnaMBD genes.
N-acetyl-L-thiazolidine-4-carboxylic acid (NATCA) is an organic amino acid derivative that functions as a plant growth regulator, enhancing growth and nutrient utilization in fruit trees and various crops. However, the molecular responses underlying its growth-promoting effects remain poorly understood. Here, we demonstrate that NATCA significantly promotes the growth and development of wheat (Triticum aestivum), with application at different concentrations enhancing physiological performance in stems, leaves, and roots. Treatment with 0.7 mg/L NATCA yielded the most pronounced positive effects. Under this treatment, chlorophyll content, free amino acids (FAA), soluble protein (SP), fresh weight, and dry weight all significantly increased compared to the control. Furthermore, NATCA elevated the activities of antioxidant enzymes including peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD). Transcriptome analysis identified 743 differentially expressed genes (DEGs, 505 up-regulated and 238 down-regulated) in response to NATCA. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed significant enrichment in phenylpropanoid biosynthesis (taes00940), starch and sucrose metabolism (taes00500), plant hormone signal transduction (taes04075), and biosynthesis of secondary metabolites. Notably, 49 DEGs (47 up, 2 down) were associated with phenylpropanoid biosynthesis, suggesting its potential involvement in NATCA-induced growth responses. Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) validated the expression patterns of seven selected DEGs. Collectively, these findings indicate that NATCA treatment associates with extensive transcriptional reprogramming and enhanced physiological performance in wheat seedlings. The observed enrichment of phenylpropanoid-related genes may contribute to growth promotion and biomass accumulation, although further biochemical and functional studies are required to establish causal relationships.
The global agricultural system is continuously facing many threats that arise from phytopathogens, which pose a serious challenge to food security worldwide. Synthetic biology approaches and advances in biotechnology have developed various methods to control these diseases, they are not yet fully effective in protecting plants from all phytopathogens. In this context, nature offers an alternative solution through plant associated microbiome. These beneficial microorganisms play a crucial role in mediating plant survival under biotic stress by influencing host immunity and metabolic responses. A better understanding of plant–microbe interactions at both genetic and metabolite levels is important. These interactions are controlled by complex regulatory networks and studying them will help us use their full potential. Consequently, research is expanding into how environmental factors, specifically light, influence plant physiology, immunity and secondary metabolism. Recent studies have suggested that light not only shapes plant immunity but also modulates the accumulation and behaviour of associated microbial community, therefore influencing the outcome of biotic stress interactions. This review focuses on the role of light as a regulatory signal in plant–microbe interactions under biotic stress. It explains how light controls secondary metabolite production and plant defence mechanisms. It also highlights how light responsive pathways can be used to develop disease-resistant and climate smart crops. The integration of photobiology with microbiome research may open new approaches for sustainable and resilient agricultural systems. This approach can help address the challenges posed by emerging phytopathogen.
Low nitrogen use efficiency in rice has increased interest in foliar nano-urea (NU) as a supplement to reduced soil-applied nitrogen. The study evaluated basmati rice (Oryza sativa L., var. Pusa Basmati-1692) under 100
The cytoplasmic–genic male sterility (CGMS) system enhances the economic efficiency of F1 hybrid seed production by exploiting the interaction between sterile cytoplasm and nuclear restorer-of-fertility (Rf) genes. Molecular markers linked to the Rf gene facilitate the development of stable CMS lines by enabling fixation of the recessive rf allele in male-sterile (A) and maintainer (B) lines, identification of restorer lines, and assessment of genetic purity. In the present study, phenotyping of an F2 population derived from IIHR4392A (rfrf) × IIHR4597R (RfRf) showed a 3:1 segregation ratio, confirming monogenic dominant inheritance of fertility restoration. Genotyping-by-sequencing (GBS) of this segregating F2 population yielded 10,443 single-nucleotide polymorphisms (SNPs) with 481 to 1,074 SNPs per chromosome. Bulk segregant analysis identified three SNPs co-segregating with the Rf gene on chromosome 6. One candidate SNP, mapped at 2,343,509 bp on chromosome 6, was converted into a derived cleaved amplified polymorphic sequence (dCAPS) marker and validated in the F2 population. Three putative candidate genes, i.e., two fertility restorer-like proteins (CA06g01070, CA06g01090) and a pentatricopeptide repeat protein (CA06g01100), were predicted as potential Rf candidates. The developed dCAPS marker associated with the Rf gene for fertility restoration provides a valuable tool for marker-assisted breeding in chilli.
Stevia rebaudiana Bertoni is a globally recognized natural sweetener owing to its zero-calorie steviol glycosides (SGs). However, drought stress, one of the leading abiotic constraints to crop productivity, adversely affects stevia growth and development, while simultaneously altering its biochemical composition. This review highlights the impact of polyethylene glycol (PEG)-induced drought stress on stevia, with particular emphasis on agronomic traits, metabolites, antioxidant activities, and SGs biosynthesis. PEG-mediated stress reduces key growth parameters, such as plant height, biomass, and leaf area, but in some cases, it promotes root elongation as an adaptive strategy to optimize water uptake. Such alterations are accompanied by biochemical adjustments, notably the up-regulation of antioxidant enzymes, such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), which neutralize reactive oxygen species (ROS)-induced oxidative stress. Moreover, PEG stress enhances the accumulation of secondary metabolites, such as phenolic, flavonoids and terpenoids, thereby improving antioxidant potential and stress tolerance. Notably, PEG-induced drought stress shapes SG biosynthesis through the up-regulation of the methylerythritol phosphate (MEP) pathway and the differential expression of key SG-related genes. Such modulation frequently increases SG accumulation, thereby strengthening their medicinal and economic value. Overall, this review covers the dual nature of PEG-induced drought stress: while limiting agronomic performance, enhances SGs biosynthesis and antioxidant capacity. Gaining insights into these mechanisms will facilitate the development of optimized cultivation strategies under water deficit conditions. Future research should prioritize molecular breeding and advanced biotechnological approaches to enhance drought tolerance and maximize the production of bioactive metabolites in stevia.
MYB transcription factors are pivotal regulators of plant cold acclimation, yet current knowledge about cold-tolerance-related MYBs (crMYBs) remains fragmented across species, with their phylogenetic relationships, regulatory mechanisms, and functional divergence poorly integrated. This review synthesizes functionally validated crMYBs within a phylogenetic framework to provide an updated perspective on their regulatory roles in plant cold acclimation. We curated 106 experimentally validated crMYBs from 45 plant species and systematically characterized their subfamily distribution, regulatory polarity, pathway associations, validation strategies, and cross-species functional patterns. R2R3-MYBs constitute the majority of characterized crMYBs, whereas 1R-MYBs and 3R-MYBs remain underrepresented despite their established links to circadian regulation, cell-cycle control, and stress adaptation. Comparative analyses further indicate that orthologous MYBs retain conserved functions or undergo functional divergence across species. Current evidence implicates crMYBs in multiple regulatory layers of cold acclimation, including ABA-associated responses, CBF/COR-related transcriptional regulation, hormonal crosstalk, osmoprotectant accumulation, phenylpropanoid metabolism, cuticular wax biosynthesis, post-translational modifications, and chromatin-level regulation. Characterization of underexplored 1R-MYB and 3R-MYB members, phylogeny-guided cross-species functional validation, clarification of the mechanisms underlying regulatory polarity divergence, and evaluation of MYB functions under combined stress conditions would contribute substantially to a more comprehensive understanding of plant cold resilience.
The seasonality of forage production is one of the main challenges in semi-arid regions, where environmental conditions limit agricultural productivity. One promising option is the use of elephant grass ‘BRS Capiaçu’, together with deficit irrigation. This study evaluated the impact of different irrigation depths with brackish water (50
The present work is performed on AtAVT6D-overexpressor and wild-type Arabidopsis thaliana plants. The objective of the study is to examine changes in the gene expression profile after treatment with abscisic acid for 12 h and 24 h using a transcriptomics approach. 24 h-ABA-treated AtAVT6D overexpressors had the highest number of differentially expressed genes [9847] in response to stress compared to wild-type plants. Many of these genes in AtAVT6D overexpressors were involved in ROS scavenging pathways. Gene-ontological analysis of 24 h-ABA-treated plants indicated an increased response to oxygen. The upregulated genes in wild-type plants were related to energy generation pathways. KEGG analysis depicted ‘Carbon metabolism’, ‘Amino acid metabolism’, and ‘Co-factor biosynthesis’ as the enriched pathways at 12 h and 24 h ABA treatment conditions. RNA-sequencing results were validated by RT-qPCR analysis of few candidate genes. The findings in this article are consistent with our previous study on AtAVT6D gene and further demonstrate that AtAVT6D overexpression broadly reprograms the transcriptome in response to ABA, particularly affecting ROS-related pathways. This work will help us understand the role of AtAVT6D gene in detail under stress response.
This study investigates the biochemical characteristics, antioxidant potential and nutritional parameters of a newly identified eustigmatophycean strain Vischeria magna MZ–E1. The strain showed strong potential to accumulate lipids, vitamins, pigments, and fatty acids, including eicosapentaenoic acid, which has significant commercial value. The identification was based on morphological features, phylogenetic analysis of the 18S rRNA gene. The strain accumulated substantial quantities of lipids (up to 185.03 mg g− 1 dry weight), vitamins (retinol up to 33.98 µg g− 1, α-tocopherol up to 465.87 µg g− 1), ascorbic acid (up to 8.12 mg g− 1), and carotenoids (up to 1.92 mg g− 1), with astaxanthin comprising 12.5–19.4
While the effects of ultraviolet radiation (UVR; 280–400 nm) on cyanobacterial systems have been extensively documented, the specific impact on photochemical yield remains less understood. To address this gap, we investigated the physiological performance of the model cyanobacterium Synechococcus elongatus PCC 7942 under UVR exposure. Employing Pulse Amplitude Modulation (PAM) fluorometry, a non-invasive technique, we assessed the photochemical efficiency of Photosystem II (PSII). Our data not only corroborate previous findings but also provide novel insights into the potential of UVR to enhance photosynthetic electron transport rates in Synechococcus elongatus PCC 7942. This study examined the combined effects of photosynthetically active radiation (PAR; 400–700 nm) and UVR on the growth and various physiological parameters of this cyanobacterium. Notably, while PAR + UVR negatively influenced growth, it did not compromise overall fitness. The observed enhancement in carotenoid production, modulation of pigment ratios, and maintenance of cellular morphology suggest the activation of acclimatization mechanisms in response to the combined light stress. Despite initial declines in photosynthetic performance, the remarkable recovery and resilience of Synechococcus elongatus PCC 7942 over time underscore its robustness. Consequently, these findings illuminate the resistance mechanisms of this commercially important cyanobacterium to changing light environments, highlighting the dual role of UVR as both an environmental stressor and a trigger for protective physiological responses.
Abiotic stresses such as drought, extreme temperatures, salinity, heavy metals, and ultraviolet radiation have severely reduced rice productivity by disrupting cellular balance and physiological processes. Rice plants perceive environmental stress through the complex signaling networks that include phytohormone-mediated pathways, transcriptional regulation, reactive oxygen species, ion transport systems, and post-translational modifications. While numerous studies have been focused on positive regulators that enhance stress tolerance, but emerging evidence also suggest that negative regulators have an equally important role in modulating stress responses and balancing stress tolerance. These regulators have been shown to function at multiple molecular levels, including TFs, protein phosphatases, ubiquitin–proteasome components, signaling repressors, and chromatin-associated modifiers that modulate ABA-dependent and independent stress signaling pathways. This review provides a comprehensive study of negative regulators identified in rice and discusses their physiological impacts on the stomatal regulation, ROS scavenging, ion homeostasis, photosynthetic efficiency, and developmental adaptation. We have further summarized the strategies that are used for the identification of negative regulators through transcriptomic, genetic, and functional genomics approaches. Finally, we highlight emerging opportunities for the manipulation of negative regulatory networks to combat stress tolerance without compromising overall yield, offering future perspectives for developing climate-resilient rice cultivars.
Clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein (Cas)-based genome editing technology has come out as very precise and effective tool for targeted modification in the gene of interest and offers unprecedented potentials in crop improvement. However, in the present regulatory framework for commercialization of genome edited crops, in many countries including India, the edited lines must be transgene-free. In India, only site directed nuclease (SDN) I and SDN II category of genome edited events which are transgene-free are permitted for commercialization. Potato is a vegetatively propagated crop, having autotetraploid genome and is highly heterozygous in nature. Removal of the transgene from potato genome of edited lines through genetic segregation, either by crossing or selfing, is not the appropriate method as the elite background of the genome gets disturbed due to heterozygous nature of the crop. Every individual seed of potato, i.e. true potato seed (TPS) behaves like a different individual than the parental line and is unable to maintain the genetic identity. In this review article, we have discussed several strategies that can be enacted for generation of transgene-free genome edited lines in potato. This article will provide deeper insight and enhance understandings about the optimum use of CRISPR as non-GMO technology in the genetic enhancement of potato and to adopt the best strategies in editing this important tuberous, clonally propagated crop.
The southern root-knot nematode (RKN), Meloidogyne incognita is the major nematode problem in vegetable crops and causes huge amounts of losses in tropical and subtropical regions of the world. The study was carried out to synthesize, characterize, and test the bio-efficacy of chitosan-saponin nanoparticles (CS-SP NPs) against M. incognita on mortality, egg hatching, host finding, and management under growth chamber and screen house conditions on tomato. The NPs were synthesized by the ionic gelation method and characterized by DLS, FTIR, FE-SEM, TEM, XRD and, BET. The NPs exhibited a size of 331 nm, 0.14 PDI, and 36.6 (+ ve) zeta potential. FTIR, FE-SEM, TEM, BET, and XRD confirmed functional groups, spherical shape, large surface area as compared to bulk material, and crystalline structure, respectively. The NPs showed 64.3
The plant cuticle is a lipid barrier that plays essential roles in reducing water loss, protecting against pathogens, and interacting with the environment. While it has been thoroughly studied in leaves, its dynamics in fruits have not been adequately explored. This research gap is significant, as the cuticle in fruits has considerable implications for crop quality, postharvest longevity, and stress resilience. This review summarizes current understanding of cuticular dynamics during the development of fleshy fruits, with a focus on evolutionary innovations that have influenced cuticle diversity in angiosperms. We explore the conserved yet highly regulated biosynthetic pathways, emphasizing compositional variations in cutin and cuticular wax specific to different species and developmental stages. The review outlines how transcriptional, hormonal, and epigenetic networks regulate cuticle formation in response to both biotic/abiotic stress, and how these changes influence fruit quality traits such as glossiness, firmness, and susceptibility to cracking. We discuss the potential of targeting cuticular genes—through breeding, transgenic methods, or CRISPR-Cas9 editing—to improve stress tolerance and fruit quality. This work highlights the importance of the cuticle in improving agricultural sustainability, especially in response to climate change, by integrating fundamental insights from model plants with applied research in fruit crops. We propose that fruit-focused research should leverage cuticle biology to develop resilient, high-quality varieties. This approach aims to reduce postharvest losses and enhance food security.
