Pramod Wasudeo Ramteke

Indole-3-acetic acid (IAA) is a central auxin regulating plant growth and developmental plasticity, including cell division, elongation, vascular differentiation, and root architecture. Beyond plants, many fungi—including endophytic fungi that reside within plant tissues without visible disease symptoms—can synthesize IAA and thereby modulate plant performance and plant–fungus interactions. However, fungal IAA biosynthesis remains less resolved than bacterial or plant pathways, and mechanistic evidence is uneven across taxa. This review summarizes recent (2020–2025) advances in IAA-producing endophytic fungi, the main proposed biosynthetic routes and intermediates, and methodological considerations for attributing IAA production to the fungal partner. The reported associations of fungal IAA with beneficial interactions are then discussed, including growth promotion, stress tolerance, and interaction-mediated changes in the root system’s architecture, with emphasis on the concentration- and context-dependent nature of plant responses. Overall, fungal IAA is associated with diverse plant–fungus interactions, as discussed in this review.

Micropropagation is an important method within plant biotechnology, allowing the bulk multiplication of high-quality, disease-free plants to occur; however, micropropagation faces several challenges, such as microbial contamination, the expensive chemical products used, and losses occurring during the key acclimatization phase of the micropropagation process. Plant growth-promoting microorganisms (PGPMs) have been shown to ameliorate many of these challenges. These microorganisms support growth and development throughout micropropagation via mechanisms such as nutrient solubilization, phytohormone production and inhibition, and inactivation of pathogens. This review focuses on the potential of the use of PGPMs in the explant initiation, shoot multiplication, rooting, and acclimatization stages and is supported by recent research and the mechanisms of action, challenges, and future perspectives of PGPMs.

Extensive use of agrochemicals and trend in climatic changes have greatly influenced agro-ecosystems and crop failures throughout the world. The ecological and economic problems of today’s agriculture have re-invigorated the idea of using natural rhizosphere microbial population in order to reduce the application of costly and environmentally-polluting agrochemicals to a minimum and alleviation abiotic and biotic stress in agricultural crops. Plant beneficial microbial resources promise to replace and/or supplement many such destructive, high intensity practices and support ecofriendly crop production. Plant growth promoting bacteria (PGPB) may promote plant growth directly through the processes such as by fixation of atmospheric nitrogen, solubilization of phosphorous, production of siderophores that solubilize and sequester iron, or production of plant growth regulators (hormones), lytic enzymes and hydrogen cyanide. Some bacteria support plant growth indirectly, by improving and/or eliminating the growth-restricting conditions either via production of antagonistic substances or by inducing resistance against plant pathogens and through competition for nutrients and space can improve significantly plant health and promote growth, as evidenced by increases in seedling emergence, vigor, and yield. Thus, application of microbial biotechnologies in crop production has ecological, environmental, and social benefits. It plays a crucial role as integral component of sustainable development.

The use of nanoparticles (NPs) in plant tissue culture systems represents a new approach to improve the efficiency of micropropagation. Owing to their nanoscale size, high surface area concomitant with volume, and controllable and targeted release, researchers have tested the experimental benefits of NPs in various ways during each phase of in vitro propagation, which include enhancing surface sterilization to reduce microbial contamination, the targeted uptake of specific macro-and micronutrients, regulating plant hormonal activity to enhance callogenesis, increased shoot multiplication and rooting, and increasing the survival rate during acclimatization. In addition, some situations where NPs are applied can reduce oxidative stress and regulate hormonal pathways, which will stabilize the physiological state of the plant and support better developmental integrity of the regenerating plantlets. In moving forward with the application of nanoparticles, the major limiting factors are nanotoxicity, persistence in the environment, species specificity, and the lack of an established regulatory framework. In this review, the recent published successes in NP-mediated micropropagation are summarized, how they impart their effects in plant science at the cellular and molecular levels are explained, and potential future innovations such as green-synthesized nanomaterials and new smart delivery platforms are also identified. Realizing the full potential of nanotechnologies for application with micropropagation will be critical for developing scalable, sustainable, and precision agricultural production systems.

High-temperature stress (HTS) is one of the significant constraints in crop production under climate change. The temperature rises from 32°C during the wheat reproductive and grain-filling stage, leading to yield penalties. In the present investigation, ten different wheat genotypes were evaluated at three different times of the same cropping year to assess the effect of HTS on developmental patterns and yield. The physiological characterization assessed chlorophyll content (CC) and cell membrane stability (CMS). However, the Canopy temperature depression (CTD) was measured at the three development stages, pre-anthesis, anthesis and post-anthesis, under HTS conditions to identify promising genotypes for developing new breeding lines. Simultaneously the morphological characterization viz. days to 50 % heading (HD), days to 50 % flowering (FD), plant height (PH), flag leaf length (FLL), flag leaf width (FLW), spike length (SL), spike numbers (SN), spike weight (SW), grain number per spike (GN/S), grain weight (GW), test grain weight (TGW) and grain yield per plot (GY/P) were analyzed to correlate the yield under HTS. Statistical analysis was done using a factorial ANOVA in all the genotypes and K910-30 showed better responses with CC, CMS and TGW values under HTS conditions. Simultaneously, the assessment of morphological traits revealed that the K910-30 genotype performed better than other genotypes. The results of the present investigation will be helpful in future studies dealing with improved high-temperature stress tolerance in wheat. They might be beneficial for identifying wheat genotypes that can withstand high-temperature stress.

Transcription factors (TFs) are critical regulators of gene expression, playing key roles in 1 various biological processes such as growth, development, and stress responses in plants. While many TF families like MYB, bZIP, and WRKY have been identified and extensively studied in model plants, a substantial number of novel TFs remain uncharacterized, particularly in non-model and economically significant plant species. The discovery of these novel TFs offers a promising avenue for advancing our understanding of plant biology and improving crop traits. Recent advancements in high-throughput sequencing, genomics, and bioinformatics have facilitated the identification of previously overlooked or newly evolved TFs, expanding the repertoire of known plant transcriptional regulators. This review highlights the emergence of novel TF families and their functional roles in regulating plant growth, adaptation to abiotic and biotic stresses, and metabolic pathways. We examine the molecular mechanisms by which these TFs govern gene expression, their interactions with other signaling pathways, and their potential applications in crop improvement. In addition, we explore the challenges and opportunities associated with the functional characterization and validation of novel TFs, as well as the technologies that are enabling these discoveries. Special attention is given to the potential of novel TFs to enhance stress tolerance, disease resistance, and overall productivity in crops, with a focus on their integration into biotechnological approaches, such as genome editing and transgenic crop development. The review concludes by outlining future research directions and the potential impact of novel TFs in addressing global agricultural challenges, including climate change, food security, and sustainability.

The primary aim of the present study was to identify bacterial isolates with yield‐enhancing potential for application as biofertilisers in the cultivation of sweet potato. Therefore, endophytic and rhizospheric strains were isolated from sweet potato plantations in Hungary to identify bacterial strains with plant growth‐promoting and antifungal potential. In total, seven Bacillus licheniformis strains were identified and subjected to detailed ecophysiological investigations. Experiments have been conducted to investigate the tolerance of selected strains to different limiting factors such as pH, temperature, and water activity, which affect survivability in various agricultural environments. The majority of tested B. licheniformis strains exhibited plant growth‐promoting potential (e.g., production of indole‐3‐acetic acid up to 40.42 μg mL⁻¹, production of ammonia up to 0.87 mg mL⁻¹, phosphorus solubilising activity, siderophore production), with two strains (SZMC 27713 and SZMC 27715) demonstrating inhibitory activity (ranging between 7% and 38%) against plant pathogenic fungi prevalent in sweet potato cultivation. Furthermore, strain SZMC 27715 induced accelerated germination and a significantly higher germination rate in tomato seeds compared to the control. In a field study, it was observed that strain SZMC 27715 had a potent yield enhancing effect in sweet potato, where a significant yield per plant increase was observed in all treatments (1.13, 1.09 and 1.40 kg) compared to the control plants (0.92 kg). The highest yield per plant was observed when the cuttings were soaked combined with two additional foliar treatments. To the best of our knowledge, this is the first report of the successful utilisation of the B. licheniformis strain as a biofertiliser for yield enhancement in sweet potato cultivation. Based on our results, strain SZMC 27715 has potential for application as a biofertiliser in sweet potato cultivation either as a standalone option or in a microbial consortium.

Heavy metal (HM) toxicity has become a global concern in recent years and is imposing a severe threat to the environment and human health. In the case of plants, a higher concentration of HMs, above a threshold, adversely affects cellular metabolism because of the generation of reactive oxygen species (ROS) which target the key biological molecules. Moreover, some of the HMs such as mercury and arsenic, among others, can directly alter the protein/enzyme activities by targeting their –SH group to further impede the cellular metabolism. Particularly, inhibition of photosynthesis has been reported under HM toxicity because HMs trigger the degradation of chlorophyll molecules by enhancing the chlorophyllase activity and by replacing the central Mg ion in the porphyrin ring which affects overall plant growth and yield. Consequently, plants utilize various strategies to mitigate the negative impact of HM toxicity by limiting the uptake of these HMs and their sequestration into the vacuoles with the help of various molecules including proteins such as phytochelatins, metallothionein, compatible solutes, and secondary metabolites. In this comprehensive review, we provided insights towards a wider aspect of HM toxicity, ranging from their negative impact on plant growth to the mechanisms employed by the plants to alleviate the HM toxicity and presented the molecular mechanism of HMs toxicity and sequestration in plants.

Iron (Fe) is the fourth most abundant element on earth and represents an essential nutrient for life. As a fundamental mineral element for cell growth and development, iron is available for uptake as ferric ions, which are usually oxidized into complex oxyhydroxide polymers, insoluble under aerobic conditions. In these conditions, the bioavailability of iron is dramatically reduced. As a result, microorganisms face problems of iron acquisition, especially under low concentrations of this element. However, some microbes have evolved mechanisms for obtaining ferric irons from the extracellular medium or environment by forming small molecules often regarded as siderophores. Siderophores are high affinity iron-binding molecules produced by a repertoire of proteins found in the cytoplasm of cyanobacteria, bacteria, fungi, and plants. Common groups of siderophores include hydroxamates, catecholates, carboxylates, and hydroximates. The hydroxamate siderophores are commonly synthesized by fungi. L-ornithine is a biosynthetic precursor of siderophores, which is synthesized from multimodular large enzyme complexes through non-ribosomal peptide synthetases (NRPSs), while siderophore-Fe chelators cell wall mannoproteins (FIT1, FIT2, and FIT3) help the retention of siderophores. S. cerevisiae, for example, can express these proteins in two genetically separate systems (reductive and nonreductive) in the plasma membrane. These proteins can convert Fe (III) into Fe (II) by a ferrous-specific metalloreductase enzyme complex and flavin reductases (FREs). However, regulation of the siderophore through Fur Box protein on the DNA promoter region and its activation or repression depend primarily on the Fe availability in the external medium. Siderophores are essential due to their wide range of applications in biotechnology, medicine, bioremediation of heavy metal polluted environments, biocontrol of plant pathogens, and plant growth enhancement.