Germination Of Rice Seeds Research Articles

Analysis of Drought Stress Effect on Inpari Germination: Survival Method

Drought stress using mannitol can inhibit the germination of rice variety seeds. These studies typically produce time-to-event data and censored observation. Survival analysis techniques are valuable for accounting for these non-germination events, as they describe how germination probability changes over time based on the likelihood of seed development. Until now, there have not been survival studies regarding rice germination affected by drought stress in Indonesia. Thus, we investigated the germination probability of three rice varieties (Inpari 19, Inpari 32, and Inpari 49) under drought stress using survival analysis. The seeds were germinated in 0%, 2%, 4%, 6%, and 8% concentrations of mannitol and evaluated daily over 14 days. Our results demonstrated that higher mannitol concentrations significantly decreased the germination percentage and delayed germination time. The survival rates varied significantly between different mannitol concentrations, highlighting the adverse effects of drought stress. However, there was no significant difference in the probability of seed germination among the varieties treated with 2% mannitol. Among the varieties studied, Inpari 19 is more likely to be drought-resistant compared to Inpari 32 and Inpari 49. It is based on the highest germination percentage, shortest germination time, and highest probability of germination compared.

OsNAL11 and OsGASR9 Regulate the Low-Temperature Germination of Rice Seeds by Affecting GA Content

Low temperatures cause serious threat to rice seed emergence, which has become one of the main limiting factors in the production of direct seeding rice. It is of great importance to study the genes controlling low-temperature tolerance during seed germination and to mine the possible regulatory mechanism for developing new rice varieties with immense low-temperature germination ability. In the current research study, two types of mutants of nal11 and gasr9, derived from the WT (wild type) ZH11, were used for the analysis of low-temperature germinability. The results showed that the nal11 and gasr9 mutants displayed no significant difference in germination rate with ZH11 at room temperature, but the mutants showed significantly lower germination rates, germination potential and germination index, and slowed seedling growth in the simulated direct seeding experiments at low temperatures compared to ZH11. Additionally, the activity of POD, SOD, CAT, and anti-superoxide anion radial activity were significantly reduced, but the levels of MDA and H2O2 were significantly higher in the nal11 and gasr9 mutant seeds that were germinated at low temperatures compared to ZH11. Further analysis revealed that the levels of total active GA, especially GA4 and GA7, were significantly lower in the nal11 and gasr9 mutants than that in ZH11 during low-temperature germination. Based on qRT-PCR analysis, the expression levels of some GA synthesis-related genes were higher, whereas some were lower in the nal11 and gasr9 mutants than those in ZH11, however, the GA metabolism-related genes OsGA2ox8 and OsGA2ox10 and the GA signaling negative regulator gene SLR1 were significantly up-regulated in both nal11 and gasr9 mutants at several time points during low-temperature germination. This may explain the lower GA levels in the nal11 and gasr9 mutants. Furthermore, the interaction between the OsNAL11 and OsGASR9 proteins was confirmed by Y2H, LUC, and Co-IP assays. This study provides preliminary insights into the regulatory mechanism of the OsNAL11 and OsGASR9 genes, which control the low-temperature germination of rice seeds by affecting the GA pathway. Our study will provide the basis for further mining the molecular mechanisms of low-temperature germination in rice and valuable theoretical reference for breeding varieties with strong low-temperature germinability.

Genome-Wide Association Study Reveals Loci and New Candidate Gene Controlling Seed Germination in Rice

Improving seed germination and seedling development can potentially increase crop yield and improve quality in direct-seeded rice. This study aimed to detect loci or genes associated with rice seed germination. We reported the phenotypic analysis of seed germination in 103 rice accessions across two years, and a genome-wide association study (GWAS) was conducted to identify loci underlying the genetic regulation of seed germination. A total of seven genetic loci were found to be associated with seed germination, including five loci that overlapped with the previously reported loci/genes, and two novel loci. Of these, two loci (qGP2 and qGP4.1) were stable across different environments. GP4 (Germination percentage 4), encoding a 9-cis-epoxycarotenoid dioxygenase, was identified as the candidate gene of the major locus qGP4.1. A sequence analysis of GP4 revealed that four functional polymorphic sites in the coding region were significantly associated with germination percentage. The disruption of GP4 by gene editing resulted in faster seed germination and seedling establishment. Taken together, we have identified GP4 as a novel gene involved in rice seed germination, and we provide a potential target gene for improving rice seed vigor via gene editing or molecular breeding.

Physiological Responses of Different Aged Rice Seeds to Osmopriming with PEG 6000

The objective of this research was to compare the quality of different aged rice seed after priming. The rice seeds were deteriorated by accelerated aging method at 44 °C and relative humidity 100 %, in different periods for 0 (without accelerated aging), 1, 2, 3, and 4 days. Then, the germination of rice seeds of different ages were induced by soaking in 30% of PEG 6000 solution at room temperature for 24 hours. After that, the rice seeds were dried in a hot air oven at 35 °C for 10 hours until the moisture content was close to the initial moisture. Finally, these treated rice seeds were examined for the seed quality of various characteristics such as seed germination rate (planted in the laboratory and field conditions), germination index, speed of germination, and electrical conductivity of solution used for soaking seeds. The results showed that the electrical conductivity of all different aged seeds decreased after priming. For the field of germination and germination uniformity, it was found that the seeds with different rates of deterioration showed different responses to the priming. Aged seeds with germination rates of 12 and 33 percent germination were able to induce germination rate by 27 and 48 percent, respectively, while aged seeds with higher deterioration rate had a decreased response.

Bacillus amyloliquefaciens LM-1 Affects Multiple Cell Biological Processes in Magnaporthe oryzae to Suppress Rice Blast.

Magnaporthe oryzae, one of the most destructive rice pathogens, causes significant losses during the rice harvest every year. Bacillus amyloliquefaciens has been explored in many crops as a potential biocontrol agent. However, the mechanisms of B. amyloliquefaciens controled rice blast are not fully understood. Here, a biocontrol strain LM-1, isolated from a contaminated medium, was identified as B. amyloliquefaciens using morphological observation, physiological and biochemical tests, and 16S rDNA sequencing. LM-1 inhibited the growth and pathogenicity of M. oryzae and Bipolaris oryzae (Breda de Haan) Shoem. The mycelia of M. oryzae co-cultured with LM-1 were enlarged and broken by fluorescence microscopy using calcofluor white. LM-1 inhibited the mycelia of M. oryzae from producing conidia. Genes itu, srf, and fenB were detected in LM-1. Furthermore, the supernatant of LM-1 interfered with the appressorium formation of M. oryzae, blocked conidial cell death, and reduced autophagy degradation but did not affect the normal germination of rice seeds and seeding growth. Additionally, we observed hypersensitivity reactions, reactive oxygen species, and iron accumulation reduction in rice cells inoculated with supernatant. Our study reveals that LM-1 has a control effect on rice blast and affects cell wall integrity, sporulation, appressorium formation, cell death, and autophagy.

Effect of Hormonal Priming on Seed Germination and Initial Growth of Cambodian Rice in Salt Stress Condition

Effect of Hormonal Priming on Seed Germination and Initial Growth of Cambodian Rice in Salt Stress Condition

Green Synthesis of Silver Nanoparticles Using Microbial Biosurfactant Produced by a Newly Isolated Klebsiella sp. Strain RGUDBI03 Through a Single Step Method and Exploring its Role in Enhancing the Chickpea and Rice Seed Germination

Green Synthesis of Silver Nanoparticles Using Microbial Biosurfactant Produced by a Newly Isolated Klebsiella sp. Strain RGUDBI03 Through a Single Step Method and Exploring its Role in Enhancing the Chickpea and Rice Seed Germination

STUDY OF THE EFFECT OF BACTERIA OF THE GENUS BACILLUS ON THE CULTURE OF RICE AND CORN SEEDS IN VITRO

The aim of the study was to investigate the effect of bacteria strains Bacillus megaterium ONU500, Bacillus velezensis ONU553, Bacillus pumilus ONU554, Bacillus subtilis ONU559 on the germination and growth of rice and corn seeds under sterile conditions. Materials and methods. Three-day cultures of the four strains were grown on LB liquid nutrient medium in a thermostat at 28 °C and the seeds of model plants were sterilized according to the standard scheme. The seeds were placed in 1% solutions of bacterial suspensions (106 CFU/ml) of each strain and inoculated for 1 hour. Results. The experiment results on both model plants indicate significant potential of the bacteria B. megaterium ONU500, B. velezensis ONU553, B. pumilus ONU554 as growth and development stimulators for plants. B. subtilis ONU559 is recommended for further study and clarification of its impact on plants in subsequent research. Conclusion. The most positive, stimulating effect on the indicators of germination, growth, and development of rice and corn seeds is exerted by inoculation with the strain B. megaterium ONU500 (for rice: increase in shoot length by 36.5%, root by 29%; for corn: 50% and 69% respectively). Further study of the influence of B. velezensis ONU553 is promising for rice cultivation, and for corn – B. pumilus ONU554.

OsSCYL2 is Involved in Regulating ABA Signaling-Mediated Seed Germination in Rice.

Seed germination represents a multifaceted biological process influenced by various intrinsic and extrinsic factors. In the present study, our investigation unveiled the regulatory role of OsSCYL2, a gene identified as a facilitator of seed germination in rice. Notably, the germination kinetics of OsSCYL2-overexpressing seeds surpassed those of their wild-type counterparts, indicating the potency of OsSCYL2 in enhancing this developmental process. Moreover, qRT-PCR results showed that OsSCYL2 was consistently expressed throughout the germination process in rice. Exogenous application of ABA on seeds and seedlings underscored the sensitivity of OsSCYL2 to ABA during both seed germination initiation and post-germination growth phases. Transcriptomic profiling following OsSCYL2 overexpression revealed profound alterations in metabolic pathways, MAPK signaling cascades, and phytohormone-mediated signal transduction pathways, with 15 genes related to the ABA pathways exhibiting significant expression changes. Complementary in vivo and in vitro assays unveiled the physical interaction between OsSCYL2 and TOR, thereby implicating OsSCYL2 in the negative modulation of ABA-responsive genes and its consequential impact on seed germination dynamics. This study elucidated novel insights into the function of OsSCYL2 in regulating the germination process of rice seeds through the modulation of ABA signaling pathways, thereby enhancing the understanding of the functional significance of the SCYL protein family in plant physiological processes.

AMPK activator 991 specifically activates SnRK1 and thereby affects seed germination in rice.

Sucrose non-fermenting-1-related protein kinase 1 (SnRK1) and AMP-activated protein kinase (AMPK) are highly conserved. Compound 991 is an AMPK activator in mammals. However, whether 991 also activates SnRK1 remains unknown. The addition of 991 significantly increased SnRK1 activity in desalted extracts from germinating rice seeds in vitro. To determine whether 991 has biological activity, rice seeds were treated with different concentrations of 991. Germination was promoted at low concentrations but inhibited at high concentrations. The effects of 991 on germination were similar to those of OsSnRK1a overexpression. To explore whether 991 affects germination by specifically affecting SnRK1, germination of an snrk1a mutant and the wild type under 1 μM 991 treatment was compared. The snrk1a mutant was insensitive to 991. Phosphoproteomic analysis showed that the differential phosphopeptides induced by 991 and OsSnRK1a overexpression largely overlapped. Furthermore, SnRK1 might regulate rice germination in a dosage-dependent manner by regulating the phosphorylation of three phosphosites, namely S285-PIP2;4, S1013-SOS1, and S110-ABI5. These results indicate that 991 is a specific SnRK1 activator in rice. The promotion and inhibition of germination by 991 also occurred in wheat seeds. Thus, 991 is useful for exploring SnRK1 function and the chemical regulation of growth and development in crops.

The molecular and metabolic events behind different germination stages of rice seeds: A metabolomics perspective

AbstractSeed germination is a crucial stage for the completion of plants' life cycle. The process of seed germination is a very important phenomenon for agricultural food and crop production and to understand the underlying food chemistry. Rice (Oryza sativa L.) being easy to grow and cheap source of phytonutrients is a fundamental food crop across the world. Several researches are going on for years to improve the production of rice, ameliorate the deadly bacterial or fungal diseases utilizing genetics, transcriptomics, and proteomics aspects. Metabolomics is a very new arena of research in this field. With the help of modern‐day metabolomic tools and technologies, researchers are incessantly trying to unveil the metabolic construction of rice seeds, and new to this topic is seed germination. The principal aim of this review on metabolomics of germinating rice seeds is to have a big picture on the key molecular, cellular, and metabolic events of germination. This review tries to summarize all the available data to fulfill the aforesaid aim.

Enhancing Seed Germination and Seedlings Growth of Khao Dawk Mali 105 Rice Cultivar via Seed Coating and Infrared Drying Apparatus

Seed coating techniques had emerged as a promising approach for precise planting and safeguarding crops against environmental stresses. Simultaneously, infrared drying, renowned for its cost-effectiveness and efficiency, held promises for enhancing the quality of drying processes. This investigation delved into the procedures applied to Khao Dawk Mali 105 rice seeds during the coating and drying process using a prototype of the hexagonal drum. The results found that the drying temperature (factor B) and duration of drying time (factor C) had substantial primary effects (p ≤ 0.05), while the drum rotational speed (factor A) did not exert a noteworthy influence. Additionally, meaningful interactions were observed among the factors AB, AC, BC, and ABC. Impressively, it resulted in germination rates of 80.56 and 80.25 %, coupled with germination indices of 84.88 and 85.47 %, when utilizing a drum speed of 20 rpm, a drying temperature of 45 °C, and a drying time of 8 min (R-204508), and a drum speed of 10 rpm, a drying temperature of 45 °C, and a drying time of 8 min (R-104508), respectively. Additionally, the mean germination time amounted to 9.64 days, and the length of the rice seedling stem reached 13.66 cm when employing a drum speed of 20 rpm, a drying temperature of 50 °C, and a drying time of 8 min (R-205008). These discoveries emphasized the potential of the prototype's seed coating and infrared drying technology integration to improve rice germination and subsequent growth. This enhancement could ultimately result in higher yields and increased productivity, especially in small-scale agricultural settings. HIGHLIGHTS These discoveries emphasized the potential of the prototype's seed coating and infrared drying technology integration to improve rice germination and subsequent growth. This enhancement could ultimately result in higher yields and increased productivity, especially in small-scale agricultural settings. Ensuring precise control over drying temperature and duration is of paramount importance in establishing optimal and consistent conditions for the germination and subsequent growth of rice seeds, thereby augmenting plant vigor and overall yield The investigation determined optimal coating and drying conditions, encompassing a drum speed of 20 rpm, a drying temperature of 45 °C, and a drying duration of 8 min (treatment R-204508), along with a drum speed of 20 rpm, a drying temperature of 45 °C, and a drying time of 8 min (treatment R-104508). These conditions resulted in the highest mean germination rates and germination indices. GRAPHICAL ABSTRACT

OsbZIP38/87-mediated activation of OsHXK7 improves the viability of rice cells under hypoxic conditions

Maintenance of energy metabolism is critical for rice (Oryza sativa) tolerance under submerged cultivation. Here, OsHXK7 was the most actively induced hexokinase gene in the embryos of hypoxically germinating rice seeds. Suspension-cultured cells established from seeds of T-DNA null mutants for the OsHXK7 locus did not regrow after 3-d-hypoxic stress and showed increased susceptibility to low-oxygen stress—in terms of viability—and decreased alcoholic fermentation activities compared to those of the wild-type. The promoter element containing the TGACG-motif, a well-known target site for the basic leucine zipper (bZIP) transcription factors, was responsible for sugar regulation of the OsHXK7 promoter activity. Systematic screening of the OsbZIP genes showing the similar expression patterns to that of OsHXK7 in the transcriptomic datasets produced two bZIP genes, OsbZIP38 and 87, belonging to the S1 bZIP subfamily as the candidate for the activator for this gene expression. Gain- and loss-of-function experiments through transient expression assays have demonstrated that these two bZIP proteins are indeed involved in the induction of OsHXK7 expression under starvation or low-energy conditions. Our finding suggests that C/S1 bZIP network-mediated hypoxic deregulation of sugar-responsive genes may work in concert for the molecular adaptation of rice cells to submergence.

Effect of Soaking with Plant Growth Promoting Rhizobacteria on Rice Seed Germination

This study aims to determine the effect of immersing rice seeds in Plant Growth Promoting Rhizobacteria (PGPR) suspension. The study used a completely randomized design (CRD) with seed immersion treatment using PGPR bacterial suspension. The rice varieties used were Ciherang, Inpari 32, and IR64, where the seeds were soaked for 30, 45, 60, and 300 minutes, respectively. There were 12 treatment units plus one control by soaking the seeds in water for 60 minutes. All treatments and controls were repeated three times. The results showed that soaking rice seeds for 60 minutes gave longer root and sprout lengths of the three rice varieties. Soaking rice seeds for 30 and 45 minutes caused slower germination, and shorter root length and sprout length than the control. Soaking rice seedlings longer than 60 minutes did not alter germination speed than soaking for 60 minutes.

RESEARCH OF WATER-SAVING AND HERBICIDE-FREE IRRIGATION TECHNOLOGY FOR RICE CROP UNDER WATER DEFICIT CONDITIONS IN KYZYLORDA REGION

Kyzylorda region is the main producer of rice in Kazakhstan. Annually, out of 195 thousand hectares of irrigated fields used in the region, about 80-90 thousand hectares are sown with rice. However, every year due to low water in the lower reaches of the Syr Darya River there are problems with water supply for water-loving rice crop. Prospects of rice production under conditions of water deficit in Kyzylorda region are conditioned by necessity of application of water-saving technologies providing favorable thermal, salt and nutrient regimes. Water consumption of rice culture is 9,0-11,0 thousand m3/ha depending on biological specificity of rice and this indicator is 3-4 times lower than irrigation norm of rice in the region. Most of the water excessively applied to rice fields is wasted in summer and increases secondary soil salinization and reduces crop yields. Besides, due to deterioration of technical condition of irrigation canals and collector-drainage systems, mineralized groundwater is located close to the ground surface. Undoubtedly, this will increase soil re-salinization and reduce crop yields. One of the most difficult problems in rice fields is weed control. Application of chemical deteriorates the ecological condition of the region and reduces its economic efficiency. As a result of research on the development of water-saving and herbicide-free technology of rice irrigation under conditions of water shortage in the Kyzylorda region was saved 6460-9070m3 of water per hectare, ie compared to the current irrigation regime was saved 25-30% of water, and rice yield increased by 6.0-8.0 centners per hectare. In addition, an effective method of weed control in rice fields is the destruction of weeds by water regime without the use of pesticides and the improvement of irrigation technology of rice crop. As a result of the research it was found that maintenance of 20 cm water layer in checks after full germination of rice seeds provides 84% weed suppression and high yield of rice without herbicides

Inoculation of Endophytic Bacteria for Increasing Plant Height and Number of Rice Roots (Oryza sativa)

Four endophytic bacteria have been isolated from banana kluthuk plants and banana ambon. Previous study showed that they produce Indole Acetic Acid (IAA). This study aimed to analyze the effect of endophytic bacterial inoculation on plant height and the number of rice root. For this reason, two endophytic bacteria of each klutuk banana and ambon banana plants were cultured and examined for growth rate using a 600 nm spectrophotometer. Isolate growth was calculated every two hours for 16 hours of bacterial growth in NB media. Bacterial inoculation experiments on rice plants were carried out with five replications. This inoculation begun with germination of rice seeds until the radicle was observed. Then germinated rice seedlings were soaked in a bacterial suspension for 1 hour at room temperature. The results showed the exponential phase of all isolates was observed at 6 hours with shaking. Inoculation using A22 and A51 isolates significantly increases plant height, number of leaves. While, A22 isolate significantly increased the number of roots compared to the uninoculated plants (control). It supports the potential of endophytic bacteria from banana kluthuk and ambon plants.

Identification of long-term flood-resistant genes in rice hybrid samples

Rice is an important grain crop known for its ability to grow in flooded soil. Sometimes rice plants resist weeds and herbicides’ application ineffectively and unprofitably. The varieties that have flood-resistant genes can help solve this problem, so the study of DNA markers is of great importance. Floodresistant loci contain the Sub1 gene, which is activated under anaerobic conditions. The locus contains three similar genes Sub1A, Sub1B, Sub1C, but only the gene Sub1A improves resistance to such conditions. The purpose of the study is to find the most effective Sub1A marker for identifying genes for tolerance to prolonged flooding in domestic hybrid rice samples as a natural method of weed control. As donors there have been used foreign varieties (Inbara-3, BR-11, TDK-1, IR-64, CR-1009, Swarna), and Russian varieties (Novator, Magnat, Stepnyak, Bakhus, Komandor, Kuban-3, Boyarin, Kontakt) as recipient forms. From the populations of F5-F9 generations, there have been selected 96 early maturing hybrids. To identify the gene in hybrid plants, three sets of locus-specific primers, the most widely used according to the literature, were used: Sub1A(1F1R), Sub1A(2F2R), and Sub1A(3F3R).The region amplicon Sub1A(1F1R) was found in 17 samples among 96 studied hybrids, the region amplicon Sub1A(2F2R) was found in 17 samples, and the Sub1A(3F3R) primer has initiated nonspecific amplification and did not allow the identification of genotypes. To further verify the phenotypic expression of the introduced locus, the morpho-physiological response of all hybrid rice lines under flooding conditions was analyzed. Under flooding conditions, the number of germinated rice seeds in the parental lines (Novator, Boyarin and Stepnyak) decreased, as well as in hybrids that did not inherit the locus according to molecular genetic analysis. As a result, it is recommended to carry out analysis using two markers to improve efficiency

Using Plasma-Activated Water Generated by an Air Gliding Arc as a Nitrogen Source for Rice Seed Germination

This research aimed to understand the use of air gliding arc (GA) plasma to generate plasma-activated water (PAW) for fixing nitrogen in water and the chemical properties of PAW on the germination of rice seeds. The N2, NO, and OH molecules in GA plasma led to NO3−, NO2−, and H2O2 formation in the PAW. The NO3−, NO2−, and H2O2 contents in PAW rapidly decreased after 5 days of storage. The experiment was arranged in a completely randomised design using GA plasma discharged above the surface of deionised (DI) water with different airflow rates (2, 3, 4, 5, and 6 L/min) compared to the control (DI water). The NO3− and NO2− contents increased, resulting in an increase in total nitrogen (N) and gibberellic acid (GA3) accumulation in rice seeds. The PAW at an airflow rate of 5 L/min was optimal for enhancing radicle emergence at 48 and 72 h, germination, germination index, shoot length, fresh weight, and dry weight of seedlings. Therefore, air GA plasma to generate PAW is an efficient method for producing nitrogen in a soluble form, which can support the germination processes and early growth of rice seedlings.

Effect of Modified Biochar Prepared by Co-pyrolysis of MgO on Phosphate Adsorption Performance and Seed Germination.

Biochar is currently used as a phosphate adsorbent in water and subsequently as a soil amendment. In this study, modified biochar was prepared directly by co-pyrolysis of MgO and rice straw, and a preliminary ecotoxicological assessment was performed before the application of modified biochar to soil. The effects of single factors, such as pyrolysis temperature, dosage, pH, and coexisting ions, on phosphate adsorption performance were investigated. In addition, after phosphate adsorption, the effects of modified biochar leachate on the germination of corn and rice seeds were examined. The results showed that phosphate adsorption by the modified biochar first increased and then decreased as the pyrolysis temperature increased, with modified biochar prepared at 800 °C showing the greatest adsorption. In addition, a comprehensive cost analysis showed that the best phosphate adsorption effect of modified biochar was achieved at a dosage of 0.10 g and a solution pH of 3. In contrast, the presence of competitive coexisting ions, Cl- , NO3 - , CO3 2- , and SO4 2- , reduced the phosphate adsorption capacity of the modified biochar. The adsorption kinetics results revealed that the process of phosphate adsorption by the modified biochar was more in line with the pseudo-second-order model and dominated by chemisorption. Moreover, the adsorption isotherm results indicated that the process was more in line with the Langmuir model and dominated by monomolecular layer adsorption, with a maximum adsorption of 217.54 mg/g. Subsequent seed germination tests showed that phosphate-adsorbed modified biochar leachate had no significant effect on the germination rate of corn seeds, whereas it improved the germination rate of rice seeds. Together, these results provide guidance for the application of modified biochar firstly as an adsorbent of phosphate and subsequently as a soil remediator.

Rice Big Grain1 enhances biomass and plant growth-promoting traits in rhizospheric yeast Candida tropicalis.

The Big Grain1 (BG1) gene of rice (Oryza sativa L.) is reported to increase the yield of rice crops; however, its molecular mechanism is largely concealed. To explore its functional prospects, we have taken a structure-function-based approach. In silico analyses suggest OsBG1 is a DNA- and phytohormone-binding protein. Heterologous expression of OsBG1 with galactose-inducible promoter GAL1p in the rhizospheric yeast Candida tropicalis SY005 revealed 7.9- and 1.5-fold higher expression of the gene at 12 and 24h, respectively, compared to the expression at 36h post-galactose induction. Functional activity of the induced OsBG1 in engineered yeast increased cell density, specific growth rate, and biomass by 28.5%, 29.8%, and 14.1%, respectively, and decreased the generation time by 21.25%. Flow cytometry-based cell cycle analysis of OsBG1-expressing yeast cells exhibited an increase in the cells of the G2/M population by 15.8% after 12h of post-galactose induction. The gene expression study of yeast transformants disclosed that OsBG1 regulates cell division by upregulating the expression of the endogenous gene cyclin B1 (CtCYB1) by 1.3- and 1.9-folds at 10 and 12h, respectively, compared to the control, and is positively influenced by the phytohormone indole acetic acid (IAA). Further, the study revealed that OsBG1 significantly increases biofilm formation, stress tolerance, and IAA production in C. tropicalis SY005, implying its prospective role in enhancing plant growth-promoting traits in microbes. OsBG1-expressing rhizospheric yeast cells significantly improved the germination and growth parameters of the bio-inoculated rice seeds. Altogether, this study suggests OsBG1 can be employed to genetically improve suitable bio-inoculants for their plant growth-promoting traits to augment crop productivity. KEY POINTS: • In silico analyses suggested OsBG1 is a phytohormone-binding transcription factor. • OsBG1 enhanced growth in rhizospheric Candida tropicalis by upregulating CtCYB1. • OsBG1 improved plant growth-promoting traits of the rhizospheric yeast C. tropicalis.