Domestication of wild plants was crucial for human settlement and the development of civilization, which arose independently in many different geographic areas on different wild species. However, these crops underwent variant domestication process displaying the ‘domestication syndrome’ with a common suite of traits. The systematical analysis of convergent selection at genome level may provide important information and genetic resources for crop breeding. Recently, a team led by Xiaohong Yang and Jiansheng Li from Chinese Agricultural University and Jianbing Yan from Huazhong Agricultural University reported the genetic basis of convergent selection between maize and rice at both single gene and whole genome levels. Particularly, they found the maize KRN2 and rice OsKRN2 genes experienced convergent selection and regulated grain number and yield in a similar pathway. Moreover, they identified a large number of orthologous gene pairs that underwent convergent selection during maize and rice evolution, which were enriched in certain pathways including starch metabolism, sugar and coenzyme synthesis. This significant work not only cloned KRN2/OsKRN2 orthologous gene pairs with great value in maize and rice breeding, but also revealed the convergent selection between maize and rice at the genome level, providing critical foundations for studying the molecular basis of domestication syndrome and their applications in breeding practices.

Proximity labeling (PL), a recently developed technique to detect protein-protein interactions and subcellular structural proteomes in living cells, has been successfully applied in various animal and plant systems. Proximity labeling is conducted by fusing an engineered enzyme with catalytic activity to a protein of interest (bait protein). With the catalysis of the enzyme, small molecular substrates such as biotin are covalently linked to endogenous proximal proteins, which can be further enriched and analyzed to identify the interactome of the bait protein. TurboID, a biotin ligase produced by directed evolution, has the advantages of non-toxicity and high catalytic efficiency. Using TurboID-based proximity labeling to analyze proximal proteins of bait proteins, we can study transient or weak protein interactions, which helps to understand the complex biological processes occurring inside cells. Here, we describe methods and related tips for TurboID-based proximal labeling in Arabidopsis thaliana, and hope to provide a reference for studying plant protein-protein interactions.

Auxin is one of the most important plant hormones and plays a key role in regulating plant growth and development. In plants, early auxin responsive gene families, such as Aux/IAA (Auxin/Indole acetic acid repressors), GH3 (Gretchen Hagen3) and SAUR (Small Auxin up RNA), are rapidly induced and up-regulated by auxin treatment. Aux/IAA gene family is generally composed of four conserved domains. Domain I inhibits the expression of downstream genes in the auxin signaling pathway, and domain II is mainly regulated by Transport Inhibitor Response 1 (TIR1) in auxin signal transduction, thus affecting the stability of Aux/IAA. Domain III/IV regulates auxin signaling by interacting with Auxin Response Factor (ARF). Aux/IAA gene family has been reported to play an important role in organ development, root formation, stem elongation and leaf expansion in dicotyledonous Arabidopsis thaliana while in monocotyledonous rice (Oryza sativa) and wheat (Triticum aestivum), Aux/IAA mainly affects root development and plant architecture. However, the functions of most Aux/IAA genes remain unclear and need to further study. In this article, we reviewed the structure and function of Aux/IAA protein, and the auxin signal transduction pathway in Arabidopsis, cereal crops and other plants to provide clues for fully revealing the biofunction of the Aux/IAA gene family.

CRISPR/Cas9 technology is a gene editing strategy using Cas9 nuclease guided by RNA to target an interest gene in genome. Recently, a large number of new-type gene editors based on the CRISPR/Cas9 have been updated rapidly and become more precisely and efficiently in gene editing, which has a great application prospect in crop molecular-designing breeding. This paper summarized the technical principles, editing effects and applications of the CRISPR/cas9 and its related gene editors, and also discussed the aspects of dilemmas, countermeasures and prospects, intending to provide reference for scientific researchers in the related fields.

In 2021, the numbers of original research articles published by Chinese plant scientists in international multidisciplinary journals and mainstream plant science journals increased significantly compared with that in 2020, and important advances have been made in the fields of male and female cell recognition and fertilization, stem cell fate determination, mycorrhizal symbiosis, photosynthetic membrane protein complex, nitrogen and phosphorus nutrient utilization, innate immunity, crop de novo domestication and genome design. Among them, ‘rapid de novo domestication of allotetraploid wild rice’ was selected as one of the ‘Top Ten Advances in Life Sciences in China’ in 2021. Here we summarize the achievements of plant science research in China in 2021, and briefly introduce 30 representative important research advances, so as to help readers understand the developmental trend of plant sciences in China, and evaluate how to better connect plant scientific research with major national needs.

Global warming is the most severe environmental challenge that mankind is facing now. In addition to effectively controlling carbon emissions, making the ecosystem work at full capacity of carbon sequestration is an important means to achieve the goal of carbon neutralization. As one of the wetland types with the highest carbon sequestration capacity, peatland is the key terrestrial ecosystem to accelerate the achievement of carbon neutrality goals. As the ‘effective ecosystem engineer’ on peatlands, peat moss (Sphagnum) plays an extremely important role in peatlands, such as carbon sink, freshwater filtering, and land protection from flooding. For more than 100 years, peat mosses, as the most economically valuable group of bryophytes, have been widely used in the fields of medicine and health care, pollution monitoring and wastewater treatment, especially in the horticultural industry as one of the most reliable soil media and moisturizing materials. In the context of global warming and the ‘two-carbon’ goal, peat moss is a research hotspot in life sciences and ecology. This paper mainly reviews the morphology, species diversity and origin, habitat and distribution, reproduction and protection, cultivation and planting, environmental indication and monitoring, usage and applications, capabilities of carbon sequestration, water storage and acidification. It provides a reference for peat moss research, peatland protection and restoration, as well as development, utilization, and industrial development of peat moss.

FLOWERING LOCUS C (FLC) is an important repressor of plant flowering. It mainly represses flowering by binding to the promoters of two downstream key floral promoting genes, FLOWERING LOCUS T (FT) and SUPPRESSOR OF OVEREXPRESSION OF CO 1 (SOC1). It also regulates flowering time by binding to other regulatory genes. While the detailed molecular mechanisms of FLC in the regulation of flowering still need to be deeply investigated. This review summarizes the new research progresses of FLC in recent years in the 8 genetic pathways of flowering regulation, and give an outlook for the future study in this field.

A large area of membrane surface and intracellular immune receptors have been evolved in higher plants to sense various pathogen signals and prevent pathogen invasion. Among them, pattern recognition receptors on the cell surface activate basic immune response after sensing pattern molecules, while nucleotide-bounding leucine-rich repeat proteins (NLRs) activate specific immune response by sensing effector proteins secreted by pathogenic microorganisms, resulting in hypersensitivity and cell death. In this review, the latest research progress of plant immunity is mainly reviewed from the aspects of NLRs on the recognition of effector proteins, plant immune activation and downstream signal regulation.

Reactive oxygen species (ROS) are a ‘double-edged sword’ in plants. On the one hand, ROS, as a signal molecule, plays pivotal roles in many aspects of life activities; on the other hand, excessive accumulation of ROS can cause oxidative damage to biological macromolecules. Accurate detection of ROS is essential to assess its intracellular redox status. Due to the characteristics of short half-life and strong reactivity of ROS components, their qualitative and quantitative analysis are difficult. It is critical to select the appropriate detection method and improve the spatiotemporal accuracy of detection for research in plant sciences and in other fields. At present, fluorescent probe analysis has attracted the attention of researchers because of its advantages of high sensitivity, good selectivity, low detection limit and strong intuition. This article introduces the detailed operation protocol and attentions for ROS detection using 2′,7′-dichlorodi-hydrofluorescein diacetate (H2DCFDA) fluorescent probe based on flow cytometry and confocal microscope. These methods can be used to detect ROS levels and distribution in model plant tissues, including Oryza sativa, Arabidopsis thaliana, Zea mays and Glycine max.

Melatonin (N-acetyl-5-methoxytryptamine) is a small molecule indoleamine that is essential for life. Melatonin is widely present in animals and plants, and plays a vital role in the growth and development. With the study of plant melatonin, its synthesis pathway and roles in plants have become clear. Studies have shown that melatonin has the regulatory effects in improving plant resistance to abiotic and biotic stresses. This review summarizes the research progress of melatonin in plant abiotic and biotic stresses in recent years; it provides reference for in-depth analysis of influence of melatonin on the regulation mechanism of plant resistance to stresses.

Calcineurin B-like proteins (CBLs) and their CBL-interacting protein kinases (CIPKs) are important regulatory network in response to abiotic stresses. The CBL-CIPK system senses and decodes Ca²⁺-signals through phosphorylation to regulate plant response to abiotic stresses. In this review, the basic structures of CBLs and CIPKs, and their phosphorylation on different substrates, as well as regulatory mechanisms of plants in response to abiotic stresses were summarized. We also put forward a perspective on the future research directions of CBLs and CIPKs, as well as their potential applications in genetic improvement of crops for stress tolerance.

In order to establish the regeneration system of Cerasus serrulata var. lannesiana cv. ‘Grandiflora’, the effects of different explants and plant hormone combinations on callus induction, adventitious bud differentiation, proliferation and rooting were studied using perennial mother plant leaflets, annual grafted seedling leaflets, axillary bud induction leaflets and proliferative first-generation leaflets as explants. The results showed that callus could be induced from all four explants, and adventitious buds could be derived from all explants except the leaflets of perennial mother plants. The higher the degree of explants’ juvenility, the greater the success of subsequent culture, with the best explants were the proliferative first generation leaflets. The best medium for callus induction was MS+0.5 mg·L^-1 6-BA+1.0 mg·L^-1 2,4-D, and the induction rate was 96.22%. The optimal medium for differentiation was MS+1.0 mg·L^-1 6-BA+0.1 mg·L^-1 2,4-D+0.1 mg·L^-1 TDZ, and the differentiation rate was 78.14%. The optimal medium for proliferation was MS+1.0 mg·L^-1 6-BA, and the proliferation coefficient reached 7.85. The optimal medium for rooting was 1/2MS without any hormone, and the regenerated plants with 100% rooting rate were obtained. The regenerated plants from different explants grew very differently, and those induced from first generation of proliferative leaflets had the best growth.

Target of rapamycin (TOR) is a highly conserved serine/threonine-protein kinase among all eukaryotes. As a central regulator, TOR integrates nutrient, energy, growth factor and environmental signals to control cell proliferation, growth, and metabolism. With the establishment of TOR research systems in plants, tremendous progress has been made in, both conserved and unique functions of plant TOR have been uncovered in recent years. Here, we reviewed TOR complexes and the mechanisms of plant TOR integrating sugar, nitrogen, phosphate, sulfur, phytohormone and stress signals to orchestrate transcription, translation, metabolism, autophagy, and stress responses. We also highlight a few fundamental questions that will be of great interest to be resolved for fully revealing biofunctions of plant TOR.

The anthers of Paeonia lactiflora cv. ‘Fenyunu’ were used as explants to study the effects of different concentrations of 2,4-D on callus induction, somatic embryogenesis and plant regeneration. The cell composition of callus and the development process of somatic embryos were observed with cytohistological method, and the ploidy of regenerated plants was identified using root tip squash method. The results showed that the suitable medium for callus induction of P. lactiflora anther was MS+1 mg·L^-12,4-D+1 mg·L^-1NAA+0.1 mg·L^-1KT+30 g·L^-1sucrose+6.5 g·L^-1agar, and the callus induction rate was 14.7%. The callus was transferred to somatic embryo induction medium and underwent stages of spherical embryo, heart-shaped embryo, torpedo embryo and cotyledon embryo, and the somatic embryo induction rate was 52.1%. Genuine leaves germinated in seedling medium and complete plants were obtained, and the seedling rate was 47.1%. Haploid and diploid plants were identified using root tip squash method. The study preliminarily established a culture system to implement plant regeneration through somatic embryogenesis, which also provided reference protocol for anther culture of other varieties of Paeonia. Regenerated plants are important materials for genetic research and haploid breeding of P. lactiflora.

The topological organization of nucleosomes across the genome is non-uniform. While densely arranged within constitutive heterochromatin, histones are depleted at regulatory loci. Chromatin accessibility is the degree to which nuclear macromolecules are able to physically contact with regulatory DNA. Following the development of next-generation sequencing technology, a variety of quantitative methods, including DNase-seq, ATAC-seq, MNase-seq and NOMe-seq, have been developed to measure genome-wide chromatin accessibility easily and efficiently. In this review, we first introduced the technical principles of the four principal methods for measuring chromatin accessibility. And then we summarized the critical biophysical determinants of chromatin accessibility, including nucleosome occupancy, histone modification and TFs combination. Finally, we described recent advances of chromatin regulation during development and stress responses in plants. Our goal is to provide a reference for researches about genome-wide chromatin accessibility mapping, identification of cis-regulatory elements, and the dissection of epigenetic and genetic regulatory networks.

Plant transformation is an important tool for genetic engineering. The key technology of genetic transformation is to introduce foreign genes into plants genomes quickly and efficiently and reduce the time to obtain transgenic offspring. Peanut (Arachis hypogaea) is an important oil and cash crop in China. The genetic transformation system is still not well established in peanuts. It seriously restricts the function research of peanut genes and the molecular breeding progress. Here, we established a rapid and stable genetic transformation system in peanuts. The Agrobacterium tumefaciens was injected into the second stem of peanut to produce transgenic plants. Then positive transgenic peanut was transplanted and tamped backfill to cover the injection point. Those seeds above the injection point were picked for further screening and analyzing. The results showed that over 40% of transgenic plants were obtained and displayed chimeric in T₀ generation. The T₀ seeds were harvested about 5 months after rapid-transformation. About 9% of T₁ peanuts were hybrids rather than chimeras. To solve the problem of few seed in some transgenic plants, the rapid-transformation system was combined with traditional tissue culture. This rapid-transformation system has potential value in garlic (Allium sativum), potato (Solanum tuberosum), and freesia (Freesia refracta). Altogether, this study establishes a rapid and stable genetic transformation system for peanuts, which sheds light on other plants’ genetic transformation.

Multispectral imaging (MSI) is an emerging technology designed for advanced imaging detection, which combines the information of spectroscopy and imaging to conduct qualitative and quantitative analysis of plant phenotypes including structural, physiological and biochemical characteristics. Recently, MSI shows a strong capability to capture detailed spectral information in combination with the applications of mathematical modeling and analysis, and displays a strong potential in the field of plant research. Here we introduce the principle of MSI technology and summarize the main applications of this technology in various aspects of plant research, which includes detection of plant damage and disease, identification of plant metabolites and characterizing plant physiological status. We alse prospect the frontier development of MSI in plant research.

Root is the most important organ of plants to absorb water and mineral nutrients for maintaining life activities. The architecture and ultrastructure of roots are species specific with different effects on the water and mineral nutrients absorption. Among them, suberin lamellae and Casparian strip in the endodermis and exodermis are two important apoplast barriers, which block water and ions transport nondirectionally and play important roles in the plant growth and response to stress. However, the structure, chemical composition, physiological functions, biosynthesis and regulation of root apoplast barriers are only studied in Arabidopsis thaliana. In recent years, studies of root apoplast barriers in barley (Hordeum vulgare), rice (Oryza sativa) and some forages have just been reported. In this review, the research progress of root apoplast barriers in A. thaliana, barley, rice and some forages in recent years are compared, and the future research direction is put forward in order to provide a theoretical basis for further exploring the roles of apoplastic barriers of gramineous crops and forages in growth, development and stress adaptation, and provide new ideas for crop and forage breeding.

Both transcription factor MYB77 and signal molecule nitric oxide (NO) are important regulators of lateral root development. However, our understanding about the role of MYB77 and NO in the regulation of lateral root formation in plants remains elusive. This study investigated the roles and interrelation of MYB77 and NO in regulating lateral root formation under drought stress by using wild type Arabidopsis, AtMYB77 deletion mutant Atmyb77-1 and overexpression lines AtOE77-1 and AtOE77-3. The results showed that the expression of AtMYB77 was induced by drought stress. When subjected to drought stress treatment, the Atmyb77-1 mutant showed down-regulation of CYCA2;1 and CDKA;1, two genes that are related with lateral root development. Meanwhile, the number and length of lateral roots in the Atmyb77-1 mutant were significantly lower than those in wild type, while AtOE77-1 and AtOE77-3 lines displayed more and longer lateral roots. These results indicated that AtMYB77 was involved in the regulation of lateral root development under drought stress. We also showed that drought stress could increase the NO content, as well as the nitric oxide synthase (NOS) and nitrate reductase (NR) enzymes activity and gene expression in roots of Arabidopsis. Such increase in NO content, NOS and NR activities as well as related gene transcript levels were attenuated by deletion of AtMYB77 but enhanced by AtMYB77 overexpression. Exogenous NO donor sodium nitroprusside (SNP) alleviated the inhibitive effects of AtMYB77 deletion on the expressions of CYCA2;1 and CDKA;1 as well as the lateral root formation, while NO sca-vengers or synthesis inhibitors attenuate the promoting effect of AtMYB77 overexpression on lateral root growth. Taken together, these results demonstrate that AtMYB77 participates in drought-induced lateral root growth by promoting NO synthesis.

Seed dormancy and germination are two distinct but closely related physiological processes, which are also key stages during plant life-cycle and have great significance to agricultural production, plant species reproduction, and geographical distribution. These processes are precisely regulated by interactions between different endogenous phytohormones and environmental signals. A large number of studies have shown that protein phosphorylation, plays an important role in regulating seed dormancy and germination, as well as plant response to stresses. This review paper briefly introduces the procedures and functions of protein phosphorylation and dephosphorylation modification, and summarizes the regulatory roles of protein phosphorylation modification in seed dormancy and germination. Finally, some future research directions are prospected.

Spatiotemporal heterogeneity is a key factor for functional differentiation in different tissues and plays an important role in regulating cell fate. Spatiotemporal transcriptomic sequencing (stRNA-seq) is an emerging omics technology that combines quantitative transcriptome with high-resolution tissue imaging. It anchors expression data to the physical map of a target organ or tissue and molecularly characterizes tissue sections and cell layers via unbiased bioinformatic analysis, which reflects the spatiotemporal heterogeneity of gene expression abundances within specific cells. Benefiting from the rapid development of high-throughput sequencing, the spatiotemporal heterogeneity of gene expression in various cells can be explored by new experimental approaches. In this review, we first briefly introduce the principle and development process of stRNA-seq, providing readers an overview on the characteristics, advantages and disadvantages of different stRNA-seq techniques. Then, we summarize the applications of stRNA-seq in animals, plants and microorganisms, which provide theoretical references for the systematic research of stRNA-seq in future.

The grana in chloroplast of higher plants is a structure composed of many thylakoid discs stacked together. The formation of the grana facilitates the distribution of the photosynthetic protein complex in different positions in thylakoids, that is, it has lateral heterogeneity and can effectively carry out photosynthesis. The key step to promote the formation of grana is to bend the thylakoid membrane. CURVATURE THYLAKOID 1 (CURT1) protein has been found to be the key factor leading to membrane bending. In this review, the recent research progresses of CURT1 protein in Arabidopsis thaliana and Cyanobacteria were summarized, and the prospect of CURT1 protein research in the future was put forward.

ABI4 is an important component of the ABA signal transduction pathway. It not only acts as a key player in ABA and GA antagonism, but also plays important roles in various aspects of ABA crosstalk with other signal chemicals. Genes regulated by ABI4 are involved in diverse processes. In this study, we got 27 homologs from 19 species in the family Brassicaceae using AthABI4 as a query, and explored their evolutionary history based on sequence polymorphism analysis, phylogenetic reconstruction, genomic synteny assay, and transcription activation activity comparison. The result revealed that ABI4 are highly conserved and might be not work as transcriptional activators independently in the Brassicaceae, which implies that the irreplaceable roles of ABI4 in plants and further research was needed to explore the molecular mechanism of its biological function.

Carvacrol and thymol, the main components of essential oil in oregano (Origanum vulgare), have strong antibacterial activity, and have big potential to replace antibiotics. In order to acquire valuable genetic variation in oregano,⁶⁰Co-γ ray radiation was utilized in breeding of oregano. The volatile components were analyzed by SPME-GC-MS, also principal component analysis and hierarchical clustering composition were performed. The effects of⁶⁰Co-γ ray radiation on morphological characteristics were studied, including glandular hair density, glandular hair size and volatile components of M₁ generation of oregano. The results showed that the LD₅₀ of oregano seeds was 16.39 Gy; The plant height, stem diameter, branching number, leaf length and width of irradiated M₁ generation were all changed, and several morphological mutants were selected; At the same time, the density and size of glandular hair changed in a variety of ways, and 25 mutants with significantly increase in density and size of glandular hair were selected from 163 surviving plants;⁶⁰Co-γ ray treatment had little effect on volatile components, but significant effect on the content of volatile components, and 5 chemotypes in oregano were induced, including carvacrol-type, thymol-type, γ-terpinene-type, β-caryophyllene- type, and germacrene-type. Six mutants with high carvacrol and thymol were obtained. These results confirmed that⁶⁰Co-γ ray radiation could be useful as an effective mutagenic method for oregano breeding, and the suitable radiation dose was 20 Gy. This study provided basic data and new way for the breeding and selection of new germplasm resources in oregano.

The nitrogen fixation efficiency of symbiotic nodules is tightly regulated by external nitrogen (N). In addition to nitrogenase activity, the leghemoglobin (Lb) amount is vital index contributing to N₂ fixation. To determine the effect of environmental N level on biological nitrogen fixation, soybean plants were inoculated with rhizobia for 30 d under low N condition (0.53 mmol·L^-1), then transplanted to hydroponic culture solution with relatively higher N concentrations, including 5.3, 10, 20, 30, and 40 mmol·L^-1 for 7 d, respectively. Lb concentration, nitrogenase activity and bacteroid development status were measured. Nodule displayed changed color from red to green with increasing N concentrations. Consistently, the red Lb concentration gradually declined with increased green Lb concentration. Moreover, the nitrogenase activity, infected cell number and area in nodules were all significantly decreased, suggesting that changes in Lb forms caused by excess N are closely associated with nitrogen fixation capacity. Bioinformatics and public expression profile data displayed that four symbiosis-associated Lbs, including GmLb1, GmLb2, GmLb3, and GmLb4 are the major Lb genes in soybean nodulation. These four GmLbs belong to the same clade of phylogenetic tree. Further analysis on the transcripts of GmLb1-4 in response to N showed that the expression levels of GmLb1-4 were all significantly inhibited by high N. This study services as a reference for future studies in understanding the underlying mechanisms of N-triggered nodule senescence as well as BNF application in agriculture.

Panicle architecture is one of the key factors determining the rice (Oryza sativa) grain yield. In this study, four short panicle mutants were identified from an EMS (ethyl methane sulfonate) mutant library of a japonica vareity Shengdao 808 (SD808). The panicle length, primary branch number, secondary branch number and grain number per panicle of these mutants were decreased in various degrees. Map-based cloning showed that these mutants were controlled by the gene PAL3 (PANICLE LENGTH 3) which encodes a peptide transporter with 12 transmembrane domains. The point mutations of pal3-1 and pal3-2 resulted in non-synonymous mutations of amino acids in the conserved region; the point mutation of pal3-3 resulted in the mis-splicing of the first exon and intron; and the point mutation of pal3-4 resulted in the premature termination of translation and thus the deletion of the 12^th transmembrane domain. Through haplotype analysis, nine haplotypes of PAL3 were identified, including three major haplotypes (Hap1-Hap3). Hap1 is dominated by japonica accessions, Hap2 contains both indica and japonica accessions, while Hap3 is dominated by indica accessions. Hap1 originated from O. rufipogon, while Hap2 and Hap3 may originate from O. nivara. Statistical analysis showed that the panicle length of Hap3 was significantly higher than that of Hap1 and Hap2, indicating that Hap3 may have the potential to improve the panicle length. In conclusion, this study revealed the important role of the peptide transporter in regulating rice panicle architecture and thus provides a new theoretical basis for rice panicle architecture improvement.

Secondary metabolites of plants induced by environmental factors are highly variable, but the given metabolic pathways may have some phylogenetic implications. Due to the difficulty in complete and systematic collections in certain plant groups, the research on the correlation between secondary metabolites and phylogeny is limited. Based on the published papers, 377 secondary metabolites in the roots, stems, leaves and flowers of Syringa were collected, which mainly derived from the mevalonic acid pathway, deoxyxylulose-5-P pathway and shikimic acid pathway. After superimposing phylogenetic background, we found that dominance of a given type of secondary metabolites was high for the firstly diverged series, and the dominance declined for subsequently diverged series with the increase of chemical diversity. Phenylpropanoids and iridoids/secoiridoids were phylogenetically conserved. After superimposing geographical distributions, we found that some local species which were lately diverged had more diverse secondary metabolites compared with widespread species firstly diverged. The high proportion of lignans was highly related to the environmental pressure. This review provided a new clue for the systematic study on the variation pattern of chemical diversity in the taxa within genus in the light of evolution.

Phosphorus is a macronutrient essential for plant growth and development, however, phosphate (Pi), the major form of phosphorus absorbed by plants, is quite limiting in soil. To cope with this nutritional stress, plants have evolved an array of adaptive responses, which are largely regulated by changing gene expression in response to Pi deficiency. The transcription factor, PHR1 plays a key role in regulating plant transcriptional response to Pi deficiency. Besides, most land plants can form symbiosis with arbuscular mycorrhizal (AM) fungi, through which plants can obtain Pi from soil more effectively. Recently, the research group of Ertao Wang of Center for Excellence in Molecular Plant Science, Chinese Academy of Sciences, reported that a PHR-centered gene regulatory network plays an essential role in promoting plant-AM symbiosis. Therefore, PHR not only functions in maintaining plant Pi homeostasis, but also in communicating with beneficial microorganisms in the environments, which provides another route for plants to obtain Pi from soil.

Simple sequence repeats located in gene transcribed regions (Genic-SSR) can play important roles in plant adaptation to environmental changes. In this study, the transcriptomes of Tamarix ramosissima from five different locations in Alax were sequenced, assembled, and compared. By using CandiSSR software, a total of 1 185 polymorphic Genic-SSRs representing 157 motif types were identified in 1 123 transcripts. Among them, the trinucleotide repeats (596, 50.30%) were the most abundant, followed by dinucleotide repeats (486, 41.01%). Location analysis showed that 411, 239, and 163 Genic-SSRs were located in CDSs, 5′UTRs, and 3′UTRs of the relevant transcripts, respectively; 78.47% of the trinucleotide SSRs were located in CDSs, and 94.07% of the dinucleotide SSRs were located in UTRs. Among SSRs distributed in CDSs, AGC/GCT, AGG/CCT, AAG/CTT, CCG/CGG, and ATC/GAT were relatively abundant, accounting for 64.48% of all the Genic-SSRs; AG/CT and AT/AT were the most abundant repeat types in UTRs, which together account for 55.22% of all the Genic-SSRs in UTRs. Functional annotation showed that polymorphic Genic-SSRs containing genes enriched in a wide range of GO terms and KEGG pathways that highly related to stress response in T. ramosissima. Of the 15 randomly selected Genic-SSRs, 14 were successfully amplified by using polymerase chain reaction technology and 64 alleles were found in these SSR loci. Genetic polymorphism estimation showed that the mean of expected and observed heterozygosity (He, Ho), polymorphism information content (PIC) of these SSRs were 0.553, 0.421, and 0.493, respectively, demonstrating the feasibility of developing SSR markers by RNA-seq.

Cryo-focused ion beam-scanning electron microscopy (Cryo-FIB-SEM) is an emerging technology designed for advanced imaging detection, which performs in situ by combining Cryo-FIB milling and Cryo-SEM imaging, and has facilitated the visualization of the native structures of biological sample in the context of the cellular environment in the frozen hydrated state. In recent years, a series of important advances have been achieved in the application of this technology in the research field of life science. In this review, we summarize its application in cryo-volume serial imaging, and in combination with cryo-correlative light and electron microscopy (CLEM), cryo-transmission SEM (TSEM), cryo-lamella preparation monitoring, and Cryo-SEM image processing. We also provide future prospective on future development and application of Cryo-FIB-SEM in three-dimensional in situ imaging of large volume biological samples.

Modern cultivated potato (Solanum tuberosum) is a clonally propagated autotetraploid, with highly heterozygous genome, complex genetic background, and severe inbreeding depression, making it difficult to combine eminent traits and resulting in a long breeding cycle and the dilemma of ‘genetic stagnation’ of potato hybrid breeding. Moreover, clonal propagation leads to low reproduction coefficient, high cost of storage and transportation, whereas tubers are easy to carry viruses and pests, which have hindered the development of potato industry for a long time. Recently a team led by Sanwen Huang in Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, successfully use genome design to develop the pure and fertile potato lines and thereby the hybrid F₁, reinvent potato from a clonally propagated tetraploid into a seed-propagated diploid. This work is a milestone in potato breeding, that starts a new era of genome design and rapid potato breeding.

Hyperhydricity (HH) or vitrification is a physiological disorder during plant growth, which shows a typical translucent phenotype like water-soaked that often occurs in the plant tissue culture. Vitrification is one of the three main influencing factors that limit the tissue culture technology and the commercialized production of seedlings during the plant tissue culture, but its molecular mechanism is still unclear by far. Using plantlets from the tissue culture as a research object often lead to an interference of man-made factors, which can be avoided by non-tissue culture material to reveal the molecular mechanism of vitrification in nature. This review summarized the recent progress of mechanism for inducing HH in non-tissue culture plants, including the abnormal deposit of suberin, the reduction of cuticular wax, the lipid peroxidation in cellular membranes and the disrupted transmembrane transport of ion or water, to provide new clues and thinking for hyperhydricity in plant seedling growth.

The wide occurrence of Cadmium (Cd)-contaminated rice in China poses significant public health risk. Breeding rice varieties with low-Cd accumulation is an effective strategy to reduce Cd accumulation in rice grain. It is necessary to understand the characteristics of Cd accumulation in rice, its physiological process and related functional genes. Here, we review the advances in physiological and molecular mechanisms of Cd uptake in roots, loading and translocation in xylem, distribution in nodes, redistribution in leaves, and accumulation in grains, which will provide theoretical reference for breeding and safe production of low-Cd rice.

Plant pathogens pose a constant and major threat to global food production, so understanding plant’s defense mechanism against pathogen and pathogen’s infection mechanism against host crops and their molecular mechanisms will be helpful to design protection strategies for durable resistance of plant. Until now, a growing number of studies have shown that some disease resistant proteins need to be transferred to the nucleus to initiate an immune response. Nucleocytoplasmic transport receptors are essential “carrier” for nuclear transport. Therefore, nucleocytoplasmic transport and receptors play important role in disease resistance. Based on the introduction of plant disease defense response mechanism, this paper focuses on research progress of nucleocytoplasmic transport and nucleocytoplasmic transport receptors in disease resistance and proposes a prospect.

Recent advances in the genomic sequencing of tea plants have laid the foundation for tea research at the molecular and gene levels. However, the transgenic technologies are immature and the life cycles are long for tea trees, it is still difficult to conduct functional analyses of tea genes. This study used young leaves of Camellia sinensis var. sinensis cv. ‘Tieguanyin’, established a useful formula by testing multiple concentration combinations of cellulase, pectinase, macerozyme and mannitol. By evaluating the quantity, viability and debris of resulted protoplast, we successfully established a highly efficient mesophyll protoplast isolation and PEG-mediated transient expression system in Tieguanyin seedling leaves, with a transformation rate reaching 56.25%. Using this system, the subcellular localization of two pivotal enzymes in the theanine metabolism pathway (the theanine synthetase (TSI) and the glutamine synthetase (GSII-1.1)) were explored. Results show that, these two enzymes are both localized in the cytosol of the Tieguanyin protoplasts. Together, the establishment of this tea mesophyll protoplast extraction and transient expression system would lay a technological foundation for studying the function of tea genome.

Precise regulation of floral transition, which ensures plants bloom in the suitable environment, is essential for the successful reproduction of plants. The flowering time genes are regulated by a variety of molecular mechanisms, including transcriptional, post-transcriptional and post-translational regulations. Alternative splicing is a universal molecular process at the post-transcriptional level that can generate multiple transcripts from a single gene, thereby enriching the diversity of the transcriptome and proteome. The accumulating evidence indicates that alternative splicing plays an important role in the floral transition. According to developmental and environmental cues, alternative splicing can regulate the levels of functional transcripts and/or proteins of flowering time genes by affecting the stability of mRNA and/or the function of protein isoforms. Therefore, revealing the roles of alternative splicing will further improve our understanding of the functions of flowering time genes and the whole regulatory network of floral transition. In this review, we introduce the research progress of alternative splicing in floral transition, and summarize from the various regulatory pathways, thereby providing a reference for further research on the regulatory mechanisms of alternative splicing and floral transition in plants.

As one of the components of urban air pollutants, pollen seriously affects our living environment and health, which is highly concerned by government and scientific community. Here, based on the airborne pollen data of past 60 years in Beijing-Tianjin-Hebei region, we summarize the major pollen types and their seasonal distribution characteristics in this region, and the data shows that the annual variation of airborne pollen concentration basically follows the ‘bimodal' pattern, viz. arboreal pollen such as Cupressaceae, Salicaceae and Betulaceae dominate the peak in spring, while herbaceous pollen like Artemisia, Humulus/Cannabis sativa, Chenopodiaceae/Amaranthaceae dominate the peak in summer and autumn. Then we discuss the dominant meteorological factors related to pollen concentration and the characteristics of pollinosis. Furthermore, we point out that human activities (e.g., land reconstruction and roadside tree planting) may have an impact on the changes of airborne pollen composition in Beijing over these years. Finally, we emphasize the important role of future long-term airborne pollen monitoring in atmospheric environment assessment, pollinosis prevention, and urban greening construction.

Vascular tissues inside the mesophyll and peripheral mechanical tissues constitute the veins. The diverse orders and network structures of veins contribute to their functional diversification and differentiation. In this review, we summarized the research progresses on the structure and function of the leaf vein system. We reviewed three aspects of veins and critically evaluated the characteristics of the leaf vein hierarchy system and its important role in leaf economic spectrum (LES), and explained the mechanisms linking vein traits and other functional traits of the leaf. Leaf veins of different orders show obvious functional differentiation in terms of hydraulic conduction and mechanical support. Among them, the first three orders of veins (major veins) play a major role in maintaining leaf shape, leaf surface area and physical support, and which is conductive to the growth of leaves with the largest light-receiving area. The higher order veins (minor veins) have the function of water regulation, and their coordination with the stomata determines the rate of leaf water transport, transpiration and photosynthesis. The patterns of dynamic variation in leaf spread and leaf vein development explain the relationship between vein density and leaf size. Leaf surface area is negatively correlated with the density of main veins and positively correlated with the diameter of main veins, but independent of the density of minor veins. The framework model of LES linking with vein traits predicts that leaves with higher vein density have short lifespan and smaller leaf mass per area, which explains the better leaf carbon assimilation rate, metabolism rate and resource acquisition strategy with higher leaf vein density.

Multidrug and toxic compound extrusion (MATE) transporters are also known as detoxification efflux carriers (DTXs) that are ubiquitously present in prokaryotes and eukaryotes. It belongs to membrane proteins, which have usually twelve transmembrane regions with arranged in a "V" shape. MATE/DTXs transporters are mainly involved in the modulation of iron homeostasis, transporting inorganic anions and secondary metabolites, the detoxification of heavy metals and xenobiotic, regulating the growth and development, and responding to diseases and abiotic stress in plants. This review summarizes the discovery, phylogeny, structure, function of MATE/DTXs family for research progresses. We look forward to provide a reference for the genetic improvement of crops or forages stress tolerance and MATE/DTXs related application potential.