Normal Growth Conditions Research Articles

OsPDIL1-5: dual role in promoting growth and development while modulating drought stress tolerance in rice (Oryza sativa L.).

Drought tolerance and plant growth are critical factors affecting rice yield, and identifying genes that can enhance these traits is essential for improving crop resilience and productivity. Using a growth-depressed and drought-tolerant (gddt) mutant of the indica rice variety Huanghuazhan (HHZ) generated by radiation mutagenesis, we discovered a novel gene, GDDT, which plays a dual role in plant biology: it acts as a positive regulator of growth and development, but as a negative regulator of drought resistance. The gddt mutant displayed a marked reduction in plant growth and seed setting rate, yet exhibited an unexpected advantage in terms of drought tolerance. Our research revealed that the enhanced drought tolerance of the gddt mutant is primarily due to a decrease in stomatal size, density, and aperture, which reduces water loss, and an activation of the reactive oxygen species (ROS) scavenging system, which helps protect the plant from oxidative stress. These physiological changes are observed both under drought conditions and in normal growth conditions. This discovery highlights the importance of GDDT as a pleiotropic gene with significant implications for both plant growth and drought resistance. Through map-based cloning, we determined that the protein disulfide isomerase-like (PDIL) gene OsPDIL1-5 is the GDDT gene. The protein encoded by this gene was localized to the endoplasmic reticulum, consistent with its predicted function. Our findings provide new insights into the role of PDIL genes in rice and suggest that further study of GDDT could lead to a better understanding of how these genes contribute to the complex interplay between plant growth, development, and stress responses. This knowledge could pave the way for the development of rice varieties that are more resilient to drought, thereby increasing crop yields and ensuring food security in water-limited environments.

Genome-Wide Identification of the Peanut ASR Gene Family and Its Expression Analysis under Abiotic Stress.

Peanut (Arachis hypogaea L.) is one of the most important oil and food legume crops worldwide. ASR (abscisic acid, stress, ripening) plays extremely important roles in plant growth and development, fruit ripening, pollen development, and stress. Here, six ASR genes were identified in peanut. Structural and conserved motif analyses were performed to identify common ABA/WDS structural domains. The vast majority of ASR genes encoded acidic proteins, all of which are hydrophilic proteins and localized on mitochondria and nucleus, respectively. The cis-element analysis revealed that some cis-regulatory elements were related to peanut growth and development, hormone, and stress response. Under normal growth conditions, AhASR4 and AhASR5 were expressed in all tissues of peanut plants. Quantitative real-time PCR (qRT-PCR) results indicated that peanut ASR genes exhibited complex expression patterns in response to abiotic stress. Notably, under drought and cadmium (Cd) stress, the expression levels of AhASR4 and AhASR5 were significantly upregulated, suggesting that these genes may play a crucial role in the peanut plant's resistance to such stressors. These results provide a theoretical basis for studying the evolution, expression, and function of the peanut ASR gene family and will provide valuable information in the identification and screening of genes for peanut stress tolerance breeding.

Maize Endophytic Plant Growth-Promoting Bacteria Peribacillus simplex Can Alleviate Plant Saline and Alkaline Stress.

Soil salinization is currently one of the main abiotic stresses that restrict plant growth. Plant endophytic bacteria can alleviate abiotic stress. The aim of the current study was to isolate, characterize, and assess the plant growth-promoting and saline and alkaline stress-alleviating traits of Peribacillus simplex M1 (P. simplex M1) isolates from maize. One endophytic bacterial isolate, named P. simplex M1, was selected from the roots of maize grown in saline-alkali soil. The P. simplex M1 genome sequence analysis of the bacteria with a length of 5.8 Mbp includes about 700 genes that promote growth and 16 antioxidant activity genes that alleviate saline and alkaline stress. P. simplex M1 can grow below 400 mM NaHCO3 on the LB culture medium; The isolate displayed multiple plant growth-stimulating features, such as nitrogen fixation, produced indole-3-acetic acid (IAA), and siderophore production. This isolate had a positive effect on the resistance to salt of maize in addition to the growth. P. simplex M1 significantly promoted seed germination by enhancing seed vigor in maize whether under normal growth or NaHCO3 stress conditions. The seeds with NaHCO3 treatment exhibited higher reactive oxygen species (ROS) levels than the maize in P. simplex M1 inoculant on maize. P. simplex M1 can colonize the roots of maize. The P. simplex M1 inoculant plant increased chlorophyll in leaves, stimulated root and leaf growth, increased the number of lateral roots and root dry weight, increased the length and width of the blades, and dry weight of the blades. The application of inoculants can significantly reduce the content of malondialdehyde (MDA) and increase the activity of plant antioxidant enzymes (Catalase (CAT), Superoxide Dismutase (SOD), and Peroxidase (POD)), which may thereby improve maize resistance to saline and alkaline stress. Conclusion: P. simplex M1 isolate belongs to plant growth-promoting bacteria by having high nitrogen concentration, indoleacetic acid (IAA), and siderophore, and reducing the content of ROS through the antioxidant system to alleviate salt alkali stress. This study presents the potential application of P. simplex M1 as a biological inoculant to promote plant growth and mitigate the saline and alkaline effects of maize and other crops.

Maternal-fetal interfaces transcriptome changes associated with placental insufficiency and a novel gene therapy intervention.

The etiology of fetal growth restriction (FGR) is multifactorial, although many cases involve placental insufficiency. Placental insufficiency is associated with inadequate trophoblast invasion resulting in high resistance to blood flow, decreased availability of nutrients, and increased hypoxia. We have developed a non-viral, polymer-based nanoparticle that facilitates delivery and transient gene expression of human insulin-like 1 growth factor (hIGF1) in trophoblast for the treatment of placenta insufficiency and FGR. Using the established guinea pig maternal nutrient restriction (MNR) model of placental insufficiency, the aim of the study was to identify novel pathways in the sub-placenta/decidua that provide insight into the underlying mechanism driving placental insufficiency, and may be corrected with hIGF1 nanoparticle treatment. Pregnant guinea pigs underwent ultrasound-guided sham or hIGF1 nanoparticle treatment at mid-pregnancy, and sub-placenta/decidua tissue was collected 5 days later. Transcriptome analysis was performed using RNA Sequencing on the Illumina platform. The MNR sub-placenta/decidua demonstrated fewer maternal spiral arteries lined by trophoblast, shallower trophoblast invasion and downregulation of genelists involved in the regulation of cell migration. hIGF1 nanoparticle treatment resulted in marked changes to transporter activity in the MNR + hIGF1 sub-placenta/decidua when compared to sham MNR. Under normal growth conditions however, hIGF1 nanoparticle treatment decreased genelists enriched for kinase signaling pathways and increased genelists enriched for proteolysis indicative of homeostasis. Overall, this study identified changes to the sub-placenta/decidua transcriptome that likely result in inadequate trophoblast invasion and increases our understanding of pathways that hIGF1 nanoparticle treatment acts on in order to restore or maintain appropriate placenta function.

Metabolomics, phytohormone and transcriptomics strategies to reveal the mechanism of barley heading date regulation to responds different photoperiod

BackgroundThe correlation between heading date and flowering time significantly regulates grain filling and seed formation in barley and other crops, ultimately determining crop productivity. In this study, the transcriptome, hormone content detection, and metabolome analysis were performed systematically to analyze the regulatory mechanism of heading time in highland barley under different light conditions. The heading date of D18 (winter highland barley variety, Dongqing18) was later than that of K13 (vernal highland barley variety) under normal growth conditions or long-day (LD) treatment, while this situation will reverse with short-day (SD) treatment.ResultsThe circadian rhythm plant, plant hormone signaling transduction, starch and sucrose metabolism, and photosynthesis-related pathways are significantly enriched in barley under SD and LD to influence heading time. In the plant circadian rhythm pathway, the key genes GI (Gigantea), PRR (Pesudoresponseregulator), FKF1 (Flavin-binding kelch pepeat F-Box 1), and FT (Flowering locus T) are identified as highly expressed in D18SD3 and K13SD2, while they are significantly down-regulated in K13SD3. These genes play an important role in regulating the heading date of D18 earlier than that of K13 under SD conditions. In photosynthesis-related pathways, a-b binding protein and RBS were highly expressed in K13LD3, while NADP-dependent malic enzyme, phosphoenolpyruvate carboxylase, fructose-bisphosphate aldolase, and triosephosphate isomerase were significantly expressed in D18SD3. In the starch and sucrose metabolism pathway, 41 DEGs (differentially expressed genes) and related metabolites were identified as highly expressed and accumulated in D18SD3. The DEGs SAUR (Small auxin-up RNA), ARF (Auxin response factor), TIR1 (Transport inhibitor response 1), EIN3 (Ethylene-insensitive 3), ERS1 (Ethylene receptor gene), and JAZ1 (Jasmonate ZIM-domain) in the plant hormone pathway were significantly up-regulated in D18SD3. Compared with D18LD3, the content of N6-isopentenyladenine, indole-3-carboxylic acid, 1-aminocyclopropanecarboxylic acid, trans-zeatin, indole-3-carboxaldehyde, 1-O-indol-3-ylacetylglucose, and salicylic acid in D18SD3 also increased. The expression levels of vernalization genes (HvVRN1, HvVRN2, and HvVRN3), photoperiod genes (PPD), and PPDK (Pyruvate phosphate dikinase) that affect photosynthetic efficiency in barley are also analyzed, which play important regulatory roles in barley heading date. The WGCNA analysis of the metabolome data and circadian regulatory genes identified the key metabolites and candidate genes to regulate the heading time of barley in response to the photoperiod.ConclusionThese studies will provide a reference for the regulation mechanism of flowering and the heading date of highland barley.

Mild Heat Stress Alters the Physical State and Structure of Membranes in Triacylglycerol-Deficient Fission Yeast, Schizosaccharomyces pombe.

We investigated whether the elimination of two major enzymes responsible for triacylglycerol synthesis altered the structure and physical state of organelle membranes under mild heat shock conditions in the fission yeast, Schizosaccharomyces pombe. Our study revealed that key intracellular membrane structures, lipid droplets, vacuoles, the mitochondrial network, and the cortical endoplasmic reticulum were all affected in mutant fission yeast cells under mild heat shock but not under normal growth conditions. We also obtained direct evidence that triacylglycerol-deficient cells were less capable than wild-type cells of adjusting their membrane physical properties during thermal stress. The production of thermoprotective molecules, such as HSP16 and trehalose, was reduced in the mutant strain. These findings suggest that an intact system of triacylglycerol metabolism significantly contributes to membrane protection during heat stress.

Genome-Wide Transcriptome Analysis of a Virulent sRNA, Trans217, in Xanthomonas oryzae pv. oryzae (Xoo), the Causative Agent of Rice Bacterial Blight.

Small non-coding RNAs (sRNAs) act as post-transcriptional regulators to participate in many cellular processes. Among these, sRNA trans217 has been identified as a key virulent factor associated with pathogenicity in rice, triggering hypersensitive reactions in non-host tobacco and facilitating the secretion of the PthXo1 effector in Xanthomonas oryzae pv. oryzae (Xoo) strain PXO99A. Elucidating potential targets and downstream regulatory genes is crucial for understanding cellular networks governing pathogenicity and plant resistance. To explore the targets regulated by sRNA trans217, transcriptome sequencing was carried out to assess differential expression genes (DEGs) between the wild-type strain PXO99A and a mutant lacking the sRNA fragment under both virulence-inducing or normal growth conditions. DEG analysis revealed that sRNA trans217 was responsible for diverse functions, such as type III secretion system (T3SS), glutamate synthase activity, and oxidative stress response. Three genes were selected for further investigation due to their significant differential expression and biological relevance. Deletion of PXO_RS08490 attenuated the pathogenicity of Xoo in rice and reduced the tolerance level of PXO99A to hydrogen peroxide. These findings suggest a regulatory role of sRNA trans217 in modulating bacterial virulence through multiple gene targets, either directly or indirectly.

Methionine Synthase 2 Represses Stem Cell Maintenance of Arabidopsis thaliana in Response to Salt Stress.

Salt stress represses the growth and development of plants that mainly depend on the continual propagation and differentiation of stem cells. WUSCHEL (WUS)/WUSCHEL-RELATED HOMEOBOX (WOX) family proteins determine stem cell fate in plants under ever-changing environments. It is not yet known how plant stem cell homeostasis is regulated under salt stress. Methionine synthase catalyzes the formation of methionine by methylating homocysteine in the one-carbon metabolism pathway. In this work, we investigated the role of Arabidopsis METHIONINE SYNTHASE 2 (AtMS2) in stem cell homeostasis under salt stress. The results showed that AtMS2 represses the stem cell maintenance of Arabidopsis in response to salt stress. Under normal growth conditions, AtMS2 is mainly localized in the cytoplasm. However, under salt stress, it exhibits significant accumulation in the nucleus. AtMS2 interacts with the WUS/WOX protein, and, together, they repress WUS/WOX expression by binding to its promoter. The mutation in AtMS2 resulted in enhanced salt tolerance. Therefore, AtMS2 might act as a key negative regulator to repress the stem cell maintenance and growth of Arabidopsis under salt stress.

Dynamics of physiological and biochemical effects of heat, drought and combined stress on potato seedlings

BackgroundHeat and drought stresses usually occur together in nature, and both are expected to increase in frequency and intensity as a result of climate change. The synergistic impacts of these compound climate extremes on potatoes are far from the effects of individual stresses. However, the dynamics of the effects of combined heat and drought stresses on potato physiology and biochemistry have yet to be thoroughly assessed. To elucidate this point, we set up a pot experiment using ‘Atlantic’ potato seedlings as test material. A total of six treatments were set up: CK (normal growth conditions: 21 ℃, 0 PEG), A1B1 (31 ℃, 20% PEG), A1B2 (31 ℃, 10% PEG), A1B3 (31 ℃, 0 PEG), A2B1 (21 ℃, 20% PEG), and A2B2 (21 ℃, 10% PEG), and 15 physiological indices were determined with the stress time of 0, 6, 12 and 18 days.ResultsAfter 18 days of stress, the phenotype of potato seedlings was significantly different. Compared with CK, the thickness of potato leaves and palisade tissue increased under heat and drought stress, and the combined stress reduced the photosynthetic efficiency of potato leaves. In all treatments except CK, the chlorophyll content decreased significantly, the antioxidant enzyme activity increased first and then decreased, and the relative conductivity and malondialdehyde content increased significantly. The heat and combined treatment made the content of the osmotic regulator first increase and then decrease, while the treatment of 21 ℃ had no significant change. According to the correlation, principal component and interaction analysis, both heat and drought treatment had significant effects on each index, and the longer the stress time, the greater the effect, and the effect of combined stress was greater than that of single stress. However, after 6 days of stress, the activity of antioxidant enzymes and the content of transparent regulatory substances increased.ConclusionsIn conclusion, potato can cope with heat, drought and combined stress by adjusting leaf tissue structure, antioxidant enzyme activity and osmotic regulatory substances in a short time.Graphical

Taxonomic and functional changes in wheat rhizosphere microbiome caused by imidazoline-based herbicide and genetic modification

Genetically modified (GM) crop cultivation has received a lot of attention in recent years due to the substantial public debate. Consequently, an in-depth investigation of excessively used GM herbicide-tolerant crops is a vital step for the biosafety of genetically modified plants. Several studies have been conducted to study the impact of transgenic GM crops on soil microbial composition; however, research into the effects of non-transgenic GM crops is inadequate. In the current work, high-throughput sequencing was used to evaluate the impact of the acetolactate synthase (ALS)-mutant (WK170B), its control (YN19B), and the imazamox (IM) herbicide on the wheat rhizobiome. Under normal growth conditions, our work revealed a minimal impact of ALS-mutant WK170B on the rhizosphere microbiome compared to the control YN10B, except for some cyanobacterial microorganisms that showed a significant increase in abundance. This suggests that the gene mutation could potentially have a beneficial impact on the bacterial communities present in the rhizosphere. Following IM exposure, taxonomic analysis revealed a significant reduction in the relative abundance of Ralstonia pickettii and an unidentified member of the genus Ancylothrix 8 PC. Analyses of both alpha and beta diversity revealed a statistically significant increase in both microbial richness and species diversity. IM-induced relative abundance modulation was also evident through Linear discriminant analysis Effect Size (LEfSe), MetaStat, and heatmap analyses. The SIMPER analysis revealed that the microbial taxa Massilia, Limnobacter, Hydrogenophaga, Ralstonia, Nitrospira, and Ramlibacter exhibited the highest vulnerability to IM exposure. The functional attributes analysis revealed that the relative abundance of genes associated with the extracellular matrix-receptor interaction, which is responsible for structural support and stress response, increased significantly following IM exposure. Collectively, our study identifies key microbial taxa in the wheat rhizobiome that are sensitive to IM herbicides and provides a foundation for assessing the environmental risks associated with IM herbicide use.

The superiority of innovative spiral-interdigital microelectrode pattern in increasing the sensitivity of tracing synchronization via serum starvation in cellular metabolism

In order to investigate the changes in the properties of the cell culture solution in the effect of cell synchronization via cell starvation (for 12, 24, and 36 h), a new spiral-interdigital pattern of microelectrode as a biosensor has been proposed. Then, to test its superiority, the results of this spiral-interdigital pattern with the results of the commercial pattern have been compared. The cells were selected from breast cancer standard lines (MDA-MB-231). Changes in CV peaks of the secretions were recorded by the spiral-interdigital pattern, in which increasing the interactive surface with homogenous electric paths had been considered by simulation before fabrication. The results of the simulation and experimental procedures showed a meaningful correlation. The occurrence of CV oxidative peaks at about 0.1–0.4 V and reductive peaks at approximately 0 V in the spiral-interdigital biosensor in the starved MDA-MB-231 cell line has been observed. The starvation situation resembles one that does not cause meaningful cell apoptosis or necrosis, and this method is only used to make the cells synchronized. Also, no peak is observed in normal cell growth conditions. In addition, by using the commercial design of the electrodes, no peak is observed in any of the conditions of normal and synchronized growth of the cells. Therefore, it seems that the observed peaks are caused by the agents that are secreted in the cell culture solution in a synchronized situation. Moreover, the design of the new spiral-interdigital electrode can significantly increase the sensitivity of the sensor to receive these peaks due to more space and a uniform electric field.

Comprehensive analysis of pepper (Capsicum annuum) RAV genes family and functional identification of CaRAV1 under chilling stress

BackgroundDespite its known significance in plant abiotic stress responses, the role of the RAV gene family in the response of Capsicum annuum to chilling stress remains largely unexplored.ResultsIn this study, we identified and characterized six members of the CaRAV gene subfamily in pepper plants through genome-wide analysis. Subsequently, the CaRAV subfamily was classified into four branches based on homology with Arabidopsis thaliana, each exhibiting relatively conserved domains within the branch. We discovered that light response elements accounted for the majority of CaRAVs, whereas low-temperature response elements were specific to the NGA gene subfamily. After pepper plants were subjected to chilling stress, qRT‒PCR analysis revealed that CaRAV1, CaRAV2 and CaNGA1 were significantly induced in response to chilling stress, indicating that CaRAVs play a role in the response to chilling stress. Using virus-induced gene silencing (VIGS) vectors, we targeted key members of the CaRAV gene family. Under normal growth conditions, the MDA content and SOD enzyme activity of the silenced plants were slightly greater than those of the control plants, and the REC activity was significantly greater than that of the control plants. The levels of MDA and electrolyte leakage were greater in the silenced plants after they were exposed to chilling stress, and the POD and CAT enzyme activities were significantly lower than those in the control, which was particularly evident under repeated chilling stress. In addition, the relative expression of CaPOD and CaCAT was greater in V2 plants upon repeated chilling stress, especially CaCAT was significantly greater in V2 plants than in the other two silenced plants, with 3.29 and 1.10 increases within 12 and 24 h. These findings suggest that CaRAV1 and CaNGA1 positively regulate the response to chilling stress.ConclusionsSilencing of key members of the CaRAV gene family results in increased susceptibility to chilling damage and reduced antioxidant enzyme activity in plants, particularly under repeated chilling stress. This study provides valuable information for understanding the classification and putative functions of RAV transcription factors in pepper plants.

Proximity driven plastid-nucleus relationships are facilitated by tandem plastid-ER dynamics.

Peri-nuclear clustering (PNC) of chloroplasts has largely been described in senescent and pathogen- or ROS- stressed cells. Stromules, tubular plastid extensions are also observed under similar conditions. Coincident observations of PNC and stromules associate the two phenomena in facilitating retrograde signaling between chloroplasts and the nucleus. However, PNC incidence in non-stressed cells under normal growth and developmental conditions, when stromules are usually not observed, remains unclear. Using transgenic Arabidopsis expressing different organelle-targeted fluorescent proteins we show that PNC is a dynamic subcellular phenomenon that continues in the absence of light and is not dependent on stromule formation. PNC is facilitated by tandem plastid-ER dynamics created through membrane contact sites between the two organelles. While PNC increases upon ER-membrane expansion, some plastids may remain in the peri-nuclear region due to their localization in ER-lined nuclear indentions. Moreover, some PNC plastids may sporadically extend stromules into ER-lined nuclear grooves. Our findings strongly suggest that PNC is not an exclusive response to stress caused by pathogens, high light or exogenous-H2O2 treatment and does not require stromule formation. However, morphological and behavioural alterations in ER and concomitant changes in tandem, plastid-ER dynamics play a major role in facilitating the phenomenon.

Multifaceted roles of Arabidopsis heat shock factor binding protein in plant growth, development, and heat shock response

Heat shock factor-binding protein (HSBP) is a 10 kDa protein in plants and animals and consists exclusively of a coiled-coil domain. During the recovery phase following a heat shock response, HSBP relocates from the cytoplasm to the nucleus in Arabidopsis (Arabidopsis thaliana), where it interacts with heat shock factors (HSFs). Here, we found that 16 out of the 19 functional known HSFs can interact with HSBP. Besides, our results indicate that HSBP negatively regulates HSF gene expression during normal growth conditions and recovery from heat shock. Expanding our understanding of HSBP's physiological functions during regular growth, co-immunoprecipitation and mass spectrometry analysis identified 16 coiled-coil domain-containing proteins co-immunoprecipitated with HSBP. These proteins encompass HSP70s, all components of the MAIGO2 complex, COP1-interactive protein1 (CIP1), CIP1-like protein, kinesin-like protein for actin-based chloroplast movement1 and 2 (KAC1/2), and HSBP itself. By examining mutant plants lacking HSBP and its interacting proteins, we elucidated their functional relationships. Our findings underscore the indispensability of the HSBP coiled-coil heptad repeat for interacting with its partners and its crucial role in growth, development, and the heat shock response. In addition to its involvement in heat shock response, Arabidopsis HSBP, a discreet small regulatory protein, exerts multiple regulatory functions in hypocotyl elongation, flowering time, chloroplast photo-relocation, and seed development.

ZmD11 Gene Regulates Tobacco Plant Floral Development under Drought Stress

Maize is most sensitive to drought stress at the floral stage by reducing tassel and silk quality, and thus improving drought tolerance at this stage may help preserve yield. It has been reported that BRs (brassinosteroids) promote floral development under drought stress. However, the function of the brassinosteroid biosynthesis gene ZmDWARF11 (ZmD11) on floral growth under drought stress has not been elucidated. This study found that under normal growth conditions, the heterologous over-expression of ZmD11 significantly enhanced both the vegetative growth and floral development of tobacco. Under drought stress, overexpressing ZmD11 reduced stress-induced tobacco flower size reduction, while it did not affect vegetative growth. After drought treatment, the activities of protective enzymes, including CAT (Catalase), SOD (Superoxide Dismutase), and POD (Peroxidase), were higher, while the content of MDA (Malondialdehyde) was lower in ZmD11 over-expression tobacco lines than that in the wild type control. The relative expression of dehydrin-related genes NtLeat5 and NtERD10 was increased in ZmD11 over-expression tobacco lines compared to that in the control. In summary, we reported that ZmD11 plays a role in tobacco floral development under drought stress. Our data are valuable in understanding the functions of BRs in regulating plant floral development under drought stress.

Overexpression of Wheat Selenium-Binding Protein Gene TaSBP-A Enhances Plant Growth and Grain Selenium Accumulation under Spraying Sodium Selenite.

Selenium (Se) is an essential trace element for humans. Low concentrations of Se can promote plant growth and development. Enhancing grain yield and crop Se content is significant, as major food crops generally have low Se content. Studies have shown that Se biofortification can significantly increase Se content in plant tissues. In this study, the genetic transformation of wheat was conducted to evaluate the agronomic traits of non-transgenic control and transgenic wheat before and after Se application. Se content, speciation, and transfer coefficients in wheat grains were detected. Molecular docking simulations and transcriptome data were utilized to explore the effects of selenium-binding protein-A TaSBP-A on wheat growth and grain Se accumulation and transport. The results showed that TaSBP-A gene overexpression significantly increased plant height (by 18.50%), number of spikelets (by 11.74%), and number of grains in a spike (by 35.66%) in wheat. Under normal growth conditions, Se content in transgenic wheat grains did not change significantly, but after applying sodium selenite, Se content in transgenic wheat grains significantly increased. Analysis of Se speciation revealed that organic forms of selenomethionine (SeMet) and selenocysteine (SeCys) predominated in both W48 and transgenic wheat grains. Moreover, TaSBP-A significantly increased the transfer coefficients of Se from solution to roots and from flag leaves to grains. Additionally, it was found that with the increase in TaSBP-A gene overexpression levels in transgenic wheat, the transfer coefficient of Se from flag leaves to grains also increased.

Overexpression of Wild Soybean Expansin Gene GsEXLB14 Enhanced the Tolerance of Transgenic Soybean Hairy Roots to Salt and Drought Stresses.

As a type of cell-wall-relaxing protein that is widely present in plants, expansins have been shown to actively participate in the regulation of plant growth and responses to environmental stress. Wild soybeans have long existed in the wild environment and possess abundant resistance gene resources, which hold significant value for the improvement of cultivated soybean germplasm. In our previous study, we found that the wild soybean expansin gene GsEXLB14 is specifically transcribed in roots, and its transcription level significantly increases under salt and drought stress. To further identify the function of GsEXLB14, in this study, we cloned the CDS sequence of this gene. The transcription pattern of GsEXLB14 in the roots of wild soybean under salt and drought stress was analyzed by qRT-PCR. Using an Agrobacterium rhizogenes-mediated genetic transformation, we obtained soybean hairy roots overexpressing GsEXLB14. Under 150 mM NaCl- and 100 mM mannitol-simulated drought stress, the relative growth values of the number, length, and weight of transgenic soybean hairy roots were significantly higher than those of the control group. We obtained the transcriptomes of transgenic and wild-type soybean hairy roots under normal growth conditions and under salt and drought stress through RNA sequencing. A transcriptomic analysis showed that the transcription of genes encoding expansins (EXPB family), peroxidase, H+-transporting ATPase, and other genes was significantly upregulated in transgenic hairy roots under salt stress. Under drought stress, the transcription of expansin (EXPB/LB family) genes increased in transgenic hairy roots. In addition, the transcription of genes encoding peroxidases, calcium/calmodulin-dependent protein kinases, and dehydration-responsive proteins increased significantly. The results of qRT-PCR also confirmed that the transcription pattern of the above genes was consistent with the transcriptome. The differences in the transcript levels of the above genes may be the potential reason for the strong tolerance of soybean hairy roots overexpressing the GsEXLB14 gene under salt and drought stress. In conclusion, the expansin GsEXLB14 can be used as a valuable candidate gene for the molecular breeding of soybeans.

Heterologous synthesis of poly-γ-glutamic acid enhanced drought resistance in maize (Zea mays L.)

Drought stress is the main factor restricting maize yield. Poly-γ-glutamic acid (γ-PGA), as a water-retaining agent and fertilizer synergist, could significantly improve the drought resistance and yield of many crops. However, its high production costs and unclear long-term impact on soil ecology limit its large-scale application. In this study, an environmentally friendly green material γ-PGA was heterologous synthesized in maize for the first time using the synthetic biology method. The genes (PgsA, PgsB, PgsC) participated in γ-PGA synthesis were cloned from Bacillus licheniformis and transformed into maize to produce γ-PGA for the first time. Under drought stress, transgenic maize significantly increased the ear length, ear weight and grain weight by 50 % compared to the control, whereas the yield characteristic of ear weight, grain number per ear, grain weight per ear and 100-grain weight increased by 1.67 %–2.33 %, 3.78 %–13.06 %, 8.41 %–22.06 %, 6.03 %–19.28 %, and 11.85 %–18.36 %, respectively under normal growth conditions. γ-PGA was mainly expressed in the mesophyll cells of maize leaf rosette structure and improved drought resistance and yield by protecting and increasing the expression of genes for the photosynthetic and carbon fixation. This study is an important exploration for maize drought stress molecular breeding and building resource-saving agriculture.

Maternal-fetal interfaces transcriptome changes associated with placental insufficiency and a novel gene therapy intervention.

The etiology of fetal growth restriction (FGR) is multifactorial, although many cases often involve placental insufficiency. Placental insufficiency is associated with inadequate trophoblast invasion resulting in high resistance to blood flow, decreased availability of nutrients, and increased hypoxia. We have developed a non-viral, polymer-based nanoparticle that facilitates delivery and transient gene expression of human insulin-like 1 growth factor ( hIGF1 ) in placental trophoblast for the treatment of placenta insufficiency and FGR. Using the established guinea pig maternal nutrient restriction (MNR) model of placental insufficiency and FGR, the aim of the study was to identify novel pathways in the sub-placenta/decidua that provide insight into the underlying mechanism driving placental insufficiency, and may be corrected with hIGF1 nanoparticle treatment. Pregnant guinea pigs underwent ultrasound-guided sham or hIGF1 nanoparticle treatment at mid-pregnancy, and sub-placenta/decidua tissue was collected 5 days later. Transcriptome analysis was performed using RNA Sequencing on the Illumina platform. The MNR sub-placenta/decidua demonstrated fewer maternal spiral arteries lined by trophoblast, shallower trophoblast invasion and downregulation of genelists involved in the regulation of cell migration. hIGF1 nanoparticle treatment resulted in marked changes to transporter activity in the MNR + hIGF1 sub-placenta/decidua when compared to sham MNR. Under normal growth conditions however, hIGF1 nanoparticle treatment decreased genelists enriched for kinase signaling pathways and increased genelists enriched for proteolysis indicative of homeostasis. Overall, this study identified changes to the sub-placenta/decidua transcriptome that likely result in inadequate trophoblast invasion and increases our understanding of pathways that hIGF1 nanoparticle treatment acts on in order to restore or maintain appropriate placenta function.

Robust soybean leaf agroinfiltration.

A robust agroinfiltration-mediated transient gene expression method for soybean leaves was developed. Plant genotype, developmental stage and leaf age, surfactant, and Agrobacterium culture conditions are important for successful agroinfiltration. Agroinfiltration of Nicotiana benthamiana has emerged as a workhorse transient assay for plant biotechnology and synthetic biology to test the performance of gene constructs in dicot leaves. While effective, it is nonetheless often desirable to assay transgene constructs directly in crop species. To that end, we innovated a substantially robust agroinfiltration method for Glycine max (soybean), the most widely grown dicot crop plant in the world. Several factors were found to be relevant to successful soybean leaf agroinfiltration, including genotype, surfactant, developmental stage, and Agrobacterium strain and culture medium. Our optimized protocol involved a multi-step Agrobacterium culturing process with appropriate expression vectors, Silwet L-77 as the surfactant, selection of fully expanded leaves in the VC or V1 stage of growth, and 5min of vacuum at -85kPa followed by a dark incubation period before plants were returned to normal growth conditions. Using this method, young soybean leaves of two lines-V17-0799DT, and TN16-5004-were high expressors for GUS, two co-expressed fluorescent protein genes, and the RUBY reporter product, betalain. This work not only represents a new research tool for soybean biotechnology, but also indicates critical parameters for guiding agroinfiltration optimization for other crop species.We speculate that leaf developmental stage might be the most critical factor for successful agroinfiltration.