Coordinating light and nitrogen (N) distribution within a canopy is essential for improving rice yield and resource use efficiency. However, limited research has examined light and N distribution in response to planting density and N rate, and their relationships with grain yield, radiation use efficiency (RUE), and N use efficiency for grain production (NUEg) in rice. A two-year field experiment was conducted with two hybrid varieties under three N levels, 0 kg ha^–1(N1), 90 kg ha^–1(N2) and 180 kg ha^–1(N3), and two planting densities, 22.2 hills m^–2(D1) and 33.3 hills m^–2(D2). Results showed 3.4% higher yield and 4.4% higher NUEg under N2D2 compared with N3D1. The extinction coefficient for N (K_N) and light (K_L) and their ratio (K_N/K_L) at heading stage were significantly influenced by N rate, planting density, and their interaction. K_Ndecreased with the increase of N input or planting density. Compared to N1, K_Ndecreased by 43.5 and 58.8% under N2 and N3, respectively, while K_Nunder D2 decreased by 16.0% compared to D1. Higher K_Land K_N/K_Lvalues occurred under low N rates, with opposite trends under high N rates. Increased planting density led to decreased K_Land K_N/K_Lvalues. N2D2 demonstrated higher K_Land K_N, and thus comparable K_N/K_L, compared to N3D1. Correlation analysis revealed K_Lnegatively correlated with RUE, while K_Nand K_N/K_Lpositively correlated with NUEg. These findings indicate that increasing planting density under reduced N input could maintain rice yield while enhancing resource use efficiency through regulation of canopy light and N distribution.

Persistent overcast rain was an essential limiting factor for summer maize production, of which immediate impact was the dual pressure of waterlogging and shading. However, the mechanisms underlying independent and combined effects of waterlogging and shading on maize yield losses remain understudied, particularly across different growth stages. Denghai 605 (DH605) was selected tobe subjected shading, waterlogging, and their combined stress at the 3rd leaf stage (V3), the 6th leaf stage (V6), and tasseling stage (VT). Results showed that shading, waterlogging and their combination significantly restricted leaf areaexpansion, reduced leaf net photosynthetic rate (P_n) and net assimilation rate (NAR), thereby decreasing the crop growth rate (CGR) and biomass accumulation. Additionally, compared to control, the process of lignin synthesiswas inhibited under stressed treatment, resulting in diminished stem mechanical strength and impaired vascular systemdevelopment, which substantially reduced assimilate remobilizationefficiency to the ear and ultimate grain yield. Waterlogging and combined stresses exhibited maximum impact atthe V3 stage, followed by V6 and VT stages, while shading effects were most pronounced atthe VT stage, followed by V6 and V3 stages. Moreover,the compound stress exacerbated the damage brought about by a single stress. As climate change is projected to increase the frequency of multiple abiotic stress occurrences, these findings provide valuable insights for future summer maize breeding research under persistent rainfall conditions.

Elevated CO₂(eCO₂) may mitigate stress-induced damage to cotton (Gossypiumspp.) growth and development.However, understanding the early-stage responses of cotton to multiple abiotic stressors at eCO₂ levels has been limited. This study quantified the impacts of chilling (CS, 22/14°C, day/night temperature), heat (HS, 38/30°C), drought (DS, 50% irrigation of the control), and salt (SS, 8 dSm^–1) stresses on pigments, physiology, growth, and development of 14 upland cotton cultivars under ambient CO₂(aCO₂, 420 ppm; current) and eCO₂(700 ppm; future) levels during the vegetative stage. The eCO₂partially negated the effects of all stresses by improving one or more of the pigments, physiological, growth, and development traits, except CS. For instance, HS at aCO₂significantly increased stomatal conductance by 36% compared with non-stressed plants at aCO₂. However, HS at eCO₂significantly decreased stomatal conductance by 18% compared with HS at aCO₂.The first squaring was delayed by one day under SS at aCO₂but two days earlier under SS at eCO₂than non-stressed plants at aCO₂.Root and shoot dry mass and the total leaf area were significantly higher under all stresses, except for CS, at the eCO₂compared with similar stresses at theaCO₂. Most growth and development traits, including plant height, leaf area, and shoot dry mass, displayed a mirroring response pattern between aCO₂and eCO₂ under all environments except CS.Cultivars exhibited significant interaction with stressed environments. Further, results revealed differential sensitivity and adaptation potential of cultivars to stress environments at varying CO₂levels. This study highlights the need to consider eCO₂in designing breeding programs to develop stress-tolerant varieties for future cotton-growing environments.

Flower and fruit abscission reduce crop yield, so decreasing abscission is a significant agricultural issue. HAESA (HAE) and HAESA-like2 (HSL2) kinases and their ligand, INFLORESCENCE DEFICIENT IN ABSCISSION (IDA) peptide, have been confirmed to be the core elements regulating floral organ abscission in Arabidopsis thaliana. Our earlier research revealed that SlIDL6, a homolog of IDA in tomato, functions similarly to AtIDA, regulating the abscission of tomato flower organs. Here, we further isolated three HAESA-like homologs, SlHSL1/2/3, which are involved in tomato flower abscission. SlHSL1/2/3are highly expressed in the abscission zone (AZ). The knockout mutant lines of Slhsl1, Slhsl2, and Slhsl3 showedlower flower pedicel abscission than wild type (WT). The double mutant of Slhsl1Slhsl2, Slhsl1Slhsl3, and Slhsl2Slhsl3 further depressed abscission than each of the single mutant lines, while triple mutants Slhsl1Slhsl2Slhsl3exhibited the lowest abscission, indicating that SlHSL1/2/3 mediated abscission is non-redundancy, at least partially. Treating tomato pedicel explants with SlIDL6 peptide significantly accelerated pedicel abscission in WT. However, it had little effect on the abscission rate of SlHSL1/2/3 knockout lines, indicating that SlHSL1/2/3 are the receptors of SlIDL6 in pedicel abscission. Ethylene action inhibitor 1-methylcyclopropene (1-MCP) can significantly depress the expression of SlHSL1/2/3. Ethylene can significantly accelerate the abscission of WT, while less abscission was found in SlHSL1/2/3knockout lines. Our findings indicate that SlHSL1/2/3 can act as receptors for SlIDL6 to positively regulate tomato pedicel abscission, and the abscission regulated by SlHSL1/2/3 was partially dependent on ethylene

Xyloglucan represents the primary hemicellulose component in higher plant cell walls, providing mechanical support. The XTH gene family encodes xyloglucan endotransferase/hydrolase, a crucial enzyme in cell wall remodeling. Studies examining XTH family-related genes in apples remain limited. This studyinvestigated the MdXTH30gene, isolated from apple (Malus×domestica), which demonstrated responsiveness to abscisic acid, NaCl, and polyethylene glycol (PEG) 6000, with cytoplasmic localization confirmed through subcellular mapping. To elucidate the role of MdXTH30in stress response, transgenic MdXTH30apple calli were generated andthe gene was heterologously expressed in ArabidopsisviaAgrobacterium-mediated transformation. The findings revealed that MdXTH30enhanced resistance to drought, salt stress, and pathogens through regulation of relevant genes inboth apple calli and Arabidopsis. These results identify potentially significant candidate genes for improving biotic and abiotic stress resistance at the cell wall level.

Osmanthusfragransis most famous for its strong aroma, and different varieties have different degrees of fragrance and color. Fragrance and color are important factors affecting the ornamental quality of O.fragrans. Terpenoids are important secondary metabolites in plants, with β-carotene (C40) being the major pigment substance and linalool (C10) being the key aromatic component in O.fragrans. The geranylgeranyl pyrophosphate synthase genes (GGPPSs) play important roles in secondary metabolism in plants. However, the functions of the GGPPS family in floral color and fragrance formation has rarely been reported in O.fragrans. In this study, 24 OfGGPPSgenes were identified and classified into two subfamilies. The OfGGPPSsshowed tissue-specific expression and OfGGPPS13had highest expression in flowers. The OfGGPPS13 protein was localized to chloroplasts. The transcriptome data of OfGGPPS13was verified by qRT-PCR and the expression level in ‘Wanyingui’ with strong aroma was higher than that in ‘Zhuangyuanhong’ with deep color at different flower development stages. Transient overexpression of OfGGPPS13in O.fragranspetals showed that OfGGPPS13increased the β-carotene content, the main color substance of O.fragrans, but decreased the linalool content, the main volatile organic compound (VOC) in the floral aroma of O.fragrans. OfGGPPS13was indicated as the critical gene related to terpenoid synthesis in the floral aroma and color formation in O.fragrans. Our findings provide gene resources on the GGPPS gene family for further revealing the molecular regulation mechanism of the floral color and aroma formation in O.fragrans.

The accuracy of genomic annotation is crucial for subsequent functional investigations; however, computational protocols used in high-throughput annotation of open reading frames (ORFs) can introduce inconsistencies. These inconsistencies, which lead to non-uniform extension or truncation of sequence ends, pose challenges for downstream analyses. Existing strategies to rectify these inconsistencies are time-consuming and labor-intensive, lacking specific approaches. To address this gap, we developed toGC, a tool that integrates genomic annotation with RNA-seq datasets to rectify annotation inconsistencies. Using toGC, we achieved an accuracy of nearly 100% accuracy in correcting inconsistencies in published PhytophthorasojaeORFs. We applied this innovative pipeline to the GPCR-bigrams gene family, which was predicted to have 42 members in the P.sojaegenome but lacked experimental validation. By employing toGC, we identified 32 GPCR-bigram ORFs with inconsistencies between previous annotations and toGC-corrected sequences. Notably, among these were 5 genes (GPCR-TKL9, GPCR-TKL15, GPCR-PDE3, GPCR-AC3, and GPCR-AC4) showed substantial inconsistencies. Experimental gene annotation confirmed the effectiveness of toGC, as sequences obtained through cloning matched those annotated by toGC. Importantly, we discovered two novel GPCRs (GPCR-AC3and GPCR-AC4), which were previously mispredicted as a single gene. CRISPR/Cas9-mediated knockout experiments revealed the involvement of GPCR-AC4but not GPCR-AC3in oospore production, further confirming their status as two separate genes. In addition to P.sojae, the reliability of the toGC pipeline in Phytophthoracapsiciand Pythiumultimumfurther emphasizes the robustness of this pipeline. Our findings highlight the utility of toGC for reliable gene model correction, facilitating investigations into biological functions and offering potential applications in diverse species analyses.

In recent years, an unusual wilt disease affecting Pyruspyrifoliahas been observed in various regions of Jiangsu, China. This disease originates from the roots and progresses with distinctive browning patterns along vascular tissues, even extending over two meters above the ground. These symptoms set it apart from recognized pear diseases and typically lead to the death of affected trees within the same or the following year. Furthermore, this disease exhibits a tendency to spread to neighboring trees even after the removal of affected trees, presenting a substantial threat to pear production. To ascertain the causative agent, the present study encompassed pathogen isolation, morphological and molecular identification, as well as validation experiments adhering to Koch’s postulates. The fungal isolates obtained were identified as Fusariumcugenangensebased on characteristics of the colonies and conidia, in addition to a phylogenetic analysis using DNA sequences of the translation elongation factor 1-alpha (tef1), calmodulin (CaM), and RNA polymerase second largest subunit (rpb2) genes. Pathogenicity of the isolated F.cugenangenseon pear was confirmed by artificial inoculation. By introducing GFP-labeled pathogens into the roots, colonization in stem and leaf tissues was observed viafluorescence microscopy and transmission electron microscopy. Furthermore, these pathogens were successfully reisolated from stems and foliage, conclusively providing evidence of systemic infection within the pear plants. To the best of our knowledge, this is the first report of F.cugenangensecausing pear wilt disease in China.

The plant pathogenic fungus Sclerotiniasclerotiorumis the causative agent of Sclerotinia stem rot (SSR) disease in most dicotyledons. Among the various proteins involved in drug efflux or substance transport, ATP-binding cassette (ABC) transporters constitute a superfamily of membrane-bound proteins that may play a crucial role in the survival of S.sclerotiorum. However, the expression patterns and functions of ABC transporter genes in S.sclerotiorumremain largely uncharacterized. This study characterized a highly expressed S.sclerotiorumABC transporter gene during inoculation on host plants, SsBMR1. Silencing SsBMR1resulted in a significant reduction in hyphal growth, infection cushion development, sclerotia formation, and virulence. Moreover, host-induced gene silencing (HIGS) of SsBMR1significantly enhanced plant resistance. Transcriptome and metabolomics analyses suggested that SsBMR1is involved in antioxidant and toxin transport, thereby influencing fungal defense and cell rescue mechanisms. In comparison to the wild-type strain, SsBMR1gene-silenced transformants exhibited a diminished response to extracellar oxidative stress and a decreased exporting of antioxidant glutathione. Tolerance assays further demonstrated the crucial role of SsBMR1in conferring resistance to the plant antifungal substances, camalexin and brassinin, as well as certain fungicides. Furthermore, SsBMR1gene-silenced transformants showed enhanced repression on virulence when sprayed with camalexin and brassinin on the leaves. Thus, SsBMR1likely contributes to virulence by facilitating the export of antioxidant and providing resistance against antifungal agents. The findings of this study provide valuable insights that could contribute to the development of novel management techniques for SSR.

The native thelytokous (TH) and arrhenotokous (AR) strains of Neochrysocharisformosa(Westwood) (Hymenoptera: Eulophidae) are promising biocontrol agents against the invasive tomato pest Tutaabsoluta(Meyrick) (Lepidoptera: Gelechiidae). This study assessed the performance and preferences of these strains in choice experiments involving five host instar ratios and evaluated their functional responses to seven densities of 1st instar larvae (5 to 40 hosts). In host-attacking behavior assays, an increasing proportion of 1st instar larvae led to a significant rise in host mortality rates for both strains. Both strains exhibited strong preferences for parasitizing and attacking 1st instar larvae over later instars, with the TH strain demonstrating significantly greater host-killing efficacy than the AR strain. Functional response experiments revealed that the attack rates of both strains were positively correlated with host density. Parasitism by both strains and host-stinging behavior by the TH strain showed type III functional responses, while host-feeding by both strains and host-stinging by the AR strain followed type II functional responses. Early establishment of the TH strain in tomato agroecosystems could enhance the management of T.absoluta. These findings provide critical insights into the functional dynamics of the TH and AR strains of N.formosathat can inform the development of effective biocontrol programs for this globally significant pest.