Riboflavin is the precursor of flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) that serve as an indispensable cofactor to maintain normal metabolism, which plays pivotal roles in mitochondrial electron transport chain, citric acid cycle, β-oxidation of fatty acids, branched-chain amino acid catabolism, redox homeostasis, chromatin remodeling, DNA repair, apoptosis and secondary metabolite biosynthesis. Riboflavin deficiency will cause metabolic disorders and a series of defective phenotypes, and death in the most severe cases. Among the living organisms, microorganisms and plants can de novo synthesize riboflavin, but humans and animals can only obtain it from food. At present, the regulation of riboflavin biosynthesis in microorganisms has been clearly studied, but the mechanism of riboflavin transport and metabolism in plants is still not clear. Isolating riboflavin deficient mutants is crucial for analyzing the molecular mechanisms of riboflavin biosynthesis, transport, and metabolism in plants and the effect of riboflavin on plant growth and development. Here we review first the riboflavin biosynthetic pathway and its key enzymes, and then the processes of riboflavin involved in plant growth and development in detail, and finally give prospects for plant riboflavin research.

As an important environmental factor, light not only provides energy for plant photosynthesis, but also acts as a signal to regulate plant growth and development. Here, we summarize the regulatory effects of red light and far-red light on plant growth and development and abiotic stress responses. This review focuses on the mechanism of phytochrome and light signaling factor regulation of seed germination, hypocotyl growth, bud development, and flowering in plants through integration with endogenous signal transduction, such as hormones. In addition, the regulatory mechanisms of red light and far-red light on plant responses to salt, drought and temperature stress were elucidated. It is expected that on the basis of exploring the mechanism of plant’ perception and response to the light environment, we can accurately supplement light for crops to improve crop yield, quality and stress resistance by using LED spectrum technology while promoting the goal of “dual carbon” to reduce energy consumption and environmental pollution.

The amide-synthase encoded by the auxin early response gene GH3 in plants could catalyze the combination of auxin, jasmonic acid and benzoic acid derivatives with amino acids respectively to form the corresponding amino acid complex. Under the high auxin concentration in plants, GH3 protein catalyzes the combination of auxin and amino acid, which acts as the auxin sink in plants. Under the low auxin concentration, the auxin-amino acid complex is hydrolyzed to auxin by proteolytic enzymes and re-participates in the auxin signaling pathway, thus regulating the dynamic balance of auxin levels in plants. When plants are subjected to biological or abiotic stress, GH3 protein catalyzes jasmonic acid and salicylic acid to bind to amino acids and participate in plant stress response. In this study, we summarized the research progress of GH3 gene in dicotyledonous model plant Arabidopsis thaliana, monocotyledonous model plant rice, and the other plants from the aspects of GH3 protein structure, GH3 gene family classification and its function, and provided some references for further study of GH3 gene family in plants.

Squamosa promoter binding protein-like (SPL) family is a class of plant-specific transcription factors, which contain a highly conserved SBP domain consisting of two zinc finger structures and a short nuclear localization sequence. The expression of most SPL genes is regulated by microRNAs at transcription level. Based on the current research progress of SPL transcription factors, this paper summarizes the biological functions of SPLs in plant growth, development, and environmental adaptation, and discusses the future research directions of SPLs.

Nitrogen, the essential macronutrient in plants, plays a critical role in regulating plant growth and development, especially for crops production. To gain high crop yield, a large amount N fertilizer is usually applied to the planting field. However, the excessive use of chemical fertilizers has aggravated the agricultural non-point source pollution (NSP). Increasing crop yield under reduced fertilizer consumption can be achieved by increasing nitrogen use efficiency (NUE), which is crucial for promoting sustainable agriculture and for achieving agriculture and food security. In response to nitrogen-deficiency condition under natural environments, high-affinity nitrate transporter 2 (NRT2) proteins have evolved in plants. Among them, NRT2.1 subfamily acts as the main component of nitrate uptake in roots under conditions of nitrate deficiency. Here we summarize the latest progresses of the function and molecular mechanism of the NRT2 proteins, particularly of the NRT2.1 subfamily in Arabidopsis and several important crops and discuss the future directions of NRT2 research. This review aims to provide an important basis for the subsequent exploration of the potential of NRT2 proteins in increasing crop yield and the underlying molecular mechanisms.

Promoter is an indispensable regulatory sequence for driving gene expression in higher plants. Different promoter elements cause diverse driving efficiency and space-time specificity. Identifying the structures and functions of promoter elements contributes to a better understanding of the growth and development, multi-stress tolerance, and evolution of plants. With the development of high-throughput sequencing technologies, artificial intelligence and synthetic biology, the techniques for identifying cis-acting elements and constructing artificial biological components that meet the design requirements has gradually emerged, providing a foundation for efficient, precise, and diverse gene regulation in molecular breeding. This article targets on the application of promoter reconstruction in molecular design, introducing the detailed structure and function of higher plant promoters and the methods of cis-acting element identification. We summarized a total of 174 inducible, tissue-specific promoter elements in 27 categories and their applications on artificial modification and synthesis. At the end, we proposed the future directions and methods of the promoter designs. This review will be helpful for the further functional analyses of promoters in higher plants and their applications on molecular design breeding.

The PLATZ transcription factor family is a class of plant-specific zinc-dependent DNA-binding proteins that play an indispensable role in plant growth and development and stress resistance. However, the PLATZ family genes have not been systematically analyzed in foxtail millet (Setaria italica). In this study, 17 PLATZ genes in the foxtail millet genome were identified and systematically named. The SiPLATZ genes were divided into five subfamilies by phylogenetic analysis, and members of the same subfamily have similar gene structures and motifs. Cis-acting element analysis demonstrated that the SiPLATZ genes may play a role in endosperm development and various stress-resistant responses. The K_a/K_s ratio analysis indicates that duplicated genes are subject to purifying selection. There were significant differences in the expression of SiPLATZ genes in different tissues and developmental stages, which were mainly divided into two categories: high expression in roots, leaves, and stems, and in spikes and seeds. This reflects the complexity of the physiological functions of SiPLATZ genes and their possible involvement in regulating seed growth and multiple stress responses. In addition, the co-expression network constructed in combination with WGCNA analysis revealed that SiPLATZ6, SiPLATZ8, SiPLATZ9 and SiPLATZ11 may be the candidates for genetic improvement of foxtail millet yield and functional gene research. These results lay the foundation for further studies on the biological functions of PLATZ transcription factors in foxtail millet growth and development.

Tn5 is a bacterial transposon. The engineered Tn5 can efficiently tag DNA while adding the adapter sequences. Therefore, it has been widely used in the preparation of high-throughput sequencing libraries. Cleavage Under Target & Tagmentation (CUT&Tag) is an improved technology for studying the interaction between protein and DNA, which has the advantages of good repeatability, high signal-to-noise ratio, and easy operation. This technology uses Protein A (pA) or Protein G (pG) and Tn5 to form a fusion protein, which can locate specific antibodies (the antibody is used to identify the target protein) and break the DNA near the target site while introducing sequencing adapters. Then, DNA was extracted, followed by PCR amplification to obtain the sequencing library. However, different types of antibodies have different affinities for pA and pG, thus limiting the application of CUT&Tag for some antibodies. To overcome this limitation, the expression vector of pG-Tn5 was constructed by recombination, and pG-Tn5 recombinant protein was obtained by prokaryotic expression and affinity purification. We used RNA polymerase II (Pol II)-specific antibodies (Pol II Ser5P, mouse IgG1 and rabbit IgG) to compare the efficiency of pA-Tn5 and pG-Tn5 in library preparation of CUT&Tag in Arabidopsis. The results showed that the IgG1 antibody had higher affinity for pG-Tn5, and the quality of the constructed library was better when pG-Tn5 was used. The rabbit IgG antibody has comparable affinities to the two enzymes. A lower starting amount of plant material can be applicable in CUT&Tag. This study provides a reference for the selection of Tn5 fusion proteins against different antibodies in future CUT&Tag experiments.

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.

Starch is the major storage material of rice (Oryza sativa) endosperm, and its accumulation process affects the subsequent growth and development of plants. As one of the main nutrients absorbed by human beings from rice, the synthesis and accumulation process of starch in rice has attracted increasing attention. This review mainly discusses the latest progress of endogenous factors affecting starch synthesis and accumulation, such as sucrose unloading from phloem, key enzymes of starch synthesis and hormones, and points out the unsettled questions in the field of endosperm starch accumulation to provide some reference ideas for further research in the future.

Soil cadmium (Cd) pollution seriously restricts the yield and quality of facility vegetables. Melatonin (MT) can enhance the resistance to various stresses in plants. However, the downstream signals, which regulated by MT during tomato seed germination under Cd²⁺ stress remains unclear. The effects of Cd²⁺ stress and exogenous MT on seed germination were investigated using tomato (Solanum lycopersicum) wild-type Alisa Craig seeds. The results showed that the germination of tomato seeds and seedling growth were significantly inhibited by Cd²⁺ treatment with more than 0.5 mmol·L^-1. Exogenous MT (0.15 mmol·L^-1) reduced the content of Cd²⁺ in the underground and above-ground tissues of seedlings, effectively alleviating the inhibitory effect of Cd²⁺ stress on tomato seed germination and seedling length. The expression of phytochelatin and transporters-related genes (PCS, NRAMP1, ABCC3, HMA3, and ABCG5) in tomato radicles were significantly increased by MT under Cd²⁺ stress, showing the positive regulation of MT in transmembrane transport and vacuolar sequestration of Cd²⁺. In addition, MT alleviated the oxidative damage induced by Cd²⁺ stress, which was related to the enhanced activities of CAT, APX, and ALDH enzymes apart from its own scavenging ability. Furthermore, MT significantly down-regulated the expressions of abscisic acid (ABA) synthesis genes (NCED1 and NCED2) under Cd²⁺ stress, and up-regulated the expression of ABA decomposition gene ABA8ox1, leading to the decrease of ABA content, which effectively regulated the GA/ABA ratio and promoted the germination of tomato seeds under Cd²⁺ stress.

The secondary metabolites produced by plants provide human beings with a wealth of pharmaceutical, perfume and industrial raw materials. With the rapid development of molecular biology and genomics research, the biosynthetic gene clusters (BGCs) of secondary metabolites of various plants have been analyzed, which opens a new path for us to quickly obtain the biosynthetic pathways of target products and discover novel natural products. This paper focuses on the definition and characteristics of plant secondary metabolite biosynthesis gene clusters, and its basic structural models, evolution and regulatory mechanisms, in order to provide theoretical basis and reference for related research.

Chimeric soybean plants with transgenic hairy roots is very important for soybean functional genomics. In this study, we used three soybean genotypes to compare their hairy root induction rate and plant survival rate under different co-cultivation conditions. Our results showed that co-culturing the explants infected by Agrobacterium rhizogenes for 1 d under dark conditions was an effective strategy to induce hairy roots. We also found that removing the adventitious roots (AR) at hypocotyl significantly increased number of hairy roots, enhanced their growth and subsequently improved the positive rate of transgenic hairy roots. Furthermore, we found that the inoculation with rhizobium at 14 d of induction was able to enhance the contact between the bacteria and the transgenic hairy roots at early growth stages, and thus improved the soybean’s nodulation efficiency. Taken together, we successfully established a simple and efficient method to generate chimeric soybean plants with transgenic hairy roots. This method can be widely used in soybean gene functional studies.

Temperature is one of the major environmental determinants of plant geographical distribution. Plants distri-

buted at high latitudes or altitudes usually suffer a period of sub-zero temperature during their life cycle. When the ambient temperature drops to the freezing point, the water molecules in plants form ice crystals, causing fatal damage to plant tissue structure. In order to adapt to the freezing environment, the pathogenesis-related protein PR (PR) and its related WRKY transcription factors in cold climate plants have evolved into antifreeze proteins (AFPs) that can bind specifically to the ice surface and effectively inhibit the formation and growth of ice crystals. Currently, AFPs have been identified in nearly 100 plant species, such as winter rye (Secale cereale). Compared with insect AFPs, plant AFPs have extremely high recrystallization inhibition activity, which can effectively prevent the formation of large ice crystals in vivo. Both low temperature and pathogens can induce AFP synthesis in cold climate plants. Interestingly, only the cold-induced AFPs have dual molecular functions as hydrolase/antifreeze activity. The PR-AFPs, however, possess only one of hydrolase/antifreeze activites, whose conversion is controlled/regulated by post-translational peptide differential folding, as suggested with growing evidence. AFP has gradually become one of the hot targets in botanical research due to its unique molecular function and its promising applications. This paper will provide a systematic review of recent progress in this area.

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.

The erection of rice leaf is one of the important agronomic traits that determine plant architecture, photosynthetic efficiency, and crop yield. Cytokinin is one of the most important plant hormones that regulate crop morphology, stress resistance and yield, but its role in the lamina joint development and leaf angle is still need to be further studied. Here, we report that rice CYTOKININ OXIDASE/DEHYDROGENASE9 (OsCKX9) controls lamina joint development and positively regulates leaf angle. Histological sections indicated that the leaf inclination changes in the WT and osckx9 resulted from the asymmetric proliferation of cells and vascular bundles in lamina joint. qRT-PCR showed that OsCKX9 was highly expressed in lamina joint. Quantification of cytokinin content in osckx9 mutant lamina joint showed that there were a mass of cytokinin accumulated. Moreover, the osckx9 showed insensitive to eBL. Therefore, our results revealed that OsCKX9 played a positive role in regulating leaf erectness, which provides genetic resources for analyzing the genetic basis of leaf angle and molecular-breeding of the ideal plant architecture rice.

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.

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.

Heavy metal-associated isoprenylated plant proteins (HIPPs) are a class of proteins characterized by the presence of heavy metal-associated domains (HMA) and C-terminal isoprenylation motifs in plants. Here, we introduce the structural characteristics of the HIPPs, review their potential roles in plant development and response to environmental changes (including biotic and abiotic stresses) as well as discuss their working mechanisms underlying their participation in heavy-metal homeostasis and detoxification. This comprehensive overview aims to provide valuable insights for future research on the HIPP family across diverse plant species.

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.

In 2023, the numbers of original research articles published by Chinese plant scientists in mainstream plant science journals increased significantly improved compared with that in 2022, and important advances have been made in the fields of regulation of intraspecific and interspecific reproductive isolation in Brassicaceae by stigma receptors, supercomplex structure of chloroplast TOC-TIC, mechanisms of crop yield, disease resistance, stress tolerance, the origin and spread of grapes and citrus plants, and the evolution of modern maize, millet and potato germplasm resources. Among them, “Crop Salt and Alkali Tolerance Mechanisms and Applications”, and “A New Method for Precise Manipulation of Single Base to Large Fragment DNA” in 2023 were selected as two of the “Top Ten Advances in Plant Sciences in China”; “The Molecular Mechanism of Mentor Pollen Effect in Plant Distant Hybridization” was selected as one of the “Top Ten Advances in Life Sciences in China” in 2023. Here we summarize the achievements of plant science research in China in 2023, by briefly introducing 30 representative important research advances and sorting out the experimental materials used in plant science research, 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.

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 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.

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.

Phytochrome is an important receptor for red and far-red light sensing in plants, and it plays a vital role in regulating the plant flowering period, improving crop yield potential and regulating plant stress resistance. Identification of PHY family genes in Gossypium, exploration of the patterns of inheritance and regulatory network of domestication and improvement, and identification of the key phytochrome genes in Gossypium, provides insights into the de novo domestication and breeding of early maturing Gossypium species. To identify the phytochrome genes of Gossypium, we used bioinformatics methods to analyze 5 phytochrome genes in Arabidopsis thaliana. Phylogenetic analysis showed that the PHY genes in Malvaceae species consisted of 4 subfamilies (PHYA, PHYB, PHYC and PHYE). Moreover, the domestication selection analysis of PHY genes among different populations of G. hirsutum showed that the domestication process of PHY genes could be divided into two stages: domestication and improvement. Furthermore, the gene expression of the PHY gene family was analyzed using leaf RNA-sequencing data obtained from wild and cultivar genotypes of G. hirsutum under short-day (SD) and long-day (LD) conditions. The results showed that the expression of GhPHYA1Dt and GhPHYB1Dt were significantly different between SD and LD conditions. After 14 hours of long-day treatment, the expression of GhPHYC1At and GHPHYE1At in the cultivar was significantly lower than that in wild species. These results lay a foundation for further study on domestication selection and functional mechanisms of Gossypium PHY genes and provide a theoretical basis for breeding new early maturing Gossypium varieties and de novo domestication.

In this study, we used the leaflets of marigold (Tagetes erecta) Milestone Yellow as explants to investigate the major factors impacting the transformation efficiency of Agrobacterium-mediated method. The factors included antibiotic concentration, strain type, bacterial concentration, infection time, co-culture time, acetosyringone concentration and anti-browning agent type. We found that the suitable concentrations of cefotaxim sodium salt and kanamycin sulfate were 100 mg·L^-1 and 10 mg·L^-1, respectively. We also found that the strain EHA105 had the highest transformation efficiency up to 4%. The best infection conditions for EHA105 were at bacterial concentration of 0.1 for OD₆₀₀, infected for 5 minutes, and co-cultured for 1 day. In addition, the bud germination rate could be improved by both applying 100 μmol·L^-1 acetosyringone during the infection process and adding 0.2 g·L^-1 polyvinyl pyrrolidone in the screening medium. This study laid a foundation for marigold gene function research and transgenic breeding.

Plant epidermis is crucial in regulating photosynthesis, respiration, heat dissipation, and water utilization. Significant progress has been made in the study of stomatal development in dicotyledonous plants, such as Arabidopsis thaliana. Three important bHLH transcription factors (SPCH, MUTE, and FAMA) have been reported to be specifically expressed at different stages of cell division and differentiation in the stomatal lineage. They form heterodimers with another transcription factors SCRM/ICE1 and SCRM2/ICE2 to regulate the morphological transformation and changes of stomatal lineage cells across three stages of division, finally forming the stomatal complex. However, in monocots, especially in Poaceae plants such as maize (Zea mays), studies on genes regulating epidermal morphogenesis are less reported. In this study, two single-gene recessive mutants, Zmice1-1 (inducer of cbf expression1-1) and Zmice2-1, were isolated using reverse genetics approaches. Compared to the control B73, Zmice2-1 exhibited dwarfism, leaf chlorosis, reduced fertility, significantly lower stomatal density and index, disrupted arrangement of epidermal long cells, and absence of spacing between stomata. Zmice1-1 leaves gradually turned yellow from the five-leaf stage and displayed complete chlorosis at later stages. The homozygous Zmice1-1 plants are growth-arrested and sterile, but the stomatal density showed no significant difference compared to the control. Different allels of Zmice2 were obtained using CRISPR-Cas9 genome editing technology. Phenotypic identification showed that Zmice2-2 had an abnormal stomatal phenotype similar to Zmice2-1, indicating that ZmICE2 is involved in the regulation of stomatal development. Transcriptome analysis of B73 and Zmice2-1 revealed that ZmICE2 primarily regulated stomatal development by affecting cell division and differentiation, participating in the formation of maize epidermal morphology. These results contribute to a better understanding of the mechanisms of epidermal morphogenesis in maize and provide valuable genetic resources for improving crop resilience and yield traits.

Double flower is characterized by the increase in the number of petals, the folding of petal or the increase in area of petal, which usually has higher ornamental and economic value. Focusing on the increased number of petal and petal-like organ in double flower, we summarized and discussed the molecular mechanism of the formation of double flower in some model plants and ornamental plants, including the key transcription factors and the epigenetic modifications such as miRNAs, DNA methylation, histone modification and chromatin remodeling involved in the regulation of petal number. And based on this, we discussed the developing trend of the future research.

Chloroplast is the main place for photosynthesis of green plants, and thylakoid is the key component of the membrane structure in the chloroplast. Various protein complexes and lipids are distributed on the plant thylakoid membrane. About half of the lipid components are glycolipids, mainly including monogalactosyldiacylglycerol, digalactosyldiacylglycerol, and sulfoquinovosyldiacylglycerol. The proportion of phospholipid in the membrane is very low, and the main phospholipid component is phosphatidylglycerol. Most protein complexes of photosynthesis are embedded in regularly arrranged polar lipids. These membrane lipids are essential for plant photosynthesis and growth. A comprehensive knowledge on the structure and function of the major lipids in thylakoid membranes in prokaryotes or eukaryotes and their biosynthesis will help our further study in understanding of the mechanism of photosynthesis light energy and substance conversion, and provide theoretical basis for the study of membrane lipids in plant thylakoids.

Photosynthesis of plants depends on the green leaves, and the most intuitive feature of leaf growth and development is its color. At present, more than 200 genes related to rice leaf color have been cloned. The regulatory mechanisms of rice leaf color are complex and diverse, which involve multiple regulatory pathways, including biosynthesis and degradation of photosynthetic pigments, pathway of nucleus-plastid signaling, and heme synthesis. In addition, external environment such as temperature and light intensity can also affect the color changes of rice leaves. Here we reviewed the molecular pathways of rice leaf color, environmental factors and leaf color related genes, as well as the genetic regulatory mechanisms of rice leaf color was revealed, which will provide theoretical basis for rice high photosynthetic breeding and application, and future research in addressing some scientific problems in this field.

The domestication of crops was a significant event in human history, which led to the emergence and prosperity of agricultural civilization. Maize is an important global food crop, and its domestication origin has long attracted the attention of both the biological and historical communities. The mainstream view in the past was that modern maize originated from the parviglumis type of teosinte. Recently, Yan Jianbing and his collaborators systematically collected and sorted various types of wild and cultivated maize resources, and comprehensively applied genomics, population genetics, and quantitative genetics methods, along with the use of archaeological findings. They found that modern maize also has the gene introgression of the mexicana type of teosinte, which has influenced many agronomic traits. A new model for the origin of modern maize has been proposed based on these findings.

Flavonoids are polyphenols compounds produced during the secondary metabolism of plants, which are widely present in plants and have various functions. Flavonoids biosynthesis takes place at the cytosolic side of the en- doplasmic reticulum (ER), but accumulation of various flavonoids is observed in the vacuole. Efficient transport and ac- cumulation systems are therefore required to transfer flavonoids from the ER into the vacuole. Certain researches for the transport of flavonoids has been done for decades. Current research results showed that: there are three transport mechanisms in plants, including glutathione S-transferase (GST), membrane transporters, and vesicle trafficking. Here, we reviewed the three transport mechanisms and advances of plant flavonoids transport in recent years. The functional cooperation of three distinct but nonexclusive mechanisms were summarized. While the biosynthesis of the flavonoids is well characterized across species, the research on flavonoids transport and accumulation is still relatively insufficient. For better understand the flavonoids transport and accumulation mechanism in plant, the relationship between flavonoids modification and transport, flavonoids transport substrate specificity and preference, and transcriptional regulation of flavonoids transport remain deeply unexplored.

Herba Epimedii is a traditional Chinese herb medicine (TCM) with a long history. Research on Herba Epimedii has attracted much attention in China due to its high medicinal value. C8-prenylated flavonol glycosides (PFGs) have been demonstrated to be the main bioactive components in Epimedium brevicornu, and their content determines the medicinal quality. Understanding the biosynthesis pathway of PFGs, exploring genes related to PFGs content, and elucidating the regulatory mechanisms of PFGs biosynthesis pathway is fundamental and essential for improving the quality of E. brevicornu. Here, we provide a comprehensive review of the research on structural and transcriptional factor genes related to the biosynthesis of PFGs, which not only contributes to unravel the regulatory mechanisms related to PFGs content, but also lay a foundation for research on molecular breeding and the synthetic biology in Epimedium plants.

Lutein can effectively reduce incidence of atherosclerosis, diabetes, cancer and multiple eye diseases. The lutein biofortification through food crop has gained more attention with improvement of daily diet. In this paper, 194 Shanxi wheat cultivars planted in three environments were used to extract lutein by organic solvent extraction, and the content of lutein in different germplasms was determined by high performance liquid chromatography (HPLC). The broad-sense heritability of lutein content in wheat and its relationship with grain color, winter/spring types, geographical origin, accession types, and main agronomic traits were analyzed, and the genetic loci associated with lutein content were identified through genome-wide association analysis. Results showed that significant variation in lutein contents occurred among Shanxi wheat accessions, the coefficient of variation was 33.12%-48.57%. Genotype was the main factor affecting lutein content. The average lutein content in three environments was 0.67-4.03 μg·g^-1, 0.16-5.05 μg·g^-1 and 0.16-3.63 μg·g^-1, respectively. The average lutein content of winter types and irrigated-wheat accessions were higher than those of spring types and dryland-wheat, respectively. There was no significant effect of grain color and released years on lutein content. Heading date, plant height and 1 000 kernel weight were significantly negative correlated with lutein content. The other agronomic traits had no significant effect on lutein. Genome-wide association analysis found four major loci related to lutein content on chromosomes 1B, 3A and 7A, among them, QLuc.3A and QLuc.7A.1 are new loci affecting the lutein content. These results provide valuable information for breeding and cultivation of wheat lutein bioaugmentation varieties.

Living organisms are often exposed to a wide range of biotic and abiotic stresses that cause severe wounding, leading to partial or complete organ loss. Being sessile, plants have evolved powerful regenerative capabilities to adapt to the environment. Wounding is a prerequisite for plant regeneration, the local wound signals that trigger regenerative responses remained unknown for centuries. A recent study has identified a small peptide, REF1, that regulates local wound responses and regeneration capabilities in plants. The study found that REF1 and its receptor PORK1 can promote plant regeneration by activating WIND1, a master regulator of wound-induced cellular reprogramming in plants. Crucially, exogenous application of the REF1 peptide can improve the regeneration efficiency of several crops to varying degrees. This discovery not only provides a new perspective on the molecular mechanisms of plant injury responses and regene- ration, but also offers potential application strategies for enhancing the regenerative capacity and transformation efficiency of crops.

Salicylic acid (SA) is a natural phenolic compound in plants that plays a crucial regulatory role in plant immune responses. Plants primarily synthesize SA through two pathways: the isochorismate synthase (ICS) pathway and the phenylalanine ammonia-lyase (PAL) pathway. The synthesized SA is perceived by receptors such as nonexpressor of pathogenesis-related genes 1 (NPR1), which subsequently activate immune responses. In Brassicaceae species like Arabidopsis thaliana, SA is mainly synthesized via the ICS pathway, whereas monocots and non-Brassicaceae dicots predominantly rely on the PAL pathway. For a long time, understanding of SA biosynthesis via the PAL pathway has been incomplete, hindering research on SA-mediated immunity in crops and significantly limiting progress in crop disease-resistant breeding. Recently, three research groups from China independently elucidated the PAL-mediated SA biosynthesis pathway in crops. Building on these breakthroughs, this review summarizes recent advances in the study of SA-mediated plant immune responses. We primarily focus on the biosynthetic pathways of SA within plants, the mechanisms by which SA is perceived and activates immune responses, and discuss current challenges and future directions in SA-mediated immunity research. We hope this review provides new insights and perspectives for both theoretical studies and practical applications in crop disease-resistant breeding.

The mechanism of sex determination in dioecious plants is a hot topic in reproductive biology, evolution and ecology, and so on. During recent years, the sex determination genes of several important crops, such as asparagus, kiwifruit, and poplar, have been revealed and applied to produce sex-specific products. New germplasms with bisexual flowers have also been developed for molecular breeding. In this review, the genetic bases of sex determination were systematically analyzed from the aspects of sex chromosomes and sex-determination genes in dioecious plants. Subsequently, the epigenetic regulatory roles of non-coding RNA and DNA methylation in plant sex determination were discussed. Finally, it was suggested that further comparative studies of sex determination genes among different dioecious plants should be carried out. More efforts are also needed to pay on the epigenetic regulations of plant sex determination. This work will not only facilitate to understand the molecular mechanisms of sex determination in dioecious plants, but also help to expand the application values of sex determination studies.

Plant roots can acquire water and nutrients selectively from soil and transport them upwards to the aerial parts for plant growth and development. These functions are closely related to their anatomical structures. The radial transport of water and solutes absorbed by roots mainly includes three different pathways, namely, the apoplastic pathway, the symplastic pathway and the transcellular pathway. The endodermis is the innermost cell layer that surrounds the central vasculature. For a long time, endodermal differentiation formed the Casparian strips has been considered to play a decisive role in blocking water and solutes transport through the apoplastic pathway. However, in recent years, it has been found that suberin lamellae formed by endodermal differentiation plays no less important role in the radial transport of water and solutes than Casparian strips, and even that suberization is the second life of an endodermal cell. In this paper, we reviewed the latest research progress on the physiological function of suberin lamellae in water and solutes transport in recent years, and discussed the relationship between suberin lamellae and drought, salt, nutrient and heavy metal stress of crops, in order to provide a reference for the theory and practice of endodermal plasticity in the regulation of plant physiological function.

In this study, a plant regeneration system via somatic embryogenesis was established in Alocasia genus. We obtained embryogenic cell suspension cultures of A. reginula through embryogenic calli induced from petioles, and achieved a high frequency of plant regeneration using embryogenic cell aggregates. Efficiency of embryogenic calli induced from petiole explants was highest (81.3%) on a Murashige and Skoog (MS) medium supplemented with 2.0 mg·L^-1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.0 mg·L^-1 thidiazuron (TDZ). The embryogenic calli were crushed into cell aggregates and then transferred to liquid MS media supplemented with 2.0 mg·L^-1 2,4-D and 1.0 mg·L^-1 TDZ for suspension cultivation. By subculturing biweekly, lots of cell aggregates were gained from embryogenic suspension cultures after 12 weeks. The cell aggregates within 28 weeks of suspension culture were transferred to solid 1/2MS media without plant growth regulator for differentiation culture, with an average of 2.3-2.5 plantlets regenerated from each cell aggregate. The formation and germination of somatic embryos were observed by optical microscopy and scanning electron microscopy (SEM). After the regenerated plantlets were transplanted to a greenhouse for 4 months, the achieved survival ratio was 95.3%. Flow cytometry (FCM) demonstrated that there was no chromosome ploidy variation in randomly selected 50 surviving plants. In addition, the nuclear DNA content was estimated at 10.94 pg·(2C)^-1, and the genome size was 5 290.12 Mb·C^-1. There was no significant variation in their phenotypes from the time the plants were transplanted to the greenhouse until they bloomed spontaneously. These results provide good technical support for the commercial production of seedlings and biotechnological breeding of A. reginula.

Aluminum (Al) is one of the common metal contaminants in acidic soils. To reveal the effects of exogenous organic acids on the physiological characteristics and root DNA damage of Helianthus tuberosus under Al stress, we used Al resistant H. tuberosus cv. ‘Xuzhou’ and Al sensitive H. tuberosus cv. ‘Ziyang’ as materials. The effects of exogenous organic acids on the physiological responses and DNA damage of H. tuberosus at various periods (7, 14, and 21 d) under Al stress were investigated by setting 0, 350 and 700 µmol∙L^-1 Al concentration treatments and applying 0, 30, 60 and 90 µmol∙L^-1 compound organic acids, respectively. The results showed that Al stress inhibits root elongation and root activity, severely inhibited the photosynthetic and antioxidant systems of H. tuberosus, and the DNA damage in the root system increased with the increase of Al concentration. In contrast, the application of compound organic acid effectively alleviated Al stress. 60 µmol∙L^-1 compound organic acid improved the activity of the antioxidant system, maximum photochemical efficiency and organic acid secretion in root tips, secretion of citric acid was 2 times (H. tuberosus cv. ‘Xuzhou’) and 0.75 times (H. tuberosus cv. ‘Ziyang’) higher than the control, reduced root tip Al content and improved root activity. Besides, H. tuberosus cv. ‘Xuzhou’ and H. tuberosus cv. ‘Ziyang’ oliver tail moment decreased by 51.53% and 35.10%, and compound organic acid reduced the DNA trailing phenomenon and repaired DNA breaks to a greater extent. In conclusion, high concentration of Al causes serious damage to H. tuberosus, which is difficult to mitigate. 60 µmol∙L^-1 compound organic acid could enhance the H. tuberosus physiological responses under low Al stress, reduce DNA damage and thus improve the stress resistance. The alleviation effect was better in H. tuberosus cv. ‘Ziyang’. This study reveals the regulatory role of exogenous organic acids on the physiological responses of H. tuberosus under Al stress, and provides a theoretical basis for planting and production of H. tuberosus and production of other cash crops in the acid-aluminium areas of southern China.