Pseudomonas ZY-1 and Bacillus FY-1 protecting the rice seedlings from the harm of Pseudomonas aeruginosa via indirect seawead lysis.

The local ecosystems, fishery and human health are all threatened by water blooms, so effectively controlling water blooms has become an urgent and challenging issue. Biological control of water blooms is given priority due to its low cost, high efficiency and environmental friendliness. In this study, Pseudomonas ZY-1 and Bacillus FY-1, two highly-effective algicidal bacteria strains which are able to indirectly lyse algae by separating and screening from the vigorous water body in the paddy alga of Northeast China were obtained. The two bacterial strains have stronger ability to lyse alga in the bacterial liquid concentration of 106 CFU/ml, and the alga-lysing rate on 7 d reached 84.03% and 83.11% respectively. The active substance secreted by ZY-1 is not sensitive to the changes of temperature and pH value, while as FY-1 cell-free filtrate is not stable in high temperature above 50 ℃ and pH of 5, it requires the sun light to have the algaecidal effect. The cell-free filtrates of strains ZY-1 and FY-1 had the best lysis effect on Microcystis aeruginosa cells, and the chlorophyll a content of algae decreased to 0.13 ± 0.02 mg/L and 0.14 ± 0.03 mg/L respectively and the Fv/Fm of Microcystis aeruginosa decreased by 97.22% after 7 days. The algaecidal process of ZY-1 and FY-1 may be that the cell-free filtrate inhibits the photosynthesis of Microcystis aeruginosa, and meanwhile it avoids the regeneration and repair of photosynthesis of algal cells by affecting the gene expression and damaging the repair system of algal cells, so the membrane lipid peroxidation is exacerbated and then the membrane of algal cells is broken, the algal cells can't do normal life activities, and finally the algal cell would be killed. The rice seedlings in the algal liquid treatment group are short and show root dysplasia, few roots and brown roots. After treated with cell-free filtrate of ZY-1 and FY-1, the oxidative damage of the rice is obviously reduced, and the harm from Microcystis aeruginosa is reduced, which has the repair effect to the roots of rice seedlings and its aboveground growth. The cell-free filtrate of FY-1 works better than ZY-1. The bacteria strains of ZY-1 and FY-1 have the indirect algaecide trait, which makes them the potential environmentally-friendly algaecidal bacteria and they show broad application in the agricultural production and the control of water blooms.

Impact of Degree of Ethoxylation on Sodium Lauryl Ether Sulfate Surfactant Adsorption onto Silicone-in-Water Emulsion Droplets.

Silicone-in-water emulsions have found widespread use as lubricants, water repellants, softeners, binders, antiblocking agents, antislip agents, and defoamers across a diverse range of markets including textiles, coatings, pharmaceuticals, and home and personal care. Stable incorporation of silicone emulsions into formulated products for these applications can be a challenge. This study seeks to enable formulation by investigating the impact of the degree of ethoxylation of sodium lauryl ether sulfate (SLES) surfactants on their ability to displace surfactant stabilizer at the silicone-water interfaces of polydimethylsiloxane (PDMS)-in-water emulsion droplets. Building this understanding will greatly enable the manufacture of home and personal care products prepared by introducing silicone emulsions into SLES-rich formulations. Nuclear magnetic resonance (NMR) measurements reveal that SLES can displace the triethanolamine dodecylbenzenesulfonate stabilizer at the droplet surfaces. Both capillary electrophoresis (CE) measurements and molecular dynamics simulations of the interfacial tension (IFT) between silicone and water measurements suggest that SLES mixtures with a higher average degree of ethoxylation are more surface active at the silicone─water interface. The molecular dynamics simulations predict a systematic decrease in PDMS-water IFT with increase in degree of ethoxylation (simulations predict a decrease of 1.3 mN/m per mole of ethylene oxide). Optical microscopy reveals that the presence of SLES at the droplet surfaces promotes the formation of loose flocs of droplets that break up upon dilution. Overall, these fundamental insights will aid in formulating silicone emulsions into products to achieve optimal performance.

Straw Incorporation with Exogenous Degrading Bacteria (ZJW-6): An Integrated Greener Approach to Enhance Straw Degradation and Improve Rice Growth.

Rice straw is an agricultural waste, the disposal of which through open burning is an emerging challenge for ecology. Green manufacturing using straw returning provides a more avant-garde technique that is not only an effective management measure to improve soil fertility in agricultural ecosystems but also nurtures environmental stewardship by reducing waste and the carbon footprint. However, fresh straw that is returned to the field cannot be quickly decomposed, and screening microorganisms with the capacity to degrade straw and understanding their mechanism of action is an efficient approach to solve such problems. This study aimed to reveal the potential mechanism of influence exerted by exogenous degradative bacteria (ZJW-6) on the degradation of straw, growth of plants, and soil bacterial community during the process of returning rice straw to the soil. The inoculation with ZJW-6 enhanced the driving force of cellulose degradation. The acceleration of the rate of decomposition of straw releases nutrients that are easily absorbed by rice (Oryza sativa L.), providing favorable conditions for its growth and promoting its growth and development; prolongs the photosynthetic functioning period of leaves; and lays the material foundation for high yields of rice. ZJW-6 not only directly participates in cellulose degradation as degrading bacteria but also induces positive interactions between bacteria and fungi and enriches the microbial taxa that were related to straw degradation, enhancing the rate of rice straw degradation. Taken together, ZJW-6 has important biological potential and should be further studied, which will provide new insights and strategies for the appropriate treatment of rice straw. In the future, this degrading bacteria may provide a better opportunity to manage straw in an ecofriendly manner.

Silicon nutrition improves the quality and yield of rice under dry cultivation.

BACKGROUND: Dry cultivation of rice is a water-saving, emission reduction and labor-saving rice farming method. However, the development of rice under dry cultivation is hampered by the limitations of dry cultivation on rice yield and rice quality. We hypothesized that additional silicon (Si) would be a measure to address these limitations or challenges. RESULTS: In the present study, we set up field trials with three treatments: flooded cultivation (W), dry cultivation (D) and dry cultivation plus Si. Yield and quality were reduced under D treatment compared to W treatment. The addition of Si promoted root development, increased plant height and leaf area, increased photosynthetic enzyme activity, net photosynthetic rate and SPAD values, and increased biomass under dry crop conditions. Under the drought conditions, silica up-regulated the expression of AGPSI, SBEI, SBEIIb, SSI and SSII-1 genes and the activities of ADP-glucose pyrophosphorylase (AGPase), soluble starch synthetase (SSS) and starch branching enzyme (SBE) enzymes, which reduced protein, amylose, chalkiness percentage and chalkiness degree, increased brown rice rate, milled rice rate and head milled rice rate, and also improved rice quality. In addition, the increase of AGPase, SSS and SBE enzyme activities promoted the filling rate and the number of spikes was guaranteed, whereas the yield was improved by promoting the seed setting rate and 1000-grain weight. CONCLUSION: The results of the present study indicate that adding appropriate amounts of Si fertilizer can improve the yield and quality of rice under dry cultivation by regulating source supply capacity and grain starch synthesis. © 2023 Society of Chemical Industry.

Effects of Soybean Phosphate Transporter Gene GmPHT2 on Pi Transport and Plant Growth under Limited Pi Supply Condition.

Phosphorus is an essential macronutrient for plant growth and development, but phosphate resources are limited and rapidly depleting due to massive global agricultural demand. This study identified two genes in the phosphate transporter 2 (PHT2) family of soybean by bioinformatics. The expression patterns of two genes by qRT-PCR at leaves and all were induced by low-phosphate stress. After low-phosphate stress, GmPHT2;2 expression was significantly higher than GmPHT2;1, and the same trend was observed throughout the reproductive period. The result of heterologous expression of GmPHT2 in Arabidopsis knockout mutants of atpht2;1 shows that chloroplasts and whole-plant phosphorus content were significantly higher in plants complementation of GmPHT2;2 than in plants complementation of GmPHT2;1. This suggests that GmPHT2;2 may play a more important role in plant phosphorus metabolic homeostasis during low-phosphate stress than GmPHT2;1. In the yeast backfill assay, both genes were able to backfill the ability of the defective yeast to utilize phosphorus. GmPHT2 expression was up-regulated by a low-temperature treatment at 4 °C, implying that GmPHT2;1 may play a role in soybean response to low-temperature stress, in addition to being involved in phosphorus transport processes. GmPHT2;1 and GmPHT2;2 exhibit a cyclic pattern of circadian variation in response to light, with the same pattern of gene expression changes under red, blue, and white light conditions. GmPHT2 protein was found in the chloroplast, according to subcellular localization analysis. We conclude that GmPHT2 is a typical phosphate transporter gene that can improve plant acquisition efficiency.

Accessing Thin Film Wetting Regimes during Polymer Growth by Initiated Chemical Vapor Deposition.

We investigate the growth of a fluorinated polymer via initiated chemical vapor deposition onto a suite of isotropic and mesogenic liquids with a range of refractive indices. The polymer morphology at fluid interfaces was found to deviate from conformal films predicted by the positive spreading coefficient, and the resulting morphology is attributed to long-range van der Waals interactions during the deposition process. Experiments systematically vary the deposition conditions and compare the liquid phase (isotropic or nematic) to evaluate the effect of kinetic factors and the liquid substrate phase on the interfacial polymer morphology and spatial organization.

LC-MS/MS-based metabolomics approach revealed novel phytocompounds from sugarcane rind with promising pharmacological value.

BACKGROUND: Sugarcane provides many secondary metabolites for the pharmacological and cosmetic industries. Secondary metabolites, such as phenolic compounds, flavonoids, and anthocyanins, have been studied, but few reports focus on the identification of alkaloid and non-alkaloid phytocompounds in sugarcane. RESULTS: In this study, we identified 40 compounds in total from the rinds of cultivated sugarcane varieties (including eight alkaloids, 24 non-alkaloids, and eight others) by using the liquid chromatography-tandem mass spectrometry (LC-MS/MS) approach. Among these compounds, 31 were novel and are reported for the first time in sugarcane. Some alkaloids such as 3-indoleacrylic acid, N,N-dimethyl-5-methoxytryptamine, tryptamine, 6-hydroxynicotinic acid, and 6-deoxyfagomine are identified the first time in sugarcane rind. Four alkaloids such as trigonelline, piperidine, 3-indoleacrylic acid, and 6-deoxyfagomine are found abundantly in sugarcane rind and these compounds have promising pharmaceutical value. Some phytocompounds such as choline and acetylcholine (non-alkaloid compounds) were most common in the rind of ROC22 and Yuetang93/159 (YT93/159). Hierarchical cluster analysis and principal component analysis revealed that the ROC22, Taitang172 (F172), and Yuetang71/210 (YT71/210) varieties were quite similar in alkaloid composition when compared with other sugarcane varieties. We have also characterized the biosynthesis pathway of sugarcane alkaloids. The rind of F172, ROC22, and YT71/210 showed the highest total alkaloid content, whereas the rind of ROC16 revealed a minimum level. Interestingly, the rind extract from YT71/210 and F172 showed maximum antioxidant activity, followed by ROC22. CONCLUSION: Our results showed the diversity of alkaloid and non-alkaloid compounds in the rind of six cultivated sugarcanes and highlighted the promising phytocompounds that can be extracted, isolated, and utilized by the pharmacological industry. © 2022 Society of Chemical Industry.

Genome-Wide Association Study in Rice Revealed a Novel Gene in Determining Plant Height and Stem Development, by Encoding a WRKY Transcription Factor.

Semi-dwarfism is a main agronomic trait in crop breeding. In this study, we performed genome-wide association study (GWAS) and identified a new quantitative trait nucleotide (QTN) for rice shoot length. The peak QTN (C/T) was located in the first coding region of a group III WRKY transcription factor OsWRKY21 (LOC_Os01g60640). Interestingly, further haplotype analysis showed that C/T difference only existed in the indica group but not in the japonica group, resulting in significant differences in plant height among the different indica rice varieties. OsWRKY21 was expressed in embryo, radicle, shoots, leaves, and stems. Most notably, overexpressing OsWRKY21 resulted in the semi-dwarf phenotype, early heading date and short internodes compared to the wild type, while the knockout mutant plants by CRISPR/Cas9 technology yielded the opposite. The overexpressing lines exhibited the decreased length of the cells near sclerenchyma epidermis, accompanied with the lower levels of indole-3-acetic acid (IAA) and gibberellin 3 (GA3), but increased levels of the abscisic acid (ABA) and salicylic acid (SA) in the internodes at heading stage. Moreover, the semi-dwarf phenotype could be fully rescued by exogenous GA3 application at seedling stage. The RNA-seq and qRT-PCR analysis confirmed the differential expression levels of genes in development and the stress responses in rice, including GA metabolism (GA20ox2, GA2ox6, and YABY1) and cell wall biosynthesis (CesA4, 7, and 9) and regulation (MYB103L). These data suggest the essential role of OsWRKY21 in regulation of internode elongation and plant height in rice.

Nematic colloids at liquid crystal-air interfaces via photopolymerization.

We demonstrate the preparation of colloidal crystals at nematic liquid crystal-air interfaces by simultaneous photopolymerization and assembly. Polymer colloids are produced by polymerization-induced phase separation of 2-hydroxyethyl methacrylate in the non-reactive liquid crystal (LC) 4-cyano-4'-pentylbiphenyl (5CB) using an open-cell setup. Colloids adsorbed to the nematic 5CB-air interface form non-close-packed hexagonal crystals that cover the entire interface area. We examine the mechanism of growth and assembly for the preparation of LC-templated interfacial colloidal superstructures.

SKP2 Promotes Hepatocellular Carcinoma Progression Through Nuclear AMPK-SKP2-CARM1 Signaling Transcriptionally Regulating Nutrient-Deprived Autophagy Induction.

BACKGROUND/AIMS: SKP2 overexpression has been associated with poor prognosis in numerous cancers. The mechanisms of autophagy in the tumor pathogenesis have been a research focus recently. How the SKP2 involved in autophagy expresses oncogenic characteristics, especially in HCC, are largely unclear. METHODS: The expression of SKP2 was detected by qPCR, Western blot, Immunohistochemical (IHC) and Immunofluorescence (IF) techniques. SKP2 was knocked down or overexpressed by lentivirus transfection in HCC cells. Functional assays such as CCK8 assays, transwell migration and invasion assays, and colony formation assays were performed to determine the role of SKP2 in HCC. Furthermore, autophagy was induced by glucose deprivation in HCC cells followed by monitoring of the levels and distributions of SKP2, CARM1 and AMPK. RESULTS: Our data showed that SKP2 levels were significantly increased in HCC cell lines and HCC tissues rather than corresponding normal liver tissues, and augmented SKP2 levels were statistically correlated with tumor grade, size and metastases. By up-regulation or down-regulation of SKP2 in HCC cells, we confirmed that SKP2 encourages proliferation, migration, invasion, and colony formation. We then found that SKP2 was inhibited, CARM1 increased and AMPKα2 became activated in the nucleus under glucose deprivation induced autophagy. Moreover, we discovered that SKP2 was repressing CARM1 in the nucleus under nutrient-sufficient conditions in HCC. CONCLUSIONS: We show that SKP2 promotes HCC progression and its nuclear functions of autophagy induction with CARM1 and AMPK, which may provide a potential target for HCC therapy.

Successive Years of Rice Straw Return Increased the Rice Yield and Soil Nutrients While Decreasing the Greenhouse Gas Intensity.

Straw return has important impacts on black soil protection, food security, and environmental protection. One year of straw return (S1) reduces rice yield and increases greenhouse gas (GHG) emissions. However, the effects of successive years of straw return on rice yield, soil nutrients, and GHG emissions in the northeast rice region are still unclear. Therefore, we conducted four successive years of straw return (S4) in a positional experiment to investigate the effects of different years of straw return on rice yield, soil nutrients, and GHG emissions in the northeast rice region. The experimental treatments included the following: no straw return (S0), a year of straw return (S1), two successive years of straw return (S2), three successive years of straw return (S3), and four successive years of straw return (S4). Compared with S1, the rice yields of S2, S3, and S4 increased by 10.89%, 15.46%, and 16.98%, respectively. But only S4 increased by 4.64% compared to S0, while other treatments were lower than S0. S4 increased panicles per m2 and spikelets per panicle by 9.34% and 8.93%, respectively, compared to S1. Panicles per m2 decreased by 8.06% at S4 compared to S0, while spikelets per panicle increased by 13.23%. Compared with S0, the soil organic carbon, total nitrogen, NH4+-N, NO3--N, available phosphorus, and available potassium of S4 increased by 11.68%, 10.15%, 24.62%, 21.38%, 12.33%, and 13.35%, respectively. Successive years of rice straw return decreased GHG intensity (GHGI). Compared with S1, the GHGI of S4, S3, and S2 decreased by 16.2%, 11.84%, and 9.36%, respectively. Thus, S4 increased rice yield and soil nutrients, reducing GHGI.

Transcriptomic Analysis and Salt-Tolerance Gene Mining during Rice Germination.

Salt stress is an important environmental factor affecting crop growth and development. One of the important ways to improve the salt tolerance of rice is to identify new salt-tolerance genes, reveal possible mechanisms, and apply them to the creation of new germplasm and the breeding of new varieties. In this study, the salt-sensitive japonica variety Tong 35 (T35) and salt-tolerant japonica variety Ji Nongda 709 (JND709) were used. Salt stress treatment with a 150 mmol/L NaCl solution (the control group was tested without salt stress treatment simultaneously) was continued until the test material was collected after the rice germination period. Twelve cDNA libraries were constructed, and 5 comparator groups were established for transcriptome sequencing. On average, 9.57G of raw sequencing data were generated per sample, with alignment to the reference genome above 96.88% and alignment to guanine-cytosine (GC) content above 53.86%. A total of 16,829 differentially expressed genes were present in the five comparison groups, of which 2390 genes were specifically expressed in T35 (category 1), 3306 genes were specifically expressed in JND709 (category 2), and 1708 genes were differentially expressed in both breeds (category 3). Differentially expressed genes were subjected to gene ontology (GO), functional enrichment analysis, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, which revealed that these genes belonged to three main classes: molecular function, cellular components, and biological processes. KEGG pathway analysis showed that the significantly enriched pathways for these differentially expressed genes included phenylpropane biosynthesis, phytohormone signaling, and the interaction of plants with pathogens. In this study, we provided a reference for studying the molecular mechanism underlying salt tolerance during germination.

Metabolomic study on the quality differences and physiological characteristics between rice cultivated in drought and flood conditions.

The differences between dry- and flood-cultivated rice and the reason behind low-quality dry-cultivated rice were clarified. The physiological traits, starch synthase activity, and grain metabolomics of 'Longdao 18' were measured and analyzed at four growth stages. The brown, milled, and whole-milled rice rates and AGPase, SSS, and SBE activity were lower after drought treatment than during flood cultivation, while the chalkiness, chalky grain rate, amylose (16.57-20.999%), protein (7.99-12.09%), and GBSS activity were higher. Related enzymatic gene expression showed significant differences. Metabolic results showed pyruvate, glycine, and methionine upregulation at 8DAF and higher citric, pyruvic, and α-ketoglutaric acid content at 15DAF. Therefore, 8DAF-15DAF represented the crucial quality formation period for dry-cultivated rice. At 8DAF, the respiratory pathways used amino acids as signaling molecules and alternative substrates to adapt to energy shortages, arid environments and rapid protein accumulation and synthesis. Excessive amylose synthesis at 15DAF accelerated reproductive growth, promoting rapid premature aging.

The role of the chloroplast localised phosphate transporter GmPHT4;10 gene in plant growth, photosynthesis and drought resistance.

In view of the importance of inorganic phosphate to plant growth and development, the role of phosphate transporters responsible for absorption and transportation in crops has attracted increasing attention. In this study, bioinformatics analysis and subcellular localisation experiment showed that GmPHT4;10 is a member of PHT4 subfamily of phosphate transporters and located in chloroplasts. The gene was induced by phosphate deficiency and drought, and was the highest in leaves. After GmPHT4;10 gene was replenished to AtPHT4;5 gene deletion mutant lines (atpht4;5 ), the phenotype of the transgenic lines was basically recovered to the level of wild-type, but there were significant differences in phosphate content and photosynthetic indicators between wild-type and revertant lines. Meanwhile, the difference of proline content and catalase activity between the two lines also indicated that GmPHT4;10 gene and its orthologous gene AtPHT4;5 were different in drought resistance and drought resistance mechanism. After overexpression of GmPHT4;10 gene in Arabidopsis thaliana , more phosphate and proline were accumulated in chloroplasts and catalase activity was increased, thus improving photosynthesis and drought resistance of plants. The results further supplement the cognition of PHT4 subfamily function, and provides new ideas and ways to improve photosynthesis by revealing the function of chloroplast phosphate transporter.

Comprehensive sequence and expression profile analysis of the phosphate transporter gene family in soybean.

The family of phosphate transporters (PHTs) mediates the uptake and translocation of Pi inside the plants. However, little is known about transporters in soybean. Therefore, Searched the Genome Database for Soybean, 57 GmPHTs family members were identified in soybean, Phylogenetic analysis suggested that members of the PHTs gene family can be divided into six clades. Collinearity analysis revealed that most of the GmPHT genes shared syntenic relationships with PHTs members in Arabidopsis thaliana and that large segment duplication played a major driving force for GmPHTs evolution in addition to tandem duplication. Further analysis of the promoter revealed that light-responsive elements and abiotic stress-responsive elements were widely distributed within the promoter regions of GmPHT genes. Based on RNA-seq data, GmPHTs showed different expression patterns in roots and leaves of soybean treated with long-term low phosphorus and short-term low phosphorus, in addition, the expression levels of GmPHT genes can be regulated by drought stresses, it was implied that the induced expression of GmPHTs could promote phosphorus uptake and transport in soybean and thus adapt to low phosphorus and drought stress, which is the first step dissection of Pi transport system and probably refers to new roles of PHTs genes in soybean.

Transcriptomic and metabolomic reveals silicon enhances adaptation of rice under dry cultivation by improving flavonoid biosynthesis, osmoregulation, and photosynthesis.

Dry cultivation is a new rice crop mode used to alleviate water shortage and develop water-saving agriculture. There is obvious genetic difference compared with drought-tolerant rice. Silicon (Si) plays an important role in plant adaptation to adverse environmental conditions and can significantly improve the drought tolerance and yield of rice. However, the regulatory mechanism via which Si provides plant tolerance or adaptation under dry cultivation is not well understood. The present study investigated the changes in plant growth, photosynthetic gas exchange, and oxidative stress of the rice cultivar "Suijing 18" under dry cultivation. Si improved photosynthetic performance and antioxidant enzyme activity and subsequently reduced lipid peroxidation of rice seedlings, promoted LAI and promoted leaf growth under dry cultivation. Further, transcriptomics combined with quasi-targeted metabolomics detected 1416 and 520 differentially expressed genes (DEGs), 38 and 41 differentially accumulated metabolites (DAMs) in the rice leaves and roots, respectively. Among them, 13 DEGs were involved in flavonoid biosynthesis, promoting the accumulation of flavonoids, anthocyanins, and flavonols in the roots and leaves of rice under dry cultivation. Meanwhile, 14 DEGs were involved in photosynthesis, promoting photosystem I and photosystem II responses, increasing the abundance of metabolites in leaves. On the other hand, 24 DAMs were identified involved in osmoregulatory processes, significantly increasing amino acids and carbohydrates and their derivatives in roots. These results provide new insight into the role of Si in alleviating to adverse environmental, Si enhanced the accumulation of flavonoids and osmoregulatory metabolites, thereby alleviating drought effect on the roots. On the other hand, improving dehydration resistance of leaves, guaranteeing normal photosynthesis and downward transport of organic matter. In conclusion, Si promoted the coordinated action between the above-ground and below-ground plant parts, improved the root/shoot ratio (R/S) of rice and increased the sugar content and enhancing rice adaptability under dry cultivation conditions. The establishment of the system for increasing the yield of rice under dry cultivation provides theoretical and technical support thereby promoting the rapid development of rice in Northeast China, and ensuring national food security.

Convergence and Divergence: Signal Perception and Transduction Mechanisms of Cold Stress in Arabidopsis and Rice.

Cold stress, including freezing stress and chilling stress, is one of the major environmental factors that limit the growth and productivity of plants. As a temperate dicot model plant species, Arabidopsis develops a capability to freezing tolerance through cold acclimation. The past decades have witnessed a deep understanding of mechanisms underlying cold stress signal perception, transduction, and freezing tolerance in Arabidopsis. In contrast, a monocot cereal model plant species derived from tropical and subtropical origins, rice, is very sensitive to chilling stress and has evolved a different mechanism for chilling stress signaling and response. In this review, the authors summarized the recent progress in our understanding of cold stress response mechanisms, highlighted the convergent and divergent mechanisms between Arabidopsis and rice plasma membrane cold stress perceptions, calcium signaling, phospholipid signaling, MAPK cascade signaling, ROS signaling, and ICE-CBF regulatory network, as well as light-regulated signal transduction system. Genetic engineering approaches of developing freezing tolerant Arabidopsis and chilling tolerant rice were also reviewed. Finally, the future perspective of cold stress signaling and tolerance in rice was proposed.

The Divergent Roles of the Rice bcl-2 Associated Athanogene (BAG) Genes in Plant Development and Environmental Responses.

Bcl-2-associated athanogene (BAG), a group of proteins evolutionarily conserved and functioned as co-chaperones in plants and animals, is involved in various cell activities and diverse physiological processes. However, the biological functions of this gene family in rice are largely unknown. In this study, we identified a total of six BAG members in rice. These genes were classified into two groups, OsBAG1, -2, -3, and -4 are in group I with a conserved ubiquitin-like structure and OsBAG5 and -6 are in group Ⅱ with a calmodulin-binding domain, in addition to a common BAG domain. The BAG genes exhibited diverse expression patterns, with OsBAG4 showing the highest expression level, followed by OsBAG1 and OsBAG3, and OsBAG6 preferentially expressed in the panicle, endosperm, and calli. The co-expression analysis and the hierarchical cluster analysis indicated that the OsBAG1 and OsBAG3 were co-expressed with primary cell wall-biosynthesizing genes, OsBAG4 was co-expressed with phytohormone and transcriptional factors, and OsBAG6 was co-expressed with disease and shock-associated genes. ß-glucuronidase (GUS) staining further indicated that OsBAG3 is mainly involved in primary young tissues under both primary and secondary growth. In addition, the expression of the BAG genes under brown planthopper (BPH) feeding, N, P, and K deficiency, heat, drought and plant hormones treatments was investigated. Our results clearly showed that OsBAGs are multifunctional molecules as inferred by their protein structures, subcellular localizations, and expression profiles. BAGs in group I are mainly involved in plant development, whereas BAGs in group II are reactive in gene regulations and stress responses. Our results provide a solid basis for the further elucidation of the biological functions of plant BAG genes.

Construction of dominant rice population under dry cultivation by seeding rate and nitrogen rate interaction.

This study used the rice cultivar Suijing 18 to investigate the effects of morphological characteristics, photosynthetic changes, yield, as well as nitrogen absorption and utilization. The interaction between seeding rate and nitrogen rate was also assessed to identify the most suitable values of the dominant population for both factors under dry cultivation. Furthermore, the photosynthetic physiological characteristics of the upper three leaves in the dominant population were also explored. The results showed that a combination of 195 kg/ha seeding rate and 140 kg/ha nitrogen rate achieved high yield, high nitrogen utilization, and moderate morphological characteristics. This was achieved by a coordination of the combined advantages of population panicle number and spikelets per panicle. The photosynthetic potential of the population was improved by coordinating the reasonable distribution of light energy in the upper three leaves, which led to the emergence of a dominant rice population under dry cultivation.

Soybean Mutants Lacking Abundant Seed Storage Proteins Are Impaired in Mobilization of Storage Reserves and Germination.

Spontaneous and radiation-induced mutants of soybean, despite loss of abundant seed proteins, have been reported to grow and reproduce normally without any apparent physiological abnormalities. Here, we report the development and characterization of a soybean line (BSH-2) that lacks several abundant seed storage proteins. One-dimensional and high-resolution two-dimensional gel electrophoresis revealed the absence of the α' and α subunits of ß-conglycinin and G1, G2, G4, and G5 glycinin in the newly developed mutant line (BSH-2). Like our earlier developed soybean mutant line (BSH-3), the seeds of BSH-2 also accumulated high levels of free amino acids as compared with wild-type DN47 seeds. An examination of the germination rates revealed that both BSH-2 and BSH-3 had significantly lower germination rates compared with the parent line DN47. Two-dimensional gel electrophoresis analysis demonstrated that these mutants had slower rates of mobilization of seed storage proteins. The delayed mobilization of storage proteins in BSH-2 and BSH-3 seeds was also correlated with a delayed induction of proteolytic activity in the mutants when compared to DN47. Similarly, qRT-PCR analysis revealed distinct expression pattern of genes involved in proteolytic pathway in the mutants when compared to DN47. Transmission electron microscopy observation of soybean seeds at two germination stages revealed striking differences in the breakdown of protein storage vacuoles and lipid bodies in the mutants. Our study demonstrates that BSH-2 and BSH-3 are compromised in mobilization of storage reserves and the absence of abundant storage proteins may affect the seed germination efficiency and post-germinative seedling establishment.