A study on nickel application methods for optimizing soybean growth.

Fertilization with nickel (Ni) can positively affect plant development due to the role of this micronutrient in nitrogen (N) metabolism, namely, through urease and NiFe-hydrogenase. Although the application of Ni is an emerging practice in modern agriculture, its effectiveness strongly depends on the chosen application method, making further research in this area essential. The individual and combined effects of different Ni application methods-seed treatment, leaf spraying and/or soil fertilization-were investigated in soybean plants under different edaphoclimatic conditions (field and greenhouse). Beneficial effects of the Soil, Soil + Leaf and Seed + Leaf treatments were observed, with gains of 7 to 20% in biological nitrogen fixation, 1.5-fold in ureides, 14% in shoot dry weight and yield increases of up to 1161 kg ha-1. All the Ni application methods resulted in a 1.1-fold increase in the SPAD index, a 1.2-fold increase in photosynthesis, a 1.4-fold increase in nitrogenase, and a 3.9-fold increase in urease activity. Edaphoclimatic conditions exerted a significant influence on the treatments. The integrated approaches, namely, leaf application in conjunction with soil or seed fertilization, were more effective for enhancing yield in soybean cultivation systems. The determination of the ideal method is crucial for ensuring optimal absorption and utilization of this micronutrient and thus a feasible and sustainable management technology. Further research is warranted to establish official guidelines for the application of Ni in agricultural practices.

Genomic analysis of a spontaneous unifoliate mutant reveals gene candidates associated with compound leaf development in Vigna unguiculata [L] Walp.

Molecular mechanisms which underpin compound leaf development in some legumes have been reported, but there is no previous study on the molecular genetic control of compound leaf formation in Vigna unguiculata (cowpea), an important dryland legume of African origin. In most studied species with compound leaves, class 1 KNOTTED-LIKE HOMEOBOX genes expressed in developing leaf primordia sustain morphogenetic activity, allowing leaf dissection and the development of leaflets. Other genes, such as, SINGLE LEAFLET1 in Medicago truncatula and Trifoliate in Solanum lycopersicum, are also implicated in regulating compound leaf patterning. To set the pace for an in-depth understanding of the genetics of compound leaf development in cowpea, we applied RNA-seq and whole genome shotgun sequence datasets of a spontaneous cowpea unifoliate mutant and its trifoliate wild-type cultivar to conduct comparative reference-based gene expression, de novo genome-wide isoform switch, and genome variant analyses between the two genotypes. Our results suggest that genomic variants upstream of LATE ELONGATED HYPOCOTYL and down-stream of REVEILLE4, BRASSINOSTERIOD INSENSITIVE1 and LATERAL ORGAN BOUNDARIES result in down-regulation of key components of cowpea circadian rhythm central oscillator and brassinosteroid signaling, resulting in unifoliate leaves and brassinosteroid-deficient-like phenotypes. We have stated hypotheses that will guide follow-up studies expected to provide more insights.

Effect of methyl jasmonate and GA3 on canola (Brassica napus L.) growth, antioxidants activity, and nutrient concentration cultivated in salt-affected soils.

Salinity stress is a significant challenge in agricultural production. When soil contains high salts, it can adversely affect plant growth and productivity due to the high concentration of soluble salts in the soil water. To overcome this issue, foliar applications of methyl jasmonate (MJ) and gibberellic acid (GA3) can be productive amendments. Both can potentially improve the plant's growth attributes and flowering, which are imperative in improving growth and yield. However, limited literature is available on their combined use in canola to mitigate salinity stress. That's why the current study investigates the impact of different levels of MJ (at concentrations of 0.8, 1.6, and 3.2 mM MJ) and GA3 (0GA3 and 5 mg/L GA3) on canola cultivated in salt-affected soils. Applying all the treatments in four replicates. Results indicate that the application of 0.8 mM MJ with 5 mg/L GA3 significantly enhances shoot length (23.29%), shoot dry weight (24.77%), number of leaves per plant (24.93%), number of flowering branches (26.11%), chlorophyll a (31.44%), chlorophyll b (20.28%) and total chlorophyll (27.66%) and shoot total soluble carbohydrates (22.53%) over control. Treatment with 0.8 mM MJ and 5 mg/L GA3 resulted in a decrease in shoot proline (48.17%), MDA (81.41%), SOD (50.59%), POD (14.81%) while increase in N (10.38%), P (15.22%), and K (8.05%) compared to control in canola under salinity stress. In conclusion, 0.8 mM MJ + 5 mg/L GA3 can improve canola growth under salinity stress. More investigations are recommended at the field level to declare 0.8 mM MJ + 5 mg/L GA3 as the best amendment for alleviating salinity stress in different crops.

Mechanism of the Pulvinus-Driven Leaf Movement: An Overview.

Leaf movement is a manifestation of plant response to the changing internal and external environment, aiming to optimize plant growth and development. Leaf movement is usually driven by a specialized motor organ, the pulvinus, and this movement is associated with different changes in volume and expansion on the two sides of the pulvinus. Blue light, auxin, GA, H+-ATPase, K+, Cl-, Ca2+, actin, and aquaporin collectively influence the changes in water flux in the tissue of the extensor and flexor of the pulvinus to establish a turgor pressure difference, thereby controlling leaf movement. However, how these factors regulate the multicellular motility of the pulvinus tissues in a species remains obscure. In addition, model plants such as Medicago truncatula, Mimosa pudica, and Samanea saman have been used to study pulvinus-driven leaf movement, showing a similarity in their pulvinus movement mechanisms. In this review, we summarize past research findings from the three model plants, and using Medicago truncatula as an example, suggest that genes regulating pulvinus movement are also involved in regulating plant growth and development. We also propose a model in which the variation of ion flux and water flux are critical steps to pulvinus movement and highlight questions for future research.

Effect of Light Conditions, Trichoderma Fungi and Food Polymers on Growth and Profile of Biologically Active Compounds in Thymus vulgaris and Thymus serpyllum.

The research investigates the influence of different lighting conditions and soil treatments, in particular the application of food polymers separately and in combination with spores of Trichoderma consortium, on the growth and development of herbs-Thymus vulgaris and Thymus serpyllum. The metabolic analysis focuses on detecting changes in the levels of biologically active compounds such as chlorophyll a and b, anthocyanins, carotenoids, phenolic compounds (including flavonoids), terpenoids, and volatile organic compounds with potential health-promoting properties. By investigating these factors, the study aims to provide insights into how environmental conditions affect the growth and chemical composition of selected plants and to shed light on potential strategies for optimising the cultivation of these herbs for the improved quality and production of bioactive compounds. Under the influence of additional lighting, the growth of T. vulgaris and T. serpyllum seedlings was greatly accelerated, resulting in an increase in shoot biomass and length, and in the case of T. vulgaris, an increase in carotenoid and anthocyanin contents. Regarding secondary metabolites, the most pronounced changes were observed in total antioxidant capacity and flavonoid content, which increased significantly under the influence of additional lighting. The simultaneous or separate application of Trichoderma and food polymers resulted in an increase in flavonoid content in the leaves of both Thymus species. The increase in terpenoid content under supplemental light appears to be related to the presence of Trichoderma spores as well as food polymers added to the soil. However, the nature of these changes depends on the thyme species. Volatile compounds were analysed using an electronic nose (E-nose). Eight volatile compounds (VOCs) were tentatively identified in the vapours of T. vulgaris and T. serpyllum: α-pinene, myrcene, α-terpinene, γ-terpinene; 1,8-cineole (eucalyptol), thymol, carvacrol, and eugenol. Tendencies to increase the percentage of thymol and γ-terpinene under supplemental lighting were observed. The results also demonstrate a positive effect of food polymers and, to a lesser extent, Trichoderma fungi on the synthesis of VOCs with health-promoting properties. The effect of Trichoderma and food polymers on individual VOCs was positive in some cases for thymol and γ-terpinene.

The tetraploid wheat (Triticum dicoccum (Schrank) Schuebl.) improves nitrogen uptake and assimilation adaptation to nitrogen-deficit stress.

MAIN CONCLUSION: The genetic diversity in tetraploid wheat provides a genetic pool for improving wheat productivity and environmental resilience. The tetraploid wheat had strong N uptake, translocation, and assimilation capacity under N deficit stress, thus alleviating growth inhibition and plant N loss to maintain healthy development and adapt to environments with low N inputs. Tetraploid wheat with a rich genetic variability provides an indispensable genetic pool for improving wheat yield. Mining the physiological mechanisms of tetraploid wheat in response to nitrogen (N) deficit stress is important for low-N-tolerant wheat breeding. In this study, we selected emmer wheat (Kronos, tetraploid), Yangmai 25 (YM25, hexaploid), and Chinese spring (CS, hexaploid) as materials. We investigated the differences in the response of root morphology, leaf and root N accumulation, N uptake, translocation, and assimilation-related enzymes and gene expression in wheat seedlings of different ploidy under N deficit stress through hydroponic experiments. The tetraploid wheat (Kronos) had stronger adaptability to N deficit stress than the hexaploid wheats (YM25, CS). Kronos had better root growth under low N stress, expanding the N uptake area and enhancing N uptake to maintain higher NO3- and soluble protein contents. Kronos exhibited high TaNRT1.1, TaNRT2.1, and TaNRT2.2 expression in roots, which promoted NO3- uptake, and high TaNRT1.5 and TaNRT1.8 expression in roots and leaves enhanced NO3- translocation to the aboveground. NR and GS activity in roots and leaves of Kronos was higher by increasing the expression of TANIA2, TAGS1, and TAGS2, which enhanced the reduction and assimilation of NO3- as well as the re-assimilation of photorespiratory-released NH4+. Overall, Kronos had strong N uptake, translocation, and assimilation capacity under N deficit stress, alleviating growth inhibition and plant N loss and thus maintaining a healthy development. This study reveals the physiological mechanisms of tetraploid wheat that improve nitrogen uptake and assimilation adaptation under low N stress, which will provide indispensable germplasm resources for elite low-N-tolerant wheat improvement and breeding.

Effect of common horsetail extract on growth characteristics, essential oil yield and chemical compositions of basil (Ocimum basilicum L.).

To investigate the effect of horsetail extract containing high silicon on morphological traits, growth, content, and compositions of essential oil of sweet basil (Ocimum basilicum L.) an experiment turned into carried out in the shape of a randomized complete block design with three replications. Foliar treatment of horsetail extract with zero, 0.5, 1, and 2% concentrations was applied on 6-8 leaf plants. The assessed traits include plant height, number of leaves per plant, number of sub-branches, leaf area index, plant fresh weight, plant dry weight, total anthocyanin, the content of total phenol and total flavonoid, antioxidant activity, essential oil content, and compounds were measured. The findings demonstrated that the increase of silicon-containing horsetail extract enhanced the improved increase in growth and phytochemical trait values. The use of horsetail extract in the 2% treatment increased plant height, the number of leaves per plant, the number of sub-branches, leaf area index, fresh weight, and dry weight of the plant by 49.79, 45.61, 91.09, 99.78, 52.78 and 109.25%, respectively, compared to the control. The highest content of total phenol (2.12 mg GAE/g DW), total flavonoid (1.73 mg RE/g DW), total anthocyanin (0.83 mg C3G/g DW), and antioxidant activity (184.3 µg/ml) was observed in the 2% extract treatment. The content of essential oil increased with increasing the concentration of horsetail extract, so the highest amount of essential oil was obtained at the concentration of 2%, which increased by 134.78% compared to the control. By using GC-MS, the essential oil was analyzed. The main components of the essential oil include methyl eugenol (12.93-25.93%), eugenol (17.63-27.51%), 1,8-cineole (15.63-20.84%), linalool (8.31-19.63%) and (Z)-caryophyllene (6.02-14.93%). Increasing the concentration of horsetail extract increased the compounds of eugenol, 1,8-cineole, and linalool in essential oil compared to the control, but decreased the compounds of methyl eugenol and (Z)-caryophyllene. Foliar spraying of horsetail extract, which contains high amounts of silicon, as a stimulant and biological fertilizer, can be a beneficial ingredient in increasing the yield and production of medicinal plants, especially in organic essential oil production.

Comparing the Potential of Silicon Nanoparticles and Conventional Silicon for Salinity Stress Alleviation in Soybean (Glycine max L.): Growth and Physiological Traits and Rhizosphere/Endophytic Bacterial Communities.

In this study, 20-day-old soybean plants were watered with 100 mL of 100 mM NaCl solution and sprayed with silica nanoparticles (SiO2 NPs) or potassium silicate every 3 days over 15 days, with a final dosage of 12 mg of SiO2 per plant. We assessed the alterations in the plant's growth and physiological traits, and the responses of bacterial microbiome within the leaf endosphere, rhizosphere, and root endosphere. The result showed that the type of silicon did not significantly impact most of the plant parameters. However, the bacterial communities within the leaf and root endospheres had a stronger response to SiO2 NPs treatment, showing enrichment of 24 and 13 microbial taxa, respectively, compared with the silicate treatment, which led to the enrichment of 9 and 8 taxonomic taxa, respectively. The rhizosphere bacterial communities were less sensitive to SiO2 NPs, enriching only 2 microbial clades, compared to the 8 clades enriched by silicate treatment. Furthermore, SiO2 NPs treatment enriched beneficial genera, such as Pseudomonas, Bacillus, and Variovorax in the leaf and root endosphere, likely enhancing plant growth and salinity stress resistance. These findings highlight the potential of SiO2 NPs for foliar application in sustainable farming by enhancing plant-microbe interactions to improve salinity tolerance.

Investigating the growth promotion potential of biochar on pea (Pisum sativum) plants under saline conditions.

Pea, member of the plant family Leguminosae, play a pivotal role in global food security as essential legumes. However, their production faces challenges stemming from the detrimental impacts of abiotic stressors, leading to a concerning decline in output. Salinity stress is one of the major factors that limiting the growth and productivity of pea. However, biochar amendment in soil has a potential role in alleviating the oxidative damage caused by salinity stress. The purpose of the study was to evaluate the potential role of biochar amendment in soil that may mitigate the adverse effect of salinity stress on pea. The treatments of this study were, (a) Pea varieties; (i) V1 = Meteor and V2 = Green Grass, Salinity Stress, (b) Control (0 mM) and (ii) Salinity (80 mM) (c) Biochar applications; (i) Control, (ii) 8 g/kg soil (56 g) and (iii) 16 g/kg soil (112 g). Salinity stress demonstrated a considerable reduction in morphological parameters as Shoot and root length decreased by (29% and 47%), fresh weight and dry weight of shoot and root by (85, 63%) and (49, 68%), as well as area of leaf reduced by (71%) among both varieties. Photosynthetic pigments (chlorophyll a, b, and carotenoid contents decreased under 80 mM salinity up to (41, 63, 55 and 76%) in both varieties as compared to control. Exposure of pea plants to salinity stress increased the oxidative damage by enhancing hydrogen peroxide and malondialdehyde content by (79 and 89%), while amendment of biochar reduced their activities as, (56% and 59%) in both varieties. The activities of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) were increased by biochar applications under salinity stress as, (49, 59, and 86%) as well as non-enzymatic antioxidants as, anthocyanin and flavonoids improved by (112 and 67%). Organic osmolytes such as total soluble proteins, sugars, and glycine betaine were increased up to (57, 83, and 140%) by biochar amendment. Among uptake of mineral ions, shoot and root Na+ uptake was greater (144 and 73%) in saline-stressed plants as compared to control, while shoot and root Ca2+ and K+ were greater up to (175, 119%) and (77, 146%) in biochar-treated plants. Overall findings revealed that 16 g/kg soil (112 g) biochar was found to be effective in reducing salinity toxicity by causing reduction in reactive oxygen species and root and shoot Na+ ions uptake and improving growth, physiological and anti-oxidative activities in pea plants (Fig. 1). Figure 1 A schematic diagram represents two different mechanisms of pea under salinity stress (control and 80 mM NaCl) with Biochar (8 and 16 g/kg soil).

Drought shortens subtropical understory growing season by advancing leaf senescence.

Subtropical forests, recognized for their intricate vertical canopy stratification, exhibit high resistance to extreme drought. However, the response of leaf phenology to drought in the species-rich understory remains poorly understood. In this study, we constructed a digital camera system, amassing over 360,000 images through a 70% throughfall exclusion experiment, to explore the drought response of understory leaf phenology. The results revealed a significant advancement in understory leaf senescence phenology under drought, with 11.75 and 15.76 days for the start and end of the leaf-falling event, respectively. Pre-season temperature primarily regulated leaf development phenology, whereas soil water dominated the variability in leaf senescence phenology. Under drought conditions, temperature sensitivities for the end of leaf emergence decreased from -13.72 to -11.06 days °C-1, with insignificance observed for the start of leaf emergence. Consequently, drought treatment shortened both the length of the growing season (15.69 days) and the peak growth season (9.80 days) for understory plants. Moreover, this study identified diverse responses among intraspecies and interspecies to drought, particularly during the leaf development phase. These findings underscore the pivotal role of water availability in shaping understory phenology patterns, especially in subtropical forests.

Unveiling the phenology and associated floral regulatory pathways of Humulus lupulus L. in subtropical conditions.

MAIN CONCLUSION: The hop phenological cycle was described in subtropical condition of Brazil showing that flowering can happen at any time of year and this was related to developmental molecular pathways. Hops are traditionally produced in temperate regions, as it was believed that vernalization was necessary for flowering. Nevertheless, recent studies have revealed the potential for hops to flower in tropical and subtropical climates. In this work, we observed that hops in the subtropical climate of Minas Gerais, Brazil grow and flower multiple times throughout the year, independently of the season, contrasting with what happens in temperate regions. This could be due to the photoperiod consistently being inductive, with daylight hours below the described threshold (16.5 h critical). We observed that when the plants reached 7-9 nodes, the leaves began to transition from heart-shaped to trilobed-shaped, which could be indicative of the juvenile to adult transition. This could be related to the fact that the 5th node (in plants with 10 nodes) had the highest expression of miR156, while two miR172s increased in the 20th node (in plants with 25 nodes). Hop flowers appeared later, in the 25th or 28th nodes, and the expression of HlFT3 and HlFT5 was upregulated in plants between 15 and 20 nodes, while the expression of HlTFL3 was upregulated in plants with 20 nodes. These results indicate the role of axillary meristem age in regulating this process and suggest that the florigenic signal should be maintained until the hop plants bloom. In addition, it is possible that the expression of TFL is not sufficient to inhibit flowering in these conditions and promote branching. These findings suggest that the reproductive transition in hop under inductive photoperiodic conditions could occur in plants between 15 and 20 nodes. Our study sheds light on the intricate molecular mechanisms underlying hop floral development, paving the way for potential advancements in hop production on a global scale.

Transcriptome analysis and functional validation reveal the novel role of LhCYCL in axillary bud development in hybrid Liriodendron.

Shoot branching significantly influences yield and timber quality in woody plants, with hybrid Liriodendron being particularly valuable due to its rapid growth. However, understanding of the mechanisms governing shoot branching in hybrid Liriodendron remains limited. In this study, we systematically examined axillary bud development using morphological and anatomical approaches and selected four distinct developmental stages for an extensive transcriptome analysis. A total of 9,449 differentially expressed genes have been identified, many of which are involved in plant hormone signal transduction pathways. Additionally, we identified several transcription factors downregulated during early axillary bud development, including a noteworthy gene annotated as CYC-like from the TCP TF family, which emerged as a strong candidate for modulating axillary bud development. Quantitative real-time polymerase chain reaction results confirmed the highest expression levels of LhCYCL in hybrid Liriodendron axillary buds, while histochemical ß-glucuronidase staining suggested its potential role in Arabidopsis thaliana leaf axil development. Ectopic expression of LhCYCL in A. thaliana led to an increase of branches and a decrease of plant height, accompanied by altered expression of genes involved in the plant hormone signaling pathways. This indicates the involvement of LhCYCL in regulating shoot branching through plant hormone signaling pathways. In summary, our results emphasize the pivotal role played by LhCYCL in shoot branching, offering insights into the function of the CYC-like gene and establishing a robust foundation for further investigations into the molecular mechanisms governing axillary bud development in hybrid Liriodendron.

Crucial role of SWL1 in chloroplast biogenesis and development in Arabidopsis thaliana.

KEY MESSAGE: The disruption of the SWL1 gene leads to a significant down regulation of chloroplast and secondary metabolites gene expression in Arabidopsis thaliana. And finally results in a dysfunction of chloroplast and plant growth. Although the development of the chloroplast has been a consistent focus of research, the corresponding regulatory mechanisms remain unidentified. In this study, the CRISPR/Cas9 system was used to mutate the SWL1 gene, resulting in albino cotyledons and variegated true leaf phenotype. Confocal microscopy and western blot of chloroplast protein fractions revealed that SWL1 localized in the chloroplast stroma. Electron microscopy indicated chloroplasts in the cotyledons of swl1 lack well-defined grana and internal membrane structures, and similar structures have been detected in the albino region of variegated true leaves. Transcriptome analysis revealed that down regulation of chloroplast and nuclear gene expression related to chloroplast, including light harvesting complexes, porphyrin, chlorophyll metabolism and carbon metabolism in the swl1 compared to wild-type plant. In addition, proteomic analysis combined with western blot analysis, showed that a significant decrease in chloroplast proteins of swl1. Furthermore, the expression of genes associated with secondary metabolites and growth hormones was also reduced, which may be attributed to SWL1 associated with absorption and fixation of inorganic carbon during chloroplast development. Together, the above findings provide valuable information to elucidate the exact function of SWL1 in chloroplast biogenesis and development.

Fine-mapping and validation of the major quantitative trait locus QFlANG-4B for flag leaf angle in wheat.

KEY MESSAGE: This study precisely mapped and validated a quantitative trait locus (QTL) located on chromosome 4B for flag leaf angle in wheat. Flag leaf angle (FLANG) is closely related to crop architecture and yield. We previously identified the quantitative trait locus (QTL) QFLANG-4B for FLANG on chromosome 4B, located within a 14-cM interval flanked by the markers Xbarc20 and Xzyh357, using a mapping population of recombinant inbred lines (RILs) derived from a cross between Nongda3331 (ND3331) and Zang1817. In this study, we fine-mapped QFLANG-4B and validated its associated genetic effect. We developed a BC3F3 population using ND3331 as the recurrent parent through marker-assisted selection, as well as near-isogenic lines (NILs) by selfing BC3F3 plants carrying different heterozygous segments for the QFLANG-4B region. We obtained eight recombinant types for QFLANG-4B, narrowing its location down to a 5.3-Mb region. This region contained 76 predicted genes, 7 of which we considered to be likely candidate genes for QFLANG-4B. Marker and phenotypic analyses of individual plants from the secondary mapping populations and their progeny revealed that the FLANG of the ND3331 allele is significantly higher than that of the Zang1817 allele in multiple environments. These results not only provide a basis for the map-based cloning of QFLANG-4B, but also indicate that QFLANG-4B has great potential for marker-assisted selection in wheat breeding programs designed to improve plant architecture and yield.

Alpha lipoic acid mitigates adverse impacts of drought stress on growth and yield of mungbean: photosynthetic pigments, and antioxidative defense mechanism.

Context: Exogenous use of potential organic compounds through different modes is a promising strategy for the induction of water stress tolerance in crop plants for better yield. Aims: The present study aimed to explore the potential role of alpha-lipoic acid (ALA) in inducing water stress tolerance in mungbean lines when applied exogenously through various modes. Methods: The experiment was conducted in a field with a split-plot arrangement, having three replicates for each treatment. Two irrigation regimes, including normal and reduced irrigation, were applied. The plants allocated to reduced irrigation were watered only at the reproductive stage. Three levels of ALA (0, 0.1, 0.15 mM) were applied through different modes (seed priming, foliar or priming+foliar). Key results: ALA treatment through different modes manifested higher growth under reduced irrigation (water stress) and normal irrigation. Compared to the other two modes, the application of ALA as seed priming was found more effective in ameliorating the adverse impacts of water stress on growth and yield associated with their better content of leaf photosynthetic pigments, maintenance of plant water relations, levels of non-enzymatic antioxidants, improved activities of enzymatic antioxidants, and decreased lipid peroxidation and H2O2 levels. The maximum increase in shoot fresh weight (29% and 28%), shoot dry weight (27% and 24%), 100-grain weight (24% and 23%) and total grain yield (20% and 21%) in water-stressed mungbean plants of line 16003 and 16004, respectively, was recorded due to ALA seed priming than other modes of applications. Conclusions: Conclusively, 0.1 and 0.15 mM levels of ALA as seed priming were found to reduce the adverse impact of water stress on mungbean yield that was associated with improved physio-biochemical mechanisms. Implications: The findings of the study will be helpful for the agriculturalists working in arid and semi-arid regions to obtain a better yield of mungbean that will be helpful to fulfill the food demand in those areas to some extent.

Genetic characterization and linkage analysis of spotted leaf 6,liguleless and lax panicle traits in mutant rice.

Phenotypic mutants are valuable resources for elucidating the function of genes responsible for their expression. This study examined mutant rice strains expressing three traits: spotted leaf 6 (spl6), lax panicle (lax), and liguleless (lg). In the mutant, the spl6 phenotype was a genetically programmed lesion-mimicking mutation (LMM) that displayed spontaneously scattered spots across the leaf surface. In the lg trait, the plant lacked a collar region, and there were no auricles and ligules at the junction of the leaf blade and leaf sheath. The lax panicle trait manifested as sparely arranged spikelets resulting from the terminal spikelet with no lateral spikelets, which caused a drastic reduction of the total seed number in the mutant. All three mutant genes were genetically recessive and had nuclear gene regulation. The dihybrid segregation of the lg gene was classified independently according to the Mendelian 9:3:3:1 dihybrid segregation ratio in the F2 generation, suggesting that the lg gene is not linked to the same chromosome as the lax and spl6 genes. On the other hand, spl6 and lax were not assorted independently, indicating that they are closely linked on chromosome 1 in rice. Additional linkage analysis from the recombination of spl6 and lax genes reconfirmed that the two genes were ~9.4 cM away from each other. The individual single-gene mutant plant from one plant with a three-gene mutation (spl6, lax, and lg) was isolated and characterized, which will be a crucial resource for the gene cloning and molecular characterization of these genes.

Buffering and phenological mismatch: A change of perspective.

The potential for climate change to disrupt phenology-mediated interactions in interaction networks has attracted considerable attention in recent decades. Frequently, studies emphasize the fragility of ephemeral seasonal interactions, and the risks posed by phenological asynchrony. Here, we argue that the fitness consequences of asynchrony in phenological interactions may often be more buffered than is typically acknowledged. We identify three main forms that buffering may take: (i) mechanisms that reduce asynchrony between consumer and resource; (ii) mechanisms that reduce the costs of being asynchronous; and (iii) mechanisms that dampen interannual variance in performance across higher organizational units. Using synchrony between the hatching of winter moth caterpillars and the leafing of their host-plants as a case study, we identify a wide variety of buffers that reduce the detrimental consequences of phenological asynchrony on caterpillar individuals, populations, and meta-populations. We follow this by drawing on examples across a breadth of taxa, and demonstrate that these buffering mechanisms may be quite general. We conclude by identifying key gaps in our knowledge of the fitness and demographic consequences of buffering, in the context of phenological mismatch. Buffering has the potential to substantially alter our understanding of the biotic impacts of future climate change-a greater recognition of the contribution of these mechanisms may reveal that many trophic interactions are surprisingly resilient, and also serve to shift research emphasis to those systems with fewer buffers and towards identifying the limits of those buffers.

Control of leaf development in the water fern Ceratopteris richardii by the auxin efflux transporter CrPINMa in the CRISPR/Cas9 analysis.

BACKGROUND: PIN-FORMED genes (PINs) are crucial in plant development as they determine the directionality of auxin flow. They are present in almost all land plants and even in green algae. However, their role in fern development has not yet been determined. This study aims to investigate the function of CrPINMa in the quasi-model water fern Ceratopteris richardii. RESULTS: CrPINMa possessed a long central hydrophilic loop and characteristic motifs within it, which indicated that it belonged to the canonical rather than the non-canonical PINs. CrPINMa was positioned in the lineage leading to Arabidopsis PIN6 but not that to its PIN1, and it had undergone numerous gene duplications. CRISPR/Cas9 genome editing had been performed in ferns for the first time, producing diverse mutations including local frameshifts for CrPINMa. Plants possessing disrupted CrPINMa exhibited retarded leaf emergence and reduced leaf size though they could survive and reproduce at the same time. CrPINMa transcripts were distributed in the shoot apical meristem, leaf primordia and their vasculature. Finally, CrPINMa proteins were localized to the plasma membrane rather than other cell parts. CONCLUSIONS: CRISPR/Cas9 genome editing is feasible in ferns, and that PINs can play a role in fern leaf development.

Impact of Fe3O4-porphyrin hybrid nanoparticles on wheat: Physiological and metabolic advance.

Iron-magnetic nanoparticles (Fe-NMPs) are widely used in environmental remediation, while porphyrin-based hybrid materials anchored to silica-coated Fe3O4-nanoparticles (Fe3O4-NPs) have been used for water disinfection purposes. To assess their safety on plants, especially concerning potential environmental release, it was investigated for the first time, the impact on plants of a silica-coated Fe3O4-NPs bearing a porphyrinic formulation (FORM) - FORM@NMP. Additionally, FORM alone and the magnetic nanoparticles without FORM anchored (NH2@NMP) were used for comparison. Wheat (Triticum aestivum L.) was chosen as a model species and was subjected to three environmentally relevant doses during germination and tiller development through root application. Morphological, physiological, and metabolic parameters were assessed. Despite a modest biomass decrease and alterations in membrane properties, no major impairments in germination or seedling development were observed. During tiller phase, both Fe3O4-NPs increased leaf length, and photosynthesis exhibited varied impacts: both Fe3O4-NPs and FORM alone increased pigments; only Fe3O4-NPs promoted gas exchange; all treatments improved the photochemical phase. Regarding oxidative stress, lipid peroxidation decreased in FORM and FORM@NMP, yet with increased O2-• in FORM@NMP; total flavonoids decreased in NH2@NMP and antioxidant enzymes declined across all materials. Phenolic profiling revealed a generalized trend towards a decrease in flavones. In conclusion, these nanoparticles can modulate wheat physiology/metabolism without apparently inducing phytotoxicity at low doses and during short-time exposure. ENVIRONMENTAL IMPLICATION: Iron-magnetic nanoparticles are widely used in environmental remediation and fertilization, besides of new applications continuously being developed, making them emerging contaminants. Soil is a major sink for these nanoparticles and their fate and potential environmental risks in ecosystems must be addressed to achieve more sustainable environmental applications. Furthermore, as the reuse of treated wastewater for agricultural irrigation is being claimed, it is of major importance to disclose the impact on crops of the nanoparticles used for wastewater decontamination, such as those proposed in this work.

Biomass ash as soil fertilizers: Supercharging biomass accumulation by shifting auxin distribution.

Growing quantities of biomass ashes (phyto-ashs) are currently produced worldwide due to the increasing biomass consumption in energy applications. Utilization of phyto-ash in agriculture is environmentally friendly solution. However, mechanisms involving the coordination of carbon metabolism and distribution in plants and soil amendment are not well known. In the present study, tobacco plants were chemically-fertilized with or without 2‰ phyto-ash addition. The control had sole chemical fertilizer; for two phyto-ash treatments, the one (T1) received comparable levels of nitrogen, phophorus, and potassium from phyto-ash and fertilizers as the control and another (T2) had 2‰ of phyto-ash and the same rates of fertilizers as the control. Compared with the control, phyto-ash addition improved the soil pH from 5.94 to about 6.35; T2 treatment enhanced soil available potassium by 30% but no difference of other elements was recorded among three treatments. Importantly, bacterial (but not fungal) communities were significantly enriched by phyto-ash addition, with the rank of richness as: T2 > T1 > control. Consistent with amelioration of soil properties, phyto-ash promoted plant growth through enlarged leaf area and photosynthesis and induced outgrowth of lateral roots (LRs). Interestingly, increased auxin content was recorded in 2nd and 3rd leaves and roots under phyto-ash application, also with the rank level as T2 > T1 > control, paralleling with higher transcripts of auxin synthetic genes in the topmost leaf and stronger [3H]IAA activity under phyto-ash addition. Furthermore, exogenous application of analog exogenous auxin (NAA) restored leaf area, photosynthesis and LR outgrowth to the similar level as T2 treatment; conversely, application of auxin transport inhibitor (NPA) under T2 treatment retarded leaf and root development. We demonstrated that phyto-ash addition improved soil properties and thus facilitated carbon balance within plants and biomass accumulation in which shifting auxin distribution plays an important role.