In 2024, the numbers of original research articles published by Chinese plant scientists in mainstream plant science journals increased significantly compared with that in 2023, and important advances have been made in the fields of plant hormone regulation, pathology, synthetic biology, stress resistance mechanism, phylogenetics and genomics. Among them, “Characterization and Heterologous Reconstitution of Taxus Biosynthetic Enzymes Leading to Baccatin III”, and “Reciprocal Conversion Between Annual and Polycarpic Perennial Flowering Behavior in the Brassicaceae” were selected as two of the “Top Ten Advances in Life Sciences in China” in 2024. Here we summarize the achievements of plant science research in China in 2024, by briefly introducing 50 representative important research advances, so as to help readers understand the trend of plant science development in China, and evaluate future research direction to meet major national strategic needs.

The external environment severely affects growth and development of plants. In recent years, the increasing extreme climates have posed a serious threat to the growth and development of plants. Understanding the regulatory mechanisms of plant stress tolerance is of great significance for ensuring the survival and development of plants (especially economic crops) and their yields. Alternative splicing is an important post-transcriptional regulatory mechanism and plays an important role in the diversity of plant gene functions and stress resistance. At present, a variety of alternative splicing variants of stress-resistant related genes have been identified in different plant species, and several regulatory mechanisms involved in alternative splicing have been elucidated, effectively advancing the relevant theoretical basis for plant stress resistance in plants. This paper reviews the types and splicing mechanisms of alternative splicing in plants, highlights the recent progress in alternative splicing regulation of plant responses to abiotic stress, and provides a prospect for the future direction of research on alternative splicing in plants.

Maize (Zea mays) is the main crop in China, and drought is a primary abiotic stress during its growth, resulting in direct reduction in grain yield and quality, thereby posing a threat to food security within the global climate context. At present, global climate change leads to extreme weather events, which aggravates the adverse effects on yield. Therefore, it is imperative to identify drought-resistant germplasm resources, elucidate the molecular mechanisms of drought stress response, and breed drought-resistant varieties. Here, we review recent advances in the genetic dissection of drought resistance in maize using methods such as genome-wide association study, quantitative trait locus gene cloning and multi-omics analysis. Additionally, we introduce potential strategies for genetic improvement of drought resistance by leveraging the identified genetic resources while discussing future perspectives within this research area.

Single-cell transcriptomics has improved the spatiotemporal resolution from multi-cell to single-cell levels, and notable progress in this technique has facilitated the identification of new rare cell types, exploration of intercellular heterogeneity, and mapping of cell developmental trajectories. Single-cell transcriptomics is currently being widely used in various research fields such as plant growth and development, stress response, and environmental adaptability, which helps to more thoroughly and precisely uncover the molecular regulatory mechanisms underlying plant life processes. However, there are numerous challenges associated with the study and analysis of different plant species. In this review, we compare and evaluate various single-cell transcription techniques and processes, summarize plant single-cell studies in recent years, and explore new single-cell analysis tools to support researchers studying plant biology with high precision and dynamics. In addition, we propose future directions in using single-cell transcriptomics technologies to address some of the key challenges in plant research and breeding. Furthermore, some important methods for addressing plant research and breeding with single-cell transcriptomics are discussed, along with their difficulties and potential applications.

Functional gene expression is a basic life process that connects the coding information of a gene to protein products. The level of gene expression is considered as a quantitative trait between genotype and phenotype and plays an important role in response to climatic and environmental changes. First, we systematically summarize regulatory elements of gene expression in plant species and empirical evidence, including the effects of transcription factors and small RNAs on gene expression regulation. Second, this review discusses the eQTL mapping for regulatory elements of gene expression through gene expression-based genome-wide association study (GWAS) and the limitations of this method. This review analyzes the intraspecific variation in gene expression in theory under the processes of mutation, drift and selection and the testing methods. This review also analyzes the interspecific evolution of gene expression under the mutation and drift processes or under the phylogeny-based drift-selection processes and the testing methods. Finally, this review discusses the regulation of gene expression by the plant mating system. Selfing reduces the effective population size, mutation rate, recombination rate and competition from exogenous pollen, and changes the efficacy of natural selection in the gametophytic and sporophytic phases. Selfing regulates intraspecific gene expression variation and interspecific gene expression evolution. This review comprehensively comments on theoretical and practical research progress and existing questions, which aids in our deep understanding of plant gene expression regulation and evolution mechanisms.

Strigolactone (SL) is a novel plant hormone that regulates important growth and developmental processes such as plant branching. In rice, the SL receptor D14 perceives SL signals, binds with the F-box protein D3, and recruits the transcriptional repressor D53, inducing the ubiquitination and degradation of D53, thereby triggering signal transduction and inhibiting tillering. A recent study discovered that nitrogen limitation induces SL biosynthesis in rice to activate the receptor D14, triggering SL signal transduction. Concurrently, nitrogen limitation also induces phosphorylation of the N-terminal disordered region (NTD) of D14, reducing the ubiquitination and degradation of receptor D14, thereby further enhancing SL perception. Through these two synergistic mechanisms, nitrogen limitation stimulates SL signal transduction, strongly inhibiting tillering and enabling rice to adapt to low nitrogen stress conditions. The study also found that the D14-D3 interaction induced by SL promotes the ubiquitination and degradation of D14, thereby mediating the termination of SL signal perception. These significant findings elucidate the mechanisms of activation and termination of SL perception in rice, revealing the crucial regulatory role of SL signals in controlling rice tillering under low nitrogen stress. This would provide key insights into plant adaptation to nutrient scarcity and guide the precise improvement of crop architecture and molecular breeding of rice for reduced fertilizer use and increased yield.

Plants encounter various abiotic stresses throughout their lifecycle, including heat, drought, and salt stress, all of which have diverse impacts on their growth and development. Global warming has exacerbated the impact of heat stress on crops such as maize, potentially leading to growth retardation and reduced reproductive capacity. As an important staple crop, the yield and quality of maize are severely compromised by heat stress. Plants respond to heat stress through complex molecular mechanisms involving multiple signal transduction pathways and the regulation of gene expression. It is crucial to use advanced techniques such as genetics, genomics, multi-omics analysis, and high-throughput phenotyping to extensively explore and analyze the genes and loci associated to abiotic stress tolerance, including heat stress, in the maize genome. These studies not only deepen our understanding of the biological mechanisms underlying maize stress tolerance but also provide valuable molecular markers and candidate gene resources for breeders to accelerate the development of new maize varieties.

Climate change-induced global average temperature rise poses a severe threat to food production, in which maize, one of the three major global staple crops, is particularly susceptible to high temperatures. High temperatures significantly impact maize at various stages of its growth and development, especially during the reproductive growth stage, which can drastically reduce maize yields. Here we summarize the effects of high temperatures on maize at different growth stages, including germination, seedling, late vegetative growth, flowering, and grain-filling stages. We also review the main molecular mechanisms by which maize responds to heat stress, including heat shock and unfolded protein responses. Furthermore, we summarize the latest advances in heat-tolerant maize breeding in China. A batch of heat-tolerant hybrids and inbred lines have been identified through artificial high-temperature treatments and open field trials under natural high-temperature. In addition, we proposed important future research strategies in developing heat-tolerance maize, including new technological methods such as phenomics, genome-wide association studies, and genomic selection-based breeding, combined with intelligent agricultural management measures. We aim to cultivate maize varieties with high heat tolerance to cope with the high-temperature challenges brought about by climate change, thereby ensuring global food security.

Maize (Zea mays) is a staple crop worldwide, serving as a major source for food, feedstock, and industrial materials. Flowering time, a key agronomic trait determining diverse environmental adaptation and yield potential of crops, is determined by two developmental transitions (namely vegetative phase change and floral transition), and complicatedly regulated by internal factors (such as genetic factors and plant hormones) and external environmental factors. Given the importance of flowering time, in this review, we summarize the research progresses on the regulation of the two-phase transitions in maize, mainly focusing on the aspects of structural basis, physiological basis, genetic basis and molecular mechanisms. We also highlight the contribution of key flowering regulators to geographical adaptation of maize, and discuss future research directions on flowering and application in breeding, aiming to deepen our understanding of the genetic regulation of maize flowering and provide a theoretical basis for genetic improvement of maize cultivars adapting to diverse environmental conditions.

INTRODUCTION: Molecular data is one of the most important bases for many biological studies, including phylogeny, ecology, and biogeography etc. Incomplete sampling may lead to biased results and inadequate conclusions. However, few studies have evaluated current state of sampling density for sequencing DNA data comprehensively. Plastid DNA sequences have been applied in scientific studies of plants extensively due to their easy accessibility, uniparental inheritance, and moderate rate of mutation. Therefore, it is essential to investigate the current state of sampling density for sequencing plastid DNA data in species and geographic area for researchers to better utilize it.

RATIONALE: The GenBank is the biggest and most commonly used database of sequencing DNA data. The data gap of plastid DNA in species and geographic area for vascular plants was investigated based on the GenBank database in this study. Firstly, the plastid DNA data of vascular plant species were downloaded from the GenBank database and cleaned. Secondly, species names were standardized according to the World Checklist of Vascular Plants (WCVP) database. Thirdly, to evaluate the current state of sampling density for plastid DNA data of vascular plants, we counted the number of species with plastid DNA sequenced and the proportion of missing data of lineages representing orders and families. We also mapped the proportion of missing data in each region to evaluate the current state of sampling density of plastid DNA data geographically. To further investigate the potential influencing factors of the plastid DNA data gap, Spearman’s correlations between the proportion of missing data and species diversity among major groups of vascular plants or regions were calculated.

RESULTS: Only 33.75% vascular plant species have at least one record of DNA in GenBank, covering 139 005 vascular plant species (angiosperms: 131 220 species, gymnosperms: 1 154 species, and pteridophytes: 6 631 species). For data gap in species, sequenced species were unevenly sampled among lineages, with the proportion of missing data generally correlated with species richness within the lineages. The top three orders of the highest proportion of missing data were Paracryphiales, Piperales, and Dilleniales, and the top three families were Triuridaceae, Pentaphragmataceae, and Xyridaceae. For data gap in geographic area, the proportion of missing data of plastid DNA of vascular plant species showed a trend of latitudinal gradient, with the degree of missing data decreasing from the equator to the poles. Regions with high proportion of missing data usually possess high biodiversity, including many biodiversity hotspots. In addition, endemic species were generally with the high proportion of missing data in the majority of regions.

CONCLUSION:Our research evaluated the current state of sampling density for plastid DNA data in species and geographic area comprehensively. Our results suggested that about 140 000 vascular plant species have been sequenced for the plastid DNAs. However, there are still large data gaps for the plastid DNA of vascular plants in the following three aspects: (1) Only 1/3 vascular plant species have been sequenced; (2) Ratios of species with plastid DNA sequenced are uneven among lineages; (3) The proportion of missing data decreases from the equator to the poles, with more deficiencies in biodiversity hotspots and endemic species. Based on the results of this study, we propose to give priority to collection and sequencing of vascular plants for groups with high proportion of missing data and regions with high biodiversity, particularly for the endemic species. Our research points out the direction of filling plastid DNA data gap and will be beneficial to biodiversity protection.

Gene editing technology has become an important tool in crop breeding. Maize, one of the globally most important food crops, has been shown with great potential in the use of gene editing technology in genome research and breeding. In this paper, we reviewed the recent progress and applications of gene editing technology in maize research, with a focus on the latest achievements in maize genome editing by CRISPR/Cas. Firstly, we introduced the basic principles and types of gene editing technology, particularly the working mechanism of the CRISPR/Cas systems, and its application advantages in maize. Secondly, we summarized the research progress of gene editing technology in maize breeding, from basic genome editing to the editing of complex multi-gene regulation, aiming at the improvement of key traits such as yield, grain quality, and stress resistance. Finally, the outstanding research work in maize gene editing in China is presented and the existing issues of gene editing technology in maize breeding are discussed, along with an outlook on future development trends.

Maize (Zea mays) is the major grain crop with the largest planting area and the highest total yield in China, and it is also a model of heterosis utilization. However, compared with developed countries, China is still facing several outstanding problems in maize production, such as low average yield, lack of breakthrough varieties and high cost of hybrid seed production. The main solution to these problems is the application of male-sterile lines with better heterosis utilization efficiency and thus increase the yield per unit area of maize. In this review, we summarize the latest advances of male sterility research in maize, including its classification, gene cloning and functional analysis, molecular regulatory network construction, and discuss the strategies of creating novel male-sterility systems and their potential/future application in maize breeding. This review provides guidelines for the male-sterility based/assisted hybrid breeding and seed production in maize.

Cryptochromes (CRYs) are blue light receptors that regulate various plant responses. CRYs exist in the dark as an inactive monomer, which absorbs photons and undergo conformational changes and oligomerization. Light alters the affinity between CRYs and interacting proteins, thereby regulating the transcription or stability of photoresponsive proteins to modulate plant growth and development. A recent study has discovered a sophisticated mechanism of CRY2 function, which is not only ‘activated’ by blue light but also by dark signals, thus constructing a more energy-efficient mode of light and dark signal dependent photoreceptor signaling. The authors found that CRY2 can inhibit cell division in root meristematic tissue even in the dark, regulate root elongation and growth, and control the expression of a large number of genes. FL1 and FL3 bind to the chromatin of cell division genes to promote their transcription. It is interesting that only the CRY2 monomer in the dark interacts with FL1/FL3, thereby inhibiting FL1/FL3 to promote root elongation, while blue light releases this inhibitory effect. This discovery reshapes people’s understanding of light receptors, and provides a new perspective for understanding plant perception and response to different signals to regulate growth and adaptability. Moreover, it is highly enlightening for a deeper understanding of sophisticated gene regulation.

Seed desiccation is a key physiological process during plant seed maturation, directly affecting seed moisture content, storage, and quality. In agricultural practice, the kernel dehydration rate (KDR) is a critical determinant of seed water content at harvest and seed quality for mechanical harvesting. Over the past decades, although physiological changes in transcriptome and hormone levels have been linked to seed dehydration, little progress for underlying mechanisms has been achieved. A recent study identified a QTL located in a non-coding region, named qKDR1, which regulates the dehydration rate during maize seed maturation. By recruiting the transcription factors ZmMYBST1 and ZmMYBR43, it suppresses the transcription of the micropeptide-encoding gene RPG upstream of qKDR1, leading to reduced expression of RPG. The encoded micropeptide, microRPG1, regulates the KDR through the ethylene signaling pathway, highlighting its potential in crop breeding and agricultural practices. This study advances our understanding of the molecular mechanisms underlying seed desiccation and provides theoretical support for breeding crops with faster KDR and improved storage qualities.

Rice (Oryza sativa) is a globally important cereal crop, and the rational application of fertilizers is necessary agricultural practice to ensure its sustainable and stable yield. Phosphorus is one of the essential nutrients for rice, primarily absorbed through the rice roots. Since rice is mostly grown in flooded conditions, the root surface of rice generally forms iron plaques rich in iron oxides, which play a crucial role in the migration of inorganic phosphorus in the rhizosphere of rice. This paper reviews the impact of biotic and abiotic factors on the formation of iron plaques in rice and discusses the effect of iron plaques on the absorption and transport of phosphorus in plant nutrition. Furthermore, we discuss the prospects of future research on iron plaques, aiming to provide clues for our further understanding of the interactions between iron and phosphorus in the rhizosphere of rice.

With the sharp change of the global climate, the ecological environment for plant is becoming increasingly harsh, therefore the molecular mechanisms underlying how circadian synergistically interacts with light or temperature receptors to transmit environmental signals and rhythmically regulate various growth and development process received widespread attention. As an endogenous timer of plants, the core oscillator of circadian clock is composed of multiple coupled transcriptional-translational feedback loops (TTFL), and it is modified from transcription, post-transcription, translation, post-translation to epigenetic levels. These multi-precise regulatory mechanisms ensure that the circadian clock can be synchronized and reset by external signals, so that the endogenous rhythm matches with external cycles, thereby endowing plants with the ability to optimize resource utilization and tend towards the optimal growth, which also has an important significance for guiding the genetic improvement and domestication of crops. In this review, we summarized the multi-level of regulatory mechanisms of core oscillator as well as the molecular function of circadian homologous genes in crops, thoroughly described the interaction network between the circadian clock and the light and temperature signal pathways and give prospects for molecular breeding based on the opinion, which provides new ideas for expanding the environmental adaptability and optimizing agronomic traits of crops.

INTRODUCTION: The cell wall-associated kinase (WAK) family has annotated approximately 130 WAK genes in the genome of rice (Oryza sativa), which play an important role in rice growth and development and stress responses.

RATIONALE: Here, we investigated the regulation and physiological mechanism of OsWAK16, an encoding gene of the cell wall-associated kinase WAK16-RLK, on rice seed vigor and anti-aging ability.

 
RESULTS: The results showed that before and after artificial aging, the seed vigor of OsWAK16 knock out mutants and overexpression lines was significantly lower and higher than that of wild-type seeds, respectively, indicating that OsWAK16 positively regulates the anti-aging ability of seeds. Physiological and biochemical analyses indicated that compared with wild-type seeds before and after artificial aging treatment, malondialdehyde (MDA) content and electrical conductivity (EC) of seed soaking solution of OsWAK16 knock out mutant seeds were significantly increased, while antioxidant enzyme activity was significantly decreased. The reverse was true in overexpression seeds. In addition, the differential expression of OsWAK16 in three types of seeds, whether artificially aged or not, also caused synergistic changes in the expression of other seed vigor-related genes OsPER1A, OsbZIP23, OsPIMT1, OsSdr4, OsMSRB5 and OsHSP18.2.

 
CONCLUSION: Therefore, it is speculated that OsWAK16 may work synergistically with other seed vigor-related genes to clear reactive oxygen species in cells, thereby regulating seed vigor and anti-aging capacity.

Nicotinamide adenine dinucleotide (NAD⁺) and nicotinamide adenine dinucleotide phosphate (NADP⁺) act as an integral regulator of plant core energy metabolism, growth and development, and stress response, which can directly and indirectly influence many key cellular functions. As the cornerstone of cell metabolism, NAD(P)⁺ homeostasis is crucial for normal plant growth and development, and stress response. Impaired synthesis of NAD(P)⁺ or deficiency can trigger metabolic disorders and a series of defective phenotypes, and may even lead to plant death in severe cases. Currently, NAD(P)⁺ biosynthesis pathway and its key enzymes have been well studied in plants, but its homeostatic regulation in plants and the mechanism of coordinating plant growth and stress response are still unclear. Therefore, isolating NAD(P)⁺ deficiency-related mutants is crucial for exploring the regulatory mechanisms of NAD(P)⁺ homeostasis and its balancing in plant growth and stress response. This review summarizes the biosynthetic metabolic pathways of plant NAD(P)⁺, focuses on the participation of NAD(P)⁺ in plant growth and stress response processes, and looks into the future on the research prospects of NAD(P)⁺ in plants.

INTRODUCTION Tomato (Solanum lycopersicum), a significant warm-season and water-dependent vegetable crop, is extensively cultivated worldwide. Whether grown in open fields or protected environments, tomatoes frequently encounter various environmental stresses, including drought and low temperatures, which significantly impact their yield and quality. Transcription factors play a pivotal role in plant stress responses by modulating the expression of specific target genes, thereby transmitting perceived stress signals downstream. WRKY transcription factors in tomatoes are known to regulate responses to multiple abiotic stresses. However, the specific role of the tomato SlWRKY45 in abiotic stress responses remains unclear.

RATIONALE Studies have demonstrated that WRKY transcription factors play a crucial regulatory role in plant responses to abiotic stress. As an important economic vegetable crop, tomato is susceptible to various environmental stresses during its growth and development. By genetically overexpressing SlWRKY45 in tomato and investigating its function under low-temperature and drought stress conditions, the findings can provide a theoretical foundation for understanding the complex regulatory mechanisms of WRKY transcription factors. Additionally, this research offers valuable candidate genes for breeding stress-resistant tomato varieties.

RESULTS Expression analysis revealed that low-temperature, drought, and abscisic acid (ABA) treatments significantly induced the expression of SlWRKY45. Overexpression of SlWRKY45 enhanced the resistance of tomato plants to drought and low-temperature stresses. Under drought and low-temperature conditions, the photosynthetic indices, antioxidant enzyme activities, and proline (Pro) contents in SlWRKY45 overexpression lines were significantly higher than those in wild-type (WT) plants. Conversely, the accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA) levels in SlWRKY45-OE plants was significantly lower than in WT plants under the same stress conditions. Transcriptome data analysis indicated that SlWRKY45 regulates tomato's response to low-temperature stress primarily by influencing antioxidant enzyme activities and stress response pathways. Dual-luciferase assays demonstrated that SlWRKY45 could directly activate the expression of SlPOD1. Furthermore, the interaction between SlWRKY45 and SlWRKY46 was confirmed through yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays.

CONCLUSION Our findings demonstrate that SlWRKY45 positively regulates drought resistance and low-temperature tolerance in tomato. Additionally, SlWRKY45 can interact with SlWRKY46 and directly activate the expression of SlPOD1. These results offer valuable insights for further research into the regulatory mechanisms underlying abiotic stress responses and provide potential gene resources for genetic improvement through molecular breeding.

Phenotypes of SlWRKY45-overexpressing and wild-type plants under drought and low-temperature treatments

INTRODUCTION Trehalose-6-phosphate synthase (TPS) is a key enzyme involved in the synthesis of trehalose and has been reported to participate in regulating photosynthesis, carbohydrate metabolism, growth and development, and stress responses in various species. Currently, reports on TPS genes in soybean are scarce.

RATIONALE  TPS is a stable non-reducing disaccharide, whose synthesis, decomposition and regulation not only provide energy for plant, but also play an important role in plant growth and development and stress tolerance. The in-depth study of soybean TPS genes and its relationships with salt stress is of great significance in elucidating the molecular mechanism of soybean salt tolerance and improving soybean yield.

RESULTS This study identified 20 soybean TPS genes and their associated 10 conserved protein motifs in the soybean genome. Molecular analysis of the promoter elements revealed that the TPS gene promoters are rich in stress-responsive elements. After salt stress treatment, the expression of 17 TPS genes changed, with 12 genes up-regulated and 5 genes down-regulated. Haplotype and selection analyses revealed two major allelic variations in TPS8, TPS13, TPS15, TPS17, and TPS18. Notably, variants carrying TPS15^H2, TPS13^H2, TPS17^H2, and TPS18^H2 were significantly enriched in improved cultivars that underwent strong artificial selection.

CONCLUSION This study reveals the molecular characteristics of the soybean TPS gene family, their expression patterns under salt stress, and their evolutionary history, providing a theoretical basis and genetic material for further elucidating the functions of soybean TPS genes and breeding salt-tolerant soybean varieties.

TPS genes were subjected to intense artificial selection. The natural variations of TPS8, TPS13, TPS15, TPS17, and TPS18 have been subjected to strong artificial selection during soybean domestication and improvement, with the variants carrying TPS15^H2, TPS13^H2, TPS17^H2, and TPS18^H2 being heavily enriched in improved cultivars.

A large number of software applications for plant identification based on plant images have been developed in recent years. However, those applications are mostly used for identifying the common species countrywide, and thus cannot meet the needs of identifying region-specific vegetation types. In this study, we developed an artificial intelligence model for identifying the dominant plants in Hulunbeier and Xilinhot grassland in Inner Mongolia, based on the image datasets in the Plant Photo Bank of China. The Top5 accuracy of this model reaches 94.6% in the actual field identification tests. Our model provides a new method for the intelligent identification of the major plant species in a specific area.

Biological small molecules, also known as monomeric compounds with relatively low molecular weight found in organisms, encompass a wide array of substances in plants, such as ions, plant hormones and metabolites. Studying the dynamic fluctuations of these small molecules in plants is crucial for analyzing their corresponding physiological functions, regulatory networks, and enhancing the precision of botanical research. Genetically encoded fluorescent biosensors/probes utilizing Förster resonance energy transfer (FRET) technology serves as a valuable tool for real-time monitoring of these small molecules within living organisms. These FRET biosensors/probes allow for the non-invasive visualization of specific small molecule concentrations, providing detailed information at a high resolution. Because of these unique advantages, this technique has been extensively applied in various research fields, including plant physiology, developmental biology, and environmental science. This review provides a comprehensive overview of FRET sensors/probes utilized in plant research in recent years, outlines the key design concepts, and highlights their applications and advances in detecting ions, plant hormones, and metabolites. Furthermore, this review demonstrates practical technological tools and potential research directions for elucidating the functions of small biomolecules in plants.

INTRODUCTION:Plant growth regulators are natural or artificially synthesized chemical substances that play an important regulatory role in the growth and development of crops, and can enhance the resistance of plants to stress.

RATIONALE To study the effects of different plant growth regulators on the growth and development of wheat under salt-alkali stress, and to explore methods to increase crop yield in saline-alkali land, we conducted spraying experiments on wheat in saline-alkali soil in the Yellow River Delta Agricultural High-tech Industry Demonstration Zone from 2023 to 2024. The experiment was divided into four groups: a distilled water control group, a 0.5% alginate aligosaccharide group, a Plant Gold group, and a mixed group of 0.5% alginate aligosaccharide and Plant Gold. The wheat was sprayed on March 28, April 12, April 28, and May 12, 2024.

RESULTS: The results showed that after spraying alginate oligosaccharide and its mixture with Plant Gold, the number of grains per ear and the 100-grain weight of wheat significantly increased. In particular, the group that received the mixture of alginate oligosaccharide and Plant Gold achieved a theoretical yield of 1 174.5 kg·hm^-2 for wheat in saline-alkali soil, which was an increase of 14.4% and 46.9% compared to the groups treated with only alginate oligosaccharide and Plant Gold, respectively.

CONCLUSION: Therefore, the combined application of alginate oligosaccharide and Plant Gold can significantly enhance the adaptability of wheat in saline-alkali land, demonstrating its important application potential in wheat production in such environments.

After selecting 1 m × 1 m sample plots within the experimental block and conducting spray tests with different plant growth regulators, the theoretical yields of different groups showed different changes. Among them, the yield of the mixed spray group was significantly higher than that of the control group.

A rapid propagation system via tissue culture for Rosa multiflora was established using the stem segments with buds of the current-year as the experimental material. The results showed that the best explants were stem segments with axillary buds. The best disinfection method was to soak the explants in 75% ethanol for 30 seconds, and then soak them in 10% sodium hypochlorite solution for 20 minutes. The survival rate can reach 96%. The optimal bud-induction medium was MS+1.0 mg∙L^-1 6-BA+0.01 mg∙L^-1 NAA+0.1 mg∙L^-1 GA₃. The budding rate can reach 98% after 30 days of cultivation. WPM was the best basal medium for the proliferation of sterile regenerated plantlets, and the proliferation coefficient was 2.87. The best medium for rooting was 1/2MS+1.0 mg∙L^-1 6-BA+0.1 mg∙L^-1 NAA, and the rooting rate can reach 93%. The transplanting survival rate of sterile regenerated plantlets was 98%. On this basis, the transient expression system of R. multiflora was established. The results showed that the optimal transformation conditions for transient expression were OD₆₀₀ of 0.8 for the bacterium culture medium, vacuum negative pressure of -0.10 MPa and vacuum suction twice for 15 minutes each time. The transient expression efficiency can reach 96%. The results of this study laid a foundation for the establishment of regeneration and genetic transformation system of R. multiflora, and also provided technical support for studying on the gene function of Rosa plants.

Mitochondria and chloroplasts are semi-autonomous organelles harboring their own genomes. RNA editing is essential for the correct expression of organelle genes. The mostly identified RNA editing is cytidine (C)-to-uridine (U). Multiple editing factors have been reported to be involved in RNA C→U editing. The PPR-motifs array in PPR proteins specifically target editing sites, and the DYW domains in PPR-DYW proteins catalyze the deaminase in the C→U editing. This paper aims to review the recent advance of PPR proteins involved in RNA C→U editing, and to discuss the potential application value of synthetic PPR editing factors.

Iron-sulfur [Fe-S] clusters, which act as cofactors for iron-sulfur proteins, are ubiquitously implicated in a diverse array of biological processes, such as photosynthesis, respiration, electron transport, and the biosynthesis of essential vitamins and cofactors. Their intracellular biogenesis is modulated by a suite of proteins that catalyze and regulate the process, with compartmentalization occurring within discrete subcellular compartments. Mitochondria, as the central organelles for cellular energy metabolism, harbor numerous key metabolic enzymes that are iron-sulfur proteins, necessitating the provision of iron-sulfur clusters by the mitochondrial assembly machinery, the iron-sulfur cluster (ISC). Advancements in research, particularly from bacteria and yeast systems, have facilitated significant strides in the identification and functional characterization of pivotal catalytic and regulatory proteins within the plant mitochondrial ISC system. Additionally, considerable progress has been made in the research of the role in iron-sulfur clusters in the plant growth and development. The elucidation of plant-specific components within the iron-sulfur cluster synthesis machinery and the mechanisms by which this system responds to environmental stress are areas of growing interest. This manuscript provides a comprehensive review of the current state of research on the mechanism of iron-sulfur cluster synthesis in plants, with a particular focus on the mitochondrial ISC assembly system. It also provides a succinct synopsis of the role of key genes within the ISC system in plant growth and development, as well as their involvement in the response to abiotic stressors.

SWEETs are a recently discovered family of bidirectional sugar transporters that are widely present in all organisms. Their high substrate specificity for hexoses (such as glucose, fructose and galactose) and sucrose in different clades underlines their significance in regulating sugar signaling during various developmental and physiological processes in plants. This review primarily focuses on how SWEETs precisely respond to various biotic and abiotic stresses. We summarized systematically the regulatory mechanisms of SWEETs in response to environmental stresses at both the transcriptional level and the post-translational level and in multiple signal transduction pathways. This review aims to provide a novel perspective and deeper understanding of the complex biological functions and regulating mechanisms of SWEET transporters, and provides valuable information for future research on plant stress resistance and molecular breeding crops with high yield and disease resistance.

In recent years, significant progresses have been made in plant stress biology, particularly in elucidating the mechanisms underlying responses to extreme temperatures and salinity-alkalinity stresses. These advancements have not only broadened our understanding of plant resilience but also provided a wealth of potential targets for molecular breeding, paving new avenues for developing climate-resilient crop varieties that maintain high yield potential under both optimal and adverse conditions. This review concisely summarizes current knowledge on signal perception and transduction mechanisms during plant adaptation to extreme temperature and saline-alkali stresses, discusses the balance regulation between growth/development and stress tolerance, particularly highlights recent breakthroughs by Chinese scientists in discovering key genes and deciphering mechanisms that synergistically improve crop stress resistance and yield. We also provide future prospects for breeding strategies.

Leaf, as a photosynthetic organ of crops, its senescence process has an important impact on yield formation, but the relationship between leaf senescence and phyllosphere microorganisms has been less studied. In order to explore the impact of the senescence process of maize leaves on the phyllosphere bacterial community, this study used three maize varieties of different maturity time (early-maturation variety Heike Yu 17 (H17), mid-maturation variety Zhongdan 111 (Z111), and late-maturation variety Shen Yu 21 (S21) in Northeast China as the experimental materials, and the leaves of the ear position of the three maize varieties were sampled five times starting from the blooming stage of early- maturation varieties, and the physiological indexes of senescence were determined. And at the same time, the community composition of endogenous and exogenous bacteria in/on the leaves was determined based on high-throughput sequencing technology. The results showed that at the late reproductive stage, leaf water content, POD and SOD activities were significantly higher in the mid- and late-maturation varieties than in the early-maturation varieties. At the phylum level, Cyanobacteria were endemic to mid- and late-maturation cultivars; at the genus level, the relative abundance of the endogenous shared bacteria Sphingomonas, Methylobacterium, and Deinococcus in maize leaves decreased significantly at later stages of maturation (IV and V). The relative abundance of endogenous bacteria Streptomyces and exogenous bacteria P3OB-42 were significantly enriched in the late senescence period, with similar trends and significant differences in relative abundance among the three species. The relative abundance of endogenous and exogenous bacteria differed significantly, with the top 5 exogenous bacteria accounting for more than 60%, while for endogenous bacteria, the top 5 accounted for only more than 30%. Soluble sugar content, photosynthetic pigment content and SOD activity were significantly correlated with bacterial community structure and abundance. In conclusion, mid- and late-maturation varieties were effective in prolonging leaf greening period, maintaining late leaf physiological activity with delaying senescence. The effects of senescence on the composition and diversity of endogenous bacterial communities were significantly greater than those of exogenous bacteria, and there were significantly different genera among three maize varieties studied. Moreover, soluble sugar content, photosynthetic pigment content and SOD activity were the key factors affecting the phyllosphere bacterial communities as well as the dominant species.

INTRODUCTION:An efficient Agrobacterium rhizogenes-mediated transformation system for Pueraria lobata was established.

RATIONALE: In this study, tissue-cultured plantlets of P. lobata were used as explants to investigate the effects of different genotypes, A. rhizogenes strains, explants, precultivation times, infection times, culture days, subculture times, and culture methods on the efficiency of hairy root genetic transformation in P. lobata.

RESULTS: The results indicated that the induction rate of hairy root formation was the highest when the immature leaves of YG-19 were used as the explant material, reaching 10.2%. A. rhizogenes K599 was identified as the most suitable strain. The optimal explant material was immature leaves that had just unfolded from the first to second nodes of the 5^th to 13^th generation tissue culture plantlets subcultured for 8 days. After 3 days of pre-culture and 15 minutes of bacterial infection, the highest induction rate of hairy roots reached 22.4%. The optimal type of culture medium for the proliferation of hairy roots in P. lobatawas solid medium culture, and the fresh weight of hairy roots grown on solid medium was 75 times greater than that of hairy roots grown in liquid medium. PCR detection and fluorescence microscopy assays revealed that the expression of GFP and rolB genes in the hairy roots of P. lobata was stable, and the rate of cotransformation was 80%.

CONCLUSION: Genotype, A. rhizogenes strain, and culture duration were the most critical factors for the efficient genetic transformation of hairy roots in P. lobata.

INTRODUCTION: The AT-hook motif nuclear localized (AHL) gene family is a highly conserved transcription factors involved in plant growth, development, and stress responses, but their roles in spinach are still unknown.

RATIONALE:To reveal the basic characteristics of the AHL family in spinach, members of the spinach SoAHLfamily were identified at the whole-genome level, and their physicochemical properties, gene structure, conserved motifs, promoter elements, and salicylic acid-responsive expression profiles were analyzed in this study.

RESULTS: The results revealed 19 SoAHL family members in the spinach genome, which were unevenly distributed across six chromosomes. These SoAHL members can be classified into three branches, with 10 members in subfamily I and 9 members in subfamily II. The sequence composition of PPC and AT-hook conserved motifs varies among subfamilies; most of the SoAHL genes are located in the nucleus, cytoplasm, and mitochondrion. Members of subfamily I of SoAHL have no introns, whereas members of subfamily II contain 4-5 introns. The varying numbers of cis-acting elements relate to phytohormones and abiotic stress responses were distributed upstream of the promoters of the SoAHL members. The SoAHL genes can be expressed in roots, leaves, and petioles, with most genes expressed at relatively high levels in roots. The expression of two SoAHL genes (SOV6g041850.1 and SOV2g038950.1) was significantly induced by salicylic acid treatment. The expression profiles and salicylic acid-induced expression levels of SOV2g031340.1 and SOV4g018880.1 were highly correlated with the folic acid content, which may play a role in the spinach response to the salicylic acid signaling pathway. The transient overexpression of SOV4g018880.1 increased the folate content of spinach leaves by 1.75 times.

CONCLUSION: The results from the sequence characteristics, expression profiles and exogenous salicylic acid treatment revealed that the SoAHLs had potential functional diversity and that specific members may have positive effects on spinach folate accumulation. Our results will lay the foundation for further resolving the function of spinach AT-hook genes.

Phenotype (A), total folate content (B) and expression analysis of SoAHL (C) under 50 μmol∙L^-1 salicylic acid (SA) treatment for 5 days (D5) and 7 days (D7). CK: Control

Cyclic nucleotide-gated channels (CNGCs) are important cation channels that play pivotal roles in the regulation of growth and development, as well as in response to stresses such as cold, heat, salt, and pathogen attacks in plants. In this review, we briefly outline the classification, structure and location of CNGCs in plants, and comprehensively summarize the recent research progress on their ionic selectivity, regulatory mechanisms, and biological functions, in order to enhance our understanding of plant CNGCs and provide a reference for future research.

INTRODUCTION: As the main grain crop, rice plays an important role in ensuring food security of China. Rise in global average temperature is detrimental to crop yield and heat stress is currently one of the major abiotic threats on rice production. There are significant variations in heat tolerance among different rice varieties. As a typical quantitative trait, heat tolerance of rice is controlled by multiple genes. Identification of new QTLs and genes related to heat tolerance is very important for the genetic research and the breeding of new heat-tolerant rice varieties.

RATIONALE:In recent years, many heat tolerant QTLs had been identified with different genetic populations and evaluation indicators at different growth stages. Most of those QTLs were mapped in large intervals due to the limited population sizes, simplified experimental designs and inaccurately controlled environments. The heat tolerance level identification in a population is very difficult for mature plants. Therefore, we developed a population of recombinant inbred lines (RILs) with 186 lines derived from japonica rice TD70 and indica rice Kasalath, which showed large variations in seedling survival rates under high temperature stress (HTSR). QTLs associated with HTSR were mapped by the high-density linkage Bin-map and candidate genes were identified.

RESULTS: Twenty-six QTLs related to the HTSR were mapped on 11 of the 12 chromosomes, with the exception of 3. The LOD values of single QTL ranged from 2.59-16.15, four of which with LOD values greater than 10. Seven QTLs were located within the same interval or adjacent to known heat tolerance QTLs. The major locus of qHTSR5.2 was located in the 26.25-26.38 Mb region of Chr. 5 with an LOD value of 12.07, which explained 7.18% of the total phenotypic variation in the HTSR. According to the annotation and sequence analysis of the genes located in the region of four major QTLs,we found that twenty-seven annotated genes with non-synonymous mutations in the coding regions between TD70 and Kasalath. Five of them were identified as potential candidate genes because the RILs sharing each of the distinct haplotypes of their parents for each gene exhibited significant different HTSR resistance level. Among them, three candidate genes encode heat shock proteins HSP20 or HSP17.5.

CONCLUSION: We detected 26 QTLs controlling seedling heat tolerance based on a high-density Bin map in a RIL population. Some of the QTLs were overlapped with known heat tolerance loci, indicating their strong effects on regulating heat tolerance of rice. Five candidate genes were identified through gene annotation, parental sequence comparison, effect analysis of heat tolerance between RILs with different haplotypes. The candidate genes identified in our study could be used for molecular mechanism research on high temperature tolerance of rice in the future.

Mapping of QTL for heat tolerance at seedling stage in rice based on a high-density Bin map. Heat tolerance of parents and RILs population during seedling stage. Location of QTLs contributing to heat tolerance at seedling stage.

Cytoplasmic male sterility (CMS) is a maternal genetic trait widely found in higher plants. CMS is not only a favorable material for studying the interaction between cytoplasmic and nuclear genomes, but also a crucial foundation for plant heterosis utilization. Maize is one of the most successful example for the utilization of heterosis in crops, and CMS has become a powerful tool for hybrid production to utilize heterosis in maize. Therefore, the molecular mechanism of CMS in maize has always been a research hotspot. In this paper, CMS related genes and fertility restorer genes discovered in the three major types of CMS in maize were summarized, and the problems that needed to be solved in CMS-related research and development prospects in the application of CMS in maize were discussed. This review provided theoretical reference for better understanding of the molecular mechanism of CMS in plant and the application of CMS system for hybrid seed production in the utilization of heterosis in maize.

Due to the long flowering cycle, unpredictable flowering period and low seed setting rate of most bamboo plants, bamboo breeding has been a challenge in the research of bamboo plants. Polyploid breeding, as a common mean of plant breeding, is able to obtain progeny with excellent traits through artificial induction. In bamboo breeding, there are fewer studies on polyploid breeding. In this study, based on the existing regeneration system of Dendrocalamus asper, the embryonic calluses of D. asper were treated with colchicine using the liquid suspension method and the solid medium mixed culture method, respectively. The results showed that, based on the differentiation and browning rates of the calluses, the better results were obtained by treating the calluses with 50 mg∙L^-1 colchicine for 48-72 hours using the liquid suspension method. A total of 54 regenerated plants, including 7 control plants, and 16 chromosome doubled plants were successfully obtained from D. asper using flow cytometry to test all the regenerated plants. In terms of chromosomal doubling, treatment with 100 mg∙L^-1 colchicine for 48 h produced the highest number of chromosome-doubled plants with a polyploidy rate of 54.54%. Compared with 6-ploid plants, the 12-ploid plants presented larger and thicker leaves, and larger lower epidermal stomata, implying their superiority in stress tolerance physiology. This study provides an efficient polyploid breeding technique based on the in vitro indirect regeneration system of bamboo, and offers a new solution for breeding new polyploid germplasm of bamboo.

ABF transcription factors are collectively referred to as basic leucine zipper proteins that can specifically recognize and bind to ABA-responsive elements (ABRE), participating in ABA signal transduction and serving as regulators of ABA signal transcriptional responses. This study analyzed the protein encoded by the BnaABF2 gene in Brassica napus. Subcellular localization results showed that the BnaABF2 protein is localized in the nucleus. Analysis of transcriptional activity in the yeast system indicated that BnaABF2 has no transcriptional activation activity; qRT-PCR detection revealed that the expression level of BnaABF2 is highest in leaves. We also found that ABA treatment, simulated drought, and salt stress can induce the expression of BnaABF2; BiFC results showed that BnaMPK1/2/6/7/9/12/13 can interact with BnaABF2. Dual-LUC results suggested that BnaMPK7 may enhance the transcriptional regulation of BnaABF2 on downstream target genes through phosphorylation. This study initially explored the basic characteristics and interacting proteins of the transcription factor BnaABF2, providing theoretical guidance for understanding its functions and mechanisms.

As one of the dual wings of innovative development, science popularization is a crucial means of enhancing national scientific literacy. Universities, as the main platforms for disseminating knowledge and nurturing talent, also bear the social responsibility of promoting science popularization. In biology, conducting science education and guiding students to extract biological knowledge from their courses to create popular science content is of great significance in advancing public science literacy. This article takes a university botany course as an example to illustrate how botany courses can integrate popular science education through course knowledge, practical activities, research outcomes, and real-life applications. By employing the “2W1H” approach (What, Why, and How), the paper guides students in creating popular science. This not only cultivates students’ comprehensive and innovative abilities but also disseminates biological knowledge, offering a valuable reference for the cultivation of popular science talents in the context of promoting science literacy for all.

INTRODUCTION Chrysanthemum × morifolium is one of the ten most famous traditional flowers in China, and it has a rich variety of cultivars with diverse floral colour and shapes. However, varieties with blue floral colour have not been found in the natural chrysanthemum, therefore, breeding blue chrysanthemums has always been a goal pursued by researchers.

RATIONALE The total flavonoid extract of C. × morifolium ‘Wandai Fengguang’ could turn blue when adding appropriate concentration of Fe³⁺, and its living petal cells could also turn blue with the participation of Fe³⁺, which proved the feasibility of breeding blue chrysanthemums with Fe³⁺. Meanwhile, C. × morifolium ‘Wandai Fengguang’ can bloom both in summer and autumn, with early flowering and long flowering period, which is also an important material for the study of flowering period. Therefore, in order to cultivate blue chrysanthemums and achieve the targeted improvement of flowering period, it is particularly important to establish an efficient and stable regeneration and genetic transformation system for the C. × morifolium ‘Wandai Fengguang’. However, chrysanthemum has a long history of cultivation and complex genetic background, so the regeneration and genetic transformation system is not universal among different varieties.

RESULTS In this study, C. × morifolium ‘Wandai Fengguang’ was used as the experimental material to study the effects of different explant types with different combinations of plant growth regulators on its regeneration, and to investigate the effects of relevant factors on the efficiency of genetic transformation with the Agrobacterium-mediated genetic transformation method. The experimental results showed that the most suitable explants for the regeneration of C. × morifolium ‘Wandai Fengguang’ was the transverse thin cell layers (tTCLs), and the optimal culture medium was MS+1.5 mg∙L^-1 6-BA+0.6 mg∙L^-1 NAA. The highest differentiation rate was 70.06% and an adventitious bud coefficient was 3.37. The kanamycin selection pressures for the differentiation of the tTCLs and the adventitious bud rooting were 7.5 mg∙L^-1 and 5.0 mg∙L^-1, respectively. The optimal procedure for genetic transformation was pre-culture for 1 day, OD₆₀₀=0.8, treatment for 5 minutes, and co-culture in the dark for 3 days. Fifteen resistant plantlets were screened on kanamycin medium, and two positive plantlets were confirmed by PCR amplification, with a transformation efficiency of 13.33%.

CONCLUSION This study laid the foundation for the gene function analysis and targeted improvement molecular breeding of chrysanthemum by using this kind of unique variety resource, and provided reference for the establishment of regeneration and transformation system for other chrysanthemum varieties.