Soil salinization is a major abiotic stress limiting wheat production. Although transcriptional responses to salt stress are well-studied, the role of posttranscriptional regulation, particularly through RNA modifications, remains unclear in wheat (Triticum aestivum L.). Here, we present an integrated analysis of the early salt stress response using Nanopore direct RNA sequencing and quantitative proteomics. We generated genome-wide maps of N6-methyladenosine (m6A) modifications, concurrently profiling alternative polyadenylation events and poly(A) tail length dynamics. This multiomics approach characterizes coordinated epitranscriptomic reprogramming and enabled the construction of a regulatory network linking m6A marks to proteomic changes. Furthermore, we identified and functionally validated the putative m6A reader protein EVOLUTIONARILY CONSERVED C-TERMINAL REGION 5 (TaECT5) as a positive regulator of wheat salt tolerance. Our study provides a systems-level view of posttranscriptional regulation during salt stress in wheat and identifies potential targets for enhancing salt tolerance.
Arabidopsis GR1 and NTRA function in pollen tube penetrating the stigma into the transmitting tract during pollination. During pollination, recognition between pollen (tube) and stigma mediates the hydration and germination of pollen, as well as the growth of the pollen tube on the stigma. Arabidopsis glutathione reductase 1 (GR1) and NADPH-dependent thioredoxin reductase A (NTRA) are involved in regulating cell redox hemostasis. Both GR1 and NTRA are expressed in pollen, but their roles in pollen germination and the growth of the pollen tube need further investigation. In this study, we performed pollination experiments and found that the Arabidopsis gr1/ + ntra/– and gr1/– ntra/ + double mutation compromised the transmission of male gametophytes. Pollen morphology and viability of the mutants did not show obvious abnormalities. Additionally, the pollen hydration and germination of the double mutants on solid pollen germination medium were comparable to those of the wild type. However, the pollen tubes with gr1 ntra double mutation were unable to penetrate the stigma and enter the transmitting tract when they grew on the surface of the stigma. Our results indicate that GR1 and NTRA play a role in regulating the interaction between the pollen tube and the stigma during pollination.
The aim was to improve the fertilizer utilization efficiency and alleviate environmental pollution risk under a wheat-maize rotation system. Here, the combinations of different nitrogen stabilizers and phosphorus activators were used to reduce nitrogen loss and phosphorus fixation in the field experiment. Compared to the control, the combination of 1.5%HQ + 0.5%DMPP + biochar showed the most significant effect on the retention of alkali-hydrolysable nitrogen (Nah), the highest with an increase of 22.6% at the 0~20 cm layer soil; and the combination of 1.5%HQ + 3.5%DCD + CMFs (compound microbial fertilizers) showed the most significant effect on the maintenance of available phosphorus (Pa), with the highest increase of 41.3%. N, P synergists combined with a basal fertilizer could effectively slow down the transformation from NH4+ to NO3−, and keep NH4+ at an increase of 7.38%~19.6%. Moreover, the N, P synergists could efficiently lock the available nutrients around the roots, preventing the migration of NO3−, NH4+, Nah, and Pa to the deeper layers. Especially for NO3−, the total accumulation at 0~60 cm decreased by 32.1%, and the activation of Pa was mainly concentrated at 0~40 cm. Under the same nutrient inputs, the combination of 0.3%NBPT + 0.5%DMPP + CMFs obtained the highest wheat yield. The combination of 1.5%HQ + 0.5%DMPP+ biochar gained the highest maize yield. Overall, the application of N, P synergists could increase the effective duration of Nah, Pa, and NH4+ in the surface soil, and reduce the accumulation of NO3− in the 0~60 cm soil layer. The capacity of holding and keeping nutrients from leaching rose obviously; simultaneously, the assimilative capacity of crops for nitrogen and phosphorus increased distinctly, which could lower the eutrophia risks from nitrogen and phosphorus.
In a wheat/maize rotation system, nitrogen (N) accounts for a large proportion of basal fertilizer, but soil N loss and the resulting environmental risk simultaneously exist worldwide. This study applied different urease/nitrification inhibitors together with basal fertilizers and investigated their effects on soil N level and grain yield. Six N stabilizing combinations consisted of two urease inhibitors (HQ and NBPT) and three nitrification inhibitors (DCD, DMPP, and Nitrapyrin). The treatments supplied with urease/nitrification inhibitors reduced, to some degree, the conversion rate of NH4+ into NO3−, and kept NH4+ content higher in surface soils for a longer time. Compared to CK, A1 treatment supplied with 1.5% HQ + 4% DCD well-maintained the levels of soil alkali-hydrolyzable N and NH4+. For example, alkali-hydrolyzable N and NH4+ contents at 0–20 cm soil layer under A1 were increased by 8.59–41.6% and 8.15–14.5% more than CK, respectively. Based on the entire growth period of wheat and maize rotation, urease/nitrification inhibitors improved soil available N in surface soils but did not prevent NH4+ and NO3− leaching, especially in the intensive rainfall season. The combinations of HQ and DCD or Nitrapyrin significantly enhanced crop yield. Specifically, crop yields under A1 and A3 (1.5% HQ + 0.25% Nitrapyrin) were 16.3% and 14.3% higher than CK, respectively. The N stabilizing combinations also promoted N intake and transport at every growth stage. The maximum N accumulation was increased by 27% under A1, when compared to CK. The treatments supplied with urease/nitrification inhibitors also achieved higher apparent N recovery efficiency, N agronomic efficiency, and N partial factor productivity. Consequently, the combinations of urease/nitrification inhibitors could improve N availability at 0–40 cm soil layer, which in turn improved N use efficiency of wheat and maize. The results suggested that the two urease/nitrification inhibitor combinations, 1.5% HQ + 4% DCD (A1) and 1.5% HQ + 0.25% Nitrapyrin (A3), were optimal N stabilizing agents and worthy of further study.
Pollen longevity is critical for plant pollination and hybrid seed production, but few studies have focused on pollen longevity. In this study, we identified an Arabidopsis thaliana gene, Protein associated with lipid droplets (PALD), which is strongly expressed in pollen and critical for the regulation of pollen longevity. PALD was expressed specifically in mature pollen grains and the pollen tube, and its expression was upregulated under dry conditions. PALD encoded a lipid droplet (LD)-associated protein and its N terminus was critical for the LD localization of PALD. The number of LDs and diameter were reduced in pollen grains of the loss-of-function PALD mutants. The viability and germination of the mature pollen grains of the pald mutants were comparable with those of the wild-type, but after the pollen grains were stored under dry conditions, pollen germination and male transmission of the mutant were compromised compared with those of the wild-type. Our study suggests that PALD was required for the maintenance of LD quality in mature pollen grains and regulation of pollen longevity.
Plant genomes encode numerous proteins with obscure features (POFs) that lack recognized domains or motifs. However, there is little functional information for POFs even in Arabidopsis because biochemical, physiological, and genetic assay are required for the functional annotations of POFs. Here, we identified a small gene family, the endoplasmic reticulum-localized POF (ERP) family, in Arabidopsis. Phylogenetic analysis revealed that the number of ERP family members was conserved in the plant kingdom, suggesting strong selective pressure was imposed on ERP family during plant evolution. No recognizable domains were identified in the predicted ERP proteins, except for the N-terminal signal peptide. ERPs were found to be widely expressed during Arabidopsis development and showed endoplasmic reticulum localization. It was reported that ERP1 is an inositol-1,4,5-trisphosphate 5-phosphatase (5PTase), but ERP1 could not substitute for At5PTase12 in precocious pollen germination, indicating that ERP1 did not have the similar functions as At5PTase12 in inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] metabolism. Further studies are needed to dissect the functions of ERP family proteins in Arabidopsis development.
为提高彩麦麸皮的综合利用率,采用联合提取法,从黑粒小麦麸皮中依次提取花青素、水溶性戊聚糖、粗膳食纤维、蛋白质、水不溶戊聚糖等功能成分.采用酸化乙醇法提取花青素,在优化最佳条件下,得率最高为13.62%;采用水提法从提取色素后的残渣中提取水溶性戊聚糖,得率最高为1.4%;采用淀粉酶法去除水溶性戊聚糖提取后残渣中的淀粉,得到粗膳食纤维,得率最高为56%;采用碱液浸提法从粗膳食纤维中提取蛋白质和水不溶性戊聚糖,采用Sevage法将蛋白质和水不溶性戊聚糖分离,蛋白质得率为6.2%,水不溶性戊聚糖得率为7.3%.
文章综述了食品加工中应用较广泛的超微粉碎、挤压膨化、超高压、超声波4种物理改性技术在食品加工副产物中的应用现状,对各种新技术的应用特点进行了总结分析,为提高食品加工副产物的利用率提供了参考.
To study the mechanism of anthocyanin-biosynthesis regulation, we examined light-regulated gene expression involved in anthocyanin biosynthesis in purple grains of wheat. Ten kinds of anthocyanins were identified from a purple-grained wheat cultivar by HPLC-ESI-MS/MS analysis. Libraries constructed from the total RNA of purple grains under light (L) or dark (D) conditions for 15 or 20 days were sequenced. In total, 1874 differentially expressed genes (DEGs) were identified in L20 vs L15, 1432 DEGs were identified in D20 vs D15, 862 DEGs were identified in D15 vs L15, and 1786 DEGs were identified in D20 vs L20. DEG functional enrichments suggested that light-signal transduction is critical to anthocyanin biosynthesis. The 911 DEGs referred to as light-regulated DEGs (LDEGs) involved a number of genes in anthocyanin biosynthesis, transcription regulation, sugar- and calcium-signaling pathways, and hormone metabolism. These findings laid the foundation for future studies on the regulatory mechanisms of anthocyanin biosynthesis in purple grains of wheat.
Plants are known for their capacity to regenerate organs, such as shoot, root and floral organs. Recently, a number of studies contributed to understanding the mechanisms of shoot and root regeneration. However, the mechanisms underlying floral organ regeneration are largely unknown. In this study, we established a carpel regeneration system in which two types of carpels were induced by exogenous cytokinin. For type I, all the floral organs in the regenerated inflorescence were transformed into carpels. For type II, carpels were generated directly from callus. The transcript level of AGAMOUS (AG), the carpel identity gene, was up-regulated during carpel induction. The expression signals of AG were detected in the initiating carpel primordia and regenerating carpels, and co-localized with those of two Type-B ARABIDOPSIS RESPONSE REGULATORs (ARRs), ARR1 and ARR10. Repression of either AG or type-B ARRs reduced carpel regeneration. Binding analyses showed that ARR1 and ARR10 directly bound to transcriptional regulatory regions of AG and positively regulated its expression. In addition, the expression of type-B ARRs overlapped with that of AG in the floral primordia in planta. Defects in type-B ARRs reduced the number of carpels. The results indicate that type-B ARRs control carpel regeneration through activating AG expression. Our results provide new information for understanding the mechanism of carpel formation.
Pollen hydration is a critical step that determines pollen germination on the stigma. KINβγ is a plant-specific subunit of the SNF1-related protein kinase 1 complex (SnRK1 complex). In pollen of the Arabidopsis kinβγ mutant, the levels of reactive oxygen species were decreased which lead to compromised hydration of the mutant pollen on the stigma. In this study, we analyzed gene expression in kinβγ mutant pollen by RNA-seq and found the expression of inward shaker K+ channel SPIK was down-regulated in the kinβγ pollen. Furthermore, we showed that the pollen hydration of the Arabidopsis spik mutant was defective on the wild-type stigma, although the mutant pollen demonstrated normal hydration in vitro. Additionally, the defective hydration of spik mutant pollen could not be rescued by the wild-type pollen on the stigma, indicating that the spik mutation deprived the capability of pollen absorption on the stigma. Our results suggest that the Arabidopsis SnRK1 complex regulates SPIK expression, which functions in determining pollen hydration on the stigma.
De novo shoot regeneration is widely used in fundamental studies and agricultural applications. Actin microfilaments are involved in many aspects of plant cell division, cell morphogenesis and cell signal transduction. However, the function of actin microfilaments during de novo shoot regeneration is poorly understood. Here, we investigated the organization of actin microfilaments during this process and found that stem cell formation was associated with microfilament depolymerization. Furthermore, inhibition of microfilament depolymerization by phalloidin treatment or downregulation of actin depolymerizing factors (ADFs) restrained stem cell initiation and shoot regeneration. Inhibition of ADF expression affected the architecture of microfilaments during stem cell formation, and the polar transport and distribution of auxin were also disrupted. Together, our results demonstrate that organization of the microfilament cytoskeleton play important roles in stem cell formation and shoot meristem induction during shoot regeneration.
In order to develop a kind of cookies that integrated nutrition and tasty,purple wheat flour were employed as the main raw material in this experiment,on the basis of the single-factor test and according to Box-Benhnken design,the interaction of butter addition,sugar addition,water addition and their influence on sensory evaluation score of color wheat cookie were investigated.The production forum of color wheat cookie was optimized by response surface methodology.The results of the experiment demonstrated that the optimized forum were as follows:color wheat powder was 40.00 g,butter was 27.53 g,sugar was 13.09 g,water was 6.77 g.The sensory index of verification experiment was 92.10.It was basically consistent with the theoretical value 92.21,these revealed that the result optimized by response surface analysis had practical guiding significance.
DNA methylation plays a critical role in diverse biological processes of plants. Arabidopsis DNA METHYLTRANSFERASE1 (MET1) represses shoot regeneration by inhibiting WUSCHEL (WUS) expression, which is essential for shoot initiation. However, the upstream signals regulating MET1 expression during this process are unclear. We analyzed the signals regulating MET1 expression using a number of established strategies, such as genetic analysis, confocal microscopy, quantitative real-time PCR and chromatin immunoprecipitation. MET1 expression patterns underwent dynamic changes with the initiation of WUS during shoot regeneration. The cell cycle regulator E2FA was characterized as an upstream factor directly promoting MET1 expression. Moreover, cytokinin promoted MET1 expression partially by enhancing CYCD3 expression. Our findings reveal that MET1-mediated shoot regeneration is regulated by the cytokinin-induced cell cycle, and provide new insights into the regulation of DNA methylation in shoot regeneration.
BACKGROUND:Phytohormone synergies and signaling interdependency are important topics in plant developmental biology. Physiological and genetic experimental evidence for phytohormone crosstalk has been accumulating and a genome-scale enzyme correlation model representing the Arabidopsis metabolic pathway has been published. However, an integrated molecular characterization of phytohormone crosstalk is still not available.RESULTS:A novel modeling methodology and advanced computational approaches were used to construct an enzyme-based Arabidopsis phytohormone crosstalk network (EAPCN) at the biosynthesis level. The EAPCN provided the structural connectivity architecture of phytohormone biosynthesis pathways and revealed a surprising result; that enzymes localized at the highly connected nodes formed a consecutive metabolic route. Furthermore, our analysis revealed that the transcription factors (TFs) that regulate enzyme-encoding genes in the consecutive metabolic route formed structures, which we describe as circular control units operating at the transcriptional level. Furthermore, the downstream TFs in phytohormone signal transduction pathways were found to be involved in the circular control units that included the TFs regulating enzyme-encoding genes. In addition, multiple functional enzymes in the EAPCN were found to be involved in ion and pH homeostasis, environmental signal perception, cellular redox homeostasis, and circadian clocks. Last, publicly available transcriptional profiles and a protein expression map of the Arabidopsis root apical meristem were used as a case study to validate the proposed framework.CONCLUSIONS:Our results revealed multiple scales of coupled mechanisms in that hormonal crosstalk networks that play a central role in coordinating internal developmental processes with environmental signals, and give a broader view of Arabidopsis phytohormone crosstalk. We also uncovered potential key regulators that can be further analyzed in future studies.
Fluorescence microscopy has some advantages for the observation of plant cells and tissues over the ordinary optical microscopy.Some teaching contents of botany experiment using fluorescence microscopy carried out in our college were summarized,including observing the cell and tissue structures by using the auto fluorescence from chlorophyll and lignin,observing the specific structures of plant cell(such as nucleus and vacuole) by using fluorescence dyes,observing the secondary cell wall of tissue by using the paraffin section stained by safranin and fast green.The above-mentioned experiments are useful for students to grasp the specific structures of plant cell and tissue,which is a beneficial supplementary for the botany experiment.
采用顶空固相微萃取(HS-SPME)和气相色谱-质谱联用(GC-MS)对紫糯配粉与普通馒头的挥发性物质进行提取、鉴定与分析.结果表明:馒头加工过程中挥发性成分物质共检测出61种.紫糯配粉馒头与普通馒头检测出25种共有成分;紫糯配粉面团与普通发酵面团分别检测出30和27种挥发性物质,其中23种共有成分中含量较高的物质;紫糯配粉与普通小麦面粉检测出22种共有成分.紫糯配粉特殊香气的来源应为紫糯配粉中高含量的特有物质苊烯、正辛醇、正己醇.
To investigate the effect of NO on the different origin and regulation of oxidative stress of Cu and/or Cd, tomato seedlings were treated with Cu, Cd, or Cu + Cd in a nutrient solution culture system. The main effect of Cu2+ was a significant reduction in root activity and nitrate reductase (NR) activity, which was similar to that under 50 μM Cd treatment, but promoted Cu accumulation. The supply of Cu under Cd treatment decreased Cd concentration, while not altered Cu concentration by contrast with Cu treatment, which is suggestive of a replacement of Cu2+ with Cd2+ and effective decrease in the boiotoxicity of 50 μM Cd2+ to tomato seedlings. However, NO alleviated the restriction to NR activity significantly and made the biomass of tomato seedlings recover under Cd treatment, and also increased root activity under Cu and Cu + Cd treatment. Exogenous NO markedly reduced the absorption and transportation of Cu but did not obviously change the translocation of Cd to the aboveground parts under Cu + Cd treatment. Both metals induced lipid peroxidation via the decreasing activation of antioxidant enzymes. The antioxidant enzyme system worked differently under Cu, Cd, or Cu + Cd stress. The activities of peroxidase (POD) and catalase (CAT) were higher under single Cd stress than under the control. Meanwhile, Cu + Cd treatment decreased the activities of POD, superoxide dismutase (SOD), and ascorbic acid peroxidase (APX). Exogenous NO increased POD and SOD activities in the leaves and roots, and CAT activity in the roots under combined Cu and Cd stress. These results suggest that a different response and regulation mechanism that involves exogenous NO is present in tomato seedlings under Cu and Cd stress.
糯小麦粉由于直链淀粉含量很低而被赋予其独特的理化性质.本实验对山农新培育出的紫糯小麦品种制粉的理化和营养性质进行了测定,并与普通小麦粉配粉制作馒头,通过质构仪检测试验和感观评价相结合的方法对馒头品质进行了研究,从而确定了山东农业大学新培育紫糯小麦品种开发馒头产品的最佳工艺.试验结果表明:山农紫糯小麦粉的脂肪、蛋白质、灰分和蛋白质中清蛋白、醇溶蛋白、谷蛋白含量比普通面粉高,而淀粉和球蛋白含量比普通面低;其糊透明度、谷值黏度、最终黏度、糊化温度较低,但崩解值、峰值黏度、回生值高.添加15%的紫糯小麦粉可显著的改善馒头的表皮色泽,并且对馒头的弹性、黏着性、黏聚性和回复性影响最大,此时馒头的总评分达到最大值.
It is difficult to derive all qualitative proteomic and metabolomic experimental data in male (pollen tube) and female (pistil) reproductive tissues during pollination because of the limited sensitivity of current technology. In this study, genome-scale enzyme correlation network models for plants (Arabidopsis/maize) were constructed by analyzing the enzymes and metabolic routes from a global perspective. Then, we developed a data-driven computational pipeline using the "guilt by association" principle to analyze the transcriptional coexpression profiles of enzymatic genes in the consecutive steps for metabolic routes in the fast-growing pollen tube and stigma during pollination. The analysis identified an inferred pattern of pollen tube-stigma ethanol coupling. When the pollen tube elongates in the transmitting tissue (TT) of the pistil, this elongation triggers the mobilization of energy from glycolysis in the TT cells of the pistil. Energy-rich metabolites (ethanol) are secreted that can be taken up by the pollen tube, where these metabolites are incorporated into the pollen tube's tricarboxylic acid (TCA) cycle, which leads to enhanced ATP production for facilitating pollen tube growth. In addition, our analysis also provided evidence for the cooperation of kaempferol, dTDP-alpha-L-rhamnose and cell-wall-related proteins; phosphatidic-acid-mediated Ca2+ oscillations and cytoskeleton; and glutamate degradation IV for γ-aminobutyric acid (GABA) signaling activation in Arabidopsis and maize stigmas to provide the signals and materials required for pollen tube tip growth. In particular, the "guilt by association" computational pipeline and the genome-scale enzyme correlation network models (GECN) developed in this study was initiated with experimental "omics" data, followed by data analysis and data integration to determine correlations, and could provide a new platform to assist inachieving a deeper understanding of the co-regulation and inter-regulation model in plant research.