RESUMEN
In gramineae-soybean intercropping systems, shade stress caused by taller plants impacts soybean growth specifically during the reproductive stage. However, the effects of shade stress on soybean senescence remain largely unexplored. In this research, we applied artificial shade treatments with intensities of 75% (S75) and 50% (S50) to soybean plants at the onset of flowering to simulate the shade stress experienced by soybeans in the traditional and optimized maize-soybean intercropping systems, respectively. Compared to the normal light control, both shade treatments led to a rapid decline in the dry matter content of soybean vegetative organs and accelerated their abscission. Moreover, shade treatments triggered the degradation of chlorophyll and soluble proteins in leaves and increased the expression of genes associated with leaf senescence. Metabolic profiling further revealed that ethylene biosynthesis and signal transduction were induced by shade treatment. In addition, the examination of nitrogen content demonstrated that shade treatments impeded the remobilization of nitrogen in vegetative tissues, consequently reducing the seed nitrogen harvest. It's worth noting that these negative effects were less pronounced under the S50 treatment compared to the S75 treatment. Taken together, this research demonstrates that shade stress during the reproductive stage accelerates soybean senescence and impedes nitrogen remobilization, while optimizing the field layout to improve soybean growth light conditions could mitigate these challenges in the maize-soybean intercropping system.
Asunto(s)
Etilenos , Glycine max , Nitrógeno , Estrés Fisiológico , Glycine max/metabolismo , Glycine max/efectos de la radiación , Glycine max/crecimiento & desarrollo , Nitrógeno/metabolismo , Etilenos/metabolismo , Etilenos/biosíntesis , Senescencia de la Planta , Hojas de la Planta/metabolismo , Hojas de la Planta/efectos de la radiación , Regulación de la Expresión Génica de las Plantas , Luz , Clorofila/metabolismoRESUMEN
Soybean [Glycine max (L.) Merr.] is a short-day (SD) plant that is sensitive to photoperiod, which influences flowering, maturity, and even adaptation. TEOSINTE-BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) transcription factors have been shown to regulate photoperiodic flowering. However, the roles of TCPs in SD plants such as soybean, rice, and maize remain largely unknown. In this study, we cloned the GmTCP40 gene from soybean and investigated its expression pattern and function. Compared with wild-type (WT) plants, GmTCP40-overexpression plants flowered earlier under long-day (LD) conditions but not under SD conditions. Consistent with this, the overexpression lines showed upregulation of the flowering-related genes GmFT2a, GmFT2b, GmFT5a, GmFT6, GmAP1a, GmAP1b, GmAP1c, GmSOC1a, GmSOC1b, GmFULa, and GmAG under LD conditions. Further investigation revealed that GmTCP40 binds to the GmAP1a promoter and promotes its expression. Analysis of the GmTCP40 haplotypes and phenotypes of soybean accessions demonstrated that one GmTCP40 haplotype (Hap6) may contribute to delayed flowering at low latitudes. Taken together, our findings provide preliminary insights into the regulation of flowering time by GmTCP40 while laying a foundation for future research on other members of the GmTCP family and for efforts to enhance soybean adaptability.
Asunto(s)
Flores , Regulación de la Expresión Génica de las Plantas , Glycine max , Fotoperiodo , Proteínas de Plantas , Flores/genética , Flores/crecimiento & desarrollo , Glycine max/genética , Glycine max/crecimiento & desarrollo , Glycine max/efectos de la radiación , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/genética , Regiones Promotoras Genéticas/genética , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Regulación hacia Arriba/genéticaRESUMEN
To improve light harvest and plant structural support under low light intensity, it is useful to investigate the effects of different ratios of blue light on petiole and stem growth. Two true leaves of soybean seedlings were exposed to a total light intensity of 200µmolm-2 s-1 , presented as either white light or three levels of blue light (40µmolm-2 s-1 , 67µmolm-2 s-1 and 100µmolm-2 s-1 ) for 15days. Soybean petioles under the low blue light treatment upregulated expression of genes relating to lignin metabolism, enhancing lignin content compared with the white light treatment. The low blue light treatment had high petiole length, increased plant height and improved petiole strength arising from high lignin content, thus significantly increasing leaf dry weight relative to the white light treatment. Compared with white light, the treatment with the highest blue light ratio reduced plant height and enhanced plant support through increased cellulose and hemicellulose content in the stem. Under low light intensity, 20% blue light enhanced petiole length and strength to improve photosynthate biomass; whereas 50% blue light lowered plants' centre of gravity, preventing lodging and conserving carbohydrate allocation.
Asunto(s)
Luz Azul , Celulosa , Glycine max , Lignina , Tallos de la Planta , Celulosa/metabolismo , Glycine max/crecimiento & desarrollo , Glycine max/efectos de la radiación , Lignina/metabolismo , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/efectos de la radiación , Tallos de la Planta/crecimiento & desarrollo , Tallos de la Planta/efectos de la radiaciónRESUMEN
While flux balance analysis (FBA) provides a framework for predicting steady-state leaf metabolic network fluxes, it does not readily capture the response to environmental variables without being coupled to other modelling formulations. To address this, we coupled an FBA model of 903 reactions of soybean (Glycine max) leaf metabolism with e-photosynthesis, a dynamic model that captures the kinetics of 126 reactions of photosynthesis and associated chloroplast carbon metabolism. Successful coupling was achieved in an iterative formulation in which fluxes from e-photosynthesis were used to constrain the FBA model and then, in turn, fluxes computed from the FBA model used to update parameters in e-photosynthesis. This process was repeated until common fluxes in the two models converged. Coupling did not hamper the ability of the kinetic module to accurately predict the carbon assimilation rate, photosystem II electron flux, and starch accumulation of field-grown soybean at two CO2 concentrations. The coupled model also allowed accurate predictions of additional parameters such as nocturnal respiration, as well as analysis of the effect of light intensity and elevated CO2 on leaf metabolism. Predictions included an unexpected decrease in the rate of export of sucrose from the leaf at high light, due to altered starch-sucrose partitioning, and altered daytime flux modes in the tricarboxylic acid cycle at elevated CO2 . Mitochondrial fluxes were notably different between growing and mature leaves, with greater anaplerotic, tricarboxylic acid cycle and mitochondrial ATP synthase fluxes predicted in the former, primarily to provide carbon skeletons and energy for protein synthesis.
Asunto(s)
Dióxido de Carbono/metabolismo , Metabolismo Energético , Glycine max/metabolismo , Redes y Vías Metabólicas , Modelos Biológicos , Fotosíntesis , Almidón/metabolismo , Cloroplastos/metabolismo , Cloroplastos/efectos de la radiación , Ambiente , Cinética , Luz , Hojas de la Planta/metabolismo , Hojas de la Planta/efectos de la radiación , Glycine max/efectos de la radiación , Sacarosa/metabolismoRESUMEN
Symbiotic nitrogen fixation is an energy-expensive process, and the light available to plants has been proposed to be a primary influencer. We demonstrate that the light-induced soybean TGACG-motif binding factor 3/4 (GmSTF3/4) and FLOWERING LOCUS T (GmFTs), which move from shoots to roots, interdependently induce nodule organogenesis. Rhizobium-activated calcium- and calmodulin-dependent protein kinase (CCaMK) phosphorylates GmSTF3, triggering GmSTF3GmFT2a complex formation, which directly activates expression of nodule inception (NIN) and nuclear factor Y (NF-YA1 and NF-YB1). Accordingly, the CCaMKSTFFT module integrates aboveground light signals with underground symbiotic signaling, ensuring that the host plant informs its roots that the aboveground environment is prepared to sustainably supply the carbohydrate necessary for symbiosis. These results suggest approaches that could enhance the balance of carbon and nitrogen in the biosphere.
Asunto(s)
Glycine max/fisiología , Fijación del Nitrógeno , Organogénesis de las Plantas/fisiología , Proteínas de Plantas/metabolismo , Nodulación de la Raíz de la Planta , Brotes de la Planta/fisiología , Rhizobium/fisiología , Luz , Raíces de Plantas/fisiología , Brotes de la Planta/microbiología , Brotes de la Planta/efectos de la radiación , Glycine max/microbiología , Glycine max/efectos de la radiación , SimbiosisRESUMEN
The combined response of exclusion of solar ultraviolet radiation (UV-A+B and UV-B) and static magnetic field (SMF) pre-treatment of 200 mT for 1 h were studied on soybean (Glycine max) leaves using synchrotron imaging. The seeds of soybean with and without SMF pre-treatment were sown in nursery bags kept in iron meshes where UV-A+B (280-400 nm) and UV-B (280-315 nm) from solar radiation were filtered through a polyester filters. Two controls were planned, one with polythene filter controls (FC)- which allows all the UV (280-400 nm); the other control had no filter used (open control-OC). Midrib regions of the intact third trifoliate leaves were imaged using the phase-contrast imaging technique at BL-4, Indus-2 synchrotron radiation source. The solar UV exclusion results suggest that ambient UV caused a reduction in leaf growth which ultimately reduced the photosynthesis in soybean seedlings, while SMF treatment caused enhancement of leaf growth along with photosynthesis even under the presence of ambient UV-B stress. The width of midrib and second-order veins, length of the second-order veins, leaf vein density, and the density of third-order veins obtained from the quantitative image analysis showed an enhancement in the leaves of plants that emerged from SMF pre-treated seeds as compared to untreated ones grown in open control and filter control conditions (in the presence of ambient UV stress). SMF pre-treated seeds along with UV-A+B and UV-B exclusion also showed significant enhancements in leaf parameters as compared to the UV excluded untreated leaves. Our results suggested that SMF-pretreatment of seeds diminishes the ambient UV-induced adverse effects on soybean.
Asunto(s)
Glycine max/efectos de la radiación , Campos Magnéticos , Hojas de la Planta/efectos de la radiación , Sincrotrones , Rayos Ultravioleta , Hojas de la Planta/anatomía & histología , Estomas de Plantas/anatomía & histología , Estomas de Plantas/fisiología , Estomas de Plantas/efectos de la radiación , Haz Vascular de Plantas/anatomía & histología , Haz Vascular de Plantas/efectos de la radiación , Espectrofotometría UltravioletaRESUMEN
Photons during the dark period delay flowering in short-day plants (SDP). Red photons applied at night convert phytochromes to the active far-red absorbing form (Pfr), leading to inhibition of flowering. Far-red photons (greater than 700 nm) re-induce flowering when applied after a pulse of red photons during the dark period. However, far-red photons at sufficiently high intensity and duration delay flowering in sensitive species. Mechanistically, this response occurs because phytochrome-red (Pr) absorbance is not zero beyond 700 nm. We applied nighttime photons from near infrared (NIR) LEDs (peak 850 nm) over a 12 h dark period. Flowering was delayed in Glycine max and Cannabis sativa (two photosensitive species) by 3 and 12 days, respectively, as the flux of photons from NIR LEDs was increased up to 83 and 116 µmol m-2 s-1. This suggests that long wavelength photons from NIR LEDs can activate phytochromes (convert Pr to Pfr) and thus alter plant development.
Asunto(s)
Cannabis/crecimiento & desarrollo , Glycine max/crecimiento & desarrollo , Rayos Infrarrojos , Fitocromo/metabolismo , Cannabis/metabolismo , Cannabis/efectos de la radiación , Flores/crecimiento & desarrollo , Flores/metabolismo , Flores/efectos de la radiación , Fotones , Tallos de la Planta/crecimiento & desarrollo , Tallos de la Planta/metabolismo , Tallos de la Planta/efectos de la radiación , Glycine max/metabolismo , Glycine max/efectos de la radiaciónRESUMEN
We have evaluated the contribution of nitric oxide (NO) in static magnetic field (SMF-200 mT for 1h) induced tolerance towards UV-B stress in soybean seedlings using various NO modulators like sodium nitroprusside (SNP), inhibitor of nitrate reductase (NR) sodium tungstate (ST), NO synthase (NOS) inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) and diphenylene iodonium (DPI) a NADPH oxidase inhibitor. The UV-B exposure significantly reduced germination, seedling growth together with activities of total amylase, NOS and NR in seedlings from un-primed seeds whereas SMF-primed seedlings showed significant enhancement in all these parameters along with higher level of NO/ROS. The supply of NO donor, SNP further improved all the seedlings parameters in un-primed and SMF-primed seeds after UV-B exposure. While ST, L-NAME and DPI significantly reduced the SMF-induced seedling performance after UV-B exposure. The gene expression study also showed significant up-regulation of α-amylase (GmAMY1, GmAMY2), nitric oxide synthase (GmNOS2) and nitrate reductase (GmNR2) encoding genes in UV-B exposed SMF-primed seedlings over un-primed seedlings. In particular, SNP+UV-B treatment enhanced the GmNOS2 expression in both unprimed (31.9-fold) and SMF-primed (93.2-fold) seedlings in comparison to their respective controls of CK+UV-B. In contrast, L-NAME+UV-B treatment reduced the SMF-induced GmNOS2 expression (4.8-fold) and NOS activity (76%). It confirmed that NO may be the key signaling molecule in SMF stimulated tolerance towards UV-B stress during early seedling growth and NOS may possibly be accountable for SMF-triggered NO production in soybean seedlings exposed to UV-B irradiations.
Asunto(s)
Germinación/efectos de la radiación , Glycine max/fisiología , Magnetismo , Óxido Nítrico Sintasa/metabolismo , Óxido Nítrico/metabolismo , Plantones/efectos de la radiación , Rayos Ultravioleta , Especies Reactivas de Oxígeno/metabolismo , Plantones/crecimiento & desarrollo , Glycine max/crecimiento & desarrollo , Glycine max/efectos de la radiación , alfa-Amilasas/metabolismoRESUMEN
Soybean is a typical short-day (SD) plant. It undergoes reproductive growth only when the day length becomes shorter than a critical length. Fourteen major genes/loci affecting soybean flowering and maturity period have been mapped to date. These are E1 and E7 on chr6, E1La, E1Lb, E6, E8, and J on chr4, E2 on chr10, E3 on chr19, E4 on chr20, E9 on chr6, E10 on chr8, Dt1 on chr19, and GmAGL1 on chr14. The functional allele of all these genes, except E6, E9, J, and GmAGL1, delay flowering, while the non-functional counterpart accelerates flowering and maturity. The contribution of the E1 gene in delaying flowering is highest. Four non-functional/dysfunctional allelic variants of the E1 gene are already known, which accelerates the flowering by 20-25 days and are being used in development of early maturing soybean varieties in many parts of the world. In this study, seeds of the late maturing Indian variety NRC 37 were irradiated with gamma rays to develop an early maturing variety. One early maturing variant was obtained. Molecular characterization of the gene responsible for early flowering proved it to be a non-functional variant of the E1 gene with major deletion.
Asunto(s)
Flores , Glycine max , Alelos , Flores/genética , Flores/efectos de la radiación , Rayos gamma , Mutación , Glycine max/genética , Glycine max/efectos de la radiaciónRESUMEN
Photoperiod sensitivity is a key factor in plant adaptation and crop production. In the short-day plant soybean, adaptation to low latitude environments is provided by mutations at the J locus, which confer extended flowering phase and thereby improve yield. The identity of J as an ortholog of Arabidopsis ELF3, a component of the circadian evening complex (EC), implies that orthologs of other EC components may have similar roles. Here we show that the two soybean homeologs of LUX ARRYTHMO interact with J to form a soybean EC. Characterization of mutants reveals that these genes are highly redundant in function but together are critical for flowering under short day, where the lux1 lux2 double mutant shows extremely late flowering and a massively extended flowering phase. This phenotype exceeds that of any soybean flowering mutant reported to date, and is strongly reminiscent of the "Maryland Mammoth" tobacco mutant that featured in the seminal 1920 study of plant photoperiodism by Garner and Allard [W. W. Garner, H. A. Allard, J. Agric. Res. 18, 553-606 (1920)]. We further demonstrate that the J-LUX complex suppresses transcription of the key flowering repressor E1 and its two homologs via LUX binding sites in their promoters. These results indicate that the EC-E1 interaction has a central role in soybean photoperiod sensitivity, a phenomenon also first described by Garner and Allard. EC and E1 family genes may therefore constitute key targets for customized breeding of soybean varieties with precise flowering time adaptation, either by introgression of natural variation or generation of new mutants by gene editing.
Asunto(s)
Adaptación Fisiológica , Flores/metabolismo , Regulación de la Expresión Génica de las Plantas/efectos de la radiación , Glycine max/metabolismo , Fotoperiodo , Proteínas de Plantas/metabolismo , Flores/genética , Flores/crecimiento & desarrollo , Flores/efectos de la radiación , Fenotipo , Fitomejoramiento , Proteínas de Plantas/genética , Glycine max/genética , Glycine max/crecimiento & desarrollo , Glycine max/efectos de la radiaciónRESUMEN
An experiment was set up to investigate physiological responses of soybeans to silicon (Si) under normal light and shade conditions. Two soybean varieties, Nandou 12 (shade resistant), and Nan 032-4 (shade susceptible), were tested. Our results revealed that under shading, the net assimilation rate and the plant growth were significantly reduced. However, foliar application of Si under normal light and shading significantly improved the net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), and decreased intercellular carbon dioxide concentration (Ci). The net photosynthetic rate of Nandou 12 under normal light and shading increased by 46.4% and 33.3% respectively with Si treatment (200 mg/kg) compared to controls. Si application also enhanced chlorophyll content, soluble sugars, fresh weight, root length, root surface area, root volume, root-shoot ratio, and root dry weight under both conditions. Si application significantly increased the accumulation of some carbohydrates such as soluble sugar and sucrose in stems and leaves ensuring better stem strength under both conditions. Si application significantly increased the yield by increasing the number of effective pods per plant, the number of beans per plant and the weight of beans per plant. After Si treatment, the yield increased 24.5% under mono-cropping, and 17.41% under intercropping. Thus, Si is very effective in alleviating the stress effects of shading in intercropped soybeans by increasing the photosynthetic efficiency and lodging resistance.
Asunto(s)
Carbono , Glycine max , Luz , Hojas de la Planta , Silicio , Carbono/metabolismo , Clorofila/metabolismo , Fotosíntesis/efectos de los fármacos , Fotosíntesis/efectos de la radiación , Hojas de la Planta/metabolismo , Hojas de la Planta/efectos de la radiación , Silicio/farmacología , Glycine max/efectos de los fármacos , Glycine max/efectos de la radiaciónRESUMEN
Soybean is an important legume crop that displays the classic shade avoidance syndrome (SAS), including exaggerated stem elongation, which leads to lodging and yield reduction under density farming conditions. Here, we compared the effects of two shade signals, low red light to far-red light ratio (R:FR) and low blue light (LBL), on soybean status and revealed that LBL predominantly induces excessive stem elongation. We used CRISPR-Cas9-engineered Gmcry mutants to investigate the functions of seven cryptochromes (GmCRYs) in soybean and found that the four GmCRY1s overlap in mediating LBL-induced SAS. Light-activated GmCRY1s increase the abundance of the bZIP transcription factors STF1 and STF2, which directly upregulate the expression of genes encoding GA2 oxidases to deactivate GA1 and repress stem elongation. Notably, GmCRY1b overexpression lines displayed multiple agronomic advantages over the wild-type control under both dense planting and intercropping conditions. Our study demonstrates the integration of GmCRY1-mediated signals with the GA metabolic pathway in the regulation of LBL-induced SAS in soybean. It also provides a promising option for breeding lodging-resistant, high-yield soybean cultivars in the future.
Asunto(s)
Giberelinas/metabolismo , Glycine max/metabolismo , Glycine max/fisiología , Luz , Proteínas de Plantas/metabolismo , Secuencia de Bases , Regulación de la Expresión Génica de las Plantas/efectos de la radiación , Tallos de la Planta/crecimiento & desarrollo , Tallos de la Planta/efectos de la radiación , Plantas Modificadas Genéticamente , Glycine max/anatomía & histología , Glycine max/efectos de la radiación , Regulación hacia Arriba/genética , Regulación hacia Arriba/efectos de la radiaciónRESUMEN
Organ-specific flavonoid destination in soybean sprouts following UV irradiation is still unclear although the metabolic pathway of flavonoid synthesis and UV responded flavonoid accumulation have been well investigated. We report the identification of organ-specific localization and specific gene expression of isoflavones and kaempferol glycosides in the soybean sprouts responded to UV-A irradiation. UV-A irradiation stimulated only root isoflavones, especially increase of genistein types. The daidzein types predominated in non-UV-A treated roots. Kaempferol glycosides were not increased in roots by UV-A, but distinctly increased in aerial organs, especially in the cotyledons. These results demonstrate that UV-A upregulates the naringenin pathway synthesizing genistin and kaempferol rather than the liquiritigenin pathway synthesizing daidzin and glycitin. High GmUGT9 and other gene expression related to isoflavone synthesis in roots clearly demonstrate the UV-A-induced isoflavone accumulation. Aerial organ specific increase of GmF3H, GmFLS1, and GmDFR1 expression by UV-A distinctly demonstrates the flavonol increase in aerial organs.
Asunto(s)
Flavonoles/genética , Flavonoles/metabolismo , Regulación de la Expresión Génica de las Plantas/efectos de la radiación , Glycine max/efectos de la radiación , Isoflavonas/genética , Isoflavonas/metabolismo , Rayos Ultravioleta , Glycine max/genética , Glycine max/metabolismoRESUMEN
Senescence is an internally systematized degeneration process leading to death in plants. Leaf yellowing, one of the most prominent features of plant aging may lead to reduced crop yields. The molecular mechanism of responses to senescence in soybean leaves is not completely clear. In our research, two soybean varieties were selected with different stay-green traits: stay-green variety (BN106) and non-stay-green variety (KF14). RNA samples extracted from the leaves of two varieties were sequenced and compared using high-throughput sequencing. Six key enzyme genes in chlorophyll degradation pathways were studied to analyze the changes in their expression at seedling, flowering and maturation stage. Meanwhile, the construction of the genetic transformation process had been constructed to identify the function of putative gene by RNA-interference. A total of 4329 DEGs were involved in 52 functional groups and 254 KEGG pathways. Twelve genes encoding senescence-associated and inducible chloroplast stay-green protein showed significant differential expression. MDCase and PAO have a significant expression in BN106 that may be the key factors affecting the maintenance of green characteristics. In addition, the function of GmSGRs has been identified by genetic transformation. The loss of GmSGRs may cause soybean seeds to change from yellow to green. In summary, our results revealed fundamental information about the molecular mechanism of aging in soybeans with different stay-green characteristics. The work of genetic transformation lays a foundation for putative gene function studies that could contribute to postpone aging in soybeans.
Asunto(s)
Cloroplastos/genética , Regulación de la Expresión Génica de las Plantas , Glycine max/genética , Pigmentación/genética , Hojas de la Planta/genética , Clorofila/genética , Clorofila/metabolismo , Cloroplastos/metabolismo , Cloroplastos/efectos de la radiación , Color , Ontología de Genes , Secuenciación de Nucleótidos de Alto Rendimiento , Complejos de Proteína Captadores de Luz/genética , Complejos de Proteína Captadores de Luz/metabolismo , Anotación de Secuencia Molecular , Oxidorreductasas/genética , Oxidorreductasas/metabolismo , Oxigenasas/genética , Oxigenasas/metabolismo , Hojas de la Planta/anatomía & histología , Hojas de la Planta/metabolismo , Hojas de la Planta/efectos de la radiación , Proteolisis , Glycine max/anatomía & histología , Glycine max/metabolismo , Glycine max/efectos de la radiación , Luz SolarRESUMEN
BACKGROUND: Plants are always exposed to dynamic light. The photosynthetic light use efficiency of leaves is lower in dynamic light than in uniform irradiance. Research on the influence of environmental factors on dynamic photosynthesis is very limited. Nitrogen is critical for plants, especially for photosynthesis. Low nitrogen (LN) decreases ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and thus limits photosynthesis. The decrease in Rubisco also delays photosynthetic induction in LN leaves; therefore, we hypothesized that the difference of photosynthetic CO2 fixation between uniform and dynamic light will be greater in LN leaves compared to leaves with sufficient nitrogen supply. RESULTS: To test this hypothesis, soybean plants were grown under low or high nitrogen (HN), and the photosynthetic gas exchange, enzyme activity and protein amount in leaves were measured under uniform and dynamic light. Unexpectedly, dynamic light caused less photosynthetic suppression, rather than more, in LN leaves than in HN leaves. The underlying mechanism was also clarified. Short low-light (LL) intervals did not affect Rubisco activity but clearly deactivated fructose-1,6-bisphosphatase (FBPase) and sedoheptulose-1,7-bisphosphatase (SBPase), indicating that photosynthetic induction after a LL interval depends on the reactivation of FBPase and SBPase rather than Rubisco. In LN leaves, the amount of Rubisco decreased more than FBPase and SBPase, so FBPase and SBPase were present in relative excess. A lower fraction of FBPase and SBPase needs to be activated in LN leaves for photosynthesis recovery during the high-light phase of dynamic light. Therefore, photosynthetic recovery is faster in LN leaves than in HN leaves, which relieves the photosynthetic suppression caused by dynamic light in LN leaves. CONCLUSIONS: Contrary to our expectations, dynamic light caused less photosynthetic suppression, rather than more, in LN leaves than in HN leaves of soybean. This is the first report of a stress condition alleviating the photosynthetic suppression caused by dynamic light.
Asunto(s)
Glycine max/fisiología , Nitrógeno/deficiencia , Fotosíntesis/efectos de la radiación , Luz , Nitrógeno/fisiología , Fotosíntesis/efectos de los fármacos , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/fisiología , Hojas de la Planta/efectos de la radiación , Ribulosa-Bifosfato Carboxilasa/efectos de los fármacos , Ribulosa-Bifosfato Carboxilasa/efectos de la radiación , Glycine max/efectos de los fármacos , Glycine max/efectos de la radiación , Estrés FisiológicoRESUMEN
Ionizing radiation is a genotoxic anthropogenic stressor. It can cause heritable changes in the plant genome, which can be either adaptive or detrimental. There is still considerable uncertainty about the effects of chronic low-intensity doses since earlier studies reported somewhat contradictory conclusions. Our project focused on the recovery from the multiyear chronic ionizing radiation stress. Soybean (Glycine max) was grown in field plots located at the Chernobyl exclusion zone and transferred to the clean ground in the subsequent generation. We profiled proteome of mature seeds by two-dimensional gel electrophoresis. Overall, 15 differentially abundant protein spots were identified in the field comparison and 11 in the recovery generation, primarily belonging to storage proteins, disease/defense, and metabolism categories. Data suggested that during multigenerational growth in a contaminated environment, detrimental heritable changes were accumulated. Chlorophyll fluorescence parameters were measured on the late vegetative state, pointing to partial recovery of photosynthesis from stress imposed by contaminating radionuclides. A plausible explanation for the observed phenomena is insufficient provisioning of seeds by lower quality resources, causing a persistent effect in the offspring generation. Additionally, we hypothesized that immunity against phytopathogens was compromised in the contaminated field, but perhaps even primed in the clean ground, yet this idea requires direct functional validation in future experiments. Despite showing clear signs of physiological recovery, one season was not enough to normalize biochemical processes. Overall, our data contribute to the more informed agricultural radioprotection.
Asunto(s)
Accidente Nuclear de Chernóbil , Glycine max/efectos de la radiación , Proteínas de Plantas/metabolismo , Proteoma/efectos de la radiación , Radiación Ionizante , Estrés Fisiológico , Electroforesis en Gel Bidimensional , Glycine max/crecimiento & desarrollo , Glycine max/fisiología , UcraniaRESUMEN
KEY MESSAGE: A simple and rapid speed breeding system was developed for short-day crops that enables up to five generations per year using LED lighting systems that allow very specific adjustments regarding light intensity and quality. Plant breeding is a key element for future agricultural production that needs to cope with a growing human population and climate change. However, the process of developing suitable cultivars is time-consuming, not least because of the long generation times of crops. Recently, speed breeding has been introduced for long-day crops, but a similar protocol for short-day crops is lacking to date. In this study, we present a speed breeding protocol based on light-emitting diodes (LEDs) that allow to modify light quality, and exemplarily demonstrate its effectiveness for the short-day crops soybean (Glycine max), rice (Oryza sativa) and amaranth (Amaranthus spp.). Adjusting the photoperiod to 10 h and using a blue-light enriched, far-red-deprived light spectrum facilitated the growth of short and sturdy soybean plants that flowered ~ 23 days after sowing and matured within 77 days, thus allowing up to five generations per year. In rice and amaranth, flowering was achieved ~ 60 and ~ 35 days after sowing, respectively. Interestingly, the use of far-red light advanced flowering by 10 and 20 days in some amaranth and rice genotypes, respectively, but had no impact on flowering in soybeans, highlighting the importance of light quality for speed breeding protocols. Taken together, our short-day crops' speed breeding protocol enables several generations per year using crop-specific LED-based lighting regimes, without the need of tissue culture tools such as embryo rescue. Moreover, this approach can be readily applied to a multi-storey 96-cell tray-based system to integrate speed breeding with genomics, toward a higher improvement rate in breeding.
Asunto(s)
Amaranthus/crecimiento & desarrollo , Productos Agrícolas/crecimiento & desarrollo , Flores/crecimiento & desarrollo , Glycine max/crecimiento & desarrollo , Oryza/crecimiento & desarrollo , Fotoperiodo , Fitomejoramiento/métodos , Amaranthus/efectos de la radiación , Productos Agrícolas/efectos de la radiación , Flores/efectos de la radiación , Germinación/efectos de la radiación , Luz , Oryza/genética , Oryza/efectos de la radiación , Fenotipo , Glycine max/efectos de la radiaciónRESUMEN
BACKGROUND: Shading includes low light intensity and varying quality. However, a low red/far-red (R/Fr) ratio of light is a signal that affects plant growth in intercropping and close- planting systems. Thus, the low R/Fr ratio uncoupling from shading conditions was assessed to identify the effect of light quality on photosynthesis and CO2 assimilation. Soybean plants were grown in a growth chamber with natural solar radiation under four treatments, that is, normal (N, sunlight), N + Fr, Low (L) + Fr, and L light. RESULTS: Low R/Fr ratio significantly increased the total biomass, leaf area, starch and sucrose contents, chlorophyll content, net photosynthetic rate, and quantum efficiency of the photosystem II compared with normal R/Fr ratio under the same light level (P < 0.05). Proteomic analysis of soybean leaves under different treatments was performed to quantify the changes in photosynthesis and CO2 assimilation in the chloroplast. Among the 7834 proteins quantified, 12 showed a > 1.3-fold change in abundance, of which 1 was related to porphyrin and chlorophyll metabolism, 2 were involved in photosystem I (PS I), 4 were associated with PS II, 3 proteins participated in photosynthetic electron transport, and 2 were involved in starch and sucrose metabolism. The dynamic change in these proteins indicates that photosynthesis and CO2 assimilation were maintained in the L treatment by up-regulating the component protein levels compared with those in N treatment. Although low R/Fr ratio increased the photosynthetic CO2 assimilation parameters, the differences in most protein expression levels in N + Fr and L + Fr treatments compared with those in N treatment were insignificant. Similar trends were found in gene expression through quantitative reverse transcription polymerase chain reaction excluding the gene expression of sucrose synthase possible because light environment is one of the factors affecting carbon assimilation. CONCLUSIONS: Low R/Fr ratio (high Fr light) can increase the photosynthetic CO2 assimilation in the same light intensity by improving the photosynthetic efficiency of the photosystems.
Asunto(s)
Glycine max/efectos de la radiación , Fotosíntesis/efectos de la radiación , Plantones/efectos de la radiación , Cloroplastos/efectos de la radiación , Cloroplastos/ultraestructura , Luz , Proteoma , Plantones/metabolismo , Glycine max/crecimiento & desarrollo , Glycine max/metabolismo , Glycine max/ultraestructuraRESUMEN
This study evaluated the applicability of a rapid analytical method using a headspace solid-phase microextraction gas chromatography/mass spectrometry (HS-SPME-GC/MS) technique to identify gamma-irradiated soybeans (0.1-5 kGy). From the partial least squares discriminant analysis used to discriminate between non-irradiated and irradiated soybean samples, 1,7-hexadecadiene was selected as the identifying marker. Response surface methodology experiments were used to determine the optimal HS-SPME extraction conditions including a carboxen/polydimethylsiloxane fiber with an extraction temperature of 98 °C and an extraction time of 55 min. 1,7-Hexdecadiene was detected in all samples irradiated at ≥ 0.1 kGy under the optimized HS-SPME-GC/MS conditions, and the unique presence of the marker in a gamma-irradiated sample was verified by comparing the results from heat, steam, microwave, sonication, and ultraviolet treatments. The comparisons of the identification properties for various conventional methods validated several advances in HS-SPME-GC/MS analysis in terms of rapid analysis, high sensitivity, and absence of solvent.
Asunto(s)
Cromatografía de Gases y Espectrometría de Masas/métodos , Glycine max/química , Glycine max/efectos de la radiación , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Microextracción en Fase Sólida/métodos , Rayos gammaRESUMEN
Improving soybean growth and tolerance under environmental stress is crucial for sustainable development. Millimeter waves are a radio-frequency band with a wavelength range of 1-10 mm that has dynamic effects on organisms. To investigate the potential effects of millimeter-waves irradiation on soybean seedlings, morphological and proteomic analyses were performed. Millimeter-waves irradiation improved the growth of roots/hypocotyl and the tolerance of soybean to flooding stress. Proteomic analysis indicated that the irradiated soybean seedlings recovered under oxidative stress during growth, whereas proteins related to glycolysis and ascorbate/glutathione metabolism were not affected. Immunoblot analysis confirmed the promotive effect of millimeter waves to glycolysis- and redox-related pathways under flooding conditions. Sugar metabolism was suppressed under flooding in unirradiated soybean seedlings, whereas it was activated in the irradiated ones, especially trehalose synthesis. These results suggest that millimeter-waves irradiation on soybean seeds promotes the recovery of soybean seedlings under oxidative stress, which positively regulates soybean growth through the regulation of glycolysis and redox related pathways.