Integrating high-throughput phenotyping and genome-wide association studies for enhanced drought resistance and yield prediction in wheat.

Drought, especially terminal drought, severely limits wheat growth and yield. Understanding the complex mechanisms behind the drought response in wheat is essential for developing drought-resistant varieties. This study aimed to dissect the genetic architecture and high-yielding wheat ideotypes under terminal drought. An automated high-throughput phenotyping platform was used to examine 28 392 image-based digital traits (i-traits) under different drought conditions during the flowering stage of a natural wheat population. Of the i-traits examined, 17 073 were identified as drought-related. A genome-wide association study (GWAS) identified 5320 drought-related significant single-nucleotide polymorphisms (SNPs) and 27 SNP clusters. A notable hotspot region controlling wheat drought tolerance was discovered, in which TaPP2C6 was shown to be an important negative regulator of the drought response. The tapp2c6 knockout lines exhibited enhanced drought resistance without a yield penalty. A haplotype analysis revealed a favored allele of TaPP2C6 that was significantly correlated with drought resistance, affirming its potential value in wheat breeding programs. We developed an advanced prediction model for wheat yield and drought resistance using 24 i-traits analyzed by machine learning. In summary, this study provides comprehensive insights into the high-yielding ideotype and an approach for the rapid breeding of drought-resistant wheat.

Metabolite profiling of liquiritin in acute myocardial infarction model rat after intragastric administration using an information-dependent acquisition-mediated ultra-high-performance liquid chromatography-tandem mass spectrometry method.

Liquiritin (LQ), a kind of flavonoid isolated from licorice, was proven to have great potential in treating heart failure. Pharmacokinetic evaluation is important for demonstrating clinical efficacy and mechanisms, and the prototype drug and its metabolite profiling are important for drug discovery and development. However, the metabolism of LQ in acute myocardial infarction (AMI) model rats still needs to be studied in depth. An information-dependent acquisition (IDA)-ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was applied to profile LQ metabolites in AMI model rat plasma. Protein precipitation and extraction were used for sample preparation. Chromatographic separation was achieved using an XSelect BEH C18 column (2.1 × 150 mm, 2.5 µm) using gradient elution method combining 0.1% formic acid and acetonitrile with a flow rate of 0.3 mL/min. Twelve metabolites were identified in IDA mode, sulfation, glucuronidation, methylation, methyl esterification, glutamine conjugation, and valine conjugation, and their composite reactions were presumed as the primary pathways of LQ metabolism. The variation in the peak areas showed that the time to reach the peak drug concentration of LQ and 12 metabolites was within 5 h. In summary, IDA-bridged UHPLC-MS/MS from characteristic fragment ions toward confidence-enhanced identification could effectively screen and profile metabolites.

Central Metal-Triggered Structural Transformation of a 2D Layered MOF: Mechanistic Studies and Applications.

The structural transformation of metal-organic frameworks (MOFs) has attracted increasing interests, which has not only produced various new structures but also served as a fantastic platform for MOF-based kinetic analysis. Multiple reaction conditions have been documented to cause structural transformation; nevertheless, central metal-induced topological alteration of MOFs is rare. Herein, we reported a structural transformation of a 2D layered Cd-MOF driven by Cd(II) ions. After being submerged in the aqueous solution of cadmium nitrate, the twofold interpenetrated 2D network of [Cd(hsb-2)(bdc)·5H2O]n [HSB-W10; bdc: 1,4-benzenedicarboxylate; hsb-2:1,2-bis(4'-pyridylmethylamino)-ethane] was converted into a novel noninterpenetrated 2D network [Cd1.5(hsb-2)(bdc)1.5(H2O)2·H2O]n (HSB-W16). This partial dissolution-recrystallization process was investigated by integrating controlled experiments, 1H NMR spectra, and photographic tracking analysis. Furthermore, a novel strategy combining in situ multicomponent dye encapsulation and central metal-triggered structural transformation was developed for the fabrication of MOF materials with white-light emission. By adopting this strategy, different dye guest molecules were concurrently introduced into the HSB-W16 host matrix, leading to a range of white-light-emitting MOF composites. This work will enable detailed studies of solid-state transformations and demonstrate a promising application prospect for structural transformation.

FARPA-based tube array coupled with quick DNA extraction enables ultra-fast bedside detection of antibiotic-resistant pathogens.

Rapid and accurate detection of pathogens and antimicrobial-resistant (AMR) genes of the pathogens are crucial for the clinical diagnosis and effective treatment of infectious diseases. However, the time-consuming steps of conventional culture-based methods inhibit the precise and early application of anti-infection therapy. For the prompt treatment of pathogen-infected patients, we have proposed a novel tube array strategy based on our previously reported FARPA (FEN1-aided recombinase polymerase amplification) principle for the ultra-fast detection of antibiotic-resistant pathogens on site. The entire process from "sample to result" can be completed in 25 min by combining quick DNA extraction from a urine sample with FARPA to avoid the usually complicated DNA extraction step. Furthermore, a 36-tube array made from commercial 384-well titre plates was efficiently introduced to perform FARPA in a portable analyser, achieving an increase in the loading sample throughput (from several to several tens), which is quite suitable for the point-of-care testing (POCT) of multiple pathogens and multiple samples. Finally, we tested 92 urine samples to verify the performance of our proposed method. The sensitivities for the detection of E. coli, K. pneumoniae, E. faecium, and E. faecalis were 92.7%, 93.8%, 100% and 88.9%, respectively. The specificities for the detection of the four pathogens were 100%. Consequently, our rapid, low-cost and user-friendly POCT method holds great potential for guiding the rational use of antibiotics and reducing bacterial resistance.

Genomes of multicellular algal sisters to land plants illuminate signaling network evolution.

Zygnematophyceae are the algal sisters of land plants. Here we sequenced four genomes of filamentous Zygnematophyceae, including chromosome-scale assemblies for three strains of Zygnema circumcarinatum. We inferred traits in the ancestor of Zygnematophyceae and land plants that might have ushered in the conquest of land by plants: expanded genes for signaling cascades, environmental response, and multicellular growth. Zygnematophyceae and land plants share all the major enzymes for cell wall synthesis and remodifications, and gene gains shaped this toolkit. Co-expression network analyses uncover gene cohorts that unite environmental signaling with multicellular developmental programs. Our data shed light on a molecular chassis that balances environmental response and growth modulation across more than 600 million years of streptophyte evolution.

Multiomics analyses provide insights into the genomic basis of differentiation among four sweet osmanthus groups.

Sweet osmanthus (Osmanthus fragrans) is famous in China for its flowers and contains four groups: Albus, Luteus, Aurantiacus, and Asiaticus. Understanding the relationships among these groups and the genetic mechanisms of flower color and aroma biosynthesis are of tremendous interest. In this study, we sequenced representative varieties from two of the four sweet osmanthus groups. Multiomics and phylogenetic analyses of varieties from each of the four groups showed that Asiaticus split first within the species, followed by Aurantiacus and the sister groups Albus and Luteus. We show that the difference in flower color between Aurantiacus and the other three groups was caused by a 4-bp deletion in the promoter region of carotenoid cleavage dioxygenase 4 (OfCCD4) that leads to expression decrease. In addition, we identified 44 gene pairs exhibiting significant structural differences between the multiseasonal flowering variety "Rixianggui" in the Asiaticus group and other autumn-flowering varieties. Through correlation analysis between intermediate products of aromatic components and gene expression, we identified eight genes associated with the linalool and α- and ß-ionone biosynthesis pathways. Overall, our study offers valuable genetic resources for sweet osmanthus, while also providing genetic clues for improving the flower color and multiseasonal flowering of osmanthus and other flowers.

[Effect and mechanism of Linggui Zhugan Decoction in regulating Sig1R on Angâ ¡-induced cardiomyocyte hypertrophy].

This study aims to explore the mechanism of Linggui Zhugan Decoction(LGZGD) in inhibiting Angiotensin Ⅱ(AngⅡ)-induced cardiomyocyte hypertrophy by regulating sigma-1 receptor(Sig1R). The model of H9c2 cardiomyocyte hypertrophy induced by AngⅡ in vitro was established by preparing LGZGD-containing serum and blank serum. H9c2 cells were divided into normal group, AngⅡ model group, 20% normal rat serum group(20% NSC), and 20% LGZGD-containing serum group. After the cells were incubated with AngⅡ(1 µmol·L~(-1)) or AngⅡ with serum for 72 h, the surface area of cardiomyocytes was detected by phalloidine staining, and the activities of Na~+-K~+-ATPase and Ca~(2+)-Mg~(2+)-ATPase were detected by micromethod. The mitochondrial Ca~(2+) levels were detected by flow cytometry, and the expression levels of atrial natriuretic peptide(ANP), brain natriuretic peptide(BNP), Sig1R, and inositol 1,4,5-triphosphate receptor type 2(IP_3R_2) were detected by Western blot. The expression of Sig1R was down-regulated by transfecting specific siRNA for investigating the efficacy of LGZGD-containing serum on cardiomyocyte surface area, Na~+-K~+-ATPase activity, Ca~(2+)-Mg~(2+)-ATPase activity, mitochondrial Ca~(2+), as well as ANP, BNP, and IP_3R_2 protein expressions. The results showed that compared with the normal group, AngⅡ could significantly increase the surface area of cardiomyocytes and the expression of ANP and BNP(P<0.01), and it could decrease the activities of Na~+-K~+-ATPase and Ca~(2+)-Mg~(2+)-ATPase, the concentration of mitochondrial Ca~(2+), and the expression of Sig1R(P<0.01). In addition, IP_3R_2 protein expression was significantly increased(P<0.01). LGZGD-containing serum could significantly decrease the surface area of cardiomyocytes and the expression of ANP and BNP(P<0.05, P<0.01), and it could increase the activities of Na~+-K~+-ATPase and Ca~(2+)-Mg~(2+)-ATPase, the concentration of mitochondrial Ca~(2+ )(P<0.01), and the expression of Sig1R(P<0.05). In addition, IP_3R_2 protein expression was significantly decreased(P<0.05). However, after Sig1R was down-regulated, the effects of LGZGD-containing serum were reversed(P<0.01). These results indicated that the LGZGD-containing serum could inhibit cardiomyocyte hypertrophy induced by AngⅡ, and its pharmacological effect was related to regulating Sig1R, promoting mitochondrial Ca~(2+ )inflow, restoring ATP synthesis, and protecting mitochondrial function.

[Construction of ecological network with protected areas as the main region in Guangzhou City, China]. / 以自然保护地为主体的广州市域生态网络构建.

In the context of the national ecological security development strategy, constructing regional ecological networks centered on protected areas and ecological corridors has become an urgent issue in protected areas system development of China. We focused on strengthening ecological connections between protected areas in Guangzhou, identified the ecological resource patches, ecological corridors, and ecological nodes by using Invest model, connectivity analysis, circuit theory models, and graph-theoretical network structure evaluation, and constructed an ecological network for the Guangzhou with nature reserves as the core. The results showed that 52 ecological resource patches were identified in the study area, covering a total area of 1450.01 km2. Nature reserves accounted for 76.4% of the total area, forming the main part of the ecological resource patches. 115 ecological corridors were identified, with a total length of 900.56 km and an average length of 7.83 km. Furthermore, 72 ecological key points were identified, covering a total area of 17.57 km2, and 81 ecological breakpoints, with a total area of 35.9 km2. The network structure indices (α=0.65, ß=2.21, and γ=0.77) indicated a reasonably structured and well-connected network. By exploring pathways for constructing regional ecological networks under the protected areas system and enriching the application of circuit theory models in ecological network construction, this study provides scientific basis for regional ecological security and biodiversity conservation.

Ling-Gui-Zhu-Gan decoction protects against doxorubicin-induced myocardial injury by downregulating ferroptosis.

OBJECTIVE: To investigate the mechanism of Ling-Gui-Zhu-Gan decoction (LGZGD) protects against doxorubicin (DOX)-induced myocardial injury. METHODS: In vivo experiment, rats were divided into six groups: normal group, model group (15 mg/kg, DOX), Dex group(150 mg/kg, Dex), LGZGD-L group (2.1 g/kg), LGZGD-M group (4.2 g/kg), and LGZGD-H group (8.4 g/kg). We used HE and Masson staining to observe the histopathological changes, echocardiography to assess the cardiac function, and western blot and RT-qPCR to detect the expressions of Nrf2, GPX4, Fpn1, and Ptgs2. In vitro experiment, we used immunofluorescence to detect ROS production, and RT-qPCR to detect gene expression of GPX4, Fpn1, and Ptgs2. KEY FINDINGS: In vivo, LGZGD improved cardiac systolic function. LGZGD significantly reduced MDA, LDH, and CK levels, increased SOD activity, enhanced the protein expression of Nrf2, GPX4, and Fpn1, and decreased Ptgs2 levels. In vitro, LGZGD-containing serum significantly reduced ROS, increased the gene expression of GPX4 and Fpn1, and decreased the gene expression of Ptgs2. Furthermore, compared with the LGZGD (si-NC) group, the LGZGD (si-Nrf2) group had decreased gene expression of Nrf2, GPX4, and Fpn1 and increased gene expression of Ptgs2. CONCLUSIONS: LGZGD can ameliorate DOX-cardiotoxicity by activating the Nrf2 signaling pathway and inhibiting ferroptosis in cardiomyocytes.

Optimizing functional zoning for Dalingshan Forest Park in China through microcosmic human disturbance evaluation.

Human disturbance stands as a prominent factor influencing the ecological environment within natural protected areas. Presently, the issue of balancing human activities and ecological preservation has emerged as a critical concern in the construction of China's natural protected area system. Functional zoning serves as the cornerstone of natural protected area management and represents a pivotal tool in achieving this equilibrium. This study endeavors to introduce a set of functional zoning methods for natural protected areas based on human disturbance assessments. Utilizing Dalingshan Forest Park in Dongguan city which is known for its significant human disturbances as a case study, field surveys were conducted to identify various types of small-scale and understory-hidden human disturbances, such as residential areas, roads, tourist areas, forestry areas, and energy facilities. Subsequently, a microcosmic human disturbance model tailored to forested areas was developed using the analytic hierarchy process. By integrating the findings of macrocosmic human disturbance assessments conducted concurrently by the research group, a functional zoning plan for Dalingshan Forest Park was proposed. The results show that ecological conservation zones within the park should be established in three specific areas, primarily in regions with low-level microcosmic human disturbance (levels 1 and 2) and terrain fluctuations ≥110 m. In contrast, the rational use zone is notably influenced by tourist infrastructure and road networks, predominantly located in regions with high human activity, such as popular tourist destinations and areas with road classifications and vehicular traffic. The microcosmic human disturbance assessment method proposed in this study enhances the rationality and accuracy of natural protected area functional zoning. It provides a more scientifically grounded research approach for similar studies concerning natural protected area functional zoning and contributes valuable insights for the further advancement of China's efforts in the integration and optimization of natural protected areas.

A platform for whole-genome speed introgression from Aegilops tauschii to wheat for breeding future crops.

Breeding new and sustainable crop cultivars of high yields and desirable traits has been a major challenge for ensuring food security for the growing global human population. For polyploid crops such as wheat, introducing genetic variation from wild relatives of its subgenomes is a key strategy to improve the quality of their breeding pools. Over the past decades, considerable progress has been made in speed breeding, genome sequencing, high-throughput phenotyping and genomics-assisted breeding, which now allows us to realize whole-genome introgression from wild relatives to modern crops. Here, we present a standardized protocol to rapidly introgress the entire genome of Aegilops tauschii, the progenitor of the D subgenome of bread wheat, into elite wheat backgrounds. This protocol integrates multiple modern high-throughput technologies and includes three major phases: development of synthetic octaploid wheat, generation of hexaploid A. tauschii-wheat introgression lines (A-WIs) and homozygosis of the generated A-WIs. Our approach readily generates stable introgression lines in 2 y, thus greatly accelerating the generation of A-WIs and the introduction of desirable genes from A. tauschii to wheat cultivars. These A-WIs are valuable for wheat-breeding programs and functional gene discovery. The current protocol can be easily modified and used for introgressing the genomes of wild relatives to other polyploid crops.

ß-catenin/TCF4-induced SCUBE3 upregulation promotes ovarian cancer development via HIF-1 signaling pathway.

The precise involvement and mechanistic role of the signal peptide-CUB-EGF-like domain-containing protein 3 (SCUBE3) in ovarian cancer (OV) remain poorly understood. Here, leveraging comprehensive data from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, we unveil the selective overexpression of SCUBE3 in ovarian cancer tissues and cells. Intriguingly, elevated SCUBE3 expression levels correlate with an unfavorable prognosis in patients. Through meticulous manipulation of SCUBE3 expression, we elucidate its consequential impact on in vitro proliferation and invasion of ovarian cancer cells, as well as in vivo tumor growth in mice. Our multifaceted investigations, encompassing luciferase reporter assays, chromatin immunoprecipitation (ChIP) experiments, and mining of public databases, successfully identify SCUBE3 as a direct downstream target gene of TCF4-a pivotal positive regulator within the ß-catenin/TCF4 complex. Furthermore, utilizing a recessive mutant mouse line (kta41) harboring a functionally impaired point mutation at position 882 in the SCUBE3 gene, we uncover SCUBE3's involvement in the intricate regulation of angiogenesis and epithelial-mesenchymal transition (EMT). Strikingly, Spearman correlation coefficient analysis unveils a close association between SCUBE3 and HIF1A in OV, with SCUBE3 exerting tight control over HIF1A mRNA expression. Moreover, functional inhibition of HIF1A significantly impedes the pro-proliferative and invasive capabilities of SCUBE3-overexpressing ovarian cancer cells. Collectively, our findings underscore the pivotal role of SCUBE3 in driving ovarian cancer progression, shedding light on its intricate molecular mechanisms and establishing it as a potential therapeutic target for this devastating disease.

Repression of GhTUBB1 Reduces Plant Height in Gossypium hirsutum.

The original 'Green Revolution' genes are associated with gibberellin deficiency. However, in some species, mutations in these genes cause pleiotropic phenotypes, preventing their application in dwarf breeding. The development of novel genotypes with reduced plant height will resolve this problem. In a previous study, we obtained two dwarf lines, L28 and L30, by introducing the Ammopiptanthus mongolicus (Maxim. ex Kom.) Cheng f. C-repeat-binding factor 1 (AmCBF1) into the upland cotton variety R15. We found that Gossypium hirsutum Tubulin beta-1 (GhTUBB1) was downregulated in L28 and L30, which suggested that this gene may have contributed to the dwarf phenotype of L28 and L30. Here, we tested this hypothesis by silencing GhTUBB1 expression in R15 and found that decreased expression resulted in a dwarf phenotype. Interestingly, we found that repressing AmCBF1 expression in L28 and L30 partly recovered the expression of GhTUBB1. Thus, AmCBF1 expression presented a negative relationship with GhTUBB1 expression in L28 and L30. Moreover, yeast one-hybrid and dual-luciferase assays suggest that AmCBF1 negatively regulates GhTUBB1 expression by directly binding to C-repeat/dehydration-responsive (CRT/DRE) elements in the GhTUBB1 promoter, potentially explaining the dwarf phenotypes of L28 and L30. This study elucidates the regulation of GhTUBB1 expression by AmCBF1 and suggests that GhTUBB1 may be a new target gene for breeding dwarf and compact cultivars.

BCL6 promotes a stem-like CD8+ T cell program in cancer via antagonizing BLIMP1.

Overcoming CD8+ T cell exhaustion is critical in cancer immunotherapy. Recently, an intratumor stem/progenitor-like CD8+ T cell (Tprog cell) population that mediates the persistence of antitumor responses has been defined, which can further develop into a terminally differentiated CD8+ T cell (Tterm cell) subpopulation with potent cytotoxic functions. Tprog cells are the main responders to immune checkpoint blockade therapies, yet how extrinsic signals via transcription factors control Tprog cell generation and persistence in tumors is unclear. Here, we found that BCL6 inhibits tumor-specific Tterm cell generation from Tprog cell downstream of TCF1. We show that Bcl6 deficiency reduced the persistence of Tprog cells, without affecting their generation, thus abrogating long-term tumor control. High-level BCL6 expression was observed in tumor-specific T cells in draining lymph nodes (LNs) and was associated with T cell exhaustion. This was observed in TOX+TCF1+ Tprog cells in both LNs and tumors. BCL6 expression in CD8+ T cells was up-regulated by TGF-ß-SMAD2 signaling but down-regulated by the IL-2-STAT5 pathway. Mechanistically, BCL6 transcriptionally repressed the expression of Tterm cell-associated genes and induced those of Tprog cell-related genes, in a manner antagonistic to BLIMP1. Prdm1 deficiency also promoted the Tprog cell program and greatly improved the efficacy of anti-PD-1 therapy. Thus, we identified the TGF-ß-BCL6 and IL-2-BLIMP1 antagonistic pathways in regulation of antitumor CD8+ T cells, which may benefit the development of long-lasting and effective cancer immunotherapy.

A de novo evolved gene contributes to rice grain shape difference between indica and japonica.

The role of de novo evolved genes from non-coding sequences in regulating morphological differentiation between species/subspecies remains largely unknown. Here, we show that a rice de novo gene GSE9 contributes to grain shape difference between indica/xian and japonica/geng varieties. GSE9 evolves from a previous non-coding region of wild rice Oryza rufipogon through the acquisition of start codon. This gene is inherited by most japonica varieties, while the original sequence (absence of start codon, gse9) is present in majority of indica varieties. Knockout of GSE9 in japonica varieties leads to slender grains, whereas introgression to indica background results in round grains. Population evolutionary analyses reveal that gse9 and GSE9 are derived from wild rice Or-I and Or-III groups, respectively. Our findings uncover that the de novo GSE9 gene contributes to the genetic and morphological divergence between indica and japonica subspecies, and provide a target for precise manipulation of rice grain shape.

Pharmacokinetic evaluation of 24 representative components of Ling-Gui-Zhu-Gan decoction in acute myocardial infarction model rats via a validated ultrahigh-performance liquid chromatography-tandem mass spectrometry method.

RATIONALE: Ling-Gui-Zhu-Gan decoction (LGZGD), one of the 100 herbal classic formulas, is clinically used to treat chronic heart failure with remarkable curative effect. However, LGZGD pharmacokinetic parameters in pathological model rats are poorly understood, in particular for special components. As physicochemical properties are specific to each representative component, no standard sample preparation is available for absolute quantification of representative components of LGZGD in rat plasma. METHODS: A specific, sensitive and high-throughput ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC/MS/MS) method capturing 24 representative components was developed and applied to evaluate the pharmacokinetic parameters of LGZGD in acute myocardial infarction (AMI) rat plasma after intragastric administration (2.4, 4.8 and 9.6 g/kg). Precipitation and extraction were selected and optimized for plasma preparation, and isopropanol precipitation could offer higher recovery and broader coverage. RESULTS: It was expected that AMI could cause less absorption and slower elimination of most of active components of LGZGD. Most of newly reported special components absorbed quickly and eliminated slowly. The average elimination half-life of the 24 representative components was 10.09 h, which is consistent with the dosage of LGZGD (twice daily). CONCLUSIONS: The specificity, linearity, precision and accuracy, recovery, matrix effect and stability were validated according to Food and Drug Administration guidance. The validation results demonstrated that the method could be applied to evaluate the pharmacokinetic parameters of LGZGD in AMI rats. The pharmacokinetic parameters showed substantial improvement in quality research of LGZGD, thereby laying the groundwork for preclinical and clinical trials in chronic heart failure clinical efficacy.

ROS accumulation-induced tapetal PCD timing changes leads to microspore abortion in cotton CMS lines.

BACKGROUND: Cytoplasmic male sterility (CMS) is the basis of heterosis exploitation. CMS has been used to hybrid production in cotton, but its molecular mechanism remains unclear. CMS is associated with advanced or delayed tapetal programmed cell death (PCD), and reactive oxygen species (ROS) may mediate this process. In this study, we obtained Jin A and Yamian A, two CMS lines with different cytoplasmic sources. RESULTS: Compared with maintainer Jin B, Jin A anthers showed advanced tapetal PCD with DNA fragmentation, producing excessive ROS which accumulated around the cell membrane, intercellular space and mitochondrial membrane. The activities of peroxidase (POD) and catalase (CAT) enzymes which can scavenge ROS were significantly decreased. However, Yamian A tapetal PCD was delayed with lower ROS content, and the activities of superoxide dismutase (SOD) and POD were higher than its maintainer. These differences in ROS scavenging enzyme activities may be caused by isoenzyme gene expressions. In addition, we found the excess ROS generated in Jin A mitochondria and ROS overflow from complex III might be the source in parallel with the reduction of ATP content. CONCLUSION: ROS accumulation or abrogation were mainly caused by the joint action of ROS generation and scavenging enzyme activities transformation, which led to the abnormal progression of tapetal PCD, affected the development of microspores, and eventually contributed to male sterility. In Jin A, tapetal PCD in advance might be caused by mitochondrial ROS overproduction, accompanied by energy deficiency. The above studies will provide new insights into the cotton CMS and guide the follow-up research ideas.

Liverwort bHLH transcription factors and the origin of stomata in plants.

Stomata are distributed in nearly all major groups of land plants, with the only exception being liverworts. Instead of having stomata on sporophytes, many complex thalloid liverworts possess air pores in their gametophytes. At present, whether stomata in land plants are derived from a common origin remains under debate.1,2,3 In Arabidopsis thaliana, a core regulatory module for stomatal development comprises members of the bHLH transcription factor (TF) family, including AtSPCH, AtMUTE, and AtFAMA of subfamily Ia and AtSCRM1/2 of subfamily IIIb. Specifically, AtSPCH, AtMUTE, and AtFAMA each successively form heterodimers with AtSCRM1/2, which in turn regulate the entry, division, and differentiation of stomatal lineages.4,5,6,7 In the moss Physcomitrium patens, two SMF (SPCH, MUTE and FAMA) orthologs have been characterized, one of which is functionally conserved in regulating stomatal development.8,9 We here provide experimental evidence that orthologous bHLH TFs in the liverwort Marchantia polymorpha affect air pore spacing as well as the development of the epidermis and gametangiophores. We found that the bHLH Ia and IIIb heterodimeric module is highly conserved in plants. Genetic complementation experiments showed that liverwort SCRM and SMF genes weakly restored a stomata phenotype in atscrm1, atmute, and atfama mutant backgrounds in A. thaliana. In addition, homologs of stomatal development regulators FLP and MYB88 also exist in liverworts and weakly rescued the stomatal phenotype of atflp/myb88 double mutant. These results provide evidence not only for a common origin of all stomata in extant plants but also for relatively simple stomata in the ancestral plant.