Drought stress severely impairs wheat growth and metabolic homeostasis, with seedlings being highly sensitive. Exogenous sodium nitroprusside (SNP) enhances plant drought tolerance by boosting antioxidant activity, regulating stomatal movement, and promoting osmolyte accumulation, yet its metabolic mechanism in mediating wheat seedling drought responses remains unclear. Using drought-sensitive Zhoumai 18 and drought-tolerant Zhengmai 1860, we investigated SNP’s alleviating effect on drought stress and its metabolic regulatory mechanism via physiological-biochemical assays and untargeted metabolomics. SNP pretreatment mitigated drought-induced damage in both cultivars: it maintained leaf relative water content, reduced cell membrane permeability, increased proline/soluble sugar accumulation, and enhanced activities of antioxidants. Metabolomic analysis revealed SNP primarily regulated arginine-proline metabolism: it upregulated Δ1-pyrroline-5-carboxylate synthetase (P5CS) and pyrroline-5-carboxylate reductase (P5CR) genes to promote proline synthesis, downregulated proline dehydrogenase (ProDH) to inhibit degradation, and modulated polyamine synthesis-related genes, including ornithine decarboxylase (ODC), arginine decarboxylase (ADC), spermidine synthase (SPDS), and S-adenosylmethionine decarboxylase (SAMDC) genes. Notably, the two cultivars showed distinct metabolic responses to SNP. In Zhengmai 1860, SNP coordinated arginine metabolic flux, prioritizing ornithine toward proline synthesis via enhanced P5CS/P5CR, driving significant proline accumulation. In Zhoumai 18, proline biosynthesis relied on the glutamate pathway, while induced ProDH accelerated degradation, leading to much lower proline levels than Zhengmai 1860. This difference in arginine flux distribution and proline synthesis-degradation balance underlies their divergent drought tolerance. Our study provides new insights into SNP-mediated metabolic regulation in wheat drought responses and a theoretical basis for drought-tolerant wheat breeding targeting arginine-proline metabolism.

Soil salinization and alkalization severely constrain crop production worldwide, yet the combined effects of mixed saline-alkaline stress on minor cereal germination have received limited investigation. This study sought to elucidate the effects of mixed saline-alkaline stress on seed germination and seedling growth of proso millet (Panicum miliaceum L.) under controlled laboratory conditions, and to comparatively assess the relative contributions of osmotic stress, ionic toxicity, and high-pH damage through analysis of different neutral-to-alkaline salt ratios at equivalent Na⁺ concentrations. Seeds were subjected to nine treatment combinations comprising three salinity levels (80, 160, and 240 mM Na⁺) and three neutral-to-alkaline salt ratios (3:1, 1:1, and 1:3), employing NaCl, Na₂SO₄, NaHCO₃, and Na₂CO₃. Germination characteristics, seedling morphology, and key physiological parameters were assessed over seven days. Mixed saline-alkaline stress markedly suppressed germination in a concentration-dependent manner, with germination percentage decreasing from 94.5% (control) to 23.8% at 240 mM Na⁺ under high-alkali conditions (P < 0.05). At equivalent Na⁺ concentrations, high-alkali treatments (pH > 9.5) diminished germination index by 35.6-52.3% relative to low-alkali treatments. The IC₅₀ values were 187.3 mM Na⁺ (95% CI: 171.2-205.8 mM; R² = 0.982), 142.6 mM Na⁺ (95% CI: 131.4-155.1 mM; R² = 0.976), and 98.4 mM Na⁺ (95% CI: 89.7-108.3 mM; R² = 0.991) for low-, medium-, and high-alkali ratios, respectively. High-alkali stress was associated with 67.4% greater electrolyte leakage and 2.3-fold higher MDA accumulation than neutral salt treatments at equivalent Na⁺ concentrations, indicating greater membrane disruption under high-pH conditions. Two-way ANOVA revealed significant main effects of both Na⁺ concentration and alkaline proportion, as well as a significant salinity × alkalinity interaction (P < 0.001; Supplementary Table S1). These results demonstrate that alkaline stress exerts stronger inhibitory effects on proso millet germination compared to neutral salt stress, with the magnitude of salinity effects being dependent on the pH level. While complete mechanistic separation of osmotic, ionic, and pH components was not achieved due to experimental design limitations (absence of iso-osmotic non-ionic controls and direct ion measurements), comparative analysis across salt ratio treatments suggests that high pH is associated with additional inhibitory effects beyond those observed in neutral salt treatments. These controlled-condition findings establish preliminary germination -stage thresholds that may inform screening protocols for saline-alkaline tolerance breeding in proso millet, pending validation under field conditions.

Curriculum ideological and political education is a way for higher education institutions to achieve the overall goal of moral education in the new era. Plant Physiology is the foundation course for the major of plant production at higher agricultural institutions, so there is rich material for ideological and political education. In accordance with the construction of new agricultural science and the strategy of serving national food security and rural revitalization, the teaching team of Plant Physiology at Henan Agricultural University has systematically carried out the following five tasks to build a trinity curriculum ideological and political education system of "knowledge transmission - ability cultivation - value guidance": reconstruction of teaching objectives, excavation of ideological and political elements, innovation of teaching models, reform of experimental teaching, and optimisation of assessment and evaluation. After many years of exploration and practice, this course has been named the Henan Provincial Quality Online Open Course and a first-class online course, and students have shown good progress in their professional ability, patriotism and practical skills. Systematically summarize the practical experience and theoretical reflection of building ideological and political education in the Plant Physiology course at Henan Agricultural University, provide a reference for the ideological and political education of foundational courses in agriculture-related majors, etc.

Drought stress severely damages wheat growth and photosynthesis, and plants at the grain-filling stage are the most sensitive to drought throughout the entire period of development. Exogenous spraying of sodium nitroprusside (SNP) can alleviate the damage to wheat caused by drought stress, but the mechanism regulating the proline pathway remains unknown. Two wheat cultivars, drought-sensitive Zhoumai 18 and drought-tolerant Zhengmai 1860, were used as materials when the plants were cultivated to the grain-filling stage. The results show that under drought stress, SNP pretreatment effectively improved the physiological basis of photosynthesis and water use efficiency of the two cultivars, increased their tolerance to photosystem II (PSII) damage, and maintained a normal photosynthetic rate and yield. Drought stress induced an increase in pyrroline-5-carboxylate synthase (TaP5CS) gene transcription, and a comparatively greater increase was detected in Zhengmai 1860. When SNP treatment was applied before drought exposure, TaP5CS transcription was further enhanced. Induction of TaP5CS transcription promoted proline accumulation in response to drought stress, increased osmotic ability, and maintained the net photosynthetic rate, thereby increasing the accumulation of dry matter and yield traits. In this study, exogenous SNP regulates the transcription of genes related to the proline metabolism pathway and provides a theoretical basis for the establishment of wheat cultivation technology using SNP to resist drought stress.

Chloroplasts are highly sensitive to heat stress. While we have previously demonstrated that chloroplast-localized small heat shock protein 26 (sHSP26) protects maize (Zea mays) photosynthetic systems from thermal damage and undergoes heat stress-induced phosphorylation, the responsible kinases and functional significance of this phosphorylation remain unknown in maize thermotolerance. In this study, we identify a chloroplast-localized casein kinase 2 (cpCK2) in maize. ZmcpCK2 expression is up-regulated by ABA and heat stress. Genetic evidence reveals that Zmcpck2-KO lines exhibit more severe chloroplast structural damage, reduced ABA content, and increased heat sensitivity compared to wild-type plants under thermal stress. Notably, ABA pretreatment restores thermotolerance in knockout lines to wild-type levels. Furthermore, biochemical characterization demonstrates that ZmcpCK2 specifically phosphorylates sHSP26 at Ser32. Structure-function analysis shows that while the phospho-dead mutant sHSP26S32A maintains normal subcellular localization and protein interactions, its overexpression confers significantly less protection of photosystem II (PSII) activity and chloroplast protein stability during heat stress compared to the wild-type sHSP26. Integrated phosphoproteomic and transcriptomic analyses reveal that ZmcpCK2 dysfunction triggers retrograde signaling that regulates the expression of nuclear-encoded genes, including those involved in ABA biosynthesis, sHSP26, and heat shock factor HSFA3. Importantly, we establish a regulatory cascade where HSFA3 activates sHSP26 expression by directly binding its promoter, while ABA positively regulates HSFA3 and sHSP26 expression. Our findings elucidate a crucial ZmcpCK2-ABA-HSFA3-sHSP26 module in maize chloroplast thermotolerance, providing valuable molecular targets for developing heat-resistant maize varieties.

TaZAT8-5B, a C2H2 zinc finger protein transcription factor, positively regulates drought tolerance in transgenic Arabidopsis. It promotes root growth under drought stress via the Aux/IAA-ARF module in the auxin signaling pathway. C2H2 zinc finger proteins (C2H2-ZFPs) represent the largest but relatively unexplored family of transcription factors in plants. This is particularly evident in wheat, where the functions of only a few C2H2-ZFP genes have been confirmed. In this study, we identified a novel C2H2-ZFP gene, TaZAT8-5B. This gene shows high expression in roots and flowers and is significantly induced by heat, drought, and salt stress. Under drought stress, overexpressing TaZAT8-5B in Arabidopsis resulted in increased proline content and superoxide dismutase (SOD) activity in leaves. It also led to reduced stomatal aperture and water loss, while inducing the expression of P5CS1, RD29A, and DREB1A. Consequently, it alleviated drought stress-induced malondialdehyde (MDA) accumulation and improved drought tolerance. Additionally, TaZAT8-5B promoted lateral root initiation under mannitol stress and enhanced both lateral and primary root growth under long-term drought stress. Moreover, TaZAT8-5B was induced by indole-3-acetic acid (IAA). Overexpressing TaZAT8-5B under drought stress significantly inhibited the expression of auxin signaling negative regulatory genes IAA12 and IAA14. Conversely, downstream genes (ARF7, LBD16, LBD18, and CDKA1) of IAA14 and IAA12 were upregulated in TaZAT8-5B overexpressing plants compared to wild-type (WT) plants. These findings suggest that TaZAT8-5B regulates root growth and development under drought stress via the Aux/IAA-ARF module in the auxin signaling pathway. In summary, this study elucidates the role of TaZAT8-5B in enhancing drought tolerance and its involvement in root growth and development through the auxin signaling pathway. These findings offer new insights into the functional analysis of homologous genes of TaZAT8-5B, particularly in Gramineae species.

To explore the possible novel microRNA (miRNA) regulatory pathways in Zhengmai 1860, a newly cultivated drought-tolerant wheat (Triticum aestivum L.) cultivar, miRNA transcriptome sequencing of the flag leaves of Zhengmai 1860, drought-sensitive variety Zhoumai 18, and drought-resistant variety Bainong 207 was performed during the grain filling stage. We also observed changes in the chloroplast ultrastructure, phytohormone levels, and antioxidant- and photosynthesis-related physiological indicators in three wheat varieties. The results showed that the flag leaves of the drought-tolerant variety Zhengmai 1860 had higher chlorophyll contents and net photosynthetic rates than those of Zhoumai 18 under drought stress during the grain filling stage; in addition, the chloroplast structure was more complete. However, there was no significant difference between Zhengmai 1860 and Bainong 207. MiRNA transcriptome analysis revealed that the differential expression of the miRNAs and mRNAs exhibited variable specificity. The KEGG pathway enrichment results indicated that most of the genes were enriched in the MAPK signaling pathway, plant hormone signal transduction, photosynthetic antennae protein, and amino acid and carbohydrate metabolism. In the drought-tolerant cultivar Zhengmai 1860, tae-miR408 was targeted to regulate the allene oxide synthase (AOS) gene, inhibit its expression, reduce the AOS content, and decrease the synthesis of jasmonic acid (JA) and abscisic acid (ABA). The results of this study suggest that Zhengmai 1860 could improve the photosynthetic performance of flag leaves by inhibiting the expression of genes involved in the JA pathway through miRNAs under drought conditions. Moreover, multiple miRNAs may target chlorophyll, antioxidant enzymes, phytohormone signal transduction, and other related pathways; thus, it is possible to provide a more theoretical basis for wheat molecular breeding.

Psb28 is a soluble protein in the photosystem II (PSII) complex, but its role in the drought stress response of wheat remains unclear. Here, we functionally characterized the TaPsb28 gene, which positively regulates drought tolerance in wheat. When the full-length 546-bp TaPsb28 cDNA was transferred into Arabidopsis thaliana, it was located in the guard cell chloroplast around the stroma. Overexpression of TaPsb28 conferred drought tolerance, as exhibited by the increases in the survival rate. Transgenic plants maintained lower MDA content and higher chlorophyll content by inducing chlorophyll synthase (ChlG) gene transcription. The content of abscisic acid (ABA) and zeatin increased significantly in wild-type (WT) plants under drought stress, and the transcriptional expression levels of RD22, dihydroflavonol 4-reductase (DFR) and anthocyanin reductase (ANR) genes were induced, thus enhancing the contents of endogenous cyanidin, delphinidin, and proanthocyanidins. However, in transgenic plants, although anthocyanins were further aggregated, the ABA increase was inhibited, zeatin was restored to the control level under drought stress, and stomatal closure was promoted. These findings indicate ABA and zeatin have opposite synergistic effects in the process of drought tolerance caused by TaPsb28 because only after the effect of zeatin is alleviated can ABA better play its role in promoting anthocyanin accumulation and stomatal closure, thus enhancing the drought tolerance of transgenic plants. The results suggest that overexpression of TaPsb28 exerts a positive role in the drought response by influencing the functional metabolism of endogenous hormones. The understanding acquired through the research laid a foundation for further in-depth investigation of the function of TaPsb28 in drought resistance in wheat, especially its relationship with anthocyanidin accumulation.

一、“互联网+”对继续教育的影响 知识经济时代下，成人高等教育是高等教育的重要组成部分。特别是进入21世纪以来，成人教育的内涵进一步扩大，“终身化”和“继续化”成为这一阶段成人教育最显著的特点，这也从侧面说明，发展成人教育是构建学习化社会的重要组成部分^([1][2])。

Drought stress during the grain-filling stage damages the photosynthetic physiology of wheat ( Triticum aestivum L.) and causes significant yield losses. To investigate the responses of polyamine synthesis of different wheat cultivars to drought stress and rewatering in the grain filling stage, a new cultivar, Zhengmai 1860, with high yields and high resistance characteristics, was selected as cultivar. The results showed that the net photosynthetic rate ( P n ), intercellular CO 2 concentration ( C i ), stomatal conductance ( g s ) and water use efficiency (WUE) of Zhengmai 1860 were significantly higher than those of Zhoumai 18 under drought stress. Compared with drought sensitive Zhoumai 18 cultivar, Zhengmai 1860 could induce the expression of polyamine synthesis-related enzyme genes, promote polyamine synthesis through both the directly and ornithine metabolism pathway of arginine, and the methionine metabolism pathway, maintain the balance of substances involved in osmotic regulation. Meanwhile, transcript levels of rbcL and rbcS were maintained, which thus protected the integrity of chloroplasts and thylakoid membrane ultrastructure as observed by transmission electron microscopy. After rewatering following drought exposure, the thylakoid lamellae of Zhengmai 1860 were arranged in an orderly manner, and the actual photochemical efficiency and net photosynthetic rate recovered more significantly. Therefore, Zhengmai 1860 maintained high grain yields when rewatering was applied after 7 days of drought stress. The results of this study indicated that the synthesis ability of endogenous polyamines was closely related to the drought stress tolerance in the grain filling stage, which could provide a reference for breeding drought-tolerant wheat cultivars.

在互联网和信息化技术快速发展的"知识经济"时代,社会人才的培养更强调自主学习和解决问题的能力.该文基于OBE理念,从课前调研、课堂教学设计、课后反馈和教学效果评价等方面在植物生理学课程中构建了PBL+LBL的教学模式.经过两年的实践结果显示,PBL+LBL教学模式明显增强学生学习兴趣,对知识点的掌握更加灵活,实际应用能力也不断提升.PBL+LBL的教学模式为新时期创新型、应用型人才的培养奠定基础.

Progesterone is a steroid hormone that performs important functions in mammals. However, studies on its physiological functions in plants have gradually increased in recent years. Therefore, this review summarizes the regulatory functions of progesterone on plant growth and development, as well as its response to stress. Moreover, the plant metabolic processes of progesterone are also discussed. Overall, progesterone is ubiquitous in plants and can regulate numerous plant physiological processes at low concentrations. Since progesterone shares similar characteristics with plant hormones, it is expected to become a candidate for plant hormone. However, most of the current research on progesterone in plants is limited to the physiological level, and more molecular level research is needed to clarify progesterone signaling pathways.

Endodormancy is the stage that perennial plants must go through to prepare for the next seasonal cycle, and it is also an adaptation that allows plants to survive harsh winters. Blueberries (Vaccinium spp.) are known to have high nutritional and commercial value. To better understand the molecular mechanisms of bud dormancy release, the transcriptomes of flower buds from the southern highbush blueberry variety “O’Neal” were analyzed at seven time points of the endo- and ecodormancy release processes. Pairwise comparisons were conducted between adjacent time points; five kinds of phytohormone were identified via these processes. A total of 12,350 differentially expressed genes (DEGs) were obtained from six comparisons. Gene Ontology analysis indicated that these DEGs were significantly involved in metabolic processes and catalytic activity. KEGG pathway analysis showed that these DEGs were predominantly mapped to metabolic pathways and the biosynthesis of secondary metabolites in endodormancy release, but these DEGs were significantly enriched in RNA transport, plant hormone signal transduction, and circadian rhythm pathways in the process of ecodormancy release. The contents of abscisic acid (ABA), salicylic acid (SA), and 1-aminocyclopropane-1-carboxylate (ACC) decreased in endo- and ecodormancy release, and the jasmonic acid (JA) level first decreased in endodormancy release and then increased in ecodormancy release. Weighted correlation network analysis (WGCNA) of transcriptomic data associated with hormone contents generated 25 modules, 9 of which were significantly related to the change in hormone content. The results of this study have important reference value for elucidating the molecular mechanism of flower bud dormancy release.

5-Aminolevulinic acid (ALA), as a precursor of plant chlorophyll synthesis, can alleviate damage to photosynthesis and thus improve the drought resistance of plants, but the mechanism behind this is still obscure, especially its correlation with functional gene transcription and noncoding RNA regulation. The leaves were collected from Aikang-58 wheat seedlings subjected to drought stress and exogenous ALA application for ultrastructure observation and gene transcription analysis. The results indicated that drought stress attenuated the photosynthesis evidenced by the decrease of net photosynthetic rate (P-n) and stomatal conductance (g(s)), damaged the chloroplast ultrastructure by destroying the thylakoid matrix, degrading the chlorophyll, and leading to lipid peroxidation of the cells due to the toxicity of free radicals, causing lipids to dissociate and combine with osmium acid to form plastoglobuli. Under drought stress, exogenous ALA pretreatment can increase the transcript abundance of the chlorophyll synthesis-related genes. Moreover, exogenous ALA increased psb28 transcript abundance under drought stress, to alleviate the damage to the chloroplast ultrastructure and photosynthesis. Our data revealed the possible gene transcriptional regulation patterns in response to drought stress and exogenous ALA alleviation.

在"停课不停学"背景下,为保障植物生理学课程的顺利实施,植物生理学课程组整合多种教学资源,借助中国大学MOOC、超星学习通、腾讯会议等多平台系统,合理地构建了网络课程体系;并利用微信、QQ等即时聊天工具,时刻保持有效的师生互动;最后在课程设计中也融入了评价与反馈相结合、引导式与讨论并重的理念,并将思政教育贯穿线上教学全程,不仅确保了植物生理学课程线上教学任务的顺利完成,同时也取得了良好的教学效果.

植物生理学几乎涵盖了农学、林学、植保、生命科学等专业,在学生的专业素质培养过程中起着承上启下的作用.随着信息化技术的快速发展,传统的教学方法和教学形式已经不能满足新时期复合型人才培养的需求.教学团队基于MOOC平台构建了线上线下混合教学模式,通过精心设置教学资源、多种教学方式并举、引导学生自主学习、采用过程性评价方法等措施,探索提升人才培养质量的路径和策略.

植物生理学实验除了对理论知识的验证,还应启发学生对相关科学领域的思考和探索.但长期以来由于"灌输式"的教学模式,实验项目和内容缺乏设计,考核模式单一等问题,导致学生积极性不高,创新能力培养不足.因此,河南农业大学从教学方法、教学内容和设计、实验方法及考核方式等方面对植物生理学实验教学进行改革,以增强学生兴趣,提高学生创新和实践能力,助力学生科学思维能力的培养.

半胱氨酸脱巯基酶(CDes)可催化降解半胱氨酸(Cys)生成硫化氢(H2S).通过克隆小麦(Triticum aestivum)中的L-半胱氨酸脱巯基酶基因TaLCD,并将其在拟南芥(Arabidopsis thaliana)中过表达,探讨TaLCD对渗透胁迫条件下种子萌发和根系生长的影响,并分析其对干旱胁迫的调节作用.结果 显示,盐胁迫条件下,TaLCD过表达植株种子萌发率显著高于野生型;甘露醇处理条件下,TaLCD过表达植株的根长也显著高于野生型,且TaLCD过表达显著提高植株抗旱性.此外,TaLCD过表达植株对ABA更加敏感,ABA处理下TaLCD过表达植株的种子萌发率及根长均显著低于野生型.干旱胁迫下,TaLCD过表达植株胁迫响应基因(COR47、RD29A、RAB18和RD22)及ABA信号途径相关基因(NCED3、HAB1、HAB2、ABI1、ABI2和ABF2)的表达水平均显著高于野生型.因此推测,TaLCD增强植株抗旱和抗盐能力可能依赖于ABA信号途径.

Cysteine desulfhydrase (CDes) can catalyze the degradation of cysteine producing hydrogen sulfide. In this study, d-cysteine desulfhydrase from wheat (TaD-CDes) was cloned and overexpressed in Arabidopsis thaliana. The physiological effects of TaD-CDes were determined by investigating seed germination, root growth, stomatal closure, and drought resistance in the TaD-CDes plants. Results showed that, compared with wild-type plants (WT), seed germination, root growth, and stomatal closure of the TaD-CDes plants were more sensitive to ABA, resulting from up-regulation of ABA-responsive genes (such as PYR1, ABI1, ABI2, HAB1, HAB2, SnRK2, ABF2, and ABF4). Moreover, although TaD-CDes mediated ABA-induced stomatal closure, TaD-CDes-overexpressing plants did not show higher drought resistance than WT, which might be attributed to their increased stomatal densities.

Drought is an environmental factor that deeply impacts wheat yield and quality. Hydrogen sulfide (H2S) is a known regulator of drought resistance in plants. To preliminarily elucidate the regulatory mechanisms of H2S on drought tolerance, the effects of H2S on drought-responsive genes were investigated by transcriptome analysis. As a result, a total of 7552 transcripts not only responded to drought stress but also exhibited differential expression relative to the polyethylene glycol (PEG) treatment (P) and the NaHS pretreatment with PEG treatment (SP). GO categories of 'transport' were especially enriched under the SP treatment and ion transport categories (especially 'iron ion transport') were more significantly enriched among up-regulated transcripts in SP versus P treatments (SP.vs.P). Indeed, a higher translocation of iron from root to shoot and iron availability in shoots was detected in SP compared to P. The KEGG pathway of 'ribosome biogenesis in eukaryotes', 'protein processing in endoplasmic reticulum', 'fatty acid degradation', and 'cyanoamino acid metabolism' was induced by H2S under drought stress. Further, H2S was involved in plant hormones signal transduction, and drought-induced transcription factors, protein kinases, and functional genes exhibited higher expression levels under SP relative to P. Additionally, several effectors or master regulatory genes of H2S were identified genome-wide. Summarily, these results showed that H2S alleviated drought damage probably related to transport systems, plant hormones signal transduction, protein processing pathway, fatty acids and amino acids metabolism, which provides a guide for future experimentation to analyze hydrogen sulfide-dependent drought tolerance mechanisms in wheat.