RNA interference (RNAi) has been used for agricultural insect pest control based on silencing of targeted insect genes. However, the effectiveness of RNAi and its applications in insect pest control remain challenging. Here we review factors that may affect the effectiveness of RNAi application, including the variability in RNAi efficacy among different insect species, a limited understanding of double-stranded RNA (dsRNA) uptake and systemic RNAi mechanisms, and the effective delivery of dsRNA in field conditions. Furthermore, we summarize recent progress in RNAi strategies for crop protection, discuss the advantages and disadvantages of RNAi-based insect control, and propose potential strategies to increase the effectiveness of RNAi in insect control.

Maize serves as a crucial cereal crop globally, yet the escalating frequency of drought stress during the reproductive phase poses a significant threat to grain yield by causing an irreversible loss in kernel number. Enhancing reproductive drought tolerance in maize requires elucidating the physiological mechanisms underlying its response to drought stress, which can then be incorporated into the development of new maize varieties through breeding programs. Additionally, innovative cultivation practices must be devised to complement these genetic improvements. In this review, the timing, duration, and severity of drought stress during the reproductive stage and their effects on maize kernel set are assessed, providing a basis for constructing a framework that links kernel setting to drought stress. Based on this framework, reproductive drought tolerance from tasseling through post-fertilization kernel establishment is subsequently examined. Evidence indicates that drought-induced fertilization failure is primarily due to delayed pollination resulting from slower silk elongation, which is caused by the loss of cell turgor and reduced carbon supply. Meanwhile, kernel abortion after fertilization is mainly triggered by carbohydrate starvation, increased ethylene emission, and the accumulation of abscisic acid (ABA). Therefore, sugar metabolism, hydraulic status, and hormone signaling collectively regulate maize’s kernel setting tolerance to drought stress in a synergistic manner. Several novel gene candidates with potential for conferring drought tolerance in maize have been identified, offering promising targets for genetic improvement through genome editing combined with targeted cultivation practices to enhance maize drought tolerance and ensure stable grain yield in future crops.

Rice (Oryza sativa L.), a thermophilic crop, is highly sensitive to cold stress, particularly during the seedling stage. Developing cold-tolerant rice varieties is a possible strategy to mitigate yield losses caused by low temperatures. However, few genes for cold tolerance have been identified. In this study, we identified OsALA4 (Aminophospholipid ATPase 4), encoding a plasma membrane-localized P4-ATPase, from a chromosomal segment substitution line (CSSL-K2832-2) harboring cold-tolerance QTL qLTS5 (Low Temperature Sensitive 5). Genetic and subcellular localization analyses revealed that OsALA4 regulates cold tolerance by maintaining plasma membrane fluidity and cellular homeostasis. Physiological assessments showed that OsALA4 reduces malondialdehyde (MDA), electrolyte leakage, reactive oxygen species (ROS), and cell death under cold stress. Promoter activity assays indicated that stronger OsALA4 expression in Nipponbare (OsALA4^Nip) correlated with enhanced cold tolerance. Further experiments demonstrated that SNP sites within the promoter regions (−1500 bp to −700 bp) of OsALA4^Nip and OsALA4⁹³¹¹ influenced their activity. This study highlights OsALA4 as a valuable genetic target for breeding cold tolerant rice.

Heat stress is a major threat to maize (Zea mays L.) production worldwide. Heat shock transcription factors (HSFs) play vital roles in plant responses to heat stress. However, the molecular and genetic mechanisms underlying HSF-meditated thermotolerance in maize remain largely unexplored. In this study, we demonstrate that the alternative splicing of ZmHsf23 modulates heat stress tolerance in maize. Hsf23 produced two functional transcripts, Hsf23L and Hsf23S, which differ by the presence of a cryptic mini-exon in Hsf23L that is spliced out in Hsf23S. Both transcripts were strongly induced by heat stress. Mutants lacking Hsf23L alone (hsf23l) or both Hsf23L and Hsf23S (hsf23l23s) exhibited increased susceptibility to heat stress, whereas overexpression of Hsf23S enhanced heat stress tolerance in maize. Subsequently, we found that Hsf23S positively regulates heat stress tolerance by directly activating the transcription of three sHSP genes (Hsp16.9, Hsp17.2, and Hsp18a) and TIL1 gene. In addition, Hsf23L physically interacted with Hsf23S and enhanced the transcriptional activation of Hsf23S on the sHSPs and TIL1 promoters. Notably, genetic analysis suggested that co-overexpression of Hsf23L and Hsf23S further improves heat tolerance of the transgenic plants. Taken together, these results reveal two splicing variants of ZmHsf23 cooperatively regulate maize heat tolerance, thus highlighting potential value of ZmHsf23 in breeding heat-tolerant maize varieties.

Gibberella stalk rot (GSR) caused by Fusarium graminearum is one of the most devastating diseases of maize, seriously impacting maize yield and quality, as well as the ability to use technology of mechanical harvesting. Environmental conditions including photoperiod affect crop disease resistance. However, the mechanism underlying photoperiod-regulated maize GSR resistance remains unexplored. We found in this study that GSR resistance is regulated by the ZmPIF4.1 (Phytochrome-Interacting Factor 4)-ZmPTI1c (Pto-Interacting 1)-ZmMYB31 module coupled with photoperiod. The functional analysis of zmpti1c mutant indicated that ZmPTI1c negatively regulates maize GSR resistance. Short day promoted the disease progression in both zmpti1c and wild-type plants. ZmPTI1c promoter contains multiple predicted cis- acting elements for light responses. Yeast one-hybrid assay (Y1H), Electrophoretic mobility shift analysis (EMSA), and Dual-luciferase (LUC) reporter assays demonstrated that ZmPIF4.1 binds to the G-box in ZmPTI1c promoter and activates its expression. Moreover, expression levels of ZmPIF4 and ZmPTI1c were significantly higher under short day than under long day. ZmPTI1c interacted with and phosphorylated ZmMYB31. GSR resistance in zmmyb31 mutant was significantly increased than in wild type, indicating that ZmMYB31 also negatively regulated GSR resistance. Furthermore, ZmMYB31 suppressed the transcriptional activation of ZmPTI1c by ZmPIF4.1. Overall, ZmPIF4.1-ZmPTI1c-ZmMYB31 negatively regulates maize immunity to GSR, which is likely modulated by photoperiod.

Brassica napus (oilseed rape) is sensitive to boron (B) deficiency and exhibits young leaf curling in response to low-B stress at the seedling stage, which leads to reduced photosynthesis and plant growth. So far, no gene has been identified to be involved in B deficiency induced leaf curling. Our previous results showed the transcription factor BnaA1.WRKY53 might be involved in B-deficiency tolerance. However, altered BnaA1.WRKY53 expression does not influence B concentration in shoot, root and leaf cell walls, which suggests BnaA1.WRKY53 might be involved in other biological processes. Indeed, phenotypic and anatomical analyses revealed that BnaA1.WRKY53 negatively regulated the leaf curling induced by leaf epinasty by suppressing the overexpansion of palisade cells under B deficiency. Further transcriptome enrichment analysis of differentially expressed genes (DEGs) between wild-type and BnaA1.WRKY53 overexpression line showed auxin response pathway was enriched. In addition, Arabidopsis DR5::GFP auxin reporter line showed B deficiency caused predominant auxin signal accumulation in the adaxial side and concomitant adaxial cell expansion, which indicated that B deficiency may induce leaf curling by altering auxin distribution. Phytohormone quantification and gene expression analysis demonstrated that BnaA1.WRKY53 prevent auxin overaccumulation in leaves by suppressing auxin biosynthetic genes under B deficiency. Furthermore, exogenous 1-naphthlcetic acid (NAA) treatment experiments revealed that high auxin could induce leaf curling and BnaA1.WRKY53 expression. Overall, these findings demonstrate that auxin and the transcription factor BnaA1.WRKY53 synergistically regulate leaf curling to maintain an optimal leaf area under B deficiency, and provide novel insights into the resistance mechanisms against B-deficiency-induced leaf curling in oilseed rape.

Sphingolipids are not only a pivotal component of membranes but also act as bioactive molecules. Cotton fiber is one of the longest plant cells and sphingolipids are closely associated with the development of cotton fiber cells. However, their function in cotton fiber cell development and its action mechanism is unclear. Through cotton genetic transformation and chemistry biological approach, we identified the function and action mechanism of the glucosylceramide synthase gene GhGCS1 and its product glucosylceramide (GluCer) in cotton fiber growth. GhGCS1 was preferentially expressed at the stage of fiber elongation and localized in the endoplasmic reticulum. Overexpression of GhGCS1 promoted GluCer synthesis and fiber elongation, which was consistent with the exogenous application of GluCer (FA-C22) (containing very long-acyl-chain fatty acid) to cotton fiber in ovule culture system in vitro. Contrarily, suppressing GhGCS1 expression inhibited GluCer synthesis and fiber elongation, which was similar as the exogenous application of GluCer synthesis inhibitor, PDMP. Transcriptome analysis revealed that the fiber elongation regulated by GhGCS1 was associated with brassinosteroid (BR) synthesis and signaling related gene expression. Meanwhile, we detected the BL content of control and transgenic fiber cells. The BL content significantly increased and decreased in up- and down-regulated transgenic fibers when compared with control fibers, respectively. Furthermore, we found that PDMP treatment blocked BR synthesis and signal transduction, while exogenous application of GluCer could enhance BR synthesis and signaling. Overall, our results revealed that GhGCS1 and GluCer regulated cotton fiber elongation by influencing BR synthesis and signaling. Our study shed a novel insight on regulatory mechanism of cotton fiber elongation and provides theoretical support, genetic resources and novel transgenic materials for improvement of crop quality.

Carbon (δ¹³C) and oxygen (δ¹⁸O) isotope compositions are considered indicators of the effect of water conditions on plant photosynthesis (δ¹³C) and transpiration (δ¹⁸O). Hydrogen isotope composition (δ²H), tracks transpiration like δ¹⁸O, while also affected by the organ trophism. Such dual behaviour, together with its highly exchangeable nature have hindered the use of δ²H to assess plant performance. We compared the effect of contrasting water pressure deficit (VPD) on the signatures of the three isotopes across different durum wheat parts. Plants were hydroponically grown under conditions, differing in VPD and the isotopic labelling of the nutrient solution (natural abundance versus δ²H and δ¹⁸O-enriched) and isotopic signatures analysed at mid-grain filling. Higher VPD increased plant-matter δ¹³C, δ²H, and δ¹⁸O, in accordance with atmospheric drought decreasing stomatal conductance and transpiration. Moreover, positive correlations within and across organs between δ²H and δ¹⁸O of organic-matter and water further supported a similar source of variation related to evaporation. However, δ²H was depleted in photoautotrophic (leaves and glumes), enriched in mixotrophic (peduncle and awns) and even more in heterotrophic (grains) organs. This study highlights the similarities and differences in mechanisms determining δ²H, δ¹⁸O, and δ¹³C through the interactions of these isotopes with VPD and plant organs.

Leaf-color mutants have proven valuable for studying chlorophyll metabolism, photosynthesis, and yield improvement. In this study, we identified a yellow-leaf (yl) mutant in soybean (Glycine max), characterized by reduced chlorophyll accumulation, lower net photosynthesis rate, and fewer grain number per plant than the wild type. To identify genes associated with chlorophyll content, we performed a large-scale linkage mapping study using recombinant inbred lines from a cross between the yl mutant and a green-leaf cultivar across three environments. Using quantitative trait locus sequencing (QTL-seq) analysis, we mapped 12 QTL to chromosomes 5, 13, 15, 19, and 20. Of these QTL, one new dominant locus with the largest LOD, named qCC1, was identified consistently and explained 31.73% of the total phenotypic variation on average. Notably, qCC1 was also associated with yield-related traits, including plant height and pod number per plant. Fine-mapping narrowed down qCC1 to an 82.29-kb region. Within this interval, we identified Glyma.15 g087500.1, encoding an ankyrin repeat-containing protein, as the most likely candidate gene, because its homologs are reported to function in thylakoid membrane biogenesis during plastid development. Phenotypic analysis of near-isogenic lines (NILs) revealed that those harboring the qCC1 allele conferring green leaves displayed significantly enhanced chlorophyll content by 136.53%-323.92%, net photosynthesis rate by 11.64%-42.13%, and yield by 111.32% compared with NILs carrying the allele conferring yellow leaves. Comparative transcriptome profiling of NILs coupled with RT-qPCR validation demonstrated that qCC1 up-regulated one differentially expressed gene (DEG) associated with chlorophyll biosynthesis and six DEGs related to photosystem, whereas it down-regulated one gene involved in chlorophyll degradation. These findings provide valuable insights into the biological function and regulatory mechanism of chlorophyll metabolism and offer guidance for breeding soybean varieties with enhanced photosynthetic efficiency and high yield.

Soybean seeds contain approximately 40% protein, making soybeans an important source of plant-based protein. Research on QTN mapping, molecular design breeding and mining of genes related to seed protein formation provides guiding significance for the analysis of the underlying genetic mechanisms of seed protein formation and the selection of high-protein varieties. The seed protein contents (SPCs) of 144 lines of a soybean four-way recombinant inbred line (FW-RIL) population were determined in 8 environments. A three-variance component multisite random effects mixed linear model (3VmrMLM) was used to conduct a genome-wide association study on protein content. A single detected QTN explained 0.53%-3.37% of the phenotypic variation. A molecular-assisted selection breeding model containing the 18 QTNs explained 51.97% of the phenotypic variation in protein content. Eight biparental and five tri-parental crosses that produced excellent lines with the greatest protein content-related genotype values that could be generated by phenotypic and molecular-assisted selection were screened. An LD block of 17 QTNs (QEIs) was identified, and one key candidate gene related to protein formation was predicted by haplotype analysis. The proportion of Hap 1 varieties in the spring-sowing soybean region in North China was lower than those in the Huang-Huai-Hai soybean region in Central China and the multiripe soybean region in South China. The proportion of Hap 1 varieties among the wild varieties and landraces was greater than that among the improved varieties. The results of this study provide important insights into the genetic basis of soybean protein content and information to aid in molecular design breeding methods to improve protein content.

Soybean mosaic virus (SMV) is a worldwide disease significantly decreasing soybean yield and seed quality. In this study, a genome-wide association study (GWAS) for SMV-SC3 resistance was conducted by using a deep re-sequencing dataset of 547 soybean accessions. A total of 11,405 SNPs and 1566 InDels were significantly associated with disease index (DI) at seedling stage and eight yield- and seed quality-related traits to SC3 resistance under eight environments. Among these genetic loci, 952 SNPs and 118 InDels were firstly identified to control SC3 resistance, and 52.42% and 42.37% of them were pleiotropic loci across multiple environments. Notably, the 8.47-8.89 Mb genomic region on chromosome 18 was firstly discovvered to associate with DI at seedling stage and four related traits at adult stage across multiple environments. Furthermore, the causal gene Gm18GRSC3 was identified and validated in this stable and pleiotropic locus for resistance to SC3 via positive and negative transgenic strategies. Overexpression of Gm18GRSC3 significantly decreased the accumulation of SC3 in transgenic soybean hairy roots, while silencing of Gm18GRSC3 significantly increased SC3 accumulation in soybean leaves. A functional marker, FM18GSC3, was developed based on the allelic variation of Gm18GRSC3, and the detection efficiency reached to 76% in another 100 soybean accessions. These findings provide valuable genetic loci and a functional gene for the improvement of SMV resistance in soybean.

Soybean (Glycine max) variety Heihe 54 has played a crucial role in the Heihe soybean breeding program in China, contributing to the development of over 85 cultivars. To elucidate the genetic changes that have occurred across multiple generations of selection during soybean breeding, we conducted comprehensive genotyping analysis using the 180K Axiom SoyaSNP array on 42 varieties from the Heihe breeding program, as well as eight parental lines. Cluster analysis revealed four distinct groups, reflecting various breeding phases that incorporated diverse genetic resources as parental lines within the pedigree. A detailed examination of the graphical genotype profile across the genome identified preferred chromosome segments for specific breeding phases. These conserved blocks, which have been consistently maintained in descendant varieties during the extensive breeding period, likely harbor genes related to critical agronomic traits. This is exemplified by the consistent transmission of two segments located on chromosomes 18 and 20, which harbor the stem growth habit-related gene Dt2 and the leaflet shape-related gene Ln, respectively. The widespread cultivation of Heihe 43, a soybean cultivar developed within this pedigree, is attributed to its broad genetic base and the pyramiding of elite alleles from its parental lines. The identification of favorable chromosome segments provides valuable insight for agronomic trait-related gene mining and targeted breeding in the future.

Protein content plays a crucial role in determining the eating and cooking quality of rice. However, the genetic and molecular basis underlying grain protein content remains to be elucidated. In this study, we identified a genomic region associated with grain protein content in rice chromosome segment substitution lines containing the flowering gene Ghd7.1, which reduced grain protein content by repressing the transcription of the gene OsAAP6. Knockout of Ghd7.1 increased grain protein content and decreased the eating and cooking quality of rice. Introduction of the functional haplotype of Ghd7.1 into two elite rice cultivars reduced their protein content and increased their eating quality and grain yield with no effect on the regulation of flowering time. Ghd7.1 might be used for regulating the protein content and improving the eating quality of rice varieties.

Roots play a critical role in acquisition and utilization of nitrogen in wheat, influencing nitrogen use efficiency (NUE), and ultimately determining yield. However, the detailed responses of root tips to fluctuations in nitrogen availability and the underlying regulatory mechanisms enabling adaptation to nitrogen-limited conditions, remain elusive. In this study, we used single-cell nuclear transcriptomics of the high-nitrogen utilization variety (HNV) Zhengmai 1860 (ZM1860) to construct a comprehensive map of root tip cells under both controlled and nitrogen starvation (N-starv) conditions. Identification of various cell types and their associated genes highlighted the diversity of cellular processes. Using single-nucleus consensus weighted gene co-expression network analysis (hdWGCNA), we identified key modules central to nitrogen metabolism. These identified the prominent role of epidermal cells (EC). The gene TaGS1.2, which is involved in glutamine synthesis, exhibited increased expression under nitrogen-deficient conditions, validating its functional significance in nutrient acquisition. Serving as a key functional gene that adapts to nitrogen-deficient conditions this gene also positively regulated root development. Analysis of the transcriptional regulatory network in EC further revealed the pivotal role of TaGS1.2 in the nitrogen metabolism network. We also uncovered mechanisms that enhance cell-to-cell communication in nitrogen-deficient environments by identifying specific receptors. Single-cell nuclear transcriptome mapping offers valuable insights into the complex responses of root tip cells to nitrogen scarcity and guides future breeding strategies aimed at developing more nitrogen-efficient wheat varieties.

Non-destructive time-series assessment of chlorophyll content in flag-leaf (FLC) accurately mimics the senescence rate and the identification of genetic loci associated with senescence provides valuable knowledge to improve yield stability under stressed environments. In this study, we employed both unmanned aerial vehicles (UAVs) equipped with red-green-blue (RGB) camera and ground-based SPAD-502 instrument to conduct temporal phenotyping of senescence. A total of 262 recombinant inbred lines derived from the cross of Zhongmai 578/ Jimai 22 were evaluated for senescence-related traits across three environments, spanning from heading to 35 d post-anthesis. The manual senescence rate (MSR) was quantified using the FLC and the active accumulated temperature, and UAV derived vegetation index were utilized to assess the stay-green rate (USG) facilitating the identification of senescent and stay-green lines. Results indicated that higher senescence rates significantly impacted grain yield, primarily by influencing thousand-kernel weight, and plant height. Quantitative trait loci (QTL) mapping for FLC, USG, and MSR using the 50K SNP array identified 38 stable loci associated with RGB-based vegetation indices and senescence-related traits: among which 19 loci related to senescence traits from UAV and FLC were consistently detected across at least two growth stages, with nine loci likely representing novel QTL. This study highlights the potential of UAV-based high-throughput phenotyping and phenology in identifying critical loci associated with senescence rates in wheat, validating the relationship between senescence rates and yield-related traits in wheat, offering valuable opportunities for gene discovery and significant applications in breeding programs.

Aegilops variabilis (S^vS^vU^vU^v) is a source of resistance to wheat stripe rust. The phKL locus in Chinese common wheat landrace Kaixian-Luohanmai (KL) can induce homoeologous wheat-alien chromosome pairing and recombination. In this study, we confirmed that the whole 2S^v chromosome introgressed into wheat from Ae. variabilis accession AS116 conferred all-stage stripe rust resistance. The underlying gene(s), named YrAev, was mapped to the long arm 2S^vL using an F₂ population. Two 2S^v-2B recombinants, derived from a cross of the 2S^v (2B) chromosome substitution line and KL, were confirmed to harbor the resistance locus. The physical region containing YrAev, determined from RNA-seq data, was 844.6-852.1 Mb on the chromosome arm 2S^l of the Ae. longissima (S^v genome donor species of Ae. variabilis) accession TL05 assembly v1.0. Differential gene expression analysis of post-inoculation with the Pst race has indicated two disease-resistance-related genes (annotated as mixed lineage kinase domain-like protein and nucleotide-binding leucine-rich repeat like protein, respectively) as promising candidates for YrAev. This study demonstrates the utility of the phKL gene system in alien gene localization and transfer. The resistant translocation line harboring YrAev can be exploited by wheat breeders as a novel source of resistance to stripe rust.

Psathyrostachys huashanica Keng ex P. C. Kuo (2n = 2x = 14, NsNs), a wild relative of wheat, represents a valuable germplasm resource for genetic improvement of wheat. We previously confirmed that a chromosome 7Ns from P. huashanica carries genes that accelerate heading and maturity in wheat. Here, we developed three small segment translocation lines (T7NsS-2BL·2BS, T7NsS-1AS·1AL#1, and T7NsS-1AS·1AL#2) along with one additional small segment translocation line (T7NsS-7BS·7BL) through ⁶⁰Co-γ irradiation, identified using genomic in situ hybridization (GISH), fluorescence in situ hybridization (FISH), and liquid chip array analyses. Our findings demonstrated that chromosome 7NsS contained a major early heading date gene, tentatively designated Ehd-7Ns, which was mapped to an approximate 31.45 Mb region, corresponding to the short arm of wheat chromosome 7A (IWGSC RefSeq v1.0). The T7NsS-1AS·1AL#2 line exhibited no significant yield penalty and possessed superior agronomic traits relative to the other translocation lines in the field, making it a promising pre-breeding donor for breeding early maturing wheat. Furthermore, 21 specific Kompetitive Allele Specific PCR (KASP) markers were developed based on transcriptome data, enabling effective tracing of alien chromosomal segments carrying this source of Ehd-7Ns in marker-assisted breeding. Collectively, these newly developed translocation lines and specific KASP markers will facilitate the transfer and utilization of favorable genes from P. huashanica chromosome 7Ns in future wheat breeding programs.

Maize (Zea mays L.), a globally significant cereal crop, is produced in vast quantities worldwide. However, its growth is severely constrained by low temperatures, particularly during seed germination, which significantly impairs seedling emergence. In this study, genetic diversity across six germination-associated phenotypic traits (RGR, RSL, RTL, RRSA, RRV, and RSVI) of 304 inbred lines was analyzed, to evaluate the capacity of these lines for low-temperature tolerance. Genome-wide association study (GWAS) was carried out by combining six germination-associated phenotypic traits and genotypic data from 30-fold resequencing. The gene ZmBARK1 was identified through integrated GWAS and RNA-seq analyses, and its association with low-temperature tolerance during maize germination was validated by quantitative real-time PCR (qRT-PCR). ZmBARK1, encoding BRASSINOSTEROID INSENSITIVE 1-associated receptor kinase 1, was located on the bin 4.09 region of maize chromosome 4. Amino acid comparison and subcellular localization analyses revealed that ZmBARK1 is highly homologous to AtBAK1 and is localized to the plasma membrane of the cell, which may be involved in regulating brassinosteroid (BR) signaling. In addition, we revealed the role of ZmBARK1 in low-temperature tolerance during maize germination. Compared with wild-type (WT), the ethyl methanesulfonate (EMS) mutant zmbark1 was characterized by substantially enhanced low-temperature tolerance. Overall, these findings provide promising candidate genes, improve low-temperature tolerance in maize, and advance the understanding of regulatory mechanisms underlying maize’s response to low-temperature stress.

Isochorismate synthase (ICS), a key rate-limiting enzyme in the salicylic acid (SA) biosynthesis pathway in plants, is essential for plant growth and defense against diseases. However, there has been no report on ICS in sugarcane (Saccharum spp.). In this study, 18 SsICSs, 42 ShICSs, and 36 SzICSs were identified from the genomes of sugarcane AP85-441 (Saccharum spontaneum), XTT22 (Saccharum spp. hybrid cultivar), and ZZ1 (Saccharum spp. hybrid cultivar), respectively. These were phylogenetically divided into three groups, forming distinct clades that were evolutionarily divergent from those in dicotyledonous species. The evolutionary profile of the ICS gene family suggested expansion through whole-genome duplication/segmental events and strong purifying selection. Promoter cis-element and transcriptome analyses indicated that the ICS gene family responded to disease stress. We cloned the ScICS (isochorismate synthase) gene from sugarcane cultivar XTT22 leaves, and found it was localized in chloroplasts. In vivo and in vitro interaction studies revealed an interaction between ScICS and an ScMYB transcription factor. We showed that ScWRKY28 positively regulated ScICS expression by binding to its promoter. ScICS overexpression in transgenic tobacco confirmed its effectiveness in enhancing disease resistance. There was a significant increase in SA content following pathogen infection along with activation of downstream signaling pathways and defense mechanisms. This study establishes the groundwork for functional studies of sugarcane ICS genes and enhances our understanding of the mechanisms of disease resistance in sugarcane.

The genus Beta encompasses economically important root crops such as sugar and table beet. A Beta diversity set including the wild relative B. vulgaris ssp. maritima was grown in the field, and a large phenotypic diversity was observed. The genomes of 290 accessions were sequenced, and more than 10 million high-quality SNPs were employed to study genetic diversity. A genome-wide association study was performed, and marker-trait associations were found for nine phenotypic traits. The candidate gene within the M locus controlling monogermity on chromosome 4 was previously unknown. The most significant association for monogermity was identified at the end of chromosome 4. Within this region, a non-synonymous mutation within the zinc-finger domain of the WIP2 gene co-segregated with monogermity. This gene plays a regulatory role in AGL8/FUL in Arabidopsis. Intriguingly, commercial hybrids are in a heterozygous state at this position. Thus, the long-sought gene for monogermity was identified in this study. Red and yellow pigmentation due to betalain accumulation in shoots and roots is an important characteristic of table and leaf beets. The strongest associations were found upstream or downstream of two genes encoding Cytochrome P450 and anthocyanin MYB-like transcription factor proteins involved in betalain biosynthesis. Significant associations for Cercospora leaf spot resistance were identified on chromosomes 1, 2, 7, and 9. The associated regions harbor genes encoding proteins with leucine-rich repeats and nucleotide binding sites whose homologs are major constituents of plant-pathogen defense.

One- time application of controlled-release blended fertilizer (CRBF, a mixture of five nitrogen (N) fertilizers in a certain ratio) can achieve high yield and N use efficiency (NUE) in rice (Oryza sativa L.). However, the effects of CRBF with one-time application on root spatial distribution and physiological characteristics remain unclear. We measured the effects of CRBF with one-time application on rice yield, NUE, root morphology and growth, and N uptake capacity in field and root box experiments. Six N treatments were set up: no nitrogen (N₀), high-yield three-split application of urea as a control (CK), urea (U) with broadcast, U with side-deep fertilization, CRBF with broadcast, and CRBF with side-deep fertilization. Our findings showed that root characters were positively correlated with yield and NUE. Compared to CK and U treatments, CRBF with one-time applications increased root characters (including root biomass, root N uptake, root activity, and the expression level of ammonium transporters) at tillering and heading stages. The root length, surface area and volume in the 0-10 cm soil layer enhanced under CRBF with one-time applications at tillering stage, and in the 0-20 cm soil layer at the heading stage. This contributed a 5.96%-39.40% and 3.69%-16.87% increase in plant dry matter accumulation and N uptake, and a 2.08%-18.28% and 14.60%-149.57% increase in yield and NUE, in 2022 and 2023, respectively. Taken together, our findings showed that one-time application of CRBF could increase rice yield and NUE by optimizing the root morphology distribution and N uptake.

With the intensification of climate change, spring low-temperature stress (SLTS) leads to floret degeneration and a decrease in grain number. This study investigated the physiological mechanisms underlying SLTS-induced floret degeneration using two wheat varieties with contrasting cold sensitivity. SLTS caused yellowing and shrinkage of floret primordia, increasing floret degeneration and fertile floret abortion, ultimately reducing grains per spike by 12.2%-26.1%. SLTS disrupted nutrient supply, impairing dry matter accumulation in young spikes. At 0-15 d after low-temperature stress (DALTS), SLTS caused a brief increase in the sugar content of young spikes (0-3 DALTS), followed by a rapid decrease (6-15 DALTS), while the total nitrogen content keeps decreasing. SLTS altered key enzyme activities, enhancing sucrose synthase and sucrose phosphate synthase but suppressing nitrate reductase and glutamine synthetase. Transcriptomic analysis revealed that SLTS perturbed starch and sucrose metabolism, carbon and nitrogen metabolism, and amino sugar pathways, altering soluble sugars, sucrose, fructose, and protein levels. SLTS disrupted carbon-nitrogen metabolic homeostasis, thereby reducing the number of fertile florets and ultimately leading to a decrease in grain number per spike. These findings enhance understanding of SLTS impacts on wheat floret development and provide insights for improving low-temperature tolerance and yield stability in wheat.

The exogenous plant growth regulator, diethyl aminoethyl hexanoate (DA-6), in combination with suitable varieties and planting densities, is important to increase yield in the maize-soybean strip intercropping system. To identify the role of DA-6 in mitigating high-density stress and increasing yield, we conducted a two-year field experiment examining changes in branching architecture and other yield traits of soybeans in maize-soybean strip intercropping systems. In the planting system, two soybean cultivars (ND: Nandou 25 and QH: Qihuang 34) were grown under three planting densities (D1: 102,000 plants ha⁻¹, D2: 130,000 plants ha⁻¹, D3: 158,000 plants ha⁻¹) with DA-6 treatments (DA0: water control; DA60: 60 mg L⁻¹; DA100: 100 mg L⁻¹). Applying DA-6 at 60 mg L⁻¹ at the fourth trifoliolate leaf stage increased soybean yield, with QH yield rising by 22.4% and 29.5% at D3 density, and ND yield by 29.5% and 30.0% at D2 density in 2022 and 2023, respectively, compared with D1 under DA0. DA-6 improved photosynthesis in both varieties under D2 density, with DA60 increasing ND canopy photosynthetic rate by 15.1%-16.4% and QG by 9.1%-20.6% over two years. In ND, DA-6 enhanced branching, raising the leaf area index by 37%, branch number from 3.6 to 4.7 per plant, and total pod number by 19.7%. In QH, yield grains were mainly due to a 17% increase in the number of stem pods and a 6.5% improvement in hundred-grain weight. In the maize-soybean strip intercropping system, QH achieved a high yield by forming a high-density (D2 to D3) main stem pod, and ND by combining moderate density (D1 to D2) with DA-6-induced branching.

Diversifying crop rotation aims to balance production and ecological concerns. However, yield and water use efficiency (WUE) of crop in diversified rotation systems have not been well documented, especially under limited irrigation. Here, we conducted a 6-year experiment with five treatments: 1) wheat-maize cropping system (WM), as control; 2) WMME, spring maize → WM rotation; 3) WMML, spring millet → WM rotation; 4) WMMP, spring peanut → WM rotation; and 5) WMMS, spring soybean → WM rotation, to explore how diversified rotations affected yield and WUE of wheat. Results showed that approximately 60% higher precipitation during wheat growing season in Cycle 1 (2015-2017) resulted in yield increases by 33.8%-55.7% compared to those in Cycle 2 (2017-2019) and Cycle 3 (2019-2021). Grain yield and WUE of wheat were 16.7% and 9.6% higher in Cycle 1, 81.5% and 86.8% higher in Cycle 2, and 56.1% and 78.7% higher in Cycle 3 on average in diversified rotations compared to those in WM, respectively. Further analysis revealed that spike number and aboveground biomass were the main contributors to the increments, which can be explained by the increased evapotranspiration during the middle-late wheat growth stages (e.g., regreening, jointing, and anthesis) in diversified rotations. In general, diversified rotations enhanced synchronization of soil water supply with crop water demand by affecting the spatiotemporal dynamics of soil moisture under varied precipitation conditions, thereby increasing yield and WUE of wheat. Hence, diversified spring crops → WM rotations offer a sustainable and efficient strategy for enhancing wheat production and water conservation in dry areas.

Global food production faces enormous challenges in increasing yields while promoting environmental sustainability. A field experiments in the ecotone between the Yangtze River Basin and the Huang-Huai-Hai Plain evaluated the effects of changing preceding crop rotation cycles (wheat and rapeseed) on long-term wheat-rice (W) and rapeseed-rice (R) rotation systems. A comprehensive evaluation of crop rotation systems was conducted using life cycle assessment, considering productivity, economic benefits, carbon footprint (CF), and soil health. Compared with fallow-rice rotation (F), alternating rapeseed and wheat rotations increased equivalent yield by 60.4%-82.2%, reduced CF by 0.3%-5.7%, and improved soil health by 0.3%-47.5%. Additionally, adding rapeseed to rotations increased soil nutrient content and raised soil organic carbon stocks by 31.3%-40.5%. The 3R rotation (3-year rapeseed-rice and 1-year wheat-rice) boosted rice yield by 82.2% and annual economic benefits by 84.4%, offering an effective model for optimizing long-term R rotations. Similarly, the 2W rotation (2-year wheat−rice and 1-year rapeseed rice) enhanced rice yield by 70.0% and annual economic benefits by 65.9%, providing a successful example for optimizing long-term W rotations. The 3R rapeseed-based rotation and the 2W wheat-based rotation demonstrated good environmental sustainability. These rotation systems have broad potential in sustainable intensive farming, especially in China and similar regions.

Subsoiling is widely used to improve soil productivity in the North China Plain (NCP). However, its effects on pore network-based hydraulic properties and their relationship with water use efficiency (WUE) are far from clear. In this study, we evaluated the effects of three tillage systems (rotary tillage at 15 cm depth, RT15; subsoiling at 40 cm depth, SS40; and subsoiling at 35 cm depth, SS35) on soil pore structure, hydraulic properties, and WUE during the 2022-2024 winter wheat seasons. Results showed that the effects of SS40 and SS35 were similar in optimizing the soil pore structure and hydraulic properties. Compared with RT15, SS40 and SS35 increased the soil macroporosity ratio, the soil pore connectivity, and the soil water storage. Structural equation modeling revealed that optimized soil pore structure under subsoiling directly and positively influenced the WUE or indirectly increasing the soil water storage. As a result, compared with RT15, SS40 and SS35 increased the spike number, kernel number per spike, and 1000-grain weight, and ultimately improved the yield (35.59% and 39.32%, respectively) and WUE (36.69% and 41.55%, respectively). Overall, the results revealed the mechanism of high-efficiency water use from the perspective of pore network-based hydraulic properties, providing a theoretical basis for food security.

Endodermal cells and starch-accumulating amyloplasts are well-known gravity sensors initiating shoot gravitropism in Arabidopsis thaliana. The transcription factors SHR and SGR1 regulate endodermal cell formation, while PGM has been demonstrated to regulate starch biosynthesis within chloroplasts, which eventually leads to starch accumulation in amyloplasts. However, the molecular mechanisms of gravity sensing in monocot shoots remain largely unexplored. In this study, we investigated the roles of these genes in rice (Oryza sativa), a model monocot, using CRISPR-Cas9 to generate single, double, and higher-order mutants. The rice genome harbors two orthologs each of SHR and SGR and a single ortholog of PGM. Our results revealed that single mutants of OsPGM, but not OsSHR or OsSGR, showed compromised shoot gravitropism. However, double mutants shr1shr2 and sgr1sgr2 displayed wider tiller angles and reduced gravity sensing, suggesting functional redundancy within each gene pair. Higher-order mutants exhibited progressively severe phenotypes, with quintuple mutants almost unresponsive to gravity stimulation. These findings suggest that these genes act additively through distinct but converging pathways in shoot gravitropism regulation. This study provides novel insights into the molecular mechanisms underlying gravity sensing in monocots and offers valuable knowledge for precision breeding to optimize rice architecture.

The three-line hybrid rice system, which relies on cytoplasmic male sterility (CMS), faces challenges in breeding efficiency. To address these challenges, we developed CMS engineering breeding technology (CEBT). First, we constructed a complementation vector containing the fertility restoration module Double Rf4-Rf20, sorting marker gene DsRed2, and pollen lethal gene ZmAA1, then transformed this into a CMS line. We obtained reproductive lines without alterations to main agronomic traits, which can produce engineering sterile lines (ESL) and reproductive line seeds at a 1:1 ratio by self-crossing. CEBT converts the traditional three-line system into an efficient ‘new two-line’ hybrid framework: the reproductive line is improved while simultaneously improving the ESL, which significantly shortens the breeding process for three-line hybrid rice.

Dairy cattle slurry is a source of nitrogen (N) that can substitute for synthetic fertilizers. This study aimed to identify combinations of synthetic fertilizers and slurry optimal for maize growth and N dynamics in Northeast China. In a two-year field experiment testing synthetic-to-slurry N fertilization ratios, slurry application increased grain yield and yield components, net economic benefit, and N use efficiency relative to synthetic fertilization but led to higher nitrous oxide and ammonia emissions. A 1:1-1:3 synthetic N: slurry N ratio and slurry application at 60-90 t ha⁻¹ balanced productivity with N losses.