A prion-like protein regulator of seed germination undergoes hydration-dependent phase separation.

Many organisms evolved strategies to survive desiccation. Plant seeds protect dehydrated embryos from various stressors and can lay dormant for millennia. Hydration is the key trigger to initiate germination, but the mechanism by which seeds sense water remains unresolved. We identified an uncharacterized Arabidopsis thaliana prion-like protein we named FLOE1, which phase separates upon hydration and allows the embryo to sense water stress. We demonstrate that biophysical states of FLOE1 condensates modulate its biological function in vivo in suppressing seed germination under unfavorable environments. We find intragenic, intraspecific, and interspecific natural variation in FLOE1 expression and phase separation and show that intragenic variation is associated with adaptive germination strategies in natural populations. This combination of molecular, organismal, and ecological studies uncovers FLOE1 as a tunable environmental sensor with direct implications for the design of drought-resistant crops, in the face of climate change.

PICKLE-mediated nucleosome condensing drives H3K27me3 spreading for the inheritance of Polycomb memory during differentiation.

Spreading of H3K27me3 is crucial for the maintenance of mitotically inheritable Polycomb-mediated chromatin silencing in animals and plants. However, how Polycomb repressive complex 2 (PRC2) accesses unmodified nucleosomes in spreading regions for spreading H3K27me3 remains unclear. Here, we show in Arabidopsis thaliana that the chromatin remodeler PICKLE (PKL) plays a specialized role in H3K27me3 spreading to safeguard cell identity during differentiation. PKL specifically localizes to H3K27me3 spreading regions but not to nucleation sites and physically associates with PRC2. Loss of PKL disrupts the occupancy of the PRC2 catalytic subunit CLF in spreading regions and leads to aberrant dedifferentiation. Nucleosome density increase endowed by the ATPase function of PKL ensures that unmodified nucleosomes are accessible to PRC2 catalytic activity for H3K27me3 spreading. Our findings demonstrate that PKL-dependent nucleosome compaction is critical for PRC2-mediated H3K27me3 read-and-write function in H3K27me3 spreading, thus revealing a mechanism by which repressive chromatin domains are established and propagated.

The interplay between the circadian clock and abiotic stress responses mediated by ABF3 and CCA1/LHY.

Climate change is a global concern for all life on our planet, including humans and plants. Plants' growth and development are significantly affected by abiotic stresses, including adverse temperature, inadequate or excess water availability, nutrient deficiency, and salinity. The circadian clock is a master regulator of numerous developmental and metabolic processes in plants. In an effort to identify new clock-related genes and outputs through bioinformatic analysis, we have revealed that CIRCADIAN CLOCK ASSOCIATED 1 (CCA1) and LATE ELONGATED HYPOCOTYL (LHY) play a crucial role in regulating a wide range of abiotic stress responses and target ABSCISIC ACID RESPONSIVE ELEMENTS-BINDING FACTOR3 (ABF3), a key transcription factor in the plant hormone Abscisic acid (ABA)-signaling pathway. Specifically, we found that CCA1 and LHY regulate the expression of ABF3 under diel conditions, as well as seed germination under salinity. Conversely, ABF3 controls the expression of core clock genes and orchestrates the circadian period in a stress-responsive manner. ABF3 delivers the stress signal to the central oscillator by binding to the promoter of CCA1 and LHY. Overall, our study uncovers the reciprocal regulation between ABF3 and CCA1/LHY and molecular mechanisms underlying the interaction between the circadian clock and abiotic stress. This finding may aid in developing molecular and genetic solutions for plants to survive and thrive in the face of climate change.

Arabidopsis DNA glycosylase MBD4L improves recovery of aged seeds.

DNA glycosylases initiate the base excision repair (BER) pathway by catalyzing the removal of damaged or mismatched bases from DNA. The Arabidopsis DNA glycosylase methyl-CpG-binding domain protein 4 like (MBD4L) is a nuclear enzyme triggering BER in response to the genotoxic agents 5-fluorouracil and 5-bromouracil. To date, the involvement of MBD4L in plant physiological processes has not been analyzed. To address this, we studied the enzyme functions in seeds. We found that imbibition induced the MBD4L gene expression by generating two alternative transcripts, MBD4L.3 and MBD4L.4. Gene activation was stronger in aged than in non-aged seeds. Seeds from mbd4l-1 mutants displayed germination failures when maintained under control or ageing conditions, while 35S:MBD4L.3/mbd4l-1 and 35S:MBD4L.4/mbd4l-1 seeds reversed these phenotypes. Seed nuclear DNA repair, assessed by comet assays, was exacerbated in an MBD4L-dependent manner at 24 h post-imbibition. Under this condition, the BER genes ARP, APE1L, and LIG1 showed higher expression in 35S:MBD4L.3/mbd4l-1 and 35S:MBD4L.4/mbd4l-1 than in mbd4l-1 seeds, suggesting that these components could coordinate with MBD4L to repair damaged DNA bases in seeds. Interestingly, the ATM, ATR, BRCA1, RAD51, and WEE1 genes associated with the DNA damage response (DDR) pathway were activated in mbd4l-1, but not in 35S:MBD4L.3/mbd4l-1 or 35S:MBD4L.4/mbd4l-1 seeds. These results indicate that MBD4L is a key enzyme of a BER cascade that operates during seed imbibition, whose deficiency would cause genomic damage detected by DDR, generating a delay or reduction in germination.

SPIRO - the automated Petri plate imaging platform designed by biologists, for biologists.

Phenotyping of model organisms grown on Petri plates is often carried out manually, despite the procedures being time-consuming and laborious. The main reason for this is the limited availability of automated phenotyping facilities, whereas constructing a custom automated solution can be a daunting task for biologists. Here, we describe SPIRO, the Smart Plate Imaging Robot, an automated platform that acquires time-lapse photographs of up to four vertically oriented Petri plates in a single experiment, corresponding to 192 seedlings for a typical root growth assay and up to 2500 seeds for a germination assay. SPIRO is catered specifically to biologists' needs, requiring no engineering or programming expertise for assembly and operation. Its small footprint is optimized for standard incubators, the inbuilt green LED enables imaging under dark conditions, and remote control provides access to the data without interfering with sample growth. SPIRO's excellent image quality is suitable for automated image processing, which we demonstrate on the example of seed germination and root growth assays. Furthermore, the robot can be easily customized for specific uses, as all information about SPIRO is released under open-source licenses. Importantly, uninterrupted imaging allows considerably more precise assessment of seed germination parameters and root growth rates compared with manual assays. Moreover, SPIRO enables previously technically challenging assays such as phenotyping in the dark. We illustrate the benefits of SPIRO in proof-of-concept experiments which yielded a novel insight on the interplay between autophagy, nitrogen sensing, and photoblastic response.

Physiology and transcriptome of Sapindus mukorossi seeds at different germination stages.

Sapindus mukorossi has a wide distribution range, high application value, and broad developmental potential. Previous studies have mostly focused on the medicinal and economic value of soapberry; however, few studies have been conducted on its seed germination. This study measured the physiological indicators and hormone content of soapberry seeds at different germination stages and preliminarily determined that abscisic acid (ABA) and indole-3-acetic acid (IAA) are the key hormones that affect the germination of soapberry seeds. Both Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG enrichment) analyses detected hormone transduction pathways, further confirming the key role of plant hormones in the germination process of soapberry seeds. Through transcriptome analysis, we speculated that CYP707A and IPA are key genes in the ABA and IAA synthesis pathways, respectively. This study revealed the close relationship between plant hormones and soapberry seed germination and provided new ideas for further exploration of the germination mechanism of soapberry seeds.

Deciphering physiological and transcriptional mechanisms of maize seed germination.

Maize is a valuable raw material for feed and food production. Healthy seed germination is important for improving the yield and quality of maize. Seed aging occurs relatively fast in crops and it is a process that delays germination as well as reduces its rate and even causes total loss of seed viability. However, the physiological and transcriptional mechanisms that regulate maize seeds, especially aging seed germination remain unclear. Coronatine (COR) which is a phytotoxin produced by Pseudomonas syringae and a new type of plant growth regulator can effectively regulate plant growth and development, and regulate seed germination. In this study, the physiological and transcriptomic mechanisms of COR-induced maize seed germination under different aging degrees were analyzed. The results showed that 0.001-0.01 µmol/L COR could promote the germination of aging maize seed and the growth of primary roots and shoots. COR treatment increased the content of gibberellins (GA3) and decreased the content of abscisic acid (ABA) in B73 seeds before germination. The result of RNA-seq analysis showed 497 differentially expressed genes in COR treatment compared with the control. Three genes associated with GA biosynthesis (ZmCPPS2, ZmD3, and ZmGA2ox2), and two genes associated with GA signaling transduction (ZmGID1 and ZmBHLH158) were up-regulated. Three genes negatively regulating GA signaling transduction (ZmGRAS48, ZmGRAS54, and Zm00001d033369) and two genes involved in ABA biosynthesis (ZmVP14 and ZmPCO14472) were down-regulated. The physiological test results also showed that the effects of GA and ABA on seed germination were similar to those of high and low-concentration COR, respectively, which indicated that the effect of COR on seed germination may be carried out through GA and ABA pathways. In addition, GO and KEGG analysis suggested that COR is also highly involved in antioxidant enzyme systems and secondary metabolite synthesis to regulate maize seed germination processes. These findings provide a valuable reference for further research on the mechanisms of maize seed germination.

SOS2-AFP2 module regulates seed germination by inducing ABI5 degradation in response to salt stress in Arabidopsis.

Soil salinity pose a significant challenge to global agriculture, threatening crop yields and food security. Understanding the salt tolerance mechanisms of plants is crucial for improving their survival under salt stress. AFP2, a negative regulator of ABA signaling, has been shown to play a crucial role in salt stress tolerance during seed germination. Mutations in AFP2 gene lead to increased sensitivity to salt stress. However, the underline mechanisms by which AFP2 regulates seed germination under salt stress remain elusive. In this study, we identified a protein interaction between AFP2 and SOS2, a Ser/Thr protein kinase known to play a critical role in salt stress response. Using a combination of genetic, biochemical, and physiological approaches, we investigated the role of the SOS2-AFP2 module in regulating seed germination under salt stress. Our findings reveal that SOS2 physically interacts with AFP2 and stabilizes it, leading to the degradation of the ABI5 protein, a negative transcription factor in seed germination under salt stress. This study sheds light on previously unknown connections within salt stress and ABA signaling, paving the way for novel strategies to enhance plant resilience against environmental challenges.

Optimisation of indole acetic acid production by Neopestalotiopsis aotearoa endophyte isolated from Thymus vulgaris and its impact on seed germination of Ocimum basilicum.

BACKGROUND: Microbial growth during plant tissue culture is a common problem that causes significant losses in the plant micro-propagation system. Most of these endophytic microbes have the ability to propagate through horizontal and vertical transmission. On the one hand, these microbes provide a rich source of several beneficial metabolites. RESULTS: The present study reports on the isolation of fungal species from different in vitro medicinal plants (i.e., Breynia disticha major, Breynia disticha, Duranta plumieri, Thymus vulgaris, Salvia officinalis, Rosmarinus officinalis, and Ocimum basilicum l) cultures. These species were tested for their indole acetic acid (IAA) production capability. The most effective species for IAA production was that isolated from Thymus vulgaris plant (11.16 µg/mL) followed by that isolated from sweet basil plant (8.78 µg/mL). On screening for maximum IAA productivity, medium, "MOS + tryptophan" was chosen that gave 18.02 µg/mL. The macroscopic, microscopic examination and the 18S rRNA sequence analysis indicated that the isolate that given code T4 was identified as Neopestalotiopsis aotearoa (T4). The production of IAA by N. aotearoa was statistically modeled using the Box-Behnken design and optimized for maximum level, reaching 63.13 µg/mL. Also, IAA extract was administered to sweet basil seeds in vitro to determine its effect on plant growth traits. All concentrations of IAA extract boosted germination parameters as compared to controls, and 100 ppm of IAA extract exhibited a significant growth promotion effect for all seed germination measurements. CONCLUSIONS: The IAA produced from N. aotearoa (T4) demonstrated an essential role in the enhancement of sweet basil (Ocimum basilicum) growth, suggesting that it can be employed to promote the plant development while lowering the deleterious effect of using synthetic compounds in the environment.

Ultrasonic treatment can improve maize seed germination and abiotic stress resistance.

Constant-frequency ultrasonic treatment helped to improve seed germination. However, variable-frequency ultrasonic treatment on maize seed germination were rarely reported. In this study, maize seeds were exposed to 20-40 kHz ultrasonic for 40 s. The germination percentage and radicle length of maize seeds increased by 10.4% and 230.5%. Ultrasonic treatment also significantly increased the acid protease, α-amylase, and ß-amylase contents by 96.4%, 73.8%, and 49.1%, respectively. Transcriptome analysis showed that 11,475 differentially expressed genes (DEGs) were found in the ultrasonic treatment and control groups, including 5,695 upregulated and 5,780 downregulated. Metabolic pathways and transcription factors (TFs) were significantly enriched among DEGs after ultrasonic treatment. This included metabolism and genetic information processing, that is, ribosome, proteasome, and pyruvate metabolism, sesquiterpenoid, triterpenoid, and phenylpropanoid biosynthesis, and oxidative phosphorylation, as well as transcription factors in the NAC, MYB, bHLH, WRKY, AP2, bZIP, and ARF families. Variable-frequency ultrasonic treatment increased auxin, gibberellin, and salicylic acid by 5.5%, 37.3%, and 28.9%, respectively. Abscisic acid significantly decreased by 33.2%. The related DEGs were upregulated and downregulated to varying degrees. Seed germination under the abiotic stress conditions of salt stress (NaCl solution), drought (PEG solution), and waterlogging (water-saturated sand bed) under ultrasonic treatment were promoted, radicle length was significantly increased by 30.2%, 30.5%, and 27.3%, respectively; and germination percentage by 14.8%, 20.1%, and 21.6%, respectively. These findings provide new insight into the mechanisms through ultrasonic to promote maize seed germination.

Assessing the climate adaptive potential of imported Chili in comparison with local cultivars through germination performance analysis.

BACKGROUND: The study offers insightful information about the adaptability of local and imported Chili cultivars. This experiment examines how three different chili cultivars Tanjung, Unpad, and Osaka perform in the germination and early growth phases while considering a wide range of environmental conditions. Research conducted in Jatinangor, Sumedang Regency, Indonesia, highlights the differences between cultivars and the varied possibilities for adaptability each variation possesses. RESULTS: Among them, Tanjung stands out as the most promising cultivar; its robust performance is demonstrated by its high germination index 91.7. Notable features of Osaka include the highest biomass output (1.429 g), the best water usage efficiency (WUE) at 0.015 g/liter, and the best distribution uniformity (91.2%) and application efficiency (73.6%) under different irrigation conditions. Tanjung's competitiveness is further evidenced by the fact that it trails Osaka closely on several metrics. Lower performance across criteria for Unpad suggests possible issues with flexibility. CONCLUSION: The value of this information becomes apparent when it comes to well-informed breeding programs and cultivation techniques, especially considering uncertain climate patterns and global climate change. This research contributes significantly to the body of knowledge, enabling well-informed choices for environmentally dynamic, sustainable chili farming.

Integrated transcriptomic and metabolomic analyses elucidate the mechanism of flavonoid biosynthesis in the regulation of mulberry seed germination under salt stress.

Seed propagation is the main method of mulberry expansion in China, an important economic forest species. However, seed germination is the most sensitive stage to various abiotic stresses, especially salinity stress. To reveal the molecular regulatory mechanism of mulberry seed germination under salt stress, flavonoid metabolomics and transcriptomics analyses were performed on mulberry seeds germinated under 50 and 100 mmol/L NaCl stress. Analysis of the flavonoid metabolome revealed that a total of 145 differential flavonoid metabolites (DFMs) were classified into 9 groups, 40 flavonols, 32 flavones, 16 chalcones and 14 flavanones. Among them, 61.4% (89) of the DFMs accumulated continuously with increasing salt concentration, reaching the highest level at a 100 mmol/L salt concentration; these DFMs included quercetin-3-O-glucoside (isoquercitrin), kaempferol (3,5,7,4'-tetrahydroxyflavone), quercetin-7-O-glucoside, taxifolin (dihydroquercetin) and apigenin (4',5,7-trihydroxyflavone), indicating that these flavonoids may be key metabolites involved in the response to salt stress. Transcriptional analysis identified a total of 3055 differentially expressed genes (DEGs), most of which were enriched in flavonoid biosynthesis (ko00941), phenylpropanoid biosynthesis (ko00940) and biosynthesis of secondary metabolites (ko01110). Combined analysis of flavonoid metabolomic and transcriptomic data indicated that phenylalanine ammonia-lyase (PAL), 4-coumarate-CoA ligase (4CL), chalcone synthase (CHS), flavonol synthase (FLS), bifunctional dihydroflavonol 4-reductase/flavanone 4-reductase (DFR) and anthocyanidin reductase (ANR) were the key genes involved in flavonoid accumulation during mulberry seed germination under 50 and 100 mmol/L NaCl stress. In addition, three transcription factors, MYB, bHLH and NAC, were involved in the regulation of flavonoid accumulation under salt stress. The results of quantitative real-time PCR (qRT‒PCR) validation showed that the expression levels of 11 DEGs, including 7 genes involved in flavonoid biosynthesis, under different salt concentrations were consistent with the transcriptomic data, and parallel reaction monitoring (PRM) results showed that the expression levels of 6 key enzymes (proteins) involved in flavonoid synthesis were consistent with the accumulation of flavonoids. This study provides a new perspective for investigating the regulatory role of flavonoid biosynthesis in the regulation of mulberry seed germination under salt stress at different concentrations.

Metabolome and transcriptome analyses reveal changes of rapeseed in response to ABA signal during early seedling development.

Seed germination is an important development process in plant growth. The phytohormone abscisic acid (ABA) plays a critical role during seed germination. However, the mechanism of rapeseed in response to ABA is still elusive. In order to understand changes of rapeseed under exogenous ABA treatment, we explored differentially expressed metabolites (DEMs) and the differentially expressed genes (DEGs) between mock- and ABA-treated seedlings. A widely targeted LC-MS/MS based metabolomics were used to identify and quantify metabolic changes in response to ABA during seed germination, and a total of 186 significantly DEMs were identified. There are many compounds which are involved in ABA stimuli, especially some specific ABA transportation-related metabolites such as starches and lipids were screened out. Meanwhile, a total of 4440 significantly DEGs were identified by transcriptomic analyses. There was a significant enrichment of DEGs related to phenylpropanoid and cell wall organization. It suggests that exogenous ABA mainly affects seed germination by regulating cell wall loosening. Finally, the correlation analysis of the key DEMs and DEGs indicates that many DEGs play a direct or indirect regulatory role in DEMs metabolism. The integrative analysis between DEGs and DEMs suggests that the starch and sucrose pathways were the key pathway in ABA responses. The two metabolites from starch and sucrose pathways, levan and cellobiose, both were found significantly down-regulated in ABA-treated seedlings. These comprehensive metabolic and transcript analyses provide useful information for the subsequent post-transcriptional modification and post germination growth of rapeseed in response to ABA signals and stresses.

Application of cold argon plasma on germination, root length, and decontamination of soybean cultivars.

Applying cold discharge plasma can potentially alter plants' germination characteristics by triggering their physiological activities. As a main crop in many countries, soybean was examined in the present study using cultivars such as Arian, Katoul, Saba, Sari, and Williams in a cold argon plasma. This study has been motivated by the importance of plant production worldwide, considering climate change and the increasing needs of human populations for food. This study was performed to inspect the effect of cold plasma treatment on seed germination and the impact of argon plasma on microbial decontamination was investigated on soybeans. Also, the employed cultivars have not been studied until now the radicals generated from argon were detected by optical emission spectrometry (OES), and a collisional radiative model was used to describe electron density. The germination properties, including final germination percentage (FGP), mean germination time (MGT), root length, and electrical conductivity of biomolecules released from the seeds, were investigated after the plasma treatments for 30, 60, 180, 300, and 420 s. The decontamination effect of the plasma on Aspergillus flavus (A.flavus) and Fusarium solani (F.solani) was also examined. The plasma for 60 s induced a maximum FGP change of 23.12 ± 0.34% and a lowest MGT value of 1.40 ± 0.007 days. Moreover, the ultimate root length was 56.12 ± 2.89%, in the seeds treated for 60 s. The plasma exposure, however, failed to yield a significant enhancement in electrical conductivity, even when the discharge duration was extended to 180 s or longer. Therefore, the plasma duration of 180 s was selected for the blotter technique. Both fungi showed successful sterilization; their infectivity inhibition was 67 ± 4 and 65 ± 3.1%, respectively. In general, the cold plasma used for soybeans in the present study preserved their healthy qualities and reduced the degree of fungal contamination.

The GA and ABA signaling is required for hydrogen-mediated seed germination in wax gourd.

BACKGROUND: Hydrogen gas (H2), a novel and beneficial gaseous molecule, plays a significant role in plant growth and development processes. Hydrogen-rich water (HRW) is regarded as a safe and easily available way to study the physiological effects of H2 on plants. Several recent research has shown that HRW attenuates stress-induced seed germination inhibition; however, the underlying modes of HRW on seed germination remain obscure under non-stress condition. RESULTS: In this current study, we investigated the possible roles of gibberellin (GA) and abscisic acid (ABA) in HRW-regulated seed germination in wax gourd (Benincasa hispida) through pharmacological, physiological, and transcriptome approaches. The results showed that HRW application at an optimal dose (50% HRW) significantly promoted seed germination and shortened the average germination time (AGT). Subsequent results suggested that 50% HRW treatment stimulated GA production by regulating GA biosynthesis genes (BhiGA3ox, BhiGA2ox, and BhiKAO), whereas it had no effect on the content of ABA and the expression of its biosynthesis (BhiNCED6) and catabolism genes (BhiCYP707A2) but decreased the expression of ABA receptor gene (BhiPYL). In addition, inhibition of GA production by paclobutrazol (PAC) could block the HRW-mediated germination. Treatment with ABA could hinder HRW-mediated seed germination and the ABA biosynthesis inhibitor sodium tungstate (ST) could recover the function of HRW. Furthermore, RNA-seq analysis revealed that, in the presence of GA or ABA, an abundance of genes involved in GA, ABA, and ethylene signal sensing and transduction might involve in HRW-regulated germination. CONCLUSIONS: This study portrays insights into the mechanism of HRW-mediated seed germination, suggesting that HRW can regulate the balance between GA and ABA to mediate seed germination through ethylene signals in wax gourd.

RGA1 regulates grain size, rice quality and seed germination in the small and round grain mutant srg5.

BACKGROUND: Generating elite rice varieties with high yield and superior quality is the main goal of rice breeding programs. Key agronomic traits, including grain size and seed germination characteristics, affect the final yield and quality of rice. The RGA1 gene, which encodes the α-subunit of rice G-protein, plays an important role in regulating rice architecture, seed size and abiotic stress responses. However, whether RGA1 is involved in the regulation of rice quality and seed germination traits is still unclear. RESULTS: In this study, a rice mutant small and round grain 5 (srg5), was identified in an EMS-induced rice mutant library. Systematic analysis of its major agronomic traits revealed that the srg5 mutant exhibited a semi-dwarf plant height with small and round grain and reduced panicle length. Analysis of the physicochemical properties of rice showed that the difference in rice eating and cooking quality (ECQ) between the srg5 mutant and its wild-type control was small, but the appearance quality was significantly improved. Interestingly, a significant suppression of rice seed germination and shoot growth was observed in the srg5 mutant, which was mainly related to the regulation of ABA metabolism. RGA1 was identified as the candidate gene for the srg5 mutant by BSA analysis. A SNP at the splice site of the first intron disrupted the normal splicing of the RGA1 transcript precursor, resulting in a premature stop codon. Additional linkage analysis confirmed that the target gene causing the srg5 mutant phenotype was RGA1. Finally, the introduction of the RGA1 mutant allele into two indica rice varieties also resulted in small and round rice grains with less chalkiness. CONCLUSIONS: These results indicate that RGA1 is not only involved in the control of rice architecture and grain size, but also in the regulation of rice quality and seed germination. This study sheds new light on the biological functions of RGA1, thereby providing valuable information for future systematic analysis of the G-protein pathway and its potential application in rice breeding programs.

WOX2 functions redundantly with WOX1 and WOX4 to positively regulate seed germination in Arabidopsis.

MAIN CONCLUSION: WOX family gene WOX2 is highly expressed during seed development, which functions redundantly with WOX1 and WOX4 to positively regulate seed germination. WOX (WUSCHEL-related homeobox) is a family of transcription factors in plants. They play essential roles in the regulation of plant growth and development, but their function in seed germination is not well understood. In this report, we show that WOX1, WOX2, and WOX4 are close homologues in Arabidopsis. WOX2 has a redundant function with WOX1 and WOX4, respectively, in seed germination. WOX2 is highly expressed during seed development, from the globular embryonic stage to mature dry seeds, and its expression is decreased after germination. Loss of function single mutant wox2, and double mutants wox1 wox2 and wox2 wox4-1 show decreased germination speed. WOX2 and WOX4 are essential for hypocotyl-radicle zone elongation during germination, potentially by promoting the expression of cell wall-related genes. We also found that WOX2 and WOX4 regulate germination through the gibberellin (GA) pathway. These results suggest that WOX2 and WOX4 integrate the GA pathway and downstream cell wall-related genes during germination.

Seed priming with gas plasma-activated water in Ethiopia's "orphan" crop tef (Eragrostis tef).

MAIN CONCLUSION: Seed priming with gas plasma-activated water results in an increased ageing resilience in Eragrostis tef grains compared to a conventional hydropriming protocol. Tef (Eragrostis tef) is a cereal grass and a major staple crop of Ethiopia and Eritrea. Despite its significant importance in terms of production, consumption, and cash crop value, tef has been understudied and its productivity is low. In this study, tef grains have undergone different priming treatments to enhance seed vigour and seedling performance. A conventional hydropriming and a novel additive priming technology with gas plasma-activated water (GPAW) have been used and tef grains were then subjected to germination performance assays and accelerated ageing. Tef priming increases the germination speed and vigour of the grains. Priming with GPAW retained the seed storage potential after ageing, therefore, presenting an innovative environmental-friendly seed technology with the prospect to address variable weather conditions and ultimately food insecurity. Seed technology opens new possibilities to increase productivity of tef crop farming to achieve a secure and resilient tef food system and economic growth in Ethiopia by sustainable intensification of agriculture beyond breeding.

Bioprospecting endophytic fungi for bioactive metabolites with seed germination promoting potentials.

There is an urgent need for new bioactive molecules with unique mechanisms of action and chemistry to address the issue of incorrect use of chemical fertilizers and pesticides, which hurts both the environment and the health of humans. In light of this, research was done for this work to isolate, identify, and evaluate the germination-promoting potential of various plant species' fungal endophytes. Zea mays L. (maize) seed germination was examined using spore suspension of 75 different endophytic strains that were identified. Three promising strains were identified through screening to possess the ability mentioned above. These strains Alternaria alternate, Aspergilus flavus, and Aspergillus terreus were isolated from the stem of Tecoma stans, Delonix regia, and Ricinus communis, respectively. The ability of the three endophytic fungal strains to produce siderophore and indole acetic acid (IAA) was also examined. Compared to both Aspergillus flavus as well as Aspergillus terreus, Alternaria alternata recorded the greatest rates of IAA, according to the data that was gathered. On CAS agar versus blue media, all three strains failed to produce siderophores. Moreover, the antioxidant and antifungal potentials of extracts from these fungi were tested against different plant pathogens. The obtained results indicated the antioxidant and antifungal activities of the three fungal strains. GC-Mass studies were carried out to determine the principal components in extracts of all three strains of fungi. The three strains' fungus extracts included both well-known and previously unidentified bioactive compounds. These results may aid in the development of novel plant growth promoters by suggesting three different fungal strains as sources of compounds that may improve seed germination. According to the study that has been given, as unexplored sources of bioactive compounds, fungal endophytes have great potential.

OsNAC3 regulates seed germination involving abscisic acid pathway and cell elongation in rice.

Seed germination is a critical trait for the success of direct seeding in rice cultivation. However, the underlying mechanism determining seed germination is largely unknown in rice. Here, we report that NAC transcription factor OsNAC3 positively regulates seed germination of rice. OsNAC3 regulates seed germination involving abscisic acid (ABA) pathway and cell elongation. OsNAC3 can directly bind to the promoter of ABA catabolic gene OsABA8ox1 and cell expansion gene OsEXP4, which consequently activates their expressions during seed germination. We also find that the expression of OsEXP4 is reduced by ABA during seed germination in rice. OsNAC3 regulates seed germination by influencing cell elongation of the embryo through directly affecting OsEXP4 expression and indirectly ABA-medicated OsEXP4 expression. The OsNAC3 elite haplotype is useful for genetic improvement of seed germination, and overexpression of OsNAC3 can significantly increase seed germination. We therefore propose that OsNAC3 is a potential target in breeding of rice varieties with high seed germination for direct seeding cultivation.